Service.
The Passat ‘97
Construction and operation
191
640.2810.10.00 Technical Status: 09/96
The Presentation
Only for internal use.
© VOLKSWAGEN AG, Wolfsburg
All rights reserved. Subject to modification.
`
Printed on chlorine-free
bleached paper.
Self Study Programme
Service Department
2
The most remarkable features of the new
Passat are its:
l
High economy
l
Dynamic body styling
l
High-quality interior equipment designed
with great attention to detail
l
Pioneering safety engineering
In this booklet, we would like to provide you
with an initial overview showing how we
justify making these claims.
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3
Page
The Passat ‘97 04
Environmental Protection and Recycling 08
Body 10
Vehicle Safety 15
Engines and Gearboxes 19
Running Gear 26
Brakes 29
Steering 30
Electrics 31
Extended Systems 36
The Self Study Programme is not a Workshop Manual.
Please refer to the relevant Service Literature for all inspection, adjustment and repair
instructions.
New
Important ! / Note
4
To avoid confusion, concise examples are used
to illustrate the various aspects of this
all-embracing vehicle concept.
You can find detailed information in Self Study
Programme No. 192 Passat ‘97 – The Engineering.
The Passat ‘97
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Service.
192
Der Passat '97
Die Technik
Konstruktion und Funktion
Selbststudienprogramm
Kundendienst
5
Dimensions and Weights
4675 mm
2707 mm
1740 mm
Track widths
front
rear
1498
1500
mm
mm
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Weights
Unladen weight
Max. permissible weight
appr. 1200
appr. 1805
kg
kg
6
The Platform - an Advantage for Workshops
The term “platform” is frequently used in
publications although its fundamental
meaning is not explained. The result of this is
that people are often unsure of what the term
“platform” implies.
The vehicle consists of a) the platform and b)
the body.
Design and vehicle characteristics dictate what
form the body takes.
In the eyes of the customer, the body characterises the styling of the vehicle as a whole.
The Passat ‘97
The platform
The body
The Passat ‘97
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7
The advantages for workshops like yourself are:
- More clarity as regards the spare parts situation
- Simplified inventory management
- Fewer different special tools and fixtures
- Easier assembly and repair
Platform
The platform comprises both common parts and system parts.
Common parts
e.g. sliding sunroof, steel rim
Common parts may only be used in platform
vehicles without change.
They do not influence the design of the
vehicle.
System parts
e.g. seat
Some system parts are identical.
They have to be adapted since they are the
interface between the platform and body.
Common part
Frame
Adapted part
Vehicle-specific seat upholstery, seat cover, etc.
191/90
System part
8
Environmental Protection and Recycling
The concept of eco-friendliness was pursued
consistently throughout development of the
new Passat.
We would now like to show you some aspects
of this topic which are also of interest to workshops.
Recycling
Not least the recycling requirements present
workshops with problems such as identifying,
presorting and storing materials and waste
operating media.
To achieve this, the following measures were
taken:
l
Identification of plastic part materials
l
Fewer composite materials
l
Reduction in fine sealing through the use of
laser welding
l
No parts containing CFCs are used.
Take bumpers for example:
Bumpers were previously manufactured from
composites. What the term “composite”
means is that different materials are combined
with one another in such a way that subsequent separation into clean material streams is
no longer possible.
If a plastic is to be recovered for recycling, it
should, if possible, be sorted according to type
for recycling purposes. This means that
different types of plastic, for example, must
not be mixed with one another.
The bumpers on the Passat are recyclable
because they do not contain composites.
.
Collection +
sorting
Recycled plastic
Cleaning +
recycling
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9
Solvents
Even during production, every effort is made to
keep environmental pollution to a minimum.
To achieve this, the following measures were
taken:
l
Full galvanisation means much less
wax and PVC underseal
l
Water-dilutable paints including
water-based clear coat
l
Stringent requirements for materials ensure
lower emissions in the vehicle interior
Energy + Resources
Raw materials and energy are in limited supply
on the planet Earth.
We must use them sparingly.
To achieve this, the following measures were
taken:
l
Less energy consumption during production
through the use of new joining techniques
(e.g. laser welding) and complete assemblies
(e.g. side section of body),
l
Full galvanisation and an 11-year warranty
against corrosion perforation ensure high
value retention and conservation of
resources.
Take laser welding for example:
During laser welding, a highly concentrated
light beam with a high energy content is used
instead of a gas flame to join the components.
No additional welding material is required, as
is the case during MIG welding for example.
Laser welded seams are extremely clean and
do not need to be reworked.
Laser welding offers a more favourable energy
balance than conventional welding techniques.
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10
Body
The following will be of interest to you:
l
The Passat in the wind tunnel
l
Fully galvanised body
l
Greater body rigidity
l
Use of high-strength steel parts
l
Strategy of using common platform for body
parts
l
Ease of repair demonstrated using door
module as example
l
Rear collision demonstrated using bumper
as example
The Passat in the Wind Tunnel
As you can see from the streamlines, the body of
the new Passat is very aerodynamic.
No turbulence, which increases aerodynamic
drag, occurs.
The new Passat has a drag coefficient of c
d
=
0.27, making it the best in its class.
Accounting for the projected vehicle area (A) of
2.1 m
2
, aerodynamic drag is (Cd x A) = 0.567 m
2
.
A = 2.1 m
2
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11
Fully-galvanised Body
For the first time, the Passat has a fully galvanised body which comes with an 11-year anticorrosion perforation warranty.
The drawing below shows you the parts which
are hot-dip galvanised and those which are
electrolytically galvanised.
Surface patterns, which are also visible after
painting, emerge during the hot-dip
galvanisation process.
That is why the outer skin of the body is
electrolytically galvanised to produce a
smooth finish.
Electrolytically galvanised
Hot-dip galvanised
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12
Body
Stability and Structure
The Passat leads its class in terms of torsional
rigidity.
This was achieved by using:
l
high-strength panels
l
different panel thicknesses
l
improved adhesive bonding techniques
(e.g. adhesive joints)
Adhesive joints increase rigidity and leakproofing
while minimising noise levels.
13
The Rear Bumpers
Repairing damage to the rear bumpers
previously involved expensive repair and
welding work, even after minor accidents.
The bumpers on the Passat ‘97 have the
capacity to absorb so much energy during a
low-speed rear collision that only plastic parts
have to be replaced.
Time-consuming welding work is no longer
necessary.
High-strength Panels
High-strength panels are used to produce a
body with greater stability and strength and
therefore to provide more safety for the
vehicle occupants.
They also substantially reduce the weight of
the body-in-white.
As you can see, the high-strength steel components in the front section of the vehicle
create a cage-type structure to protect the
vehicle occupants.
The wings are also manufactured from highstrength steel.
Advantages:
- Less weight
- Greater resistance to buckling
- Higher strength
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High-strength panels
Adhesive joints
Laser-welded
Mash seam welded
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14
Body
Body Platform
The floorpan assembly, side members and
luggage compartment floor assembly were
adopted from the Audi A4 as a platform.
To enhance ride comfort for rear-seat passengers,
a steel floor plate 86 mmwide was inserted.
+
8
6
m
m
+86 mm
New parts in Passat ‘97
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15
Vehicle Safety
As you will no doubt already know, we make a
distinction between active and passive safety.
Active safety
Braking systems
Steering
Running gear
Airbag systems
Restraint systems
Inside door panels and side
trims with integral pelvis
paddings
Safety body
Steering column
The following features will be of interest to
you:
l
Active and passive safety
l
ABS as standard
l
The Passat already complies with the new
European standard for crashworthiness
l Door module with enclosed subframe
l Driver, front passenger and side airbags
as standard
l New seat belt tensioner with force limiter
l Inside door panels with pelvis paddings
Passive safety
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Vehicle Safety
Crashworthiness
The new Passat offers the driver and front passenger more safety, particularly during a side
impact.
