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Series 451

SMART Series 451, fortwo Series 451, fortwo coupé, fortwo cabrio Service Manual

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smart USA
Introduction of the smart fortwo
Model Series 451
Introduction into Service Manual
SN_Typ 451_us.book Seite 1 Freitag, 30. November 2007 1:56 13
Page 3
Copyright
All rights reserved. Reproduction by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system or translation in whole or part is not permitted without written authorization from the publisher.
Published by smart USA, 2007 Printed in U.S.A.
www.smartusa.com
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Page 4
Content
3
Introduction of the smart fortwo, Model Series 451
Preface 7
Complete vehicle
Overview 8
Technical data 10
Maintenance 13
Safety concept 17
Electrical system
On-board electrical system/power supply 20
Complete networking 22
Wiring harnesses 24
Diagnosis 26
SAM control unit 28
Engine M132
Engine description 30
Performance graph 30
Engine data 32
Valve assembly 33
Valve timing 34
Gasoline injection and ignition system 35
Belt drive 38
Cooling system 39
Engine mount 41
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Content
4
Introduction of the smart fortwo, Model Series 451
Fuel system
Fuel supply 42
Exhaust system
Overview 45
Secondary air injection 46
Automated manual transmission
Transmission description 47
Transmission data 48
Shift mechanism 49
Synchronization 54
Transmission control 55
Park pawl 61
Clutch 62
Chassis
Front axle 64
Rear axle 65
Rear module 66
Tire pressure monitor 67
Brakes 69
Steering 75
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Content
5
Introduction of the smart fortwo, Model Series 451
Body
Interior 82
Doors/flaps 86
Roof systems 90
Central locking 96
Anti-theft alarm system (ATA [EDW]) 99
Exterior lights 101
Audio system 102
Climate control 104
Customized Bodypanel System (CBS) 106
Seats 108
Supplemental restraint system 109
Body 113
Accessories
smart accessories 116
Index 120
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Page 7
Content
6
Introduction of the smart fortwo, Model Series 451
SN_Typ 451_us.book Seite 6 Freitag, 30. November 2007 1:56 13
Page 8
Preface
7
Introduction of the smart fortwo, Model Series 451
Dear reader,
This Introduction into Service Manual presents the new smart fortwo in model series 451.
The purpose of this manual is to inform you of the technical features of this new vehicle. This brochure is intended to provide information for people employed in service, maintenance and repair as well as for aftersales staff.
In terms of the contents, the emphasis in this Intro­duction into Service manual is on presenting the major assemblies and systems.
This Introduction into Service manual is not intended as an aid for repairs or for the diagnosis of technical problems. For such needs, more extensive information is available in the Workshop Information System (WIS) and in the Diagnosis Assistance System (DAS).
WIS is updated monthly. Therefore, the information available there reflects the latest technical status.
This Introduction into Service Manual presents initial information relating to the new smart fortwo in model series 451 and, as such, is not stored in WIS. The contents of this brochure are not updated. No provi­sion is made for supplements.
We will publicize modifications and new features in the relevant WIS documents. The information presented in this Introduction into Service Manual may therefore differ from the more up-to-date information found in WIS.
All information relating to technical data, equipment and options is valid as of the copy deadline in September 2007 and may therefore differ from the current production configuration.
smart USA aftersales
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Page 9
Overview
8
Complete vehicle
Introduction of the smart fortwo, Model Series 451
P00.10-4192-00
P00.10-4198-00
smart fortwo coupé
smart fortwo cabrio
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Page 10
Overview
Complete vehicle
9
Introduction of the smart fortwo, Model Series 451
Vehicle concept
Externally, the smart fortwo is immediately distin­guishable by its compactness with the tridion safety cell and its two-tone design. The smart fortwo is avail­able in a variety of colors. The tridion safety cell in black or silver can be combined with six different basic colors.
The model series can be ordered as the smart fortwo coupé or the smart fortwo cabrio.
Despite its compact appearance, the smart fortwo provides the occupants with a generous amount of legroom and sufficient trunk capacity.
The interior compartment has a classic design. The instrument panel was designed with straight lines and the colors have been kept refined. Repeated aluminum accent trim on the air vents and the inside door handles gives the interior design a harmonic yet modern aspect.
Vehicle characteristics
• Overall vehicle exterior External dimensions to suitably accommodate the occupants and provide sufficient the trunk capacity. Plastic panoramic sunroof or full roof on the smart fortwo coupé. Tritop soft top on the smart fortwo cabrio.
• Overall vehicle interior Numerous color and pattern variants in the interior. Ergonomic instrument cluster in the instrument panel. Clearly arranged and user-friendly center console. Rear-end door with integral stowage compartment for the smart fortwo coupé or tight-fitting stowage areas without retaining straps for the roof side supports in the smart fortwo cabrio.
• Engine/injection system 3-cylinder gasoline engine with 52 kW. Fuel injection system with Bosch Multi-Point­Injection.
• Transmission 5-speed automated manual transmission AMT 2 (2nd generation).
• Suspension MacPherson front suspension with torsion stabilizer bars. DeDion rear axle.
• Brake Hydraulic 2-circuit brake system with ESP and TT (front/rear) split, version 8.1 from Bosch.
• Steering Equipped with rack-and-pinion steering as standard. Electromechanical power steering with active steering centering and adaptation of the steering forces available as special equipment.
• Maintenance Maintenance concept: Maintenance service only every two years, with only the Oil Service Plus once a year in between. Service flap at front for easy access to the maintenance points.
• Safety Restraint system with airbags and emergency tensioning retractors. Bodyshell made of high-strength steels. Door reinforcements made of high-strength steels. Full-length knee guard for driver and passenger.
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Page 11
Technical data
10
Complete vehicle
Introduction of the smart fortwo, Model Series 451
P00.10-4259-00
Dimensions - smart fortwo coupé
48.0
50.0
27.7
28.7
106.1
15.9
73.5
16.7
24.4
19.7
39.7
21.0
11.5
21.0
54.5
61.4
69.0
50.5
60.7
Dimensions Unit smart fortwo coupé (model 451)
Vehicle length in (mm) 106.1 (2695)
Vehicle width in (mm) 61.4 (1559)
Vehicle height in (mm) 60.7 (1542)
Wheelbase in (mm) 73.5 (1867)
Front track width in (mm) 50.5 (1283)
Rear track width in (mm) 54.5 (1385)
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Technical data
Complete vehicle
11
Introduction of the smart fortwo, Model Series 451
P00.10-4260-00
Dimensions - smart fortwo cabrio
48.0
50.0
27.7
28.7
106.1
15.9
73.5
16.7
24.4
19.7
39.7
21.0
11.5
21.0
54.5
61.4
69.0
50.5
60.7
Dimensions Unit smart fortwo cabrio (model 451)
Vehicle length in (mm) 106.1 (2695)
Vehicle width in (mm) 61.3 (1559)
Vehicle height in (mm) 60.7 (1542)
Wheelbase in (mm) 73.5 (1867)
Front track width in (mm) 50.5 (1283)
Rear track width in (mm) 54.5 (1385)
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Page 13
Technical data
12
Complete vehicle
Introduction of the smart fortwo, Model Series 451
Models and major assemblies
Loads, weights and other data
smart fortwo Model Engine Transmission
smart fortwo coupé 451.331
132.910 (52 kW) 717.482
smart fortwo cabrio 451.431
Unit smart fortwo coupé smart fortwo cabrio
Powerplant kW 52 52
Permissible front axle load lb
(kg)
969
(440)
Permissible rear axle load lb
(kg)
1458
(660)
Curb weight as per DIN lb
(kg)
1652 (820)
1740 (840)
Permissible gross vehicle weight lb
(kg)
2247
(1050)
2247
(1050)
Payload lb
(kg)
595
(230)
507
(210)
of which max. in luggage compart­ment
lb
(kg)
110
(50)
Max. seating capacity 2
Luggage compartment volume
up to belt line
up to roof
in
3
(l)
in
3
(l)
7.8
(220)
12
(340)
Turning circle yd
(m)
9.57
(8.75)
Tank capacity/including reserve US gal
(l)
8.72/1.32 33/5
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Maintenance
Complete vehicle
13
Introduction of the smart fortwo, Model Series 451
Ma xintenance concept
Consistent product development has enabled a future-oriented servicing concept to be implemented in model series 451.
The servicing concept of the smart fortwo has allowed the service intervals to be extended significantly, as shown below.
Maintenance intervals
* depending on first occurrence
smart fortwo kW Interval
Gasoline engine 52 Every 2 years or 20,000 miles*
Oil Service Plus
In combustion engines with a high engine output per unit of displacement, the engine oil is subjected to extreme loads. With 3.7 US qt (3.5 liters), the smart fortwo has a relatively small quantity of engine oil, meaning that it has to be replaced at regular time/mileage intervals.
To help optimize operating costs, the "Oil Service Plus" has been introduced, which is due every 10 000 miles or once per year. It comprises merely an engine oil change and inspection of the safety-relevant components and functions.
This servicing concept has benefits for both the workshops and the customers:
• Customers have lower vehicle operating costs due to the reduced maintenance costs as a whole. This improves customer satisfaction.
• The workshops improve their competitiveness in the servicing business especially. Longer-lasting customer loyalty and better chances of follow-up business are possible with this concept.
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Maintenance
14
Complete vehicle
Introduction of the smart fortwo, Model Series 451
Maintenance interval display (WIA)
The maintenance interval display is located in the multifunction display of the instrument cluster.
The maintenance intervals are indicated by the lighting of one or two wrench symbols.
In addition, approximately one month in advance of a scheduled service date the multifunction display shows the remaining time (in days) until it is due. After engine start the range (in miles) is displayed for about ten seconds.
P54.32-5676-00
Instrument cluster
A1 Instrument cluster A1p13 Multifunction display
i Note
When the Oil Service Plus or a maintenance service has been performed, the maintenance interval display can be reset to the starting distance on the instrument cluster itself or via STAR DIAGNOSIS. (See WIS for a detailed description.)
Meaning of wrench symbols:
• 1 wrench means Oil Service Plus
• 2 wrenches mean maintenance service
P54.32-5677-00
Multifunction display with maintenance interval display
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Maintenance
Complete vehicle
15
Introduction of the smart fortwo, Model Series 451
Service flap
The smart fortwo is equipped with a detachable service flap which allows convenient access to all maintenance points in the front section. Customer­relevant maintenance items can be performed by the customer accordingly.
To remove the service flap, levers located in the air grille on each side must be operated to unlock the service flap. The service flap can then be removed and suspended by two brackets on the front of the vehicle. A check strap prevents the service flap from falling down.
Maintenance points at front end
The most important maintenance points at the front of the car are:
• Brake fluid reservoir
• Windshield washer fluid reservoir
• Coolant expansion reservoir
• Lamp units for bulb replacement
P00.20-2629-00
Maintenance points at front end
1 Brake fluid reservoir 2 Windshield washer fluid reservoir 3 Coolant expansion reservoir
4 Lamp unit for bulb replacement 5 Service flap 6 Check strap
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Maintenance
16
Complete vehicle
Introduction of the smart fortwo, Model Series 451
Maintenance points in engine compartment
The maintenance points in the engine compartment can be accessed once the engine compartment cover in the luggage compartment floor has been removed.
The most important maintenance points in the engine compartment are:
• Oil filler neck
• Oil dipstick
• Air filter housing
• Spark plugs
P00.20-2630-00
Maintenance points in engine compartment
7 Oil filler neck 8 Oil dipstick
9 Air filter housing
10 Ignition coils (spark plugs)
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Safety concept
Complete vehicle
17
Introduction of the smart fortwo, Model Series 451
In the smart fortwo, high levels of active safety are provided by both tried-and-tested and newly devel­oped systems and components.
Active safety
Active safety includes measures and equipment that help to prevent detected dangers from occurring in the first place, or that warn the driver of dangers in advance, or that assist him in critical driving situa­tions: A distinction is drawn between the following safety aspects:
• Driving safety
• Stress-reducing safety
• Perceptual safety
• Operating safety
The components responsible for maintaining driving safety include:
• Electromechanical power steering (SA)
• 5-speed automated manual transmission
• Vehicle dynamics systems: ABS (antilock brake system) ASR (acceleration skid control) ESP (electronic stability program)
High levels of stress-reducing safety are due to:
• Comfortable seats with integral head restraints
• Temperature-regulated air conditioning
High levels of perceptual safety are assured by the following components:
• Auto on/off headlamps (SA)
• Center high-mounted brake lamp in the roof spoiler
Operating safety is provided by:
• Ergonomically designed driver area
• Clearly arranged and easily reachable controls
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Page 19
Safety concept
18
Complete vehicle
Introduction of the smart fortwo, Model Series 451
Passive safety
The goal of a vehicle's passive safety is to minimize as much as possible the effects of an accident on the people involved. Some of the most important aspects of this are the preservation of the survival space (rigid passenger cell), high energy dissipation in the event of an accident thanks to exploitable crumple zones at the front and rear, and energy-absorbing restraint systems in the interior.
