Mercedes-Benz OM 904-926 LA BlueTec, OM 904-926 LA Operating Instructions Manual
®
OM 904-926 LA BlueTec
Operating Instructions
, OM 904-926 LA
Symbols
$
%
!
i
X
YY
(Y page)
Warning
Environmental note
Possible vehicle damage
Tip
Instructions
Continuation symbol
Page reference
Welcome to the world of Mercedes-Benz
Familiarise yourself
with your engine and read
the Operating Instructions before you use the
engine. This will help you to avoid endangering yourself or others.
The standard equipment and product description of your engine may vary, depending on
individual specifications. This is described on
the engine data card.
Mercedes-Benz constantly updates its
engines to the state of the art.
Mercedes-Benz reserves the right to make
changes to the following:
R
design
R
equipment
R
technical features
You cannot therefore base any claims on the
data, illustrations or descriptions in this manual.
The manual/instructions are comprised of:
R
Operating Instructions
R
Maintenance Booklet
Always keep these documents together with
the engine/vehicle/device. These documents should be passed on to the new owner
if you sell the engine/vehicle/device.
i
You can find out about your engine's
important functions in German and English
in the online Owner's Manual at: http://
www.mercedes-benz.de/betriebsanleitungen
The technical documentation team at
Daimler AG wishes you safe and pleasant
motoring.
9265840681
É9265840681ÁËÍ
Contents
3
Index ....................................................... 4
General information .............................. 7
At a glance ........................................... 13
Safety ................................................... 29
Driving mode/working mode ............. 33
Maintenance and care ........................ 45
Notes on maintenance ....................... 59
Decommission and protection ........... 79
Breakdown assistance ....................... 85
Technical data ..................................... 99
Index
4
A
Adaptation module .............................. 21
AdBlue®/DEF
Components .................................... 19
Consumption ................................... 41
Refuelling
Replacing the filter ...........................
......................................... 42
69
Service product ............................... 54
ADM (FR (drive control) unit) ............. 21
Antifreeze ............................................. 73
B
Bio-diesel fuel
see FAME fatty acid methyl ester fuel
Bleeding the fuel system .................... 86
Bleeding the fuel system manually ... 86
BlueTec
®
Exhaust gas aftertreatment ................ 9
Sensors ............................................ 19
BlueTec® exhaust gas aftertreatment
AdBlue® service product .................. 54
Braking
Continuous brake ............................ 40
C
Capacities .......................................... 104
Care products ...................................... 55
Charge current .................................... 37
Checking the fluid level ...................... 34
Cleaning and care
Engine cleaning ................................
56
High-pressure cleaning .................... 55
Notes on care .................................. 55
Cold-start aid
....................................... 27
Consumption
AdBlue®/DEF .................................. 41
Fuel .................................................. 41
Oil (engine) ...................................... 41
Continuous brake ................................ 26
Coolant ................................................. 34
Mixing ratio ...................................... 48
Renewing ......................................... 75
Service product ............................... 48
Coolant (engine)
Topping up
....................................... 76
Coolant additive .................................. 48
Cooling system
Degreasing ....................................... 76
Flushing ........................................... 76
Correct use ............................................ 9
Corrosion inhibitor/antifreeze
agent .................................................... 48
Cranking device ................................... 64
D
Data card ............................................
Decommissioning
................................ 81
100
Decommissioning the engine ............. 80
DEF/AdBlue
®
see AdBlue®/DEF service products
Description of the engine ................... 21
Diesel
Flow improvers ................................ 52
Fuels ................................................ 50
Low outside temperatures ............... 52
refuelling .......................................... 41
Sulphur content table ...................... 51
Dimensions ........................................ 101
Disposal of service products .............. 46
Draining the coolant ........................... 75
Draining the fuel prefilter ................... 86
Driving tips .......................................... 40
E
Electronic engine control ................... 38
Emergency mode .................................