The inside door panel, which is fitted complete
with built-in door fittings, is bolted to the door.
To protect the occupants, the inside door panel
has an enclosed surface to prevent intrusion of
the built-in door fittings into the interior of the
vehicle.
The side impact beams made of pressed sheet
metal are arranged diagonally and glued to the
outer panel to increase door rigidity.
Impact energy can therefore be better
absorbed, distributed and converted.
Pelvis and rib paddings give the vehicle
occupants added protection.
The size of the overlap between the door and
the sill, columns and side section has been
increased.
Deformation strength is increased due to the
larger contact surface.
Side impact beam
Pelvis paddings
Inside door panel
Overlap
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Rib paddings
16
Airbag Systems
In addition to the driver and front passenger
airbags, the Passat is equipped with side airbags as standard.
Depending on the side and angle of impact,
only the airbags in the immediate vicinity of
the danger zone are inflated.
Therefore, an uninflated airbag on the side
facing away from the accident need not
necessarily be defective.
The driver and front passenger airbags, which
have filling volumes of roughly 65 ltr. and 120
ltr. respectively, conform to the new international-standard airbag sizes.
The volume of the standard side airbag is
roughly 12 litres.
Side impact,
right-hand side
Head-on collision
Side impact,
left-hand side
60°
60°
60°
Detected by:
crash sensor
located beneath the
left-hand seat and a
safety sensor
integrated in the airbag
control unit
Detected by:
crash sensor and a
safety sensor
integrated in the airbag
control unit
Detected by:
crash sensor
located beneath the
right-hand seat and a
safety sensor
integrated in the airbag
control unit
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17
Vehicle Safety
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Seat belt tensioner
Belt force limiter
The Seat Belt Tensioner
The pyrotechnical seat belt tensioner, together
with the “belt fastened” sensor and belt force
limiter, are combined in a single assembly.
This compact design greatly simplifies replacement.
The “belt fastened” sensor prevents the seat
belt tensioner from being activated when the
seat belt is not worn.
18
Engines and Gearboxes
In addition to the six tried and tested engines listed below, the new
VR5 unit will also be mounted in the Passat.
1.6-ltr. Engine AHL
Displacement 1595 cc
Compression ratio 10.3 : 1
Max. torque 140 Nm at 3800 rpm
Max. power output 74 kW at 5300 rpm
Engine management Simos 2
Fuel 95 RON unleaded premium
This engine is also used in the Audi A3.
It is mounted in the Passat without a twin-path
intake manifold.
1.8-ltr. 5V Engine ADR
Displacement 1781 cc
Compression ratio 10.3 : 1
Max. torque 173 Nm at 3950 rpm
Max. power output 92 kW at 5800 rpm
Engine management Motronic M 3.8.2
Fuel 95 RON unleaded premium
This engine is also used in the Audi A6.
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Engines and Gearboxes
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1.8-ltr. 5V Turbo Engine AEB
Displacement 1781cc
Compression ratio 9.3 : 1
Max. torque 210 Nm
at 1750-4600 rpm
Max. power output 110 kW at 5700 rpm
Engine management Motronic M 3.8.2
Fuel 95 RON unleaded premium
This engine is also used in the Audi A4.
2.8-ltr. V6 Engine ACK
Displacement 2771cc
Compression ratio 10.3 : 1
Max. torque 280 Nm at 3200 rpm
Max. power output 142 kW at 6000 rpm
Engine management Motronic M 3.8.2
Fuel 98 RON unleaded premium
This engine is also used in the Audi A6.
20
2.3-ltr. VR5 Engine AGZ
The new VR5 engine has a displacement of 2.3
litres. It is derived from the VR6 engine and is
designed for in-line or transverse mounting.
Power output is 110 kW.
The engineering of the VR5 engine is explained in a separate Self Study Programme.
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21
Engines and Gearboxes
1.9-ltr. TDI Engine AHU
Displacement 1896 cc
Compression ratio 19.5 : 1
Max. torque 202 Nm at 1900 rpm
Max. power output 66 kW at 4000 rpm
Fuel 45 CN diesel
Mixture preparation Direct injection with
electronically controlled
distributor injection
pump
1.9-ltr. TDI Engine AFN
Displacement 1896 cc
Compression ratio 19.5 : 1
Max. torque 235 Nm at 1900 rpm
Max. power output 81 kW at 4150 rpm
Fuel 45 CN diesel
Mixture preparation Direct injection with
electronically controlled
distributor injection
pump
This engine features a variable-rate
turbocharger. You will find further
information on this engine in
Self Study Programme SSP190.
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22
Range of Engines and Gearboxes
Manual gearbox Engines Automatic gearbox
1.6-ltr.
012/01W
74kW
01N
1.8-ltr. 5V
92kW
1.8-ltr. 5V
turbo
01V
110kW
2.3-ltr.
VR5
110kW
01A
1.9-ltr.
TDI
66kW
1.9-ltr.
TDI
81kW
2.8-ltr.
V6 5V
142kW
01V
Syncro
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Engines and Gearboxes
5-speed Manual Gearbox 012/01W
The 012/01W is a manual gearbox as used in
the Audi A4.
This gearbox has a magnesium housing for
installation in the 1.6-ltr./74kW aluminium
engine block.
5-speed Manual Gearbox 01A
The 01A is the manual gearbox for
four-wheel drive vehicles as used in the
Audi A4.
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4-speed Automatic Gearbox 01N
The 01N is also installed in the Audi A6, for
example.
You can find detailed information on this
gearbox in Self Study Programe No. 172.
5-speed Automatic Gearbox 01V
You will also be familiar with the 01V from the
Audi A4.
It is equipped with Tiptronic control as
standard.
You can find detailed information on this
gearbox in Self Study Programme No. 180.
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25
Running Gear
In addition to the four-link front suspension,
we will show you on the following pages the
newly developed torsion beam rear suspension as well as the new double-wishbone rear
suspension unique to Syncro models.
The Four-link Front Suspension
The four-link front suspension is standard in all
front- and four-wheel drive vehicles.
In the case of vehicles with tripoid joints, these
joints can be repaired.
Tripoid joint
26
191/37
The Torsion Beam Rear Suspension
Single-tube damper
Coil spring
191/55
Advantages of torsion beam rear suspension:
- Larger through-loading width due to the fact
that the coil springs and shock absorbers are
kept physically apart
- Use of single-tube dampers
- Downward-facing V-section of axle beam
- Self-aligning twin-grooved oblique ball
bearings act as wheel bearings
27
Running Gear
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The Double-wishbone Rear Suspension
The double-wishbone rear suspension was
developed in order to provide a through-loading
width of over 1000 mm.
Engine power is transmitted to all four wheels by a Torsen differential.
28
Brakes
The Passat is equipped with the Bosch 5.3 antilock braking system as standard.
Two different sizes of brake disc are available
for the front axle. The rear suspensions also
have disc brakes as standard.
Disc brakes, front Disc brakes, rear
280 x 22 mm brake disc
The front disc brakes are
vented.
The smaller disc diameter is
based on a smaller vehicle
mass and lower power output
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282.5 x 25 mm brake disc
This disc brake is vented and
larger in size.
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Rear brake caliper
The Passat has rear
disc brakes.
The brake caliper is made of
aluminium.
29
Steering
Height and Reach Adjustment of Steering Column
The Passat is equipped with power steering.