The passive safety concept includes:
• tridion safety cell consisting of 50% high-strength steel
• Crash management system (CMS) at the front and rear, which absorbs energy at low vehicle speeds and prevents expensive bodyshell damage
• Front end with no major assemblies, for effective exploitation of the short overhang as a crumple zone
• Inclusion of the wheels and axles/frame-type integral support in the crumple zone and for force application
• Front and rear structures with several impact planes and large cross sections to transfer and disperse the crash energy that is generated
• Long forward displacement area for the driver and passenger with restraint systems adapted to compensate for the "short" crumple zone
• Sturdy steel seat structures for effective protection against shifting cargo and for specific deformation in rear-end collisions
• Side doors made of solid steel frame profiles including side impact protection
• Safe positioning of the fuel tank in the underfloor area between the axles
• Deformable steering column to dissipate energy, prevent intrusion and lengthen the forward displacement distance in a frontal collision
• Full interior lining to reduce head injuries
The occupant restraint systems comprise:
• 2-stage driver airbag in steering wheel
• 2-stage top-mounted passenger airbag with deployment opening on the top surface of the instrument panel
• Head/thoraxbags in the backrests
• Three-point seat belts with emergency tensioning retractors, belt force limiters and belt guides on the backrests
• Seat belt reminders for driver and passenger
• Belt tension sensor on passenger side
• Passenger seat with Weight Sensing System (WSS) with automatic passenger airbag deactivation for the corresponding weight classes and airbag OFF indicator lamp
• Full-length knee guard
• Two frontal acceleration sensors on front crossmember
• Two satellite sensors on inner side wall in area of left and right B-pillar
• Restraint systems control unit
P91.60-3663-00
1 Driver airbag 2 Passenger airbag 3 Head/thoraxbag
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Safety concept
Complete vehicle
19
Introduction of the smart fortwo, Model Series 451
Protective measures for pedestrians and cyclists comprise:
• Single-piece front end module
• Main headlamps with predetermined fracture point
• Concealed and retracting windshield wiper shafts
• Energy-absorbing covering on the center piece in front of the windshield
• Large, soft plastic surfaces at the front
The extended range of functions following an accident includes:
• Automatic engine off feature
• Interruption of the fuel supply
• Unlocking of the doors
• Activation of the hazard warning system
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On-board electrical system/power supply
20
Electrical system
Introduction of the smart fortwo, Model Series 451
General
The on-board electrical system ensures that the power supply to all the electrical consumers and components in the vehicle is appropriate for the requirements and the situation.
The on-board electrical system consists of the following main components:
• Starter
• Battery
• Alternator
• ME-SFI [ME] control unit
• Instrument cluster
Starter
The starter has an output of 0.95 kW and supplies the torque necessary to start the engine. It takes the necessary energy from the adequately charged battery.
Battery
The battery (42 Ah) supplies the consumers when the engine is off, the starter while the engine is being started, and the on-board electrical system when the alternator is unable to provide the required consumer current.
The battery is located in the passenger footwell under the carpeting.
There are three fuses located in the area of the battery:
F36 Secondary air injection pump fuse F58 Starter/alternator fuse F91 SAM prefuse
P54.10-2890-00
G1 Battery F36 Secondary air injection pump fuse F58 Starter/alternator fuse F91 SAM prefuse
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On-board electrical system/power supply
Electrical system
21
Introduction of the smart fortwo, Model Series 451
Alternator
The alternator supplies the electrical consumers while the engine is running and recharges the battery so that a subsequent engine start is possible. The alternator is equipped with an overvoltage protection function that limits the on-board power supply voltage in the event of a defect in the governor. The alternator is monitored by the ME-SFI [ME] control unit.
The alternator is pre-excited via a direct line. The alternator load is reported back to the ME-SFI [ME] control unit over a separate line and monitored.
Instrument cluster
The on-board power supply voltage is monitored by the engine control. If the voltage is < 11.5 V for a period of over 3 min, a signal is sent over CAN to the instrument cluster and the alternator charge moni­toring and warning lamp (A1e5) lights up.
P54.10-2891-00
G2 Alternator
P54.32-5684-00
A1 Instrument cluster A1e5 Alternator charge monitoring and warning lamp
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Complete networking
22
Electrical system
Introduction of the smart fortwo, Model Series 451
Overall network - location of components
P00.19-4338-00
Overall network - full equipment
A1 Instrument cluster
on the left side of the instrument panel
A15p4 Tachometer
(with code (V31) Cockpit clock and tachome­ter package) in the center of the instrument panel
B24/15 Yaw rate, lateral and longitudinal accelera-
tion sensor under the floor covering near the driver seat
B32 ATA [EDW] microwave sensor
(with code (V01) Anti-theft alarm system (FFO)) under the center console near the handbrake lever
B38 Rain sensor/light sensor
(with code (V54) Rain/light sensor) in the middle of the windshield near the in­side rearview mirror
H3/2 Alarm siren with inclination sensor
(with code (V01) Anti-theft alarm system (FFO)) on the right in front of the fuel tank
N2/7 Restraint systems control unit
in the center under the instrument panel
N3/10 ME-SFI [ME] control unit
behind the right side paneling in the rear
N10/10 SAM control unit
on the left under the instrument panel
N15/5 Electronic selector lever module control
unit
(Legend continued on the next page)
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Page 24
Complete networking
Electrical system
23
Introduction of the smart fortwo, Model Series 451
Overall network - CAN bus/LIN bus
P00.19-4339-00
Block diagram - Full equipment
N15/6 Automated manual transmission control unit
under the floor covering near the driver seat
N23 Heater/AC operating unit
(with code (I01) Air conditioning Plus and code (V30) Outside temperature sensor (FFO)) in the center of the instrument panel
N25/5 Front HS [SIH] control unit
(with code (S17) Seat heaters (FFO)) in the center under the instrument panel
N47-5 ESP control unit
on ESP hydraulic unit
N49 Steering angle sensor in steering wheel
N57/2 Power window convenience feature control
unit (with code (V43) Power windows) on the left under the instrument panel
N68 Power steering control unit
(with code (V26) Power steering, EPS (FFO)) in interior compartment on left of firewall
N88 TPM [RDK] control unit
on left below instrument panel
N110 Weight Sensing System (WSS) control unit
on underside of passenger seat
X11/4 Data link connector
on the bottom of the instrument panel on the driver side
CAN Controller Area Network bus
(data bus/CAN bus)
CAN-B Controller Area Network bus class B
(interior compartment) LIN B Interior Local Interconnect Network 1 LIN C Interior Local Interconnect Network 2
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Wiring harnesses
24
Electrical system
Introduction of the smart fortwo, Model Series 451
P54.18-4507-00
Wiring harness groups
The wiring harness is divided into the following groups:
1 Main wiring harness 2 Engine wiring harness 3 Transmission wiring harness 4 Battery wiring harness
Not illustrated:
- Door wiring harness
- Soft top wiring harness (in smart fortwo cabrio)
- Rear-end door wiring harness
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Wiring harnesses
Electrical system
25
Introduction of the smart fortwo, Model Series 451
General
The wiring harness variants result from the basic standard equipment, the special equipment items and the national versions.
Repair capability
A basic wiring harness repair kit in a case is available for repairing individual lines, wiring harnesses and connectors without sealed plugs. All the above repairs can be carried out using this kit.
It is also possible to expand the kit with a supple­mental repair set to allow wiring harnesses with sealed plugs to be repaired.
i Note
W000 589 13 99 00
Basic wiring harness repair kit. Tools for repairing individual lines, wiring harnesses and connectors in combination with the wiring harness repair kit supplement for passenger cars (W220 589 04 99 00).
W220 589 04 99 00
Wiring harness repair kit supplement for passenger cars Tools for repairing individual lines, wiring harnesses and connectors in combination with the basic wiring harness repair kit (W000 589 13 99
00).
P54.18-4140-00
Wiring harness repair kit
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Page 27
Diagnosis
26
Electrical system
Introduction of the smart fortwo, Model Series 451
General
The network architecture in model 451 allows external access to individual control units in the CAN bus system.
Data link connector
The CAN bus is accessed by means of a diagnostic tester that is connected to the vehicle via the data link connector. The data link connector is linked directly to the CAN bus and can therefore access all the control units that have diagnostic or programming capability. The data link connector is located in the vehicle interior on the underside of the instrument panel on the driver side.
Diagnostic tester
By connecting the diagnostic tester, the vehicle with all its equipment variants can be precisely identified. This enables accurate fault evaluation and rectifica­tion and the analysis of vehicle-specific values and parameters.
P54.22-2048-00
Location of data link connector (X11/4)
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Page 28
Diagnosis
Electrical system
27
Introduction of the smart fortwo, Model Series 451
Diagnosis capability
The following control units have diagnosis capability:
• Instrument cluster
• Restraint systems control unit
• WSS control unit
• ME-SFI [ME] control unit
• SAM control unit
• Automated manual transmission control unit
• Heater/AC operating unit
• ESP control unit
• Steering assist control unit
• TPM [RDK] control unit
• Electronic selector lever module control unit
Fault memory
Each of the control units listed above has a fault memory that provides information about the associ­ated systems. The stored faults are displayed by the diagnostic tester and must be rectified. When all the faults have been eliminates, the fault memory must be erased and read out again. There should be no fault entries left afterwards.
Maintenance intervals
The diagnostic tester is used to reset the mainte­nance interval in the instrument cluster following an Oil Service Plus or a maintenance service.
Programming control units
The following control units can be programmed:
• ME-SFI [ME] control unit
• SAM control unit
• Automated manual transmission control unit
• ESP control unit
TAN generator
For the following applications a TAN (transaction number) must be generated:
• Retrofitting the steering wheel gearshift (SAL)
• Replacing the ME-SFI [ME] control unit
• Replacing the SAM control unit
• Teach-in of transmitter keys (after loss or detection of additional transmitter keys)
SCN (Software Calibration Number) coding
The following control units can be coded via the SCN coding process:
• ME-SFI [ME] control unit
*)
• SAM control unit
• ESP control unit
• Automated manual transmission control unit
*)
• Restraint systems control unit
• Instrument cluster
*) The control unit is relevant to exhaust emissions, i.e. the SCN is written in the control unit and can be interrogated. For the other control units a virtual SCN is generated during the coding process, but this is not written to the control unit.
i Note
Up to six transmitter keys in total can be taught in at the same time.
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Page 29
SAM control unit
28
Electrical system
Introduction of the smart fortwo, Model Series 451
Almost all of the fuses in model 451 are accommodated on the SAM control unit. Slots 1-31 are located on the front of the SAM control unit; slots 32-35 are located on the rear. The following fuses are not accommodated on the SAM control unit:
• Secondary air injection pump fuse (F36)
• Starter/alternator fuse (F58)
• SAM prefuse (F91)
The SAM control unit is installed in the vehicle interior on the left side near the A-pillar under the instrument panel.
The SAM control unit is linked with the CAN in order to exchange data. It communicates with the following components:
• Instrument cluster
• ESP control unit
• Restraint systems control unit
• ME-SFI [ME] control unit
• Heater/AC operating unit
• Steering assist control unit
• TPM [RDK] control unit
• Weight Sensing System (WSS) control unit
• Yaw rate, lateral and longitudinal acceleration sensor
• Steering angle sensor
• Data link connector
P54.21-2702-00
SAM control unit (front)
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Page 30
SAM control unit
Electrical system
29
Introduction of the smart fortwo, Model Series 451
The SAM control unit also communicates over:
• LIN B with the tachometer and the rain sensor/light sensor
• LIN C with the ATA [EDW] microwave sensor and the alarm siren with inclination sensor.
The fuse and relay box is integrated in the SAM control unit.
The following relays are not accommodated on the SAM control unit:
• Left turn signal/brake light relay (K52/11)
• Right turn signal/brake light relay (K52/12)
• Secondary air injection pump relay (K64)
• Soft top opening relay (K66/1) (only cabrio)
• Soft top closing relay (K66/2) (only cabrio)
P54.21-2703-00
SAM control unit (rear)
i Note
Up to six transmitter keys can be stored in the SAM control unit.
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Page 31
Engine description
30
Engine M132
Introduction of the smart fortwo, Model Series 451
Engine M132
At market launch, the smart fortwo is available with a 3-cylinder gasoline engine with 61 in
3
(999 cm3)
displacement and 52 kW
P01.10-2942-00
3-cylinder gasoline engine (M132)
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Page 32
Performance graph
Engine M132
31
Introduction of the smart fortwo, Model Series 451
Power and torque graph
The red characteristic represents the power curve (P) in relation to the engine speed (n). The blue characteristic represents the torque curve (M) in relation to the engine speed (n).
P01.00-2999-00
Power and torque graph M132
M Torque (lb-ft)
P Engine power (kW) n Engine speed (rpm)
0
0 1000 2000 3000 4000 5000 6000 7000
20
40
60
80
100
120
140
160
180
M (lb-ft) P (kW)
n (1/min)
0
10
20
30
40
50
60
70
SN_Typ 451_us.book Seite 31 Freitag, 30. November 2007 1:56 13
Page 33
Engine data
32
Engine M132
Introduction of the smart fortwo, Model Series 451
* Fuel requirements:
Only unleaded premium fuel may be used. The octane number (shown on the gasoline pump) should be at least 91. This is an average value based on tests of the octane number (RON) and motor octane number (MON) (RON+MON/2). It is also known as the anti-knock index.