Emergency running program
................ 8
87
Engine
Capacities ...................................... 104
Changing the oil and oil filter ........... 62
Checking for leaks and general
condition .......................................... 77
Cleaning ........................................... 55
Data ............................................... 101
Data card ....................................... 100
Data plate ...................................... 100
Diagnostics (indicator lamp) ............ 94
Oil consumption ............................... 41
Operating data ............................... 104
Index
5
Protective treatment ........................ 81
Re-commissioning ........................... 83
Rectifying faults ............................... 89
Running-in period ............................. 40
Starting
Stopping .......................................... 39
Engine brake
Condition and setting ....................... 72
Function ........................................... 26
Engine control unit .............................. 22
Engine data ........................................ 101
Engine data card ............................... 100
Engine description .............................. 21
Engine model designation ................ 100
Engine oil
Adding ............................................. 63
For winter operation ........................ 46
Mixing .............................................. 48
Oil change ........................................ 47
Siphoning and draining .................... 62
Topping up ....................................... 48
Engine oil consumption ...................... 41
Engine overview .................................. 14
Engine type plate .............................. 100
Exhaust gas aftertreatment indica-
tor lamp ................................................ 95
............................................ 36
F
Filling up the pressure reservoir ....... 71
Flow improvers .................................... 52
FR (drive control) unit
see ADM
Fuel
Additives
Consumption ................................... 41
Diesel ............................................... 50
FAME fatty acid methyl ester fuel .... 53
refuelling .......................................... 41
Sulphur content table ...................... 51
Fuel filter .............................................. 67
Fuel grade ............................................ 50
.......................................... 52
G
Genuine Mercedes-Benz
parts ................................................... 7, 8
Getting started .................................... 35
H
High-pressure cleaning ....................... 55
I
Identification plate ............................ 100
Indicator and warning lamps
BlueTec® exhaust gas aftertreat-
ment ................................................ 25
Installation ........................................... 10
L
Lines and hoses
Checking for leaks ........................... 77
M
Maintenance ........................................ 56
Mercedes-Benz Service Centre
see Qualified specialist workshop
Modifications and changes .................. 7
O
Oil (engine)
For winter operation ........................ 46
Oil change ........................................
Scope of use
Oil change ............................................ 62
Oil filter replacement .......................... 62
Oil pressure ......................................... 38
Operating data ................................... 104
Operating restriction override ........... 39
Operating safety .................................... 7
Operational monitoring ...................... 37
Organisational measures ................... 30
Original parts ......................................... 7
Overview, sensors ............................... 18
Overview of maintenance work ......... 60
Overview of work plans ...................... 60
.................................... 47
47
P
Personnel ............................................. 30
Poly-V-belt
Checking condition .......................... 66
Damage patterns ............................. 66
Routing ............................................ 97
Index
6
Preparing for starting operation
see Starting operation
Protection of the environment ............. 7
Protective treatment .......................... 81
Q
Qualified specialist workshop ........... 11
R
Re-commissioning ............................... 83
Refuelling
AdBlue®/DEF .................................. 42
Fuels ................................................ 41
Replacing the fuel filter
Replacing the fuel prefilter ................. 68
Replacing the poly-V-belt .................... 97
Requirements of the personnel ......... 30
Roadside Assistance ........................... 86
Running the vehicle in ........................ 40
...................... 69
S
Safety and
gram ....................................................... 8
Safety precautions .............................. 30
Service products
AdBlue®/DEF .................................. 54
Coolant ............................................ 48
DEF/AdBlue® .................................. 54
Diesel fuel ........................................ 50
Disposal ........................................... 46
Disposing of AdBlue®/DEF .............. 55
Engine oil ......................................... 46
FAME fatty acid methyl ester fuel .... 53
Flow improvers ................................ 52
Fuel additives ................................... 52
Purity of AdBlue®/DEF .................... 55
Storing AdBlue®/DEF ...................... 55
Specialist workshop ............................ 11
Starting
see Starting (engine)
Starting (engine) .................................. 36
Starting the engine for the first
time ...................................................... 35
Stopping and switching off the
engine ................................................... 39
emergency running pro-
Sulphur content of fuel ....................... 51
T
Technical data ................................... 101
Dimensions .................................... 101
Filling capacities
Operating data ............................... 104
Weights .......................................... 101
Tightening torques ............................ 105
Torque reduction ............................... 106
Transport ................................................ 9
Troubleshooting .................................. 94
............................ 104
V
Valve clearance
Checking and adjusting ................... 63
Valve clearance special tool ...............