The steering column can be adjusted manually
50 mm fore and aft and 28 mm for height.
The steering column is attached to the body by
a mounting pedestal with sliding guide.
A damper element located above the double
universal joint prevents vibrations and noise
from being transmitted to the body.
A clamped connection links the steering
column to the power steering gear.
Mounting pedestal with
sliding guide
Damper element
Double universal joint
Clamped connection
191/38
You can find additional information on the steering in Self Study Programme SSP 167.
30
Electrics
The following features will be of interest to
you:
l Decentralised vehicle electrical system
l Dash panel insert
l Gas discharge headlights
l Washer jets
Decentralised Vehicle Electrical System
Advantages:
- Short wiring harnesses make cable
connections easier to find and assign.
- The short cables achieve substantial weight
savings.
- Test points can be assigned more easily.
- The components of the vehicle electrical
system are well protected against moisture.
- The decentralised vehicle electrical system
results in easier servicing.
Example of the arrangement
of control units
ABS control unit
Fuse carriers,
located on side of dash panel
Airbag control unit
Master control for
extended central locking system
Engine control unit
The main feature of the decentralised vehicle
electrical system is that the central electrics are
subdivided into separate connector stations,
relay carriers and fuse carriers. These submodules are arranged locally. This means that
they are located close to the assemblies and
functional units to which they belong.
The functions of the “car” as an integrated
system are divided up among several control
units with specific tasks.
Repair work on the vehicle electrical system may only be
carried out using Wiring Harness Repair Kit VAS1978.
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Electrics
Dash panel insert
The following features will be of interest to
you:
l Electronic immobiliser integrated
in dash panel insert
l Capable of diagnosis
l Can be encoded
l Fuel gauge
The dash panel insert is available in two
versions which differ from one another in
terms of the displays in the centre of the dash
panel insert.
In vehicles equipped with a navigation system,
this display is complemented by the Auto
Check System with a multi-function display.
The immobiliser is an integral feature of the
dash panel insert. However, the matching
functions of the immobiliser have been left
unchanged.
Self-diagnosis:
The diagnostic functions can be retrieved using
address word “17”.
Both instruments can be encoded. This means
that the dash panel insert can be encoded
depending on country and engine configuration.
It is also possible to enter the current mileage
when the dash panel insert is replaced.
Auto Check System with
multi-function display
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Fuel gauge
In previous systems, the fuel gauge tended to
fluctuate, e.g. when cornering. To counteract
this, damping of the fuel gauge was increased
using electronic devices.
However, the drawback of this was that the
fuel gauge took longer to display the correct
fuel level after refueling.
The new fuel gauge eliminates this drawback.
If the ignition is switched off and fuel tank
capacity increases by four litres or more, the
new
fuel level is recalculated and displayed straight
after the ignition is restarted.
If the ignition is switched on and the vehicle is
stationary, the damping cuts out and the fuel
level is displayed immediately.
Do not refuel the vehicle with the ignition
switched on.
Fuel gauge
when cornering (previously)
Fuel gauge
when cornering (today)
Fuel gauge
when refueling
Damping On Damping Off
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1 Lux
1 Lux
0 50 100 150 200 250 m
Electrics
Gas Discharge Headlights
Gas discharge headlights, which are integrated
into the headlights, are available for the Passat
as an option.
However, the use of gas discharge technology
is limited to the dipped beam headlight
because it takes up to three seconds to achieve
maximum luminous intensity. Therefore, H4
halogen lights will continue to be installed for
the main beam headlight.
Advantage of gas discharge headlights:
- Greater luminous efficiency than
conventional headlights
- Better brightness distribution by virtue of a
lens
- Fog light is no longer necessary
On acount of the greater danger of dazzling
oncoming traffic, vehicles with gas discharge
headlights are equipped with dynamic headlight range control.
Consequently, the switch for the manual headlight range control is not required.
Electronic Headlight Range Control
This function gathers its information on body
tilt angle relative to the vehicle axes from two
sensors located inside the front and rear wheel
housings on the left-hand side of vehicle.
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H4 halogen headlights
Gas discharge headlights
34
Fan Jet Nozzle
The Passat features new fan jet nozzles for
washing the windscreens.
Advantages:
- Better fluid distribution over the
entire surface of the windscreen
- Lower water consumption
- Better cleansing effect
- No adjustment required
Mode of operation
For the sake of simplicity, the mode of operation can be compared to that of a garden hose
when it is swung from side to side.
Moving the garden hose quickly produces a
fan jet.
A nozzle insert for producing the pendulum jet
is integrated in the spray nozzle. It ensures a
fan jet.
A heated version of the spray nozzle is also
available.
Fan-type jet
with an opening angle
of 45° - 50°
Installation from
below
Engine bonnet
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35
Extended Systems
Various systems cater for ride comfort and
ease of operation in the new Passat.
The following features will be of interest to
you:
llllExtended central locking system
– Decentralised system concept
l Heater/air-conditioning
– Innovations in the air-conditioning
l Navigation + communications
– Preparation for mobile cellular phone
Extended Central Locking System
The extended central locking system is based on
a decentralised system concept.
It has a central control unit and a separate door
control unit with a control panel for every door.
Self-diagnosis:
Diagnosis is initiated using the address word “46”.
Extended central locking system
with four door control units
191/62
Master control units.
Located in front of driver´s seat.
Front door control units
Located on control panel on driver´s side
Located on window lifter motor on front
passenger side
Rear door control units
Located on window lifter motors
(available only in combination with electric window lifters in rear doors)
36
fi
fi
Functions of the Extended Central Locking System
The master control unit assumes the following functions
Radio remote control
Interface to vehicle electrical system
Anti-theft warning system
with “interior monitor” function
Interior light control
Central locking
of rear doors (only in combination
with mech. window lifters at rear)
Central locking of boot lid
191/45
Diagnosis
Address word „46”
Slide/tilt sunroof
Electrically adjustable, folding and
heated door mirrors
Electric window lifters with
excess power limitation
Central locking of
doors, with Safe mode
Diagnosis
Address word „46”
The door control units assume the following functions
37
Extended Systems
The heater
Unlike predecessor models, the new heater is
constructed in one piece.
The air distributing housing and the air duct
with shutoff flap are combined in a single
component.
The heater, which is controlled at the air intake
side, permits fresh-air and air-recirculation
modes. A main shutoff flap is therefore no longer
required.
Central flap
Fresh-air/air-recirculation flap
- By virtue of the stepped form of the central flap, the central air vent is closed in
defrost mode.
- An electric-motor-operated fresh-air/air-recirculation flap is integrated.
- In defrost mode, the air recycle function is switched off.
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38
Pleasant air-conditioning for comfort and safety in the Passat.
AUTO
ECON
CLIMAtronic
Temperature sensor
191/47
The CLIMAtronic
Operating and display unit with control unit
- The controls have been rearranged.
- The temperature sensor dash panel and blower is integrated in the operating and
display unit.
- The photosensor measures incident sunlight over a large area.
There is greater sensitivity for controlling the interior climate.
- Average outflow temperature is registered by a transmitter.
39
Extended Systems
- The fresh-air/air-recirculation flap is
combined with the back pressure flap.
- Fresh-air blower with integrated
control unit.
- The shape of the central flap has been
modified to allow separate airflow to
the central and side vents.
- All flaps are electic-motor-operated.
Air-conditioning without back pressure flap is installed
in right-hand drive vehicles.