M132
Engine model designation 132.910
Rated output kW
at rpm
52
5800
Rated torque lb-ft (Nm)
at rpm
68 (92)
4500
Compression ratio e 10.0:1
Engine configuration/no. of cylinders Inline/3
Camshaft configuration/number Overhead/2
Displacement in
3
(cm3)
61
(999)
Bore in
(mm)
2.83 (72)
Stroke in
(mm)
3.22
81.8
Cylinder angle ° 45
Fuel * Premium gasoline
unleaded
Emission regulations ULEV
SN_Typ 451_us.book Seite 32 Freitag, 30. November 2007 1:56 13
Page 34
Valve assembly
Engine M132
33
Introduction of the smart fortwo, Model Series 451
Valve assembly
The timing chain is driven by the crankshaft via the crankshaft gear and thus drives the intake camshaft via the camshaft adjuster and the exhaust camshaft via the exhaust camshaft sprocket. The timing chain is guided by a slide rail. A tensioning rail and chain tensioner ensure that the chain is at the right tension to prevent wear and noises.
The intake and exhaust camshafts control the gas exchange in the engine via the intake and exhaust valves. Variable camshaft adjustment allows for greater torque at low engine speeds and better response time in the idle and partial-load ranges. At the same time, the camshaft adjustment helps to achieve the stipulated exhaust emissions limits.
P05.00-2082-00
Valve assembly
1 Exhaust camshaft sprocket 2 Exhaust camshaft 3 Camshaft adjuster 4 Intake camshaft 5 Crankshaft gear 6 Crankshaft
7 Timing chain 8 Intake valve
9 Exhaust valve 10 Valve spring 11 Cup tappet
SN_Typ 451_us.book Seite 33 Freitag, 30. November 2007 1:56 13
Page 35
Valve timing
34
Engine M132
Introduction of the smart fortwo, Model Series 451
General
Engine M132 is equipped with mechanical cup tappets. The mechanical stress on the cams and cup tappets makes it necessary to check and adjust the valve clea­rance.
The cup tappets must be measured using a micro­meter.
Find and insert the appropriate cup tappet by refer­ence to its markings. The valve clearance is adjusted by exchanging the cup tappets. These are available in various thicknesses.
P05.30-2151-00
1 Cylinder head 2 Camshaft bearing cap 3 Intake camshaft 4 Exhaust camshaft 5 Cup tappet 6 Intake valve
7 Exhaust valve 8 Valve spring retainer
9 Valve locks 10 Valve spring 11 Valve stem seal 12 Valve seat
SN_Typ 451_us.book Seite 34 Freitag, 30. November 2007 1:56 13
Page 36
Gasoline injection and ignition system
Engine M132
35
Introduction of the smart fortwo, Model Series 451
Injection control
Engine M132 features an ME (motor electronics) gasoline injection and ignition system. The central control unit of this system is the ME-SFI [ME] control unit. It is networked over CAN with the following components:
• Instrument cluster
• SAM control unit
• Automated manual transmission control unit
• Heater/AC operating unit
• ESP control unit
• Steering assist control unit
• Data link connector
The ME-SFI [ME] control unit puts its information on the CAN, making it accessible to all the other networked components on the CAN. The information from other components reaches the ME-SFI [ME] control unit in the same way. For example, the signal from the clutch motor, which is read directly by the automated manual transmission control unit, reaches the ME-SFI [ME] control unit in this way.
Direct input signals come from:
• Knock sensor
• Fuel tank pressure sensor
• Camshaft Hall sensor
• Coolant temperature sensor
• Accelerator pedal sensor
• O2 sensor downstream of TWC [KAT]
• O2 sensor upstream of TWC [KAT]
• Crankshaft position sensor
• Throttle valve actuator
• Oil pressure switch
Direct output signals go to:
• Fuel pump relay
• Fuel pump with fuel level sensor
• Secondary air injection pump relay
• Secondary air injection pump
• Secondary air injection pump switchover valve
• Throttle valve actuator
• Cylinder 1 ignition coil
• Cylinder 2 ignition coil
• Cylinder 3 ignition coil
• Outside air shutoff valve
• Adjustable camshaft timing solenoid
• Cylinder 1 fuel injection valve
• Cylinder 2 fuel injection valve
• Cylinder 3 fuel injection valve
• Fuel tank vent valve
There are also the following inputs on the ME-SFI [ME] control unit:
• Circuit 15
• Circuit 30
• Circuit 31
Function
The engine is controlled according to load by the performance map based on the signals arriving either directly or over CAN. The actuators are actuated via direct lines in accordance with the values computed by the ME-SFI [ME] control unit. Information intended for other components is put on the CAN.
The ME-SFI [ME] control unit has an integral fault memory and can exchange information with STAR DIAGNOSIS via a data link connector that is connected to the CAN.
SN_Typ 451_us.book Seite 35 Freitag, 30. November 2007 1:56 13
Page 37
Gasoline injection and ignition system
36
Engine M132
Introduction of the smart fortwo, Model Series 451
P07.61-3578-00
Data flow chart of M132 injection system
SN_Typ 451_us.book Seite 36 Freitag, 30. November 2007 1:56 13
Page 38
Gasoline injection and ignition system
Engine M132
37
Introduction of the smart fortwo, Model Series 451
15/30/31 Circuit status
A1 Instrument cluster A16 Knock sensor B4/3 Fuel tank pressure sensor B6/1 Camshaft Hall sensor B11/4 Coolant temperature sensor B28 Intake manifold pressure sensor B37 Accelerator pedal sensor G3/1 O2 sensor downstream of TWC [KAT] G3/2 O2 sensor upstream of TWC [KAT] K27 Fuel pump relay K64 Secondary air injection pump relay L5 Crankshaft position sensor M3/3 Fuel pump with fuel level sensor M16/6 Throttle valve actuator M33 Secondary air injection pump N3/10 ME-SFI [ME] control unit
N10/10 SAM control unit N15/6 Automated manual transmission
control unit N23 Heater/AC operating unit N47-5 ESP control unit N68 Steering assist control unit S41/1 Oil pressure switch T1/1 Cylinder 1 ignition coil T1/2 Cylinder 2 ignition coil T1/3 Cylinder 3 ignition coil X11/4 Data link connector Y32 Secondary air injection pump switchover
valve Y49 Adjustable camshaft timing solenoid Y50 Outside air shutoff valve Y58 Tank vent valve Y62/1 Cylinder 1 fuel injection valve Y62/2 Cylinder 2 fuel injection valve Y62/3 Cylinder 3 fuel injection valve
CAN Controller Area Network
(data bus/CAN bus)
SN_Typ 451_us.book Seite 37 Freitag, 30. November 2007 1:56 13
Page 39
Belt drive
38
Engine M132
Introduction of the smart fortwo, Model Series 451
Belt adjustment and description of stretch belt
Self-tensioning belt drive
The alternator and coolant pump are driven by a poly­V belt with tensioning device.
The poly-V belt is tensioned via a new spring-loaded tensioning device. To install and remove the poly-V belt the tensioning device must be rotated clockwise using a special tool to slacken the tension in the belt drive. The tensioning device can then be locked in place and the poly-V belt removed.
Stretch belt
The refrigerant compressor is driven by a stretch belt.
The stretch belt does not need a tensioning device, but it must be replaced after a specified mileage. It is removed and installed with the aid of a special tool that guides the stretch belt over the belt pulley of the refrigerant compressor. The stretch belt can be pulled on or off the belt pulley by cranking the engine in its normal direction of rotation.
P13.20-2055-00
Belt drive
1 Alternator belt pulley 2 Poly-V belt 3 Coolant pump belt pulley 4 Refrigerant compressor belt pulley
5 Crankshaft pulley 6 Tensioning device 7 Tensioning device belt pulley 8 Stretch belt
SN_Typ 451_us.book Seite 38 Freitag, 30. November 2007 1:56 13
Page 40
Cooling system
Engine M132
39
Introduction of the smart fortwo, Model Series 451
Coolant circuit
In the small cooling circuit, the coolant is pumped through the engine, the heater heat exchanger and back to the engine via the expansion reservoir by the coolant recirculation pump. In the large coolant circuit, the coolant flows from the thermostat straight to the radiator and on to the coolant recirculation pump. The switchover between the small and large coolant circuit is performed by the thermostat depending on the coolant temperature.
In the expansion reservoir the circuit is split again, with one stream flowing direct to the coolant recircu­lation pump and the other passing through the radi­ator.
The coolant fan motor is switched on or off depending on the engine temperature recorded by the coolant temperature sensor and cools the coolant.
P20.00-2339-00
1 Radiator 2 Expansion reservoir 3 Coolant return line 4 Coolant feed line (large circuit) 5 Coolant pump 6 Coolant pump belt pulley 7 Thermostat
8 Coolant feed line (small circuit) 9 Heater heat exchanger
10 Coolant pipe
B11/4 Coolant temperature sensor M4/2 Coolant fan motor
SN_Typ 451_us.book Seite 39 Freitag, 30. November 2007 1:56 13
Page 41
Cooling system
40
Engine M132
Introduction of the smart fortwo, Model Series 451
Bleeding cooling system
General
If some or all of the coolant has been drained, the cooling system must be bled after refilling.
Fill
Unscrew the cooling system cap and fill the cooling system up to the "MAX" mark in the expansion reser­voir.
Bleeding
Unfasten the clamp, pull off the coolant hose and wait until coolant emerges from the coolant hose and the cylinder head. Then reconnect the coolant hose and fasten it with the clamp. Top up the expansion reservoir to the "MAX" mark again and screw on the cooling system cap. Warm up the engine until the thermostat opens. Switch off the engine and check the coolant level in the expansion reservoir.
P20.00-2340-00
1 Cooling system cap 2 Expansion reservoir
3 Coolant hose 4 Clamp
i Note
The cooling system must be filled and bled only when the engine is cold.
SN_Typ 451_us.book Seite 40 Freitag, 30. November 2007 1:56 13
Page 42
Engine mount
Engine M132
41
Introduction of the smart fortwo, Model Series 451
Engine mount/torque support
The engine with transmission is mounted on two mounts and a torque support. They were designed to dampen inherent engine vibrations. They also consid­erably reduce the rocking of the drive assemblies during load changes. The reduction in vibrations and in the tendency to rock provides a higher level of driving safety and ride comfort.
P22.10-2299-00
Engine mount, transmission mount and torque support
1 Frame-type integral support 2 Engine mount
3 Transmission mount 4 Torque support
SN_Typ 451_us.book Seite 41 Freitag, 30. November 2007 1:56 13
Page 43
Fuel supply
42
Fuel system
Introduction of the smart fortwo, Model Series 451
Fuel supply
A non-return fuel system is used for the fuel supply. The fuel is pumped by a flow pump via the fuel filter in the fuel tank into the fuel distributor rail according to requirements. Any surplus fuel is pumped via the fuel pressure regulator straight into the buffer of the fuel pump. The fuel pressure regulator is designed to ensure that there is always a pressure of 46 psi (3.24 bar) at the fuel distributor rail. The fuel tank fill level is measured by a float-and-lever sensor.
Fuel tank
The fuel tank is located in front of the rear axle under the seats. It is made of polyethylene and is formed such that the available installation space is used to an optimum. The capacity of the fuel tank is 8.72 gallons (33 liters), including a 1.32 gallon (5 liter) reserve.
The intank fuel supply system consists of a fuel pump with fuel level sensor, fuel pressure regulator and an integrated fuel filter.
Evaporative emission control system (purging)
The evaporative emission control system prevents fuel vapors escaping to the atmosphere. The fuel vapors are stored in the activated charcoal filter and then sent later to the engine for combustion.
Leak test
The leak test for the fuel evaporation control system must detect leaks with a diameter as of 0.02 in (0.5 mm) and must take place in three stages (function chain):
• Test for gross leaks (equal to or greater than 0.12 in (3 mm))
• Test for fine leaks (equal to or greater than 0.04 in (1 mm))
• Test for very fine leaks (equal to or greater than
0.02 in (0.5 mm))
Test for gross leaks
The outside air shutoff valve is closed and the tank vent valve is opened. Intake manifold vacuum present in fuel tank. This vacuum is measured by the tank pressure sensor.
If no vacuum is built up in the fuel tank (approx. -0.1 psi (-6 mbar) within approx. 12 seconds) there is a major leak (e.g. tank cap open, hose line loose). The test will be interrupted and the "gross leak" fault will be registered. If the ME-SFI [ME] control unit detects a system with a gross leak, the fuel reserve warning lamp in the instrument cluster flashes and the message "CHECK FILLER CAP" appears in the multifunction display.