64
W
Warning and indicator lamps
Charge indicator .............................. 25
Cold-start aid ................................... 25
Electronics
Weights .............................................. 102
Winter diesel ........................................ 52
Winter operation ................................. 43
....................................... 25
General information
7
Environmental note
Environmental note
H
Daimler AG has a declared policy of comprehensive environmental protection.
The objectives are to use the natural resources which form the basis of our existence on
this planet sparingly and in a manner which
takes the requirements of both nature and
humanity into account.
You
by operating your engine in an environmentally responsible manner.
The fuel consumption and wear and tear of an
engine depend upon the conditions under
which it is operated. For this reason, you
should:
R
R
R
R
Always have maintenance work carried out at
a qualified specialist workshop, e.g. a
Mercedes-Benz or MTU Service Centre.
can help to protect the environment
also
not warm up the engine in neutral
switch off the engine during operation-related delays
monitor the fuel consumption
carry out the specified maintenance work.
Operating safety and vehicle approval
Operating safety
The operating
safety of an engine depends on
its professional installation in the overall system (e.g. the vehicle or working machinery).
As the operator of the engine, you also affect
its safe operation.
Through compliance with the prescribed
maintenance intervals, you fulfil part of the
requirements for safe operation of the
engine.
However, safe operation of the engine also
depends upon its proper use, which includes,
for example, regular checks of the oil level.
WARNING
G
Accidents can occur as a result of engine
damage caused by improper use of the
engine.
Therefore,
instructions included in the Owner's Manual.
WARNING
G
Faulty or incomplete maintenance work, as
well as disregarded maintenance intervals,
can decrease the engine's operating life,
cause engine damage and lead to accidents.
Therefore,
instructions included in the Owner's Manual.
follow the engine operating
please
follow the engine operating
please
Notes on electronic systems
WARNING
G
If work on electronic equipment and its software
carried out incorrectly, this equipment
is
could stop working. The electronic systems
are networked via interfaces. Tampering with
these electronic systems could cause malfunctions in systems which have not been
modified. Malfunctions such as these can
seriously jeopardise the vehicle's operating
safety and therefore your own safety.
Other work or modifications incorrectly carried out on the vehicle could also jeopardise
operating safety.
Some safety systems only function when the
engine is running. You should therefore never
switch off the engine when driving.
Conversion parts and modifications to the engine
WARNING
G
Unauthorised changes to the engine can
reduce its functionality and safety, lead to
accidents and consequently to personal
injury.
tion to the engine carried out at a qualified
specialist workshop which has the necessary
have maintenance or modifica-
Always
Z
General information
8
specialist knowledge and tools to carry out
the work required. Mercedes-Benz recommends that
Service Centre for this purpose.
!
Unauthorised intervention in the injection
you use a Mercedes-Benz or MTU
system and the engine electronics can
affect the performance and emissions of
the engine. Compliance with factory settings and legal environmental protection
conditions can then no longer be guaranteed.
The implied warranty does not cover damage
resulting from unauthorised modifications to
the engine.
Safety/emergency running program
The engine is equipped with an electronic
control system, which monitors both the
engine and itself (self-diagnosis).
When the
electronic control system detects a
malfunction, one of the following measures is
automatically implemented after an appraisal
of the malfunction:
R
The corresponding warning lamp displays
the faults occurring during operation
(Y page 25).
R
In conjunction with the electronic engine
control, fault codes can be shown on a display.
R
The system switches to a suitable backup
function for the continued, albeit restricted
operation of the engine (e.g. constant
emergency running speed).
WARNING
G
If maintenance and repair work on the engine
is
carried out correctly, the operation and
not
safety may be affected, which can result in
accidents and personal injury.
Always have work on or modifications to the
engine carried out at a qualified specialist
workshop that has the necessary special
skills and tools for the work required.
Mercedes-Benz recommends a MercedesBenz or MTU Service Centre.