The following components are integrated in
the refrigeration circuit:
- Plate evaporator
- Controlled swash plate compressor
- Condenser
- Butterfly valve
- Collecting vessel
The Air-conditioning
Central flap
Fresh-air blower
Back pressure flapFresh-air/air-recirculation flap
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40
Navigation
The navigation system enables the driver to
reach his (her) destination easily and safely.
It replaces the road map and enhances
road safety.
This system employs a map stored on a
CD-ROM. The driver can select his (her)
destination on this map.
Directions for the driver are then given on the
display in the dash panel insert and via the
loudspeaker built into the control unit.
The system comprises the following elements:
- The navigation computer with integrated
CD-ROM drive
- The control unit with control and
loudspeaker
- The display integrated in the dash panel
insert
- The earth magnetic field sensor
- ABS wheel speed sensor
- The sensor for the global positioning
satellite system (GPS)
- The GPS satellite network
ABS-control unit
Operating unit
Display in
dash panel insert
ABS wheel speed
ssensor
Navigation computer
Earth magnetic field sensor
GPS sensor
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41
Extended Systems
Navigation computer with CD-ROM drive
The navigation computer determines the position of the vehicle by means of the above-mentioned sensors. It then compares the calculated
position with the map stored on the CD-ROM
and the chosen destination.
The computer then calculates directions for the
driver from this comparison.
Control unit with control and loudspeaker
The control unit is the interface to the
navigation computer. The system is switched
on or off and the destination is entered by operating the control. In addition to the display
integrated in the dash panel insert, a voice output can also be provided by means of the
built-in loudspeaker.
Display integrated in dash panel insert
The navigation system displays information
visually via the display of the Auto Check
System with multifunction display integrated
in the dash panel insert.
Depending on selected function, the display
shows a letter field for entering a destination
or pictograms representing directions for the
driver .
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42
191/83
However, this particular navigation system is not yet able to make allowance
for traffic lights, one-way roads, building sites, traffic jams, etc.
ABS wheel speed sensor
The wheel speed sensors of the rear suspension
are used to provide the navigation computer
with iinfomation on distance travelled.
Earth magnetic field sensor
The earth magnetic field sensor determines
the direction of travel relative to the north pole
for the navigation computer.
GPS sensor
GPS stands for Global Positioning System, a
global navigation system.
The sensor is integrated in the roof aerial.
The navigation computer uses the data
supplied by the GPS sensor as a correction
factor or when relocating the vehicle if the
computer loses track of the current position
(e.g. during rail transport).
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Connector
GPS sensor
Base of aerial
43
Extended Systems
Advantage:
- Easy to install
- No complex cable installation necessary
- One roof aerial for all functions
Depending on equipment specification of
the vehicle, three types of aerial can be
installed:
- Radio only
- Radio and telephone
- Radio, telephone and navigation (GPS)
With the cellular phone provision, only mobile phones with a VDA-standard connection
can be operated.
Cellular Phone Preparation
Scope of cellular phone provision:
- Hands-free microphone integrated in left-hand
A pillar
- VDA-standard cable
(standard connection for mobile phone)
- Radio mute function
- Change-over relay for left-hand door
loudspeaker
- Combined roof aerial with
high-frequency line to mobile phone
The Passat is available with a mobile phone
or cellular phone provision as equipment variants.
Diagnositic
connection
191/68
44
Notes
45
Notes
46
47
Service.
The Passat ‘97
Design and Function
192
640.2810.11.10 Technical status: 11/96
The Engineering
For internal use only.
Ó VOLKSWAGEN AG, Wolfsburg
All rights reserved. Specifications subject to change.
` Printed on chlorine-free
bleached cellulose paper.
Self Study Programme
Service Department
2
The Passat ‘97
Having provided you with an initial overview
of the new Passat in the Self Study Programme
entitled “The Passat ‘97 – The Presentation”,
we now want to describe in detail how the
car’s various components are designed and
how they function.
The subjects of the VR5 engine, convenience
electronics and navigation system are so wideranging that it would be beyond the scope of
this Self Study Programme.
We will therefore deal with them separately.
SSP 192/107
3
Page
Introduction 04
Vehicle Safety 06
1.8-ltr. 5V Engine ADR 20
1.8-ltr. 5V Turbo Engine AEB 22
2.8-ltr. V6 Engine ACK 26
1.9-ltr. TDI Engine AFN 34
Gearbox 38
Drive Shafts 40
Running Gear 43
ABS/EDL 48
Electrics 55
Air-conditioning 60
This Self Study Programme is not a Workshop Manual!
Please refer to the relevant Service Literature for all inspection, adjustment and repair
instructions.
New!
Important! / Note!
4
Engines
Given that the engine concepts used in the
Passat ‘97 are tried and tested, we will confine ourselves solely to special innovations
such as the variable valve timing featured
in the 2.8-ltr. V6 engine.
Gearbox
Non-ferrous metals, such as aluminium or
magnesium, are being used increasingly in
vehicle construction. In this booklet we will
explain the advantages and special features
of magnesium components.
Drive shafts
We will explain how length compensation
works in the triple roller drive shafts.
Introduction
Electrics
You will be given information regarding
the gas discharge headlights.
Overview of topics
5
Running gear
In addition to information about the torsion
beam rear axle and the double wishbone
rear axle, we will show you the new design
of the new wheel bearing generation.
ABS/EDL
As a part of the ABS/EDL system, we will
present you the new hydraulic unit with
an integrated control unit.
Air-conditioning
The latest developments and the special features of the CLIMAtronic will be described.
Vehicle safety
We will describe the gradual action of the
side airbag and the belt tensioner with
belt force limiter.
SSP 192/001
6
Vehicle Safety
Mode of operation of the restraint systems
Two different restraint systems are used in the
new Passat:
l
Seat belts with belt tensioner and
belt force limiter, used on all outer
seats,
l
Front and side airbags for the driver
and front passenger.
Airbag control unit
Central module of convenience
central locking system
Side airbag
crash sensor
Door lock
Seat with integrated side airbag
Belt tensioner with
belt force limiter
SSP 192/047
Integrated
front airbags
7
Effect of the restraint systems during minor accidents
During minor accidents, the body only partially
absorbs the impact energy of components
such as bumpers and impact absorbers.
The seat belts provide adequate protection; the
belt tensioners restrain the car’s occupants in
their seats.
The belt force limiter reduces the risk of the
belt causing injury.
In this case, the airbags are not triggered.
The belt tensioners are
triggered mechanically on
impact.
SSP 192/048
8
Vehicle safety
The effect of the restraint systems during serious accidents
During serious accidents, the car body absorbs
the impact energy. The passenger compartment remains by and large intact and the
airbags are triggered.
In addition to the protection afforded by the
seat belts, the restraint systems protect the
front passengers from more serious injuries in
the upper body and head areas.
The car’s central locking system is opened.
SSP 192/049
The belt tensioners are triggered
mechanically on impact.
Central locking system is opened.
Airbags are
triggered.
Airbag control unit
Central module of convenience central locking system
Side airbag crash
sensor
IN OUT
9
When carrying out work on the airbag systems, always follow the instructions given in
the Workshop Manuals.
Side airbag
The new side airbag system is integrated in the
driver’s and front passenger’s seats.
The side airbag is described as a thorax airbag.
It mainly protects the thorax, and with it the
lungs and pelvis, from lateral bruising.
In terms of its appearance, the new airbag
control unit has a different connector
housing code to the previous model.
Airbag control unit
J234
Side airbag
(illustrated as triggered)
Crash-sensor G179
Connection
SSP 192/006
10
Vehicle safety
Side airbag design
The side airbags are integrated in the front
seat backrests.
The folded airbag and gas generator are
accommodated inside the plastic housing.