Test for fine leaks
The tank vent valve is closed at a vacuum of around -
0.1 psi (-6 mbar). The system is closed and thereby
airproof. The vacuum is then measured for approx. 30 seconds. The vacuum must not reduce more rapidly than 0.004 to 0.007 psi/s (0.3 to 0.5 mbar/s) (depends on fuel level). If the vacuum drops more rapidly, there is a fine leak.
The test will be interrupted and the "fine leak" fault will be registered.
SN_Typ 451_us.book Seite 42 Freitag, 30. November 2007 1:56 13
Page 44
Fuel supply
Fuel system
43
Introduction of the smart fortwo, Model Series 451
Check for very fine leaks
If no fine leak is recognized then purging is briefly enabled and then the vacuum of about -0.1 psi (-6 mbar) is built up again. The vacuum must not reduce more rapidly than 0.0014 to 0.002 psi/s (0.1 to 0.15 mbar/s) in the closed system (depends on fuel level).
If the vacuum drops more rapidly, the fault "very fine leak" will be registered.
The reduction in vacuum depends on the fuel level in the fuel tank and on outgassing of the fuel. The outgassing of the fuel is measured just before the test by the fuel tank pressure sensor and is allowed for during fault determination.
The test for fine and very fine leaks is aborted if an excessive lean correction of the lambda control takes place during the build-up of the vacuum.
The function of the tank vent valve is checked at the same time by the actuation. If the closed tank vent valve jams, the fault "gross leak" is stored.
Test requirements
• Engine at idle
• Vehicle stationary
• Drive position "D" or "R" is engaged
• Off-period after engine start elapsed (approx. 16 minutes) or mixture adaptation performed
• Lambda control enabled
• Intake air temperature <113° F (<45 °C)
• Coolant temperature at engine start <212° F (<100 °C)
• Air injection not active
• Air pressure >1.12 psi (>780 hPa) (i.e. no tests performed above approx. 2735 yd (2500 m) altitude)
• Low loading of activated charcoal canister
• Fuel level in fuel tank between approx. ¼ and ¾
• No fault in outside air shutoff valve
• No fault in the fuel tank pressure sensor
• No fault in tank vent valve
• Battery voltage > 11 V
The outside air shutoff valve is reopened after the tests.
SN_Typ 451_us.book Seite 43 Freitag, 30. November 2007 1:56 13
Page 45
Fuel supply
44
Fuel system
Introduction of the smart fortwo, Model Series 451
P47.-10-2433-00
Fuel system
1 Fuel tank 2 Activated charcoal filter 3 Vent line 4 Filler neck 5 Filler neck hose connection 6 Purge line 7 Fuel distributor rail
B4/3 Fuel tank pressure sensor M3/3 Fuel pump with fuel level sensor Y50 Outside air shutoff valve Y58 Tank vent valve
SN_Typ 451_us.book Seite 44 Freitag, 30. November 2007 1:56 13
Page 46
Overview
Exhaust system
45
Introduction of the smart fortwo, Model Series 451
Design
The exhaust system is made of stainless steel and consists of the following components:
• Exhaust manifold
• Catalytic converter
• Main muffler
Muffler system
When designing the muffler systems, it was important both to minimize the exhaust back pressure and achieve optimum acoustic tuning. The muffler system is rigidly fixed to the vehicle body.
Exhaust aftertreatment
A control sensor and a diagnostic sensor are installed for exhaust aftertreatment. Aftertreatment of the exhaust gases is performed by a catalytic converter with monolithic coating.
P49.00-2109-00
Exhaust system
1 Exhaust manifold 2 Catalytic converter 3 Main muffler
G3/1 O2 sensor downstream of TWC [KAT] G3/2 O2 sensor upstream of TWC [KAT]
SN_Typ 451_us.book Seite 45 Freitag, 30. November 2007 1:56 13
Page 47
Secondary air injection
46
Exhaust system
Introduction of the smart fortwo, Model Series 451
Secondary air injection
Engine 132 is fitted with a secondary air injection pump (electric air pump), which injects additional fresh air in order to reduce exhaust gas emissions after a cold start and to accelerate the warming of the catalytic converter to its reaction temperature.
The necessary air is injected into the exhaust ports in the cylinder head by the secondary air injection pump via the combination valve. The secondary air injection pump is actuated by the ME-SFI [ME] control unit via a relay.
The secondary air injection pump switchover valve is supplied with vacuum from the vacuum reservoir at the intake manifold via a check valve.
When actuated, the secondary air injection pump switchover valve releases vacuum to the combination valve. This opens and the air injected by the secondary air injection pump passes through to the exhaust ports in the cylinder head.
The injected air reacts with the hot exhaust gases in the outlet port. The carbon monoxide (CO) and hydro­carbon (HC) are oxidized. This "afterburning" process increases the exhaust temperature and reduces pollutants.
The duration of secondary air injection is dependent on the coolant temperature. The secondary air injection pump is only actuated at a coolant temperature of 45 °F to 97 °F (7 °C to 36 °C) and for a maximum duration of 33 seconds.
P14.30-2183-00
Secondary air injection
1 Cylinder head 2 Combination valve 3 Air hose 4 Vacuum hose
M33 Secondary air injection pump Y32 Secondary air injection pump switchover
valve
SN_Typ 451_us.book Seite 46 Freitag, 30. November 2007 1:56 13
Page 48
Transmission description
Automated manual transmission
47
Introduction of the smart fortwo, Model Series 451
5-speed automated manual transmission (AMT 2)
The smart fortwo is fitted with the newly developed 2nd generation 5-speed automated manual transmis­sion (AMT 2).
Advantages of the 5-speed automated manual trans­mission:
• Greater shift comfort
• Reduced fuel consumption
Features:
• 5-speed transmission
• Two-drum control
• Potentiometer-free position sensor system
• Mechanical park pawl
The driver can choose between two operating modes:
• Automatic mode (selector lever in position “D“)
• Manual mode (selector lever in position M “+/-“) with operation via the selector lever or paddle shifts on the steering wheel (SAL)
P26.10-2167-00
5-speed manual transmission (AMT 2)
SN_Typ 451_us.book Seite 47 Freitag, 30. November 2007 1:56 13
Page 49
Transmission description
48
Automated manual transmission
Introduction of the smart fortwo, Model Series 451
AMT 2 in model 451
Unit
Transmission model G 717.482
Number of forward/reverse gears 5/1
Max. transferable torque lb-ft
(Nm)
88
(120)
Clutch Single-plate dry clutch
Overall length (including 3 in (75 mm) for clutch) in
(mm)
14.3
(364)
Housing material Aluminum alloy
Weight (without oil charge) lb
(kg)
Approx. 74.9
(34)
Oil charge (permanent charge) US qt
(l)
2.4
(2.3)
Housing Two-piece with bell housing
SN_Typ 451_us.book Seite 48 Freitag, 30. November 2007 1:56 13
Page 50
Shift mechanism
Automated manual transmission
49
Introduction of the smart fortwo, Model Series 451
Shift mechanism
The central components of the shift mechanism are two selector drums for moving the shift forks. Each selector drum is driven by a separate electric motor via two sintered spur gear sets. One selector drum shifts the odd gears, while the other shifts the even gears and reverse gear.
The position of the selector drum, and thus the current shift position, is determined by two incre­mental sensors in each electric motor.
Both electric motors and the spur gears are located in a common aluminum housing, the actuator unit, which is mounted on the transmission.
The two selector drums are arranged to allow over­lapping shift operations to minimize shift times. It is possible to skip gears (e.g. double downshifts).
P26.60-2320-00
Design of shift mechanism
1 Shift fork for shift collar 5 2 Shift fork for reverse gear sliding gear 3 Shift fork for shift collar 1/3 4 Shift fork for shift collar 2/4 5 Main shaft
6 Selector drum 1/3, 5 7 Selector drum 2/4, R 8 Input shaft M17/3 Transmission motor 1 M17/4 Transmission motor 2
SN_Typ 451_us.book Seite 49 Freitag, 30. November 2007 1:56 13
Page 51
Shift mechanism
50
Automated manual transmission
Introduction of the smart fortwo, Model Series 451
Function
The shift forks are displaced by the selector drums parallel to the transmission shafts. They in turn slide the shift collars on the input shaft or the main shaft towards the respective idler gears.
The actuation of the shift forks is conducted by two independent selector drums, each of which has a groove. The sliding blocks for two shift forks run in each groove.
Selector drum 1/3, 5:
• Sliding block of shift fork for shift collar 1/3
• Sliding block of shift fork for shift collar 5
Selector drum 2/4, R:
• Sliding block of shift fork for shift collar 2/4
• Sliding block of shift fork for sliding gear, reverse gear
The positions of both sliding blocks in the same groove are offset to each other by 120°. If a sliding block displaces a shift fork from the center position, the other sliding block is in the straight area of the groove (in center position of respective shift fork).
Shift positions
Neutral (N) and reverse gear (R)
a Selector drum 1/3, 5 b Selector drum 2/4, R c Selector drum adjustment (1 grid square = 40°) d Sliding block deflection (1 grid square = 0.3 in
(7.5 mm))
Neutral position (N)
The sliding blocks in the grooves of the selector drum are in the neutral position. No gear is engaged.
Reverse gear (R)
The selector drum 2/4, R rotates through 120° downwards. This displaces the upper sliding block by 0.89 in (22.5 mm) to the left. The reverse gear sliding gear engages in the outer teeth of shift collar 1/3.
The sliding blocks in the selector drum 1/3, 5 are in the neutral position.
P26.60-2356-00
SN_Typ 451_us.book Seite 50 Freitag, 30. November 2007 1:56 13
Page 52
Shift mechanism
Automated manual transmission
51
Introduction of the smart fortwo, Model Series 451
Shift positions
1st gear (1) and 2nd gear (2)
a Selector drum 1/3, 5 b Selector drum 2/4, R c Selector drum adjustment (1 grid square = 40°) d Sliding block deflection (1 grid square = 0.3 in
(7.5 mm))
1st gear (1)
The selector drum 1/3, 5 rotates through 40° down­wards. This displaces the upper sliding block by 0.3 in (7.5 mm) to the left. The shift collar 1/3 is slid into the idler gear of the first gear. The sliding blocks in the selector drum 2/4, R are in the neutral position.
2nd gear (2)
For the change from 1st gear to 2nd gear, the two selector drums rotate through 40° upwards. This in turn displaces the lower sliding block in the selector drum 2/4, R by 0.3 in (7.5 mm) to the left. The shift collar 2/4 is slid into the idler gear of the second gear. The sliding blocks in the selector drum 1/3, 5 are in the neutral position.,
P26.60-2357-00
SN_Typ 451_us.book Seite 51 Freitag, 30. November 2007 1:56 13
Page 53
Shift mechanism
52
Automated manual transmission
Introduction of the smart fortwo, Model Series 451
Shift positions
3rd gear (3) and 4th gear (4)
a Selector drum 1/3, 5 b Selector drum 2/4, R c Selector drum adjustment (1 grid square = 40°) d Sliding block deflection (1 grid square = 0.3 in
(7.5 mm))
3rd gear (3)
For the change from 2nd gear to 3rd gear, the two selector drums rotate through 40° upwards. The upper sliding block in the selector drum 1/3, 5 is displaced by 0.3 in (7.5 mm) to the right. It presses the shift collar 1/3 into the idler gear of the third gear. The other sliding blocks are in the neutral position.
4th gear (4)
For the change from 3rd gear to 4th gear, the two selector drums rotate through 40° upwards. The lower sliding block in the selector drum 2/4, R is displaced by 0.3 in (7.5 mm) to the right. It presses the shift collar 2/4 into the idler gear of the fourth gear. The other sliding blocks are in the neutral position.
P26.60-2358-00
SN_Typ 451_us.book Seite 52 Freitag, 30. November 2007 1:56 13
Page 54
Shift mechanism
Automated manual transmission
53
Introduction of the smart fortwo, Model Series 451
Shift positions
5th gear (5)
a Selector drum 1/3, 5 b Selector drum 2/4, R c Selector drum adjustment (1 grid square = 40°) d Sliding block deflection (1 grid square = 0.3 in
(7.5 mm))
5th gear (5)
For the change from 4th gear to 5th gear, the selector drum 1/3, 5 rotates through 40° upwards. The lower sliding block in the selector drum 1/3, 5 is displaced by 0.3 in (7.5 mm) to the left. It presses shift collar 5 into the idler gear of the fifth gear. The selector drum 2/4, R is rotated through 40° downwards. The sliding blocks in the selector drum 2/4, R are in the neutral position.
P26.60-2362-00
SN_Typ 451_us.book Seite 53 Freitag, 30. November 2007 1:56 13
Page 55
Synchronization
54
Automated manual transmission
Introduction of the smart fortwo, Model Series 451
Borg-Warner synchronization
All forward gears are equipped with a Borg-Warner synchronization. Reverse gear is not synchronized.
Function
Before the shift collar (3) positively connects the sleeve carrier with the corresponding idler gear, the tapered pairs of faces contact the clutch body (1), synchronizer ring (2) and, where applicable, an intermediate ring. The engine's gear is run at the speed of the corresponding drive-side gear; only then do the locking splines (4) release the remaining travel of the shift collar. The shift collar travel from neutral to complete engagement in the relevant idler gear is approx. 0.3 in (7.7 mm).