The Daimler diagnostic tester can be
attached to the 14-pin diagnostic socket on
the equipment,
or to the service plug according to the EU Directive. Both the malfunction
message memory and the saved engine data
can be read by this device.
Warning lamp electronics (example)
Genuine Mercedes-Benz parts
Make sure of the suitability of the replacement parts
for your engine. Parts that lead to
a modification of the engine/vehicle/equipment are considered in many countries to
render the general operating permit invalid.
Such modifications include, for example:
R
modifications that change the approved
equipment type/vehicle type, as defined by
the general operating permit.
R
modifications that could endanger road
users or persons in the vicinity of the vehicle/equipment.
R
modifications that change the exhaust or
noise level.
The use of unapproved parts can adversely
affect safety levels.
Environmental note
H
For more economic repairs, Mercedes-Benz
offers Mercedes-Benz reconditioned assembly and
parts as part of the recycling process.
The same quality standards and warranty
apply as to new parts.
General information
9
You can find more information on recommended conversion
parts and accessories, as well
as permitted technical modifications at a
Mercedes-Benz or MTU Service Centre
(Y page 11).
Always state the engine number with the
model designation when ordering genuine
Mercedes-Benz parts. You can find the numbers on the identification plate of your engine
(Y page 100) and on the engine data card
(Y page 100).
BlueTec® exhaust gas aftertreatment
The engines meet the requirements of the
relevant emissions
level and are correspond-
ingly certified.
Compliance with emissions laws and regulations is a condition of the operating permit for
the vehicle/equipment.
Engines with BlueTec® exhaust gas aftertreatment must be operated with AdBlue®/
DEF in order to meet the emissions laws and
regulations.
The operating permit is invalidated if the vehicle/equipment is operated without AdBlue®/
DEF. The legal consequence of this is that
operation of the vehicle/equipment is no longer permitted. This may be an offence or a
breach of road traffic regulations in certain
countries. Special concessions granted
either at the time of purchase or to reduce
operating costs of the vehicle/equipment,
e.g. reduced taxes or tolls, may also be rendered retroactively invalid. This can be the
case in the country of registration. Or also in
another country where you operate the vehicle/equipment.
This normally affects the following operating
states:
R
driving without AdBlue®/DEF
R
the permissible nitrogen oxide (NOx)
thresholds are exceeded
R
there is a fault or emissions-relevant malfunction in the monitoring or exhaust gas
aftertreatment system
can
You
find details in the “Engine diagnostics
indicator lamp” section(Y page 94).
Fault detected in the monitoring system
If the monitoring system detects a fault in the
BlueTec® exhaust gas aftertreatment, operation is limited in accordance with the relevant
regulations (Y page 37).
Correct use
The engine may only be installed as contractually specified.
The manufacturer of the end product is
responsible for the correct installation and
compatibility of
the engine in the overall sys-
tem.
The engine may not be modified. If the engine
is modified, Mercedes-Benz and MTU do not
accept responsibility for any damage arising
as a result.
Correct use of the engine requires adherence
to the instructions in this Owner's Manual.
This also requires compliance with the maintenance intervals and the professional execution of maintenance work in accordance
with this Owner's Manual.
Transport
Legal requirements
If the engine/vehicle/equipment is not operated within the limits of the emissions laws
and regulations, it can lead to sanctions.
WARNING
G
The engine can detach and cause injuries if it
overturns or falls out.
Z
General information
10
R
To lift the engine, only use lifting points
attached to the engine.
R
Only use Mercedes-Benz transport equipment intended for this purpose.
R
Only lift and transport the engine in the
installation position. Also, observe the maximum permitted angle of 30° while lifting
the engine in and out of vehicles.
Lifting point flywheel-side (example)
Lifting point belt-side (example)
Installation
The engine may only be installed as contractually specified.
The manufacturer of the end product is
responsible for the correct installation and
compatibility of
the engine in the overall sys-
tem.
Observe the sections "Correct use"
(Y page 9) and "Modification and changes to
the engine" (Y page 7).
The Operating Instructions contains information required
for installation in the "Technical
Data" section" (Y page 101).