When the side airbag is triggered, the gas
cartridges in the gas generator are opened
and the pyrotechnical charge ignites. The
highly pressurised gas contained inside
the cartridge expands instantaneously,
inflating the airbag.
While expanding, the gas cools and mixes with
the hot gas of the pyrotechnical charge. The
temperature of the gas mixture is therefore so
low that there is no risk of burning.
The side airbag has a capacity of approx. 12
litres.
Housing
Air bag
Gas generator
with gas cartridge and
pyrotechnical charge
SSP 192/005
11
A two-stage crash recognition system is used to ensure reliable side airbag activation.
Crash sensors G179/G180
The crash sensors for the side airbags are located
below the two front seats on the seat cross members.
They are conditioned to respond to lateral force
application.
The crash sensors are known as
intelligent sensors.
They operate independently of each other.
In addition to an electronic acceleration sensor,
the entire electronics are integrated in the sensor
housing.
When a sensor recognises a crash, it sends a
signal to the airbag control unit.
SSP 192/119
SSP 192/070
When an impact occurs, the
crash sensor G179 informs the
airbag control unit that it has
recognised a crash.
12
Vehicle safety
Airbag control unit J234
In parallel to the crash sensors, sensors in the
airbag control unit evaluate the severity of the
crash. The relevant side airbag is not triggered
until these sensors have also rcognised that an
accident has occurred and a crash sensor
sends an airbag trigger request.
The two crash sensors below the front seats
perform a function check at regular intervals,
providing feedback to the airbag control unit.
The system status of the side airbags can be
displayed via the self-diagnosis. The airbag
control unit also indicates when a fault may
possibly have occurred in the crash sensors or
the side airbags via the airbag warning lamp.
There is an additional energy storage device in the
airbag control unit for igniting the side airbags. If
the power supply fails during an accident, this
energy storage device has sufficient energy to
power the control unit and, if necessary, to ignite
the airbags.
Self-diagnosis:
The self-diagnosis is started using address word
“15”.
SSP 192/120
The side airbag
is triggered by the
airbag control unit.
The sensors in the control unit have
recognised an accident
in addition to crash
sensor G178.
13
Belt tensioner
The pyrotechnical belt tensioner combines
with the force limiter and the seat belt
recognition device in a single unit. It is only
triggered if the mechanical seat belt fastened
recognition system recognises an unreeled
belt.
Its compact design makes for much easier
replacement.
When an impact occurs, the belt tensioners
reel in the belt and thus take up any slack
(clearance between belt and body).
The mode of operation of the belt tensioner is
very different to that of its predecessors.
There are two belt tensioner variants:
l
A ball-driven belt tensioner, used on the
front seats.
l
Belt tensioners operating according to
the same principle as the Wankel
engine, used on the rear seats.
Trigger unit
Propellant charge
Feed tube containing
balls
Gearwheel
Ball retainer
SSP 192/126
Front belt tensioner
Belt
14
Functional description of front belt tensioner
The belt tensioner is activated by balls mounted in a feed tube.
When the belt tensioner is triggered, a pyrotechnical propellant charge ignites. It sets the
balls in motion and drives them into the ball
retainer via a gearwheel.
The belt reeling device is driven by the kinetic
energy of the balls, thus reeling in the belt.
Vehicle safety
Propellant charge
Belt
Gearwheel
Ball retainer
Feed tube
Mechanical trigger unit
Belt reeling device
SSP 192/124
SSP 192/125
15
Rear belt tensioner
The belt tensioner can be described in simpler
terms as a “pyrotechnical Wankel engine”.
This “Wankel engine” is driven by 3 propellant
charges. They are ignited in succession.
Belt tensioner triggering
mechanism
Belt
Locking mechanism with
child safety seat lock
Belt force limiter
Belt tensionerReeling mechanism
SSP 192/066
16
Functional description of rear belt tensioner.
The first propellant charge is ignited by a
mechanical triggering device.
The released gas causes the rotor to rotate.
The belt is tightened.
After a certain angle of rotation, the piston
opens the inlet port of the second firing pin,
thus igniting the second propellant charge.
The released gas makes the rotor rotate until
the next inlet channel is opened.
The third charge ignites.
The belt tensioner is able to perform approximately two full turns in this way.
Vehicle safety
Firing pin
Propellant charge
Wankel rotor
SSP 192/009
SSP 192/010
SSP 192/011
SSP 192/012
Mech. triggering device
17
Belt force limiter
Functional description of belt force limiter
If, due to acceleration, the tensile force of the
belt is so high that bruising or internal injuries
can occur, the tensile force of the belt must be
limited to a tolerable level.
It is limited by the belt reeling device torsion
shaft. The torsion shaft operates in much the
same way as a spring. Depending on its tensile
force, the belt “gives”.
Both types of belt tensioner use the same
system
Belt reeling device
The end of the slot limits
the distance which the
reeling device can
“give”.
The torsion shaft is connected to the gearwheel
on this side.
Belt
The torsion shaft is connected to the reeling
device on this side.
The reeling device is able
to rotate freely within
gearwheel inner race.
The torsion shaft runs through the
belt reeling device.
SSP 192/065
18
1. Which components belong to the restraint system of the Passat ‘97?
2. The side airbag has a capacity of
a) 8 litres,
b) 12 litres or
c) 15 litres.
3. The side airbag crash sensors respond to the application of ................................. force.
Test your knowledge
4. What is the function of the belt force limiter?
19
5. The rear belt tensioner
a) operates according to the Wankel engine principle,
b) uses a diaphragm pump,
c) is ball-activated.
6. Annotate the following drawing.
SSP 192/126
a)
c)
b)
d)
f)
e)
20
1.8-ltr. 5V Engine ADR
The 1.8-ltr. 5V engine has a twin path intake
manifold.
The twin path intake manifold is designed so
that it is possible to switch between long and
short intake paths.
Long intake path
A long intake path permite optimum charging
of the cylinder, and consequently high torque,
in the low speed range.
Short intake path
Switching over to the short intake manifold
permits high power output in the upper speed
range.
Twin path intake manifold
SSP 192/085
On the following page, we will show you the new technical features of the 1.8-ltr. 5V engine,
1.8-ltr. 5V turbo, 2.8-ltr. V6 and TDI engines.
Twin path intake manifold
Vacuum unit
21
Electric circuit
30
15
X
31
30
15
X
31
N156
S
J220
64 4 3
2
Components
J17 Fuel pump relay
J220 Motronic control unit
N156 Intake manifold pressure
change valve
S Fuse
J17
IN OUT
SSP 192/106
The engine control unit sends a signal to the
intake manifold pressure change valve.
It uses the vacuum unit to change over the
intake manifold. Power is supplied via the fuel
pump relay.
Engine control unit J220
IIntake manifold pressure
change valve N156
Vacuum unit
SSP 192/127
22
1.8-ltr. 5V Turbo Engine AEB
System overview
Sensors
Lambda probe
G39
Actuators
Air mass meter
G70
Knock sensors
G61 + G66
Intake manifold
temperature sender
G72
The 1.8-ltr. 5V turbo engine is equipped with the Motronic M 3.8.2 engine management system.