P26.50-2173-00
1 Clutch body 2 Synchronizer ring 3 Shift collar 4 Locking splines
SN_Typ 451_us.book Seite 54 Freitag, 30. November 2007 1:56 13
Page 56
Transmission control
Automated manual transmission
55
Introduction of the smart fortwo, Model Series 451
Transmission rpm sensor (L2)
Location
The transmission rpm sensor is mounted to the transmission housing.
Task
The rpm sensor determines the rotational speed of the input shaft. The recorded speeds of the crank­shaft and input shaft are used to monitor the clutch operation. The speeds of the input shaft and the drive wheels are used to determine the actual gear engaged.
The diagram illustrates the oscilloscope picture of an rpm sensor.
P26.19-2104-00
1 Input shaft L2 Transmission rpm sensor
SN_Typ 451_us.book Seite 55 Freitag, 30. November 2007 1:56 13
Page 57
Transmission control
56
Automated manual transmission
Introduction of the smart fortwo, Model Series 451
Transmission motors 1 and 2 (M17/3 and M17/4)
Location
The transmission motors are located on the trans­mission housing.
Task
Depending on the shift request from the automated manual transmission control unit (N15/6), the transmission motors adjust the selector drums via a two-stage spur gear transmission. Actuation is pulse-width modulated by two output stages with four electronic switches each. Upon reaching the specified position the transmission motor is braked. It can, if necessary, be actuated with opposing voltage, if an overshoot beyond the spec­ified position is to be prevented or reversed.
Actuation of the transmission motors is monitored by the incremental sensors, which are located on each motor shaft. These detect the rotation angle and rotation direction of the respective transmis­sion motor using the integrated Hall sensors.
The transmission motors are only actuated to execute the shift operations. Once a target position is reached, a pin engages in the locking groove of the selector drum to maintain the selected gear.
P26.60-2321-00
1 Transmission motor 1 selector drum 2 Transmission motor 2 selector drum M17/3 Transmission motor 1 M17/4 Transmission motor 2
SN_Typ 451_us.book Seite 56 Freitag, 30. November 2007 1:56 13
Page 58
Transmission control
Automated manual transmission
57
Introduction of the smart fortwo, Model Series 451
Automated manual transmission control unit (N15/6)
Location
The automated manual transmission control unit is located in the passenger compartment under the driver seat.
General
The transmission control converts the driver's shift requests into corresponding control signals to the clutch and the 5-speed automated manual transmission.
This is done by relaying the shift signal about the shift request at the electronic selector lever module control unit over a direct line to the auto­mated manual transmission control unit.
The automated manual transmission control unit checks the plausibility of the shift request in relation to the vehicle speed, the load (acceler­ator pedal position) and the engine speed.
If the plausibility check is passed, the automated manual transmission control unit sends the signal to initiate the selected shift operation to the two actuator motors for the two selector drums and to the clutch motor to open or close the clutch.
Task
The automated manual transmission control unit controls the following functions depending on the input information:
• Engaging first gear at vehicle standstill
• Gear change
• Compulsory upshift just before maximum engine speed is reached
• Compulsory downshift when engine idle speed is approached
• Downshift for kickdown
• Disengaging the gear after 1 s when a door is opened without the service brake or accelerator pedal being actuated
• Crawl function
• Clutch operation
• Monitoring of clutch load
P26.19-2145-00
N15/6 Automated manual transmission control unit
The automated manual transmission control unit directly reads the signals from the following compo­nents:
• Transmission rpm sensor (L2)
• Transmission motor 1 (M17/3)
• Transmission motor 2 (M17/4)
• Clutch motor (M18)
• Electronic selector lever module control unit (N15/5)
• Park pawl switch (S16/2)
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Transmission control
58
Automated manual transmission
Introduction of the smart fortwo, Model Series 451
The following components are actuated directly by the automated manual transmission control unit:
• Transmission motor 1 (M17/3)
• Transmission motor 2 (M17/4)
• Clutch motor (M18)
Communication via CAN takes place with the following components:
• Instrument cluster (A1)
• ME-SFI [ME] control unit (N3/10)
• SAM control unit (N10/10)
• Electronic selector lever module control unit (N15/5)
• ESP control unit (N47-5)
Electronic selector lever module control unit (N15/5)
Location
The electronic selector lever module control unit is located in the center console.
Task
The electronic selector lever module control unit records the shift requests of the driver.
The shift positions “N”, “R”, “+” and “-” are detected by Hall sensors in the electronic selector lever module control unit and are read and evalu­ated by the electronics in the electronic selector lever module control unit. The signals corre­sponding to the shift lever positions are trans­ferred to the automated manual transmission control unit.
The release button on the selector lever must be actuated in order to move the selector lever to the following positions:
• From P to R, N or D
• From R to P
• From N to R or P
The transmitter key can only be removed in position 0 if the selector lever is in position P.
When the transmitter key is removed, the selector lever is locked in position P.
P26.60-2375-00
1 Unlock button N15/5 Electronic selector lever module control unit
P Park R Reverse gear N Neutral position D Automatic mode M Manual mode + Upshift
- Downshift
i Note
When reverse gear is requested, the backup light is actuated directly by the electronic selector lever module control unit.
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Page 60
Transmission control
Automated manual transmission
59
Introduction of the smart fortwo, Model Series 451
Manual mode
In manual mode (selector lever in position M), the gears are shifted either using the selector lever or using the paddle shifts on the steering wheel (SAL).
The gear which is currently selected is displayed on the multifunction display in the instrument cluster. The gear indicator may change to provide gearshift recommendations (arrow up or down). The gearshift recommendations are based on a driving style which optimizes fuel consumption.
Automatic mode
In automatic mode (selector lever in position D), the automated manual transmission control unit deter­mines the gear changes. The selected gear range D is displayed on the multifunction display in the instrument cluster.
P54.32-5683-00
1 Gear range display (automatic mode) 2 Gear display (manual mode)
A1 Instrument cluster A1p13 Multifunction display
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Page 61
Transmission control
60
Automated manual transmission
Introduction of the smart fortwo, Model Series 451
P26.19-2141-00
1 Circuit status 2 Shift request 3 Transmission speed 4 Clutch request 5 Clutch motor status 6 Gear change request 7 Transmission motor status 8 Engine speed
9 Backup light actuation 10 Vehicle speed 11 Shift program selection 12 Accelerator pedal position 13 Brake pedal status 14 Door status 15 Engaged gear 16 Gear indicator actuation 17 Park pawl status
A1 Instrument cluster A45 Fanfare horns and airbag clock spring con-
tact E3e3 Left backup light E4e3 Right backup light L2 Transmission rpm sensor M17/3 Transmission motor 1 M17/4 Transmission motor 2 M18 Clutch motor N3/10 ME-SFI [ME] control unit (gasoline engine) N10/10 SAM control unit N15/5 Electronic selector lever module
control unit N15/6 Automated manual transmission
control unit N47-5 ESP control unit S16/2 Park pawl switch S112s1 Steering wheel gear shifter PLUS (SAL) S112s2 Steering wheel gear shifter MINUS (SAL)
CAN Controller Area Network
(data bus/CAN bus)
Data flow chart of transmission control
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Page 62
Park pawl
Automated manual transmission
61
Introduction of the smart fortwo, Model Series 451
Mechanical park pawl
In addition to the parking brake, the 5-speed auto­mated manual transmission is equipped with a mechanical park pawl to prevent the vehicle from rolling away. The mechanical park pawl is operated by the electronic selector lever module control unit via a cable.
The status of the park pawl is reported to the auto­mated manual transmission control unit via the park pawl switch (S16/2).
P26.60-2377-00
1 Transmission 2 Cable 3 Park pawl
N15/5 Electronic selector lever module control unit S16/2 Park pawl switch
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Page 63
Clutch
62
Automated manual transmission
Introduction of the smart fortwo, Model Series 451
Single-plate dry clutch
A single-plate dry clutch, consisting of clutch plate and pressure plate, is installed on model 451.
An internal computer in the automated manual trans­mission control unit evaluates the clutch load. If a threshold value is exceeded, the clutch starts to pulse as an overload warning to the driver. If the overloading continues, e.g. if the car is being held with the clutch on a gradient, the clutch is closed in order to provoke a stall.
P25.00-2010-00
Single-plate dry clutch
1 Pressure plate 2 Clutch plate 3 Flywheel with starter ring gear
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Page 64
Clutch
Automated manual transmission
63
Introduction of the smart fortwo, Model Series 451
Clutch motor
General
Model 451 is fitted with a 5-speed automated manual transmission. This means that a single-plate dry clutch is installed instead of the torque converter that is usual with conventional automatic transmissions. The single-plate dry clutch is actuated by the clutch motor.
Function
When the automated manual transmission control unit issues a request for a gear change, the clutch motor is actuated at the same time. The electric motor inte­grated in the clutch motor operates the clutch via the actuating plunger. The power flow is interrupted and the shift operation can be performed.
P25.19-2010-00
4 Electric motor 5 Electric motor connector 6 Actuating plunger
M18 Clutch motor
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Page 65
Front axle
64
Chassis
Introduction of the smart fortwo, Model Series 451
Front axle
The front axle has a classic McPherson design.
The supporting ball joint is press-fitted with the transverse control arm forming a single component unit. If repairs are necessary, the supporting ball joint must be replaced complete with the cross­member since a satisfactory press-fit cannot be guaranteed in the repair shop.
The wheel bearing in the steering knuckle is not available separately either because it is pressed into the steering knuckle and can only be ordered as a complete unit with the steering knuckle.
Adjustment capabilities
On the front axle it is only possible to adjust the toe; the camber can only be corrected by utilizing the "play" at the attachment points of the front axle.
P33.00-2086-00
Front axle - smart fortwo model 451
1 Front axle crossmember 2 Stabilizer bar 3 Transverse control arm with press-fitted support-
ing ball joint
4 Coil spring 5 Two-tube shock absorber 6 Wheel carrier, cast iron
with pressed-in wheel bearing
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Page 66
Rear axle
Chassis
65
Introduction of the smart fortwo, Model Series 451
Rear axle with suspension
The rear axle consists of:
• Axle tube
• Frame-type integral support
• Coil springs
• Bar link
• Single-tube shock absorbers
• Center bearing
The frame-type integral support supports the rear wheel drive module. The coil springs are located at the outsides and support the body against rolling move­ments.
The single-tube shock absorbers are fixed in place at the top with pin bearings.
P35.00-2075-00
Rear axle - smart fortwo model 451
7 Axle tube 8 Frame-type integral support 9 Coil spring
10 Bar link
11 Single-tube shock absorber pin bearing 12 Single-tube shock absorber 13 Center bearing
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Page 67
Rear module
66
Chassis
Introduction of the smart fortwo, Model Series 451
Lowering the rear module
On model 451, the rear wheel drive module can be lowered.
This shortens removal/installation time for various major assemblies such as the refrigerant compressor, starter, alternator etc., because all the attached parts on the engine and the engine itself can be reached very quickly and with relatively little effort. This shortens repair times and reduces costs while improving customer satisfaction at the same time.
P35.00-2085-00
Lowered rear drive module
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Page 68
Tire pressure monitor
Chassis
67
Introduction of the smart fortwo, Model Series 451
General
The tire pressure monitoring system (TPM [RDK]) monitors the air pressure in the individual tires and improves active safety. A previously stored tire pres­sure is used as a comparative value. If a relevant loss of pressure occurs, the tire pressure monitor warning lamp in the instrument cluster warns the driver. The tire pressure measuring range is p = 0 to 78 psi (p = 0 to 5.5 bar).
The TPM [RDK] system has the following subfunctions:
• Tire pressure sensing
• Warning display
• Manual restart
Function requirements
• Circuit 15 ON
• Tire pressure monitor (TPM [RDK]) system functional
Tire pressure sensing
The TPM [RDK] control unit is permanently opera­tional. Each time the CAN wakes up, the control unit performs a re-initialization. While driving, the tire pressure monitoring (TPM [RDK]) system continuously monitors the tire pressure of all rotating wheels (with circuit 15 OFF for a further t = 19 min). When the vehicle is parked for t > 19 min, on-board wheel detection and axle assignment must first be completed via the TPM [RDK] wheel sensors. While driving, the TPM [RDK] wheel sensors transmit data telegrams every 60 seconds.
These data telegrams contain the following informa­tion:
• Tire pressure
• Tire air temperature
• Individual serial number
• Status information (manufacturer, direction of rotation, operating mode etc.)
In addition the TPM [RDK] control unit takes into account the outside temperature and the vehicle speed for the tire pressure determination. These data are provided via CAN by the instrument cluster.
Warning indicator
A warning is issued when a relevant loss of pressure has been detected in at least one of the tires. The warning is issued in the instrument cluster via the tire pressure monitor warning lamp, but the specific tire where pressure loss has occurred is not specified.