Please consult a Mercedes-Benz or MTU
Service Centre if you have any questions
(Y page 11).
Information on the implied warranty
A well-developed network of Mercedes-Benz
and MTU
Service Centres is available to carry
out maintenance work.
Mercedes-Benz and MTU Service Centres:
R
have special equipment and tools as well
as specialists who receive continuous
training
R
guarantee that your engine is repaired and
maintained thoroughly and expertly
R
carry out all repairs within the framework
of the engine warranty and the implied warranty
R
carry out all maintenance work expertly
R
confirm in the Maintenance Booklet that
the maintenance work has been carried out
at the required time
R
handle warranty claims that are admissible
according to the sales contract
Please observe the instructions and recommendations as well as the maintenance services in the Maintenance Booklet. Please
observe these instructions even if you let a
third party use and care for your engine. This
is the only way to ensure that you do not lose
your entitlements.
If the prescribed maintenance work is not
carried out, claims can only be decided after
the manufacturer has inspected the claim.
General information
11
During the engine warranty period in particular, have
the prescribed maintenance service
carried out as follows:
R
regularly
R
punctually
R
at a qualified specialist workshop which
has the necessary specialist knowledge
and tools to carry out the work required.
Mercedes-Benz recommends that you use
a Mercedes-Benz or MTU Service Centre
for this purpose. In particular, work relevant to safety or on safety-related systems
must be carried out at a qualified specialist
workshop.
If there are legal requirements on exhaust gas
aftertreatment, please note that:
R
maintenance on the engines must be carried out according to specific regulations
and using special measuring devices.
R
it is prohibited to modify or tamper with
components relevant to emissions.
All Mercedes-Benz and MTU Service Centres
are aware of the relevant regulations.
Maintenance work does not include repair
work. Repair work requires a separate order.
You may also consult a Mercedes-Benz or
MTU Service Centre for further information.
Always have the following work on the vehicle
carried out
R
work relevant to safety
R
service and maintenance work
R
repair work
R
modifications such as installations or con-
at a qualified specialist workshop:
versions
R
work on electronic components
Please have warranty and ex gratia work carried out at authorised workshops/Service
Centres.
R
For on-highway applications, contact a
Mercedes-Benz Service Centre.
R
For off-highway applications, contact an
MTU or MTU-authorised Mercedes-Benz
partner.
Qualified specialist workshop
A qualified specialist workshop has the necessary specialist knowledge, tools and qualifications to
carry out the work required on the
engine to a professional standard. This is
especially important for work relevant to
safety.
A qualified specialist workshop must carry
out the required service, maintenance and
repair work and document it according to the
specifications of Daimler AG. Failure to comply with these specifications could lead to the
loss of warranty entitlements.
Mercedes-Benz recommends that you use a
Mercedes-Benz or MTU Service Centre.
Z
12
Exterior view ....................................... 14
General information ............................ 21
13
At a glance
Exterior view
14
Exterior view
Engine overview
At a glance
Engine overview OM 904 LA
:
Filler neck
;
Stop button
=
Start button
?
Air compressor
A
Power-steering pump
B
Engine control (MR) control unit
C
Oil dipstick
D
Refrigerant compressor
E
Tensioning pulley
F
Coolant pump
G
Fuel prefilter
H
Fuel filter
Exterior view
15
At a glance
Engine overview OM 904 LA
:
AdBlue®/DEF metering unit
;
Charge air pipe of the charge-air cooler
=
Charge air pipe to the charge-air cooler
?
Crankcase ventilation hose
A
Oil filter
B
Tensioning pulley
C
Alternator
D
Starter
E
Intake air inlet
F
Engine brake
Exterior view
16
At a glance
Engine overview OM 906 LA
:
Filler neck
;
Stop button
=
Start button
?
Air compressor
A
Power-steering pump
B
Engine control (MR) control unit
C
Oil dipstick
D
Refrigerant compressor
E
Tensioning pulley
F
Fuel filter
G
Coolant pump
H
Fuel prefilter
I
Coolant outlet to the radiator
Exterior view
17
At a glance
Engine overview OM 906 LA
:
AdBlue®/DEF metering unit
;
Charge air pipe of the charge-air cooler
=
Charge air pipe to the charge-air cooler
?