Hall sender
G40
Engine speed
sender G28
Coolant temperature sender G62
Altitude sender
F96
Additional signals
Throttle valve control valve J338
Injection valves
N30, N31, N32, N33
Output stage
N122
Ignition coils
N, N128, N158, N163
Throttle valve control unit J338
Activated charcoal
filter system solenoid valve N80
Charge pressure limitation solenoid valve
N75
Additional signals
Diagnostic connection
Fuel pump G6
with fuel pump relay
J17
Engine control unit
J220
SSP 192/074
Immobiliser control unit
J362
Function diagram 1.8-ltr. 5V turbo engine AEB
Components
F96 Altitude sender
G6 Fuel pump
G28 Engine speed sender
G39 Lambda probe
G40 Hall sender
G61 Knock sensor I
G62 Coolant temperature sender
G66 Knock sensor II
G70 Air mass meter
G72 Intake manifold temperature sender
J17 Fuel pump relay
J220 Control unit for Motronic
J338 Throttle valve control unit
N Ignition coil
N30 Injection valve, cylinder 1
N31 Injection valve, cylinder 2
N32 Injection valve, cylinder 3
N33 Injection valve, cylinder 4
N75 Charge pressure limitation solenoid valve
N80 Activated charcoal system solenoid valve
N122 Output stage
N128 Ignition coil 2
N158 Ignition coil 3
N163 Ignition coil 4
S Fuse
Additional signals
Pin 5 Actual engine torque (out)
Pin 6 Speed signal (out)
Pin 7 Throttle valve potentiometer
signal (out)
Pin 8 Air-conditioner compressor signal
(in + out)
Pin 18 Fuel consumption signal (out)
Pin 20 Road speed signal (in)
Pin 22 Gear engaged signal for automatic
gearbox (in)
Pin 23 Auto. gearbox CU retard signal to engine
CU (in)
Pin 49 Upshift/downshift signal for
automatic gearbox (in)
Colour code
Input signal
Output signal
Positive
Negative
23
30
50 5050
5050
5050 50 50 50 50 5
0
0
S
N30N31N32N33
G39
N80
N75
3
G61
G62
G28
G72
G66
N
G70
15 64 65 58 80 73 4 3 1
J17
27 25 26 12 13 2 68 60 56 63 53 54 67
G6
IN OUT
15
31
X
5050
J220
5
J3
24
30
50 50
50 50
50
50 50 50
N163
N158N128
F96
G40
77 78 70 19
59 69 75 11 74 76 62 61
5 6 7 8 18 20 22 23 49
15
X
31
N122
SSP 192/076
25
2.8-ltr. V6 Engine ACK
Variable valve timing
It provides high torque when driving in low gears
at low speeds, thus improving fuel economy and
reducing exhaust emissions.
High output is needed at high speeds. To
achieve both, the cylinder must be well-filled
in all speed ranges.
At low speeds, the piston moves so slowly that
the gas mixture in the intake manifold follows
the movement of the piston.
The inlet valve must be closed early so that the
fuel-air mixture is not forced back into the
intake manifold.
At high speeds, the flow rate inside the intake
manifold is so high that the mixture can continue
to flow into the cylinder although the piston is
moving back up.
The inlet valve is closed when the fuel-air mixture
can no longer enter the cylinder.
In engines with variable valve timing, the closing
times of the inlet valve are adapted to the speed
range.
Injection valve
closes early
SSP 192/130
26
Injection valve
closes late
SSP 192/131
The principle of variable valve timing:
Performance position
In the “Performance” position, the lower section
of the chain is short while the upper one is long.
The inlet valve closes late.
The rapid air flow within the intake manifold
ensures that the cylinder charge is high. The
engine is thus able to develop high output at high
speeds.
Torque position
Moving the variable valve timer down shortens
the upper chain section and lengthens the lower
one.
The inlet camshafts therefore rotate in relation
to the exhaust camshaft. The exhaust camshaft
cannot rotate at the same time, since it is
restrained by the toothed belt.
The inlet valve closes early.
In this position, high torque is produced in the
lower and medium speed ranges.
The exhaust camshaft is driven by the
crankshaft by means of a toothed belt.
The inlet camshaft is driven by the exhaust
camshaft by means of a chain.
With variable valve timing, the opening times
of the inlet valves are adjusted depending on
engine speed. The drive chain therefore turns
the inlet camshaft.
Inlet camshaftExhaust camshaft
Variable valve timer
SSP 192/081
SSP 192/080
27
2.8-ltr. V6 Engine ACK
Variable valve timer
A hydraulic cylinder lifts and lowers the variable
valve timer. Oil is supplied to the hydraulic cylinder
via the engine oil circuit.
The engine control unit controls the hydraulic cylinder via the variable valve timing valve, which is bolted directly to the variable valve timer housing.
Variable valve timer with
integrated chain tensioner
Bank1, variable valve timing
valve N205
Hydraulic cylinder
Inlet camshaft
SSP 192/108
Exhaust camshaft
28
The design of the V6 engine makes particularly
heavy demands on variable valve timing.
Viewed from above, the exhaust camshafts are
arranged on the outside and the inlet camshafts on the inside.
As a result, the variable valve timers of the left
and right bank of cylinders have to operate in
opposite directions.
Variable valve timing in the V6 engine
Idling
When the engine is idling, the inlet valves are
closed late.
Torque position
The inlet valves are closed early above an engine
speed of 1000 rpm. The camshaft adjuster of the
left bank of cylinders moves down while the
right cylinder bank variable valve timer moves
up.
Performance position
At a speed of 3700 rpm, the inlet valves are
closed late.
SSP 192/129
SSP 192/103
SSP 192/104
SSP 192/103
Inlet camshaft
Exhaust camshaft
29
2.8-ltr. V6 Engine ACK
System overview
Sensors
Actuators
The 2.8-ltr. V6 engine is equipped with variable valve timing and is controlled by the
Motronic M 3.8.2 engine control unit.
Lambda probes I+II
G39 + G108
Air mass meter
G70
Knock sensors
G61 + G66
Sensor for intake
manifold temperature G72
Hall sender
G40
Engine speed
sender G28
Coolant temperature sender G62
Additional signals
Throttle valve control unit J338
Hall sender II
G163
Injectors
N30, N31, N32,
N33, N83, N84
Ignition transformer
N152
Throttle valve control unit J338
Activated charcoal
filter system solenoid valve N80
Bank1, variable valve
timing N205
Additional signals
Diagnostic connection
Intake manifold
pressure change
solenoid valve
N156
Bank2, variable valve
timing N208
Immobiliser control unit
J362
Fuel pump G6
with fuel pump relay
J17
Engine control unit
J220
SSP 192/073
30
Function diagram of 2.8-ltr. 6V Engine ACK
Components
G6 Fuel pump
G28 Engine speed sender
G39 Lambda probe
G40 Hall sender
G61 Knock sensor I
G62 Coolant temperature sender
G66 Knock sensor II
G70 Air mass meter
G72 Intake manifold temperature sender
G108 Lambda probe II
G163 Hall sender II
J17 Fuel pump relay
J220 Motronic control unit
J338 Throttle valve control unit
N Ignition coil
N30 Injection valve, cylinder 1
N31 Injection valve, cylinder 2
N32 Injection valve, cylinder 3
N33 Injection valve, cylinder 4
N83 Injection valve, cylinder 5
N84 Injection valve, cylinder 6
N75 Charge pressure limitation solenoid
valve
N80 Activated charcoal system solenoid
valve
N152 Ignition transformer
N156 Twin path intake manifold valve
N205 Camshaft adjustment valve I
N208 Camshaft adjustment valve II
Additional signals
Pin 5 Actual engine torque (out)
Pin 6 Speed signal (out)
Pin 7 Throttle valve potentiometer
signal (out)
Pin 8 Air-conditioner compressor signal
(in + out)
Pin 18 Fuel consumption signal (out)
Pin 20 Road speed signal (in)
Pin 22 Gear engaged signal for automatic
gearbox (in)
Pin 23 Aut. gearbox CU retard signal for
engine CU (in)
Pin 45 ABS signal (in)
Pin 49 Upshift/downshift information for
automatic gearbox (in)
Colour code
S Fuse
Input signal
Output signal
Positive
Earth
31
0
1
5050 50 50 50
5050 50 50 50
5050 50 50 50 50 50 50
50 50 50 50
S
N30N31N32N33N83N84
G39 G108
N80
N156
N205
N208
G61
G40 G163
G66
S
15
26 39 40 44 11 76 68 60
64 55 79 72 65 58 80 73 4 3
5
X
J17
S
G6
25
32
30
15
X
31
N152
50
5050 50 50 50
J338
G62
G70
3 56 53 54 67 66 59 69 75 62 74 14
12 13 70 71 78
19
2
5 6 7 8 18 20 22 23 45 49
IN OUT
G72
SSP 192/075
33
1.9-ltr. TDI Engine AFN
Radiator fan run-on
Electric circuit
30
15
X
31
30
15
X
31
S
V7
J248
J397
N39
3
A radiator fan run-on facility controlled by the
engine management system is being used in
the 1.9-ltr. 81kW TDI engine for the first time.