Manual restart
The tire pressure to be monitored can be reset via the TPM [RDK] switch on the cockpit switch panel. When the TPM [RDK] switch is pressed, the current tire pressure is stored in the memory of the TPM [RDK] control unit and is then used as the reference pres­sure, as long as it is within the permissible limits.
The tire pressure monitor warning lamp in the instru­ment cluster flashes to indicate that a manual restart has taken place.
i Note
A manual restart must be performed each time the tire inflation pressure is changed and when a wheel, wheel sensor or the TPM [RDK] control unit is replaced. If the nut on the valve element of a wheel sensor is loosened, all components of the valve element must be replaced.
See the Workshop Information System (WIS) for further instructions and information.
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Tire pressure monitor
68
Chassis
Introduction of the smart fortwo, Model Series 451
P40.15-2424-00
Location of TPM [RDK] components
A1 Instrument cluster A1e66 Tire pressure monitor warning lamp A69/1 Left front TPM [RDK] wheel sensor A69/2 Right front TPM [RDK] wheel sensor A69/3 Left rear TPM [RDK] wheel sensor A69/4 Right rear TPM [RDK] wheel sensor
B14 Outside temperature display temperature
sensor N10/10 SAM control unit N88 TPM [RDK] control unit S6/1 Cockpit switch group S6/1s9 TPM [RDK] switch
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Page 70
Brakes
Chassis
69
Introduction of the smart fortwo, Model Series 451
Task
The task of the brake system is to brake the vehicle or hold it at a standstill. The system includes the service brake, which brakes the vehicle while it is being driven, and the parking brake, which secures the vehicle when it is at a stand­still.
Components of the parking brake
• Hand brake lever with hand brake cables
• Parking brake mechanism integrated into rear drum brake
Function of parking brake
When the handbrake lever is actuated, a relay lever is actuated at the rear brake shoes of the left and right drum brakes via the handbrake cables. This presses the brake shoes of the drum brakes against the insides of the brake drums to build up the required brake force.
Components of the service brake
• Disk brakes with brake calipers on front axle
• Drum brakes with aluminum wheel brake cylinders on rear axle
• Brake fluid reservoir
• Brake lines and brake hoses
• Brake pedal module
• ESP unit, consisting of ESP control unit and ESP hydraulic unit
Function of service brake
The service brake is a hydraulic 2-circuit brake system with TT (front/rear) split.
The force applied to the brake pedal is transferred to the brake booster via a linkage. The brake booster multiplies this forces and uses it to pressurize the master brake cylinder. The brake pressure is built up via the master brake cylinder. The brake force is distributed to the disk brakes and drum brakes by the ESP unit via the integrated antilock brake system (ABS) and the electronic brake force distribution (EBD) system.
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Page 71
Brakes
70
Chassis
Introduction of the smart fortwo, Model Series 451
P40.10-2711-00
Brake system
1 Brake pedal module 2 Brake disk 3 Brake caliper 4 Expansion reservoir 5 ESP unit 6 Hand brake cables 7 Drum brake (consisting of: anchor plate, wheel
brake cylinder, brake shoe, springs and brake drum)
8 Hand brake lever
B24/15 Yaw rate, lateral and longitudinal accelera-
tion sensor L6/1 Left front rpm sensor L6/2 Right front rpm sensor L6/3 Left rear rpm sensor L6/4 Right rear rpm sensor N47-5 ESP control unit N49 Steering angle sensor
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Page 72
Brakes
Chassis
71
Introduction of the smart fortwo, Model Series 451
Brake pedal module
The brake pedal module is located on the underfloor and consists of the following assemblies:
• Pedals
• Carrier
• Brake booster
• Master brake cylinder
Pedals
The pedals consist of:
• Pedal head
• Perforated boot
• Pedal assembly seal
• Housing
• Linkage rod
• Brake pedal module cover
• Seal for brake pedal module cover
• Brake light switch
P42.10-2712-00
Brake pedal module
9 Pedal head 10 Housing 11 Carrier 12 Brake booster 13 Master brake cylinder 14 Grommet 15 Brake pedal module cover
16 Linkage 17 Seal 18 Pedal assembly seal 19 Perforated boot 20 Bolt
S9/1 Brake light switch
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Brakes
72
Chassis
Introduction of the smart fortwo, Model Series 451
Pedals
The seals and the boot on the pedals may not be damaged otherwise moisture can penetrate into the interior compartment. To ensure that the pedals remain leaktight, the brake pedal module cover must be replaced each time the pedals are disassembled.
Brake light switch
The brake light switch in the pedal assembly is only accessible after the brake pedal module cover has been removed. The brake light switch is actuated via the linkage in the pedal assembly when the brake is actuated. The signal from the brake light switch is read by the ESP control unit. The free travel of the brake light switch must be correctly adjusted to ensure that the brake light switch operates properly.
Brake lines
All brake lines may only be retightened twice at the most when work is performed on the vehicle. If a threaded connection on a brake line is loosened and then retightened, this must be documented. The respective threaded connection must be marked in color with a suitable safety paint.
The following color codings are specified:
• First retightening: yellow marking
• Second retightening: red marking
If the respective threaded connection is loosened again after being retightened for a second time, the detached brake line must be replaced. This also applies if it is not possible to trace how often the threaded connection has previously been loosened.
Brake system bleeding
Whereas the brake fluid can be replaced by one person, the hydraulic brake system can only be bled by two people working together. When bleeding the primary and secondary circuit, one person must build up the pressure required by the brake fluid changer by repeatedly actuating the brake pedal. The second person is needed to:
• Actuate the ESP hydraulic unit via diagnosis at the same time and perform the bleeding procedure when bleeding the primary circuit
• Perform the bleeding procedure when bleeding the secondary circuit
i Note
To ensure that the brake system is not damaged, the filling pressure on the brake fluid changer may be set to max. 2.8 psi (2 bar).
i Note
See the Workshop Information System (WIS) for the exact procedure for repairing the brake system and for the relevant safety information.
Basic adjustment of brake shoes
After brake shoes are replaced or removed/installed, basic adjustment of the drum brake must be performed. To do so, the brake shoes are measured and adjusted using the slack adjuster.
Drum brake adjustment
Manual adjustment of the clearance between brake shoe and brake drum is not permissible. Adjustment may only be performed via the automatic slack adjuster of the brake shoes to prevent grinding or locking of the drum brake.
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Page 74
Brakes
Chassis
73
Introduction of the smart fortwo, Model Series 451
ESP system
The latest ESP system (version 8.1) is installed next to the brake pedal module on the underfloor and features the following functions:
• ABS
• ASR
• HBA
• EBD
• ESP
• EBR
• Start-off assist
Antilock brake system (ABS)
Prevents individual wheels from locking up by regu­lating the brake pressure at the relevant wheel brakes. The vehicle remains steerable, enabling the driver to take evasive action himself to avoid sudden obstacles during emergency braking.
Acceleration skid control (ASR)
Prevents the drive wheels from spinning by inter­vening in the engine management and brake pressure regulation. ASR provides good traction and improves vehicle stability and steerability when moving off and accelerating.
Hydraulic brake assist (HBA)
Regulates the pressure buildup in the brake system in relation to the vehicle speed and the actuation speed of the brake pedal. When emergency braking is detected by means of characteristics defined before­hand, the ESP control unit actuates the return flow pump that is integrated in the hydraulic unit. The maximum brake pressure is built up.
Electronic brake force distribution (EBD)
Regulates the brake pressure at the rear wheels in the partial braking range in order to improve the stability of the vehicle and the braking effect.
Electronic stability program (ESP)
Minimizes oversteer or understeer by means of specific intervention by the brake system at each wheel on the front and rear axles. There may also be intervention in the engine and transmission control systems if necessary.
Engine braking regulation (EBR)
Reduces slip of the drive wheels in deceleration mode and thereby improves directional stability and road adhesion.
Start-off assist
Maintains the brake pressure for approx. 0.7 s after the brake pedal is released to facilitate start-off on uphill slopes.
Rpm sensors
The rpm sensors are active sensors, i.e. they must be connected to a voltage source in order to operate. They deliver a signal with an rpm-independent, constant amplitude, and utilize the Hall effect to detect the rpm signal.
Yaw rate, lateral and longitudinal acceleration sensor
The yaw rate, lateral and longitudinal acceleration sensor is a combined sensor of micromechanical design. It registers the yaw rate (yaw angle velocity) of the vehicle about the vertical axis, the longitudinal acceleration and the lateral acceleration.
i Note
In the event of an emergency stop in which the vehicle is braked to a standstill from a speed in excess of 43 mph (70 km/h), the SAM control unit automatically activates the hazard warning system. Deactivation of the hazard warning func­tion occurs automatically when the vehicle speed is detected to have risen above 6 mph (10 km/h) or manually by actuation of the hazard warning system switch.
SN_Typ 451_us.book Seite 73 Freitag, 30. November 2007 1:56 13
Page 75
Brakes
74
Chassis
Introduction of the smart fortwo, Model Series 451
P42.45-2662-00
Data flow chart of Electronic Stability Program ESP
1 ESP/ABS/ASR status 2 ESP/ABS/ASR display status 3 Wheel speed signal 4 Steering angle 5 Steering rate 6 Lateral and longitudinal acceleration 7 Yaw rate 8 Engine torque control
9 Transmission control intervention 10 Brake pedal status 11 Emergency stop reference speed 12 Driver door closed status 13 Handbrake status 14 Brake fluid status
A1 Instrument cluster A1e41 ESP warning lamp
B24/15 Yaw rate, lateral and longitudinal accelera-
tion sensor L6/1 Left front rpm sensor L6/2 Right front rpm sensor L6/3 Left rear rpm sensor L6/4 Right rear rpm sensor N3/10 ME-SFI [ME] control unit N10/10 SAM control unit N15/6 Automated manual transmission
control unit N47-5 ESP control unit N49 Steering angle sensor S9/1 Brake light switch S11 Brake fluid indicator switch S12 Parking brake indicator switch
CAN Controller Area Network
(data bus/CAN bus)
SN_Typ 451_us.book Seite 74 Freitag, 30. November 2007 1:56 13
Page 76
Steering
Chassis
75
Introduction of the smart fortwo, Model Series 451
Rack-and-pinion steering
The smart fortwo features rack-and-pinion steering as standard. The steering ratio is 22:1.
Electric power steering EPS (special equipment)
Electric Power Steering (EPS) is available as special equipment. The steering ratio is 21:1.
The tasks of the EPS system are as follows:
• Power assistance with Servotronic
• Adaptation of the steering forces
• Active steering centering
General
Electric Power Steering (EPS) is a direct steering system with integral speed-dependent power assis­tance and active steering centering. This ensures that steering wheel forces remain low when the vehicle is being maneuvered. An electromechanical system offers the following advantages compared to a conventional hydraulic power steering system:
• Less weight and smaller installation space
• Greater degree of freedom to adjust the steering assistance
• Reduced fuel consumption.
EPS operates without hydraulic components such as pumps, reservoirs, coolers, lines and hydraulic fluid, and is therefore a dry, environmentally compatible system.
P46.10-2935-00
Electric power steering EPS
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Page 77
Steering
76
Chassis
Introduction of the smart fortwo, Model Series 451
Design
The main components of the electric power steering (EPS) system are the power steering motor, a DC brush-type electric motor with maximum 35 Ampere power consumption and the power steering control unit.
The power steering control unit communicates via the CAN data bus and is located in the vehicle interior on the left of the firewall.
The rack-and-pinion mechanical components for the electric power steering (EPS) are accommodated in a steering housing made of diecast aluminum, to which the power steering motor is also flange-mounted.
To provide steering assistance, the steering gear pinion shaft transmits the rotational movement of the steering gear input shaft to the teeth of the toothed rack. The power steering motor transmits force for steering assistance to the spur toothing of the hyper­bolic gear via a worm shaft. The hyperbolic gear is fixed to the pinion of the steering gear pinion shaft. The power steering torque sensor is located in the steering gear housing between the steering gear input shaft and hyperbolic gear.
P46.10-2933-00
Components of the electric power steering (EPS)
1 Steering gear housing 2 Steering gear pinion shaft 3 Steering gear input shaft 4 Toothed rack 5 Worm shaft 6 Hyperbolic gear
B23 Power steering torque sensor M19 Power steering motor N68 Steering assist control unit
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Page 78
Steering
Chassis
77
Introduction of the smart fortwo, Model Series 451
Function
Function requirement
Steering assistance is activated after engine start and at a minimum engine speed of 500 rpm.
Steering power assistance
As the driver turns the steering wheel, a steering torque is produced at the drag link which is regis­tered by the power steering torque sensor and forwarded to the power steering control unit.
The steering torque is used as an actuating variable for the electric assistance force. It is derived from the rotation of the torsion bar, which is located between the steering gear input shaft and steering gear pinion shaft on the same axis. The power steering torque sensor is located around the torsion bar. This determines the torque over a range of +/- 8.1 lb-ft (11 Nm) and at a resolution of
0.037 lb-ft (0.05 Nm).