Crankcase ventilation hose
A
Oil filter
B
Tensioning pulley
C
Alternator
D
Starter
E
Intake air inlet
F
Exhaust gas turbocharger
G
Engine brake
Exterior view
18
Sensors overview
Sensors, general
At a glance
Example: OM 926 LA
:
Oil temperature
;
Oil pressure
=
Coolant temperature
?
Charge-air temperature/charge-air pressure
A
TDC sensor (on camshaft gear)
B
Crankshaft position sensor (on flywheel)
C
Oil level
D
Fuel temperature
AdBlue®/DEF components
Exterior view
19
At a glance
BlueTec® sensors, overview OM 924 LA
:
Valve preheating, AdBlue®/DEF system
;
Silencer
=
Temperature and humidity sensor (air filter, clean air side)
?
Metering unit
A
Temperature sensor downstream of catalytic converter
B
NOx sensor
C
Temperature sensor upstream of catalytic converter
D
SCR frame module
E
Supply unit
F
AdBlue®/DEF filter
G
AdBlue®/DEF tank
Exterior view
20
At a glance
BlueTec® sensors, overview OM 926 LA
:
Valve preheating, AdBlue®/DEF system
;
Silencer
=
Temperature and humidity sensor (air filter, clean air side)
?
Metering unit
A
Temperature sensor downstream of catalytic converter
B
NOx sensor
C
Temperature sensor upstream of catalytic converter
D
SCR frame module
E
Supply unit
F
AdBlue®/DEF filter
G
AdBlue®/DEF tank
General information
21
At a glance
BlueTec® sensors and test connection on the metering unit. Example: OM 926 LA
:
AdBlue®/DEF pressure sensor
;
AdBlue®/DEF temperature sensor
=
Pressure sensor for compressed air
?
Metering unit test connection
A
Metering unit heater
B
Metering valve
General information
Description of the engine
The engine is a water-cooled four-stroke diesel engine with direct injection.
The cylinders
inder has two inlet valves and one outlet
valve.
Each cylinder has its own fuel injection pump
(unit pump) with a short high-pressure fuel
injection line to the multi-hole nozzle at the
centre of the combustion chamber. The unit
are arranged in a row. Each cyl-
pumps sit directly in the crankcase and are
driven by the camshaft.
The engine is equipped with exhaust gas turbocharger and intercooler as standard. The
engine can
brakes (brake valve and constant throttle
valves).
It is a low-emission engine. Start of injection,
injection period and injection quantity are
controlled entirely electronically.
be equipped with optional engine
General information
22
Electronic drive control
The engine has a fully electronic control system which,
along with the engine and its associated sensors, consists of the following components:
R
the engine control unit (MR) and
R
the drive control unit (FR) and/or other
At a glance
vehicle-specific control units, e.g. ADM
R
SCR frame module (only for engines with
BlueTec® exhaust gas aftertreatment)
The control units are interconnected by a
CAN line (Controller Area Network line) which
facilitates the exchange of all necessary data.
In addition to the engine and the BlueTec
exhaust gas aftertreatment, the electronic
engine control also monitors itself. Depending on the malfunctions/failures that occur,
a safety and emergency mode (Y page 8) may
be automatically selected.
For vehicle engines, the electronic engine
control only allows the engine to be started
when the transmission is in neutral.
Engine control unit (engine resident)
The engine control unit is on the left side of
the engine.
These values are analysed together with data
the
from
engine sensors. They are compared
with the charts or characteristic curves
stored in the engine control unit.
Data from the sensors derives from, e.g.:
R
charge-air pressure and charge-air temperature
R
coolant temperature
R
fuel temperature
R
oil pressure
Start of injection, injection period and injection quantity are calculated on this basis and
the unit pump is controlled via the solenoid
valve accordingly.
®
If BlueTec® exhaust gas aftertreatment is
available, the associated sensors are also
analysed and the AdBlue®/DEF dosage is
controlled.
i
To obtain a replacement engine control
unit, you will require all the data on the
control unit type plate.