The advantage of this is that the radiator fan
run-on time is variable and can consequently
be adapted to the previous operating
conditions and load conditions of the engine.
The run-on time is determined by the engine
control unit via a characteristic map. Allowance
is also made for the coolant temperature and
engine load during the final minutes of car
operation before the engine is turned off.
IN OUT
Components
J248 Diesel direct injection
system control unit
J397 Cooling fan run-on
relay
N39 Series resistor for
coolant fan
S Fuse
V7 Coolant fan
SSP 192/086
Radiator fan run-on relay J397 Self-diagnosis
Open circuit /short circuit to earth
Short circuit to positive
The radiator fan run-on relay J397 is designated as blower relay J323 in the self-diagnosis.
34
b)a)
Test your knowledge
1. Which of the following diagrams represents the “Performance” position
and the “Torque” position in the 2.8-ltr. V6 engine?
2. Complete the following text.
At low speeds, the piston moves so
that the gas mixture in
follows the movement of the piston. The inlet valve
so that the fuel-air mixture is not forced back into the intake manifold.
At high speeds, the flow rate in the intake manifold is so
that the mixture
although the piston is moving back up.
The inlet valve is not
until the fuel-air mixture can no longer enter the cylinder.
,
,
,
,
a)
c)
b)
d)
e)
f)
35
Gearbox
Comparison of insertion depths between magnesium, aluminium and iron
SSP 192/058 SSP 192/059 SSP 192/060
Magnesium
Lightweight construction now plays a central
role in vehicle development, due to the tough
demands on performance, safety and fuel
economy.
Weighing roughly 34% less than aluminium,
magnesium is, as a material, well-suited to
meeting these demands.
We will show you the advantages and impacts
of magnesium using the 5-speed manual
gearbox housing 012/01W.
The strength of a material depends on its
density, among other things. Low density goes
hand in hand with low strength. This loss of
strength has to be compensated for somehow.
Density comparison
Iron:
7.873 g/cm3
Aluminium:
2.699 g/cm3
Magnesium:
1.738 g/cm3
The housing is therefore ribbed more intensively
and the wall thickness has been increased. As a
result, the magnesium housing actually weighs
27% less than the aluminium housing.
Bolt insertion depth has also been increased.
36
Electrochemical voltage series
Aluminium Iron Lead Copper Gold
Al Fe Pb Cu Au
Magnesium
H
2
O
SSP 192/096
Excerpt from electrochemical voltage series
In the presence of water, an electric current
develops between two different metals. The
car battery operates according to a similar
principle.
The electric current causes one of the two
metals to decompose. If a metal decomposes
easily, it is termed a non-precious metal. If a
metal does not decompose easily, it is termed
a precious metal.
An electrochemical voltage series is produced
by arranging the metals in a series extending
from non-precious metal to precious metal.
The further the metals in the voltage series are
apart from one another, the higher the current
and the more readily the less precious metals
decompose.
37
Gearbox
Contact corrosion, using a bolted connection
as an example
In this example, a magnesium component is
attached using a bolt made is an iron alloy. If
the contact surface is wetted with water, an
electric current occurs between the two
metals. This leads to contact corrosion. The
magnesium is decomposed at the same time.
Contact corrosion can be prevented by inhibiting
the electric current between the two metals by
coating the bolt with an insulating layer. This
insulating layer is composed of a special
non-conductive coating.
A special coating is applied to all add-on parts which come into direct contact with
magnesium. Please follow the instructions given in the Workshop Manual.
Water
Special coating
Magnesium
Water
Corrosion
SSP 192/097
SSP 192/061
38
Test your knowledge
a) b) c) d) e)
f)
1. What is the insertion depth for magnesium compared to that for iron?
a) 2.0 times greater,
b) 5.2 times greater,
c) 2.5 times greater.
2. Assign the metals of gold, iron, magnesium, copper, aluminium and lead to the following
drawing.
39
Drive shafts
CV
ball joint
Triple roller joint
Tripod star
Race
Drive shaft
Housing
SSP 192/056
SSP 192/071
Roller
Triple roller constant velocity joint
The triple roller CV joint reduces the transmission of vibrations and noise from the engine/
gearbox unit to the body.
Design
The triple roller joint has three spherical journals
with a roller fitted to each of them.
The rollers are located in races and can slide and
swivel on the tripod star.
Triple roller joints are principally used in diesel
and automatic cars.
This is necessary due to the high vibrations
which occur in diesel engines and the pretensioning forces which occur in automatic drive
trains.
40
Triple roller joint pin
Drive shaft
Triple roller joints
Race
Function
The principal task of the drive shafts is to transmit
power from the gearbox to the wheels.
They are also responsible for length compensation.
The engine/gearbox unit runs in elastic
bearings. At certain speeds, the unit begins to
oscillate in its mountings.
This movement is compensated by the triple
roller joints, whereby the tripod star, together
with the rollers, slide within their races.
The triple roller joint housing is pushed over the
tripod star rollers by the movement of the engine/
gearbox unit.
The drive shaft remains stationary in the process.
SSP 192/041
SSP 192/042
SSP 192/043
Roller
Moving parts
Stationary parts
41
drive shafts
In addition to the vibrations of the
engine/gearbox unit, the triple roller
joints have to equalise wheel bump and
rebound.
The joint housing remains stationary in the
process.
The drive shaft is moved away from the
gearbox by the rebound action of the wheels.
At the same time, the rollers are displaced in
only one plane within their races, thereby
reducing friction and noise transmission
to the body.
SSP 192/044
Housing
SSP 192/045
42
SSP 192/046
The following pages describe the design modifications to the axles of the Passat ‘97 as presented
to you in Self Study Programme SSP 191.
Running Gear
Torsion beam rear axle
The anti-roll bar used in the new torsion beam
rear axle is located in front of the axis of
rotation. The rear axle mountings are located
on the far outer side of the axle. This considerably reduces the forces acting on the rear
axle mountings.
The mounting housing is made of aluminium
and bolted to the trailing arms.
When designing the rear axle, comfort was a
major consideration. The rear axle mountings
and the large rubber bases of the coil springs
minimise noise transmission from the axle to
the body.
Anti-roll bar
Rear axle mounting
Rubber base
SSP 192/100
On axles where the rear axle mounting is
located on the inside, the mountings have
to absorb large forces when cornering.
Locating the rear axle mountings on the outside makes the lever arms shorter, with the
result that the mountings only absorb smaller
forces. They can therefore be designed with a
softer rating.