The power steering control unit uses the steering torque measurement to determine the level of torque that needs to be provided to supplement the steering force. Based on this information and depending on the vehicle speed signal from the ESP control unit and the engine speed signal from the ME-SFI [ME] control unit, the power steering control unit determines the current requirement of the power steering motor as per the programmed characteristic field.
The power steering motor transmits the appropriate supplementary steering torque to the face of the hyperbolic gear via the worm shaft.
P46.10-2934-00
Steering torque of the electric power steering (EPS)
2 Steering gear pinion shaft 3 Steering gear input shaft 5 Worm shaft 6 Hyperbolic gear 7 Torsion bar
B23 Power steering torque sensor M19 Power steering motor N68 Steering assist control unit
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Page 79
Steering
78
Chassis
Introduction of the smart fortwo, Model Series 451
Steering centering
This function returns the steering to the center posi­tion once the driver stops applying steering torque. The power steering motor is actuated accordingly by the power steering control unit.
"Active center feeling" function
When the steering wheel is registered in the center position and there are no steering movements, the power steering motor is energized by the steering assist control unit so that a sufficient torque is produced to hold the steering in the straightahead position. This actuation conveys an improved steering center feel to the driver. The system is continuously calibrated and learns the center position automati­cally. The long-term calibration is performed via the ESP wheel sensor system.
Limp-home function
The steering assist control unit constantly checks all the input signals for plausibility. In the case of a faulty component the steering, power assistance is shut down and a fault is stored in the steering assist control unit. The steering then continues to function as a conventional rack-and-pinion steering.
i Note
If the electric steering suffers a function failure, the electric steering indicator lamp in the instru­ment cluster lights up to indicate this.
i Note
The steering power assistance is at a maximum at low speeds and when the vehicle is stationary and decreases as the vehicle speed increases. Once the vehicle stops and the engine is switched off, the steering power assistance is deactivated in stages after approx. 3 s.
To comply with EMC requirements, the energy line from the power steering control unit to the power steering motor is 85 % shielded against external influ­ences.
The power steering control unit is a CAN bus subscriber in the overall network. The vehicle speed, the steering angle and other data are read in over CAN.
SN_Typ 451_us.book Seite 78 Freitag, 30. November 2007 1:56 13
Page 80
Steering
Chassis
79
Introduction of the smart fortwo, Model Series 451
P46.35-2034-00
Data flow chart of electric power steering EPS
1 Vehicle speed 2 Steering torque 3 Warning and fault message output 4 Power steering motor actuation 5 Steering angle, steering rate 6 Engine speed
A1 Instrument cluster A1e18 Electric steering indicator lamp B23 Power steering torque sensor M19 Power steering motor N3/10 ME-SFI [ME] control unit N47-5 ESP control unit N49 Steering angle sensor N68 Steering assist control unit
CAN Controller Area Network
(data bus/CAN bus)
SN_Typ 451_us.book Seite 79 Freitag, 30. November 2007 1:56 13
Page 81
Steering
80
Chassis
Introduction of the smart fortwo, Model Series 451
Steering wheel
Two steering wheel variants are available for model series 451.
Variants
• Leather two-spoke steering wheel of dia. 14.6 in (370 mm) as standard equipment on the pure
• Three-spoke sport steering wheel with integrated paddle shift of dia. 13.8 in (350 mm) as standard equipment on the passion
Paddle shifts on steering wheel
In vehicles that are fitted with a three-spoke sport steering wheel, the paddle shifts on each side of the steering wheel can be used to shift up and down through the gears. It is therefore possible to select a gear on the steering wheel as well as via the gear selector lever. The left-hand paddle shift is used to downshift and the right-hand paddle shift is for upshifts. The gear which is currently engaged is displayed on the multifunction display in the instrument cluster.
P46.10-2839-00
Two-spoke steering wheel
P46.10-2840-00
Three-spoke sport steering wheel with paddle shifts
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Page 82
Steering
Chassis
81
Introduction of the smart fortwo, Model Series 451
Steering wheel removal and installation
The following components of the steering wheel are replaceable:
• Contact unit with steering angle sensor
• Airbag module
• Paddle shifts (three-spoke sport steering wheel only)
The steering wheel must be detached first before replacing or removing/installing any of the above components.
Care must be taken to ensure that the front wheels are in the straightahead position, the battery is discon­nected and the handbrake is applied before the steering wheel is removed.
The exact procedure for removal/installation of the steering wheel and its components is described in the Workshop Information System (WIS).
i Note
All control units must be de-energized before the steering wheel is removed. For this reason, at least 15 minutes must elapse after the battery is disconnected before it is removed.
i Note
Care must be taken to ensure that the turn signal is not set when removing/installing the steering wheel otherwise the trigger tab may be damaged.
P46.10-2841-00
SN_Typ 451_us.book Seite 81 Freitag, 30. November 2007 1:56 13
Page 83
Interior
82
Body
Introduction of the smart fortwo, Model Series 451
Interior design
The interior compartment has a classic look while still displaying modern, typical smart features. This well­balanced overall concept helps the smart fortwo create an exclusive overall impression with high perceived quality.
This is helped by the lines of the instrument panel, the door linings and the seats shaped to match. The harmonized color scheme of the interior also gives a positive impression in combination with the passenger compartment as a whole.
P68.00-5039-00
Shown on the smart coupé pure
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Page 84
Interior
Body
83
Introduction of the smart fortwo, Model Series 451
Instrument panel
For the design of the instrument panel, particular emphasis was placed on the following criteria:
• Ergonomics
• Clear layout
• Passenger safety
The instrument panel is designed with straight lines and equipped with airbags and a full length knee bolster to improve passenger protection.
Two additional instruments (tachometer and clock) are available as special equipment (SA) and are posi­tioned above the center console. The air vents on the instrument panel have a cylindrical shape.
P68.10-3852-00
Shown on the smart coupé passion
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Page 85
Interior
84
Body
Introduction of the smart fortwo, Model Series 451
Instrument cluster
In the center of the instrument cluster is the speed­ometer scale with the multifunction display under­neath. On each side is a strip with indicators and warning displays, as well as the control buttons for the multi­function display.
The task of the instrument cluster is to provide the driver with information about the various operating states and to provide acoustic or visual warnings in the event of critical operating conditions. It is the display unit for the vehicle speed and for other systems. In addition, the instrument cluster computes the maintenance intervals and shows them in the multifunction display.
The instrument cluster is a device on the data bus/CAN bus in the overall network. Most of the signals are transmitted or received over CAN. The following signals are supplied to the instrument cluster over direct lines:
• Signal from outside temperature indicator temperature sensor
• Signal from "Fanfare horns and airbag clock spring contact“ (only on variant with SAL).
The vehicle speed is displayed by an electronic speedometer that is driven by a stepper motor. The ESP control unit reads the information for the speed display from the wheel speed sensors in the form of signals, and forwards it over CAN to the instrument cluster. The instrument cluster processes the incoming signals and uses them to calculate the vehicle speed and distance traveled.
Multifunction display
The task of the multifunction display is to provide the driver with information about variable changes in the vehicle, the ambient conditions and the road.
The variable displays include:
• Outside temperature
• Main odometer
• Trip odometer
• Gear indicator (in manual mode)
• Automatic transmission indicator (in automatic mode)
• Fuel reserve indicator (US gal)
• Maintenance interval display with symbol
• Fuel level and reserve indicator
• Clock
P54.32-5677-00
Multifunction display
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Page 86
Interior
Body
85
Introduction of the smart fortwo, Model Series 451
P54.30-9683-00
Instrument cluster
1 Left button, select multiple display / set
clock
2 Right button, instrument illumination / set
clock
A1 Instrument cluster A1e1 Left turn signal indicator lamp A1e2 Right turn signal indicator lamp A1e3 High beam indicator lamp A1e5 Alternator charge monitoring and warning
lamp
A1e7 Brake fluid and parking brake warning lamp
A1e9 Seat belt warning lamp A1e15 Airbag indicator and warning lamp A1e17 ABS indicator lamp A1e18 Electric steering indicator lamp A1e26 CHECK ENGINE indicator lamp A1e30 Oil pressure warning lamp A1e41 ESP warning lamp A1e54 Coolant temperature warning lamp A1e66 Tire pressure monitor warning lamp A1e67 Low beam indicator lamp A1p8 Electronic speedometer A1p13 Multifunction display
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Page 87
Doors/flaps
86
Body
Introduction of the smart fortwo, Model Series 451
Side doors
The doors of the new smart fortwo follow the typical smart brand construction principle with a metal carrier part and the plastic CBS door paneling. The doors of the smart coupé and the smart cabrio are identical.
The triangular windows located above each door handle are stationary windows held in place by bolts.
Crash requirements
The door support structure in model 451 is made of steel. In addition, panels and sections of high­strength steel are used at strategically important points. This is the case, for example, with the diagonal struts and the side window slot frames.
In combination with the cockpit crossmember, this makes the passenger compartment highly resistant to side impacts in this section of the vehicle.
P72.00-2185-00
Door structure
1 Door carrier module 2 Diagonal strut 3 Side window slot frame 4 Cockpit crossmember
Emergency opening
Normally, the smart fortwo is opened from outside via the standard-equipment central locking system using the transmitter key. If the battery in the transmitter key cannot supply enough power, a lock cylinder installed behind a small cover under the handle of the left door can be used to open the driver door manually in an emergency.
P80.20-3225-00
1 Lock cylinder for emergency opening
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Page 88
Doors/flaps
Body
87
Introduction of the smart fortwo, Model Series 451
P72.10-3403-00
Design of driver door with power window and electric outside mirror
1 Door carrier module 2 Window lifter mechanism 3 Diagonal strut 4 Top door hinge assembly 5 Bottom door hinge assembly 6 Inner door lining 7 CBS door paneling 8 Curved handle 9 Side window
10 Triangular window
H4/9 Left front speaker M10/3 Left power window motor M14/6 Left door CL [ZV] motor M14/6s1 Left door CL [ZV] microswitch M21/1 Left electrically adjustable and heated out-
side mirror S21/1 Left power window switch S21/2 Right power window switch S50 Outside mirror adjustment switch S87/7 Left door rotary tumbler microswitch
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Page 89
Doors/flaps
88
Body
Introduction of the smart fortwo, Model Series 451
Rear-end door
P72.20-2599-00
Design of rear-end door shown on the smart fortwo coupé
1 Upper rear-end door 2 Upper rear-end door paneling 3 Rear spoiler 4 Upper rear-end door hinges 5 Gas-operated strut 6 Rear window 7 CBS rear-end door paneling 8 Lower rear-end door 9 Right door lock of lower rear-end door
10 Left door lock of lower rear-end door
11 Door lock of upper rear-end door 12 Door panel lining 13 Lower rear-end door hinges 14 Seal
E21 Center high-mounted brake lamp M6/4 Rear-end door wiper motor S88/9 Rear-end door handle switch
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Page 90
Doors/flaps
Body
89
Introduction of the smart fortwo, Model Series 451
Emergency unlocking of rear-end door
The rear-end door in the smart fortwo can be unlocked from the inside in an emergency, if the trunk lid central locking motor for operating the rotary tumbler is defective or de-energized.
Emergency unlocking in smart fortwo coupé
To do this, a small tab at the side of the trunk lid lock paneling must be carefully bent over or broken off to produce a small hole.
A shop-made wire must then be inserted through the small hole so that enough downward pressure is exerted on the relay lever in the door lock to unlock the rear-end door at the top.
A description of the procedure for manufacturing the emergency release wire in the workshop is given in the Workshop Information System (WIS).
Emergency unlocking in smart fortwo cabrio
In order to open the two door locks in the cabrio, a hole must be accurately marked on the inside of the rear-end door on each side. Then a hole of 0.2 in (5 mm) diameter is drilled through the paneling on each side of the rear-end door..
A suitable screwdriver is inserted into each hole and the rear-end door is unlocked by moving the screw­driver handles simultaneously in the directions of the arrows.
The exact dimensions for the holes and a detailed description of the procedure can be found in the Workshop Information System (WIS).
P72.20-2583-00
A Actuation direction
1 Tab/paneling hole on trunk lid lock 2 Emergency release wire
P72.20-2582-00
B Actuation direction
3 Hole (0.2 in (5 mm)) 4 Screwdriver
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Page 91
Roof systems
90
Body
Introduction of the smart fortwo, Model Series 451
Variants of roof system
Two roof variants are available for the model series 451 coupé. A fully electric Tritop fabric soft top is installed in the cabrio.
smart fortwo coupé
• Full roof made of glass fiber reinforced polyurethane (PU)
• Panoramic sunroof made of polycarbonate (PC)
smart fortwo cabrio
• Fully electric Tritop fabric soft top
P65.00-2119-00
Vehicle with PU roof
P77.21-2226-00
Vehicle with panoramic sunroof
P77.00-2338-00
Vehicle with fully electric Tritop fabric soft top
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Page 92
Roof systems
Body
91
Introduction of the smart fortwo, Model Series 451
Hard roofs on smart fortwo coupé
Full roof
In the standard equipment pure version the smart fortwo coupé is supplied with the polyurethane (PU) full roof. The PU roof is only available in pitted matt black.