Example: OM 926 LA engine control unit
The engine control unit processes values
from the
FR (drive control) unit and the ADM.
These are, for example, the value from the
position sensor (accelerator pedal), the
engine brake or engine start/stop, etc.
Control unit type plate
:
Data record
;
Certification no.
=
Engine number
?
Equipment code
General information
23
FR (drive control) unit or ADM (on the
equipment)
The engine can be adapted to the various
operation-specific requirements
using the FR
(drive control) unit or the adaptation module
ADM.
Example: FR (drive control) unit
Various operation specific data such as
engine idling speed, maximum working
engine speed or speed limiter are stored in
the FR (drive control) unit or the ADM.
The FR (drive control) unit or the ADM
receives data from:
R
user (values from the position sensor,
engine start/stop)
R
engine brake switch
R
other systems (e.g. acceleration skid control)
R
engine control unit (e.g. oil pressure and
coolant temperature)
Values for the engine control (MR control
unit) are derived from this and conveyed via
the CAN line.
The FR (drive control) unit or the ADM controls various displays, e.g. the electronics
warning lamp, the engine brake and the constant throttle valve.
If the electronic engine control detects a
fault, the fault code is saved in the control
units. It
can be read out with the corresponding diagnostic testers (STAR DIAGNOSIS or
minidiag2).
In addition, the ^ electronics warning
lamp is switched on.
i
Mercedes-Benz diagnostic
testers can be
connected to the 14-pin diagnostic socket
on the equipment or with the EU compliant
service connector. Both fault memory and
stored engine data can be read out using
this equipment.
SCR frame module (on the frame)
SCR frame module
The SCR frame module reads signals and
transmits them
via the CAN line to the engine
control unit.
The following signals are read:
R
Temperature sensor upstream of the SCR
catalytic converter
R
Temperature sensor downstream of the
SCR catalytic converter
R
NOx sensor downstream of the SCR catalytic converter
R
Combination sensor for level and temperature in the AdBlue®/DEF tank
R
Combination sensor for humidity and air
charge temperature
Example: diagnostic socket
At a glance
General information
24
At a glance
Example: EU compliant service connector
Warning and indicator lamps
Engine, general
General information
25
Symbol
;
1
Reason for display/displayed message
Fault lamps Impermissible operating conditions
Text in the engine
symbol: "CHECK"
;
STOP lamp
Serious fault
2
Text in the engine
symbol: "STOP"
k
#
Electronic
engine control
malfunction
Charge current
(power generation)
Lights up in the event of an electronic engine control malfunction. Engine may only be operated in
emergency mode.
Lights up in the event of a charge current (power
generation) malfunction.
If the warning lamp does
not go out after starting the engine, or if it goes
on while the engine is running, the alternator or
poly-V-belt is faulty.
%
BlueTec® exhaust gas aftertreatment on-highway version
Cold-start aid Lights up if the cold-start aid is active.
3
The following indicator lamps could be available on the instrument panel:
Symbol
þ
1
Reason for display/displayed message
AdBlue®/DEF level
Fault message/action required
(warning before reduction in
operating performance)
;
È
NOx bulb
Engine indicator lamp Exhaust system fault
Reduction in operating perform-
Active torque limitation
ance
At a glance
1
Symbols may vary depending on the vehicle/equipment version.
2
In addition, a warning tone may sound.
3
On-highway: vehicles with MOT approval.
General information
26
BlueTec® exhaust gas aftertreatment off-highway version
4
The following indicator lamps could be available on the instrument panel:
Symbol
þ
1
Reason for display/displayed message
AdBlue®/DEF level
Fault message/action required (warning
before reduction in operating performance)
At a glance
!
È
lights up
Check engine/exhaust gas
aftertreatment
Torque/speed limiter
2
active
Fault and misuse (failure in the monitoring
system)
Slight reduction in operating performance
(level 1)
È
flashes
Significant reduction in operating performance
(level 2)
Continuous brake
If increased braking power is required, the
engine can be equipped with a brake valve
downstream from the exhaust gas turbocharger in
conjunction with constant throttle
valves.
OM 926 LA constant throttle valve