SSP 192/112
SSP 192/111
Trailing armr
Axis of rotation
Long lever arm
Short lever arm
Rear axle mounting
43
Conventional rear axles have a V section which
is open facing forward. In this configuration, the
shear centre of the axle is located behind the V
section.
The centre of rotation is an imaginary axis about
which the axle rotates when the suspension
experiences a bump on one side.
If the shear centre is behind the V section, then
diagonally aligned track-correcting mountings
have to be used to achieve a self-steering effect.
The new torsion beam rear axle has a V
section which is open downwards. The shear
centre is located above the V section.
The axle has different rotational characteristics
as a result.
SSP 192/116
SSP 192/114
SSP 192/117
Shear centre
Centre of rotation
Running Gear
When cornering, the inside and outside cornering
wheels go through rebound and bump respectively, because the car body tilts to the outside.
The axle is twisted in itself. The bumped wheel
adopts the toe-in position, while the rebound
wheel adopts the toe-out position.
V section of torsion beam rear axle
Toe-out Toe-in
SSP 192/134
SSP 192/118
44
V section of rear axle is twisted
when cornering.
Hub/wheel bearing unit
The newly developed wheel bearing generation
is used on the rear axle of front-wheel-drive
vehicles. The twin-tracked ball bearing has a
stationary outer race which is bolted to the rear
axle mounting plate.
The bearing inner race serves as the carrier for
the brake disc and wheel. This design eliminates
the need for an axle pivot.
The ABS speed sensor is inserted into the wheel
bearing and secured with a clip to prevent it
from falling out.
The advantages of the new wheel bearing
generation are as follows:
l Minimal wear due to improved sealing.
l The rotor is protected by the inserted
speed sensor and cannot be damaged by
external influences.
l The wheel bearing does not have to be
adjusted any longer because the bearing
preload is predetermined by its design.
Speed sensor
Inner race
Outer race
Speed sensor rotor
SSP 192/057
45
Running Gear
Double wishbone rear axle
The newly developed double wishbone rear
axle allows the same through-loading width as
the torsion beam rear axle. It has an enclosed
subframe to which the transverse links are
attached.
The subframe is connected to the body by four
large bonded rubber mountings.
Single-tube gas-filled shock absorbers are
used on the double wishbone rear axle. Their
diameter is smaller than that of twin-tube
shock absorbers.
The low-lying position of the upper wishbone
and the smaller shock absorber diameter
permit a lower loading platform and a
larger through-loading width.
Bonded rubber mounting
Enclosed subframe
Upper wishbone
Lowerwishbonek
SSP 192/098
SSP 192/099
46
Test your knowledge
1. How is the high transverse rigidity of the torsion beam rear axle achieved?
a)
b)
2. The V section of the new torsion beam rear axle is open .
3. The advantages of the new wheel bearing generation are as follows:
a) Minimal wear,
b) The ABS speed sensor rotor is protected,
c) It is self-adjusting,
d) It has to be adjusted using a hexagon nut.
4. On the double wishbone rear axle, the upper wishbone is located
the wheel. As a result of this,
achieved.
is
47
ABS/EDL
System overview
The anti-lock braking system is a 4-channel system. This means that two valves are assigned to
each wheel (inlet and outlet valves).
The hydraulic unit and the ABS control unit are combined in a single module and can only be
renewed as one unit.
A Self Study Programme relating to the ABS 5.3 system is in preparation.
Braking system
warning lamp
ABS recirculating
pump V39
Hydraulic unit with
solenoid valves
N99-102/ N133-136
N166-168
ABS warning lamp
Additional signals
Diagnostic connection
Actuators
Brake light
switch
F
Front left + right
speed sensor
G45/G47
Rear left + right
speed sensor
G44/46
Additional signals,
e.g. time signal
Sensors ABS/EDL control unit
J104
SSP 192/062
48
ABS/EDL hydraulic unit
Recirculating pump
Features of hydraulic unit:
- One-piece cast iron housing.
- ABS/EDL solenoid valves each with two hydraulic connections and operating positions.
- Noise-optimised recirculating pump,
- Accumulator size for each brake circuit: approx. 3 cm
3
,
- Two diaphragm outlet dampers are connected upstream of the EDL hydraulic blocks.
They help improve the low-temperature performance of the EDL control system.
Diaphragm outlet dam-
per
SSP 192/063
Front right brake caliper
Hydraulic block
Brake master cylinder
Secondary piston
circuit
Front left brake caliper
Brake master cylinder
Primary piston circuit
Rear left brake caliper
Rear right brake caliper
Connection for:
49
ABS/EDL
ABS/EDL control unit J104
Features of control unit:
- Redundant computer concept with
separate watchdog,
- Self-diagnosis capability,
- 26-pin connector contact.
Redundant computer concept
In this case, redundant stands for a computer
concept with several backups.
In the control unit there are two computers
which work with the same program
independently and check one another.
The two computers are, in turn, monitored by
a third computer which assumes the task of
controlling the solenoid valve relays.
This third computer is known as the watchdog.
If it detects a fault, it stores the fault message
in a read-only memory and can be read out
during the self-diagnosis. The fault is indicated
by the ABS warning lamp.
SSP 192/064
ABS/EDL control unit
50
ABS speed sensor
Features of speed sensor:
- It is inserted into the wheel bearing and is
thus protected against external
influences.
- It generates signals contactlessly.
Signal utilisation
The signal supplied by the ABS speed sensor
is used to control the anti-lock braking system.
The navigation system calculates the distance
travelled from this signal.
Effect of signal failure
- The ABS system is switched off and the
ABS warning lamp comes on.
- The navigation system is de-energised.
- The brake warning lamp comes on.
This is how it works:
The rotor is integrated and the speed sensor
inserted in the wheel bearing.
The speed sensor comprises a permanent
magnet with two pole plates. A coil is wound
around the pole platesand the permanent
magnet.
When the wheel moves, the rotor rotates
about the speed sensor. In the process, it cuts
the field lines of the pole plates, thus inducing
a voltage in the coil. This voltage serves as the
signal for the ABS control unit and the
navigation system.
Rotor
Permanent
magnet
Coil
SSP 192/057
SSP 192/132
Speed sensor rotor
Speed sensor
Pole plate
Pole plate
51
ABS/EDL
SS
N99 N100 N101
J105
V39
J106
15
3
1
17 18
16
IN OUT
Components
F Brake light switch
G44 Rear right speed sensor 4
G45 Front right speed sensor 2
G46 Rear left speed sensor 3
G47 Front left speed sensor 1
J104 Control unit for ABS with EDL
J105 ABS recirculating pump relay
J106 Solenoid valve relay
J220 Control unit for Motronic
J285 Control unit with display unit
in dash panel insert
J401 Control unit for navigation system
with CD-ROM drive
K 47 ABS warning lamp
N99 Front right ABS inlet valve
N100 Front right ABS outlet valve
N101 Front left ABS inlet valve
N102 Front left ABS outlet valve
N133 Rear right ABS inlet valve
N134 Rear left ABS inlet valve
N135 Rear right ABS outlet valve
N136 Rear left ABS outlet valve
N166 Front right EDL switchover valve
N167 Front right EDL outlet valve
N167 Front left EDL switchover valve
N168 Front left EDL outlet valve
S Fuse
V39 ABS recirculating pump
Colour code
Input signal
Output signal
Positive
Earth
Function diagram
30
15
31
X
G44
52
G46 G47
3
0
5
X
1
J401
F
K47
N133 N134 N135 N136
N166 N167 N168 N169
5 4 9 8 7 6 19 23 24 13 21 10 14 11
SSP 192/087
1
3
102
J104
45
J220
J285
53
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