The PU full roof sits on the body and is bonded to the bodyshell structure.
Panoramic sunroof
A polycarbonate (PC) panoramic sunroof with step­lessly variable roller sun blind is available for some equipment variants.
The roof module is bonded to the tridion safety cell. The latest in plastics technology makes it possible to use breakproof material extensively in the vehicle.
The material is covered with a scratch-resistant coating and the light transmission of the tint is approx. 13 %. The material also provides 100 % protection against UV light.
The steplessly adjustable inside roller blind can be used to block out the sun. The roller sun blind is made of a polyester fabric and covers the entire trans­parent area of the panoramic sunroof. The roof and roller blind can be replaced separately.
The panoramic sunroof is manufactured by a two­component injection molding process in which the second component material serves to blacken the edges.
P77.21-2225-00
Panoramic sunroof with roller sun blind
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Page 93
Roof systems
92
Body
Introduction of the smart fortwo, Model Series 451
Tritop fabric soft top
The Tritop fabric soft top of the smart fortwo cabrio is the only one in the world that can be opened and closed while driving up to the maximum speed. The name TRITOP comes from the three main components of the soft top:
• Folding top open
• Rear soft top stowed
• Side supports removed
The soft top control system is fully electronic and features the following functions:
• Opening the folding top
• Closing the folding top
• Lowering the rear soft top
• Raising the rear soft top
P77.30-2390-00
Components of Tritop textile soft top
1 Folding top 2 Rear soft top
3 Left and right side supports
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Page 94
Roof systems
Body
93
Introduction of the smart fortwo, Model Series 451
Soft top operation
The folding top and rear soft top are opened and closed using the power soft top switch on the elec­tronic selector lever module control unit. The folding top can also be opened remotely and auto­matically by means of a button on the transmitter key.
To operate the soft top via the power soft top switch the vehicle's ignition must be switched on. A short press of the power soft top switch in the "Open" direction causes the folding top to open all the way to its end position. The folding top must always be fully opened before the rear soft top can be opened. If the power soft top switch is then pressed again and held in the "Open" direction, the rear soft top is folded away for as long as the switch is actuated. As soon as the rear soft top has been stowed in its end position, its motors cut out and the switch can be released.
To close the soft top, the power soft top switch is pressed and held in the "Close" direction until the rear soft top has reached its upper end position and the motors of the rear soft top cut out; the switch can then be released. If the power soft top switch is pressed and held again, the folding top closes until it reaches its own end position and the motor cuts out; then the switch can be released again. The rear soft top and folding top lock automatically as soon as they reach their end positions.
i Note
For safety reasons, it is not possible to close the folding top automatically. There would be a risk of injury during the closing process because limbs of vehicle occupants could become trapped between the roof frame and folding top in the area of the windshield.
P80.35-2333-00
3 Folding top automatic open button
A Transmitter key
P77.00-2332-00
S84 Power soft top switch
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Page 95
Roof systems
94
Body
Introduction of the smart fortwo, Model Series 451
Targa roof position
In the targa roof position, the folding top is fully opened, the side supports are removed and the rear soft top is closed.
The targa roof position is important with regard to the operation of the folding top because the side supports must be inserted before the folding top can be closed. The side supports are detected by a mechanical catch in the roof cassette lock.
Soft top control
The central controller unit of the soft top is the SAM control unit.
The SAM control unit reads in the actuation request from the power soft top switch and actuates the appropriate motors depending on the position and status of the soft top.
The soft top is powered by a total of three motors. A central motor in the roof cassette is responsible for opening and closing the folding top. The folding and raising of the rear soft top is carried out by two motors in the left and right main bearings of the soft top.
The soft top also incorporates the center high­mounted brake lamp and a glass rear window with an integral rear window heater, which is also activated by the SAM control unit.
Function sequence of soft top actuation
Function requirements:
• Switch circuit 15 ON
Pressing the power soft top switch sends a direct signal to open or close to the SAM control unit. The SAM control unit reads in the signal, checks whether the function requirements are satisfied and deter­mines the status of the soft top via the microswitches installed on the soft top. If all the preconditions are met, the SAM control unit actuates the appropriate motor(s) for the desired operation.
P77.00-2340-00
Targa roof position
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Page 96
Roof systems
Body
95
Introduction of the smart fortwo, Model Series 451
P77.39-2210-00
Data flow chart of soft top control
1 Circuit 15 ON 2 Request to open folding top 3 Request to open rear soft top 4 Request to close rear soft top 5 Request to close folding top 6 Status of soft top 7 Status of roof cassette latch 8 Status of rear soft top 9 Vehicle speed
A1 Instrument cluster K66/1 Open soft top relay K66/2 Close soft top relay M12/6 Electric soft top motor M12/7 Left soft top drive M12/8 Right soft top drive N10/10 SAM control unit S2/1 Ignition/starter switch S84 Power soft top switch S84/37 Folding top microswitch S84/38 Left roof cassette microswitch S84/39 Right rear soft top microswitch S84/40 Right roof cassette microswitch S84/41 Left rear soft top microswitch
A Transmitter key CAN Controller Area Network
(data bus/CAN bus)
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Page 97
Central locking
96
Body
Introduction of the smart fortwo, Model Series 451
Central locking (CL [ZV])
The central locking in the smart fortwo includes the locking and unlocking of both doors and the fuel filler flap, and the opening of the rear-end door in the smart coupé or the opening of the soft top on the smart cabrio. A distinction is drawn between manual and automatic functions.
Manual functions:
• Remote control with the transmitter key
• Door opening from the inside
• Operation via the interior CL [ZV] locking and unlocking switches in the cockpit switch group
• Manual unlocking with the transmitter key at the driver-side door lock
Automatic functions:
• Speed-dependent locking
• Emergency opening after crash detection
• Relocking
Unlocking or locking via the transmitter key
When the Unlock or Lock button on the transmitter key is pressed, it sends a radio signal to the SAM control unit. The SAM control unit checks the access authori­zation of the transmitter key. If the access authoriza­tion is valid, it actuates the following motors directly to unlock or lock the vehicle:
• Right door CL [ZV] motor
• Left door CL [ZV] motor
• Fuel filler flap CL [ZV] motor
When the vehicle is globally unlocked, the rear-end door handle switch is enabled; and when the vehicle is locked, it is disabled. If the rear-end door handle switch is actuated when the central locking has been globally unlocked, the SAM control unit directly actuates the trunk lid CL [ZV] motor to unlock the rotary tumbler.
Selective unlocking
If the Unlock button on the transmitter key is pressed once, only the driver door and fuel filler flap are unlocked. The anti-theft alarm system is deactivated and all turn signal indicators flash once.
Global unlocking
If the Unlock button on the transmitter key is pressed again, the passenger door is unlocked and the rear­end door handle switch is enabled. The turn signal indicators flash again once.
Door opening from the inside
The vehicle doors can always be opened from the inside with the door handle regardless of the status of the central locking. In this case, only the respective vehicle door and the fuel filler flap are unlocked.
P80.35-2332-00
A Transmitter key 1 Locking button 2 Unlocking button 3 Open folding top button (cabrio)
Open rear-end door button (coupé)
4 PANIC button
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Page 98
Central locking
Body
97
Introduction of the smart fortwo, Model Series 451
PANIC alarm
Pressing the PANIC button for at least 1 s triggers an acoustic alarm. The turn signal indicators also flash. The alarm is deactivated when
• Circuit 15 is switched ON or
• The PANIC button is pressed
Unlocking and locking from the inside via the switches in the cockpit switch group
When the side doors and the rear-end door are closed, pressing the "Lock or unlock" switch in the cockpit switch group causes a signal to be sent straight to the SAM control unit. This actuates the central locking motors. The vehicle doors and the fuel filler flap are either locked or unlocked accordingly and the rear-end door handle switch is either enabled or disabled.
Special function:
If the vehicle cannot be locked using the transmitter key due to a flat battery in the key, proceed as follows:
• Open driver door
• Switch circuit 15 ON
• Actuate inside CL [ZV] switch
• Within 5 s, switch circuit 15 OFF and remove transmitter key
• Close driver door, vehicle is locked.
Manual unlocking of the driver door with the trans­mitter key at the door lock
When the door lock on the driver door is operated with the transmitter key, the driver door and (if the on­board power supply voltage is sufficient) the fuel filler flap are unlocked. If the antitheft alarm system on the vehicle is armed, an alarm is triggered.
Speed-dependent locking
The vehicle is automatically locked if circuit 15 is ON and the vehicle speed exceeds 8 mph (14 km/h). Speed-dependent locking can be activated or deacti­vated as required.
Relocking
This function relocks the vehicle automatically if none of the doors is opened 60 s after unlocking.
Emergency opening after crash recognition
This functions unlocks the doors after an accident that triggers a crash signal.
Remote rear-end door opening (smart fortwo coupé only)
When the "Open rear-end door" button on the trans­mitter key is pressed, it sends a radio signal to the SAM control unit. This checks the access authorization of the transmitter key. If the access authorization is valid, the SAM control unit actuates the trunk lid CL [ZV] motor directly.
Remote folding top opening (smart fortwo cabrio only)
When the "Open folding top" button on the transmitter key is pressed, it sends a radio signal to the SAM control unit. This checks the access authorization of the transmitter key. If the access authorization is valid, the SAM control unit actuates the electric soft top motor directly.
i Note
The radio signal for unlocking the door is picked up by an antenna integrated in the SAM control unit. There is no external antenna for the central locking.
SN_Typ 451_us.book Seite 97 Freitag, 30. November 2007 1:56 13
Page 99
Central locking
98
Body
Introduction of the smart fortwo, Model Series 451
1 Unlocking/locking request 2 Doors status 3 Rear-end door status 4 Unlocking/locking actuation 5 Rear-end door unlocking request 6 Visual feedback actuation 7 Rear-end door unlocking actuation 8 Unlocking via inside door opener request
9 Inside unlocking/locking request 10 Emergency opening request 11 Rear-end door opening request (coupé) 12 Open soft top actuation (cabrio) 13 Open soft top request (cabrio) 14 Vehicle speed
A1 Instrument cluster E1e5 Left turn signal light E2e5 Right turn signal light E3e11 Left brake/turn signal light E4e11 Right brake/turn signal light
E22/1 Left additional turn signal lamp E22/2 Right additional turn signal lamp M12/6 Electric soft top motor (cabrio) M14/5 Right door CL [ZV] motor M14/5s1 Right door CL [ZV] microswitch M14/6 Left door CL [ZV] motor M14/6s1 Left door CL [ZV] microswitch M14/7 Rear-end door CL [ZV] motor M14/10 Fuel filler flap CL [ZV] motor N2/7 Restraint systems control unit N10/10 SAM control unit S6/1 Cockpit switch group S6/1s1 Hazard warning flasher switch S6/1s11 Inside unlock CL [ZV] switch S6/1s12 Inside lock CL [ZV] switch S15 Remote trunk opening switch
(coupé)
S17/8 Trunk lid rotary tumbler microswitch
(cabrio)
S88/9 Rear-end door handle switch
A Transmitter key CAN Controller Area Network
(data bus/CAN bus)
P80.20-3177-00
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Page 100
Anti-theft alarm system (ATA [EDW])
Body
99
Introduction of the smart fortwo, Model Series 451
ATA [EDW] system
The anti-theft alarm system (ATA [EDW]) monitors all relevant inputs for their non-actuated state. If a change of status is detected at one of the monitored inputs, an acoustic and visual alarm is issued.
The acoustic signals are output by the alarm signal siren with inclination sensor. The visual signals are output via the turn signal indicators. The SAM control unit is the master control unit for the anti-theft alarm system (ATA [EDW]). When armed, the anti-theft alarm system (ATA [EDW]) monitors:
• The doors
• The rear-end door
• The alarm siren with inclination sensor
• The position change of the vehicle
• Movements in the interior compartment
Activation and deactivation
The anti-theft alarm system (ATA [EDW]) is activated when the vehicle is locked with the transmitter key. The anti-theft alarm system (ATA [EDW]) is deacti­vated by unlocking the vehicle with the transmitter key or by inserting an authorized transmitter key in the ignition lock and turning circuit 15 ON.
Alarm triggering
An alarm is triggered when the SAM control unit receives a status change from the following compo­nents:
• ATA [EDW] microwave sensor
• Inclination sensor in alarm siren
• Trunk lid rotary tumbler microswitch
• Right door rotary tumbler microswitch
• Left door rotary tumbler microswitch
Alarm output
The alarm is output via the turn signal indicators and the alarm siren with inclination sensor.
Interior protection/tow-away protection
The ATA [EDW] microwave sensor is activated approx. 30 s after the vehicle is locked. Interior protection can be deactivated using the tow-away protec­tion/interior protection switch.
The inclination sensor in the alarm siren with inclina­tion sensor registers a positional change of the vehicle. The inclination sensor, and thus the tow-away protection, can be deactivated using the tow-away protection/interior protection switch.
The interior protection or tow-away protection is reactivated automatically the next time the vehicle is locked.
SN_Typ 451_us.book Seite 99 Freitag, 30. November 2007 1:56 13
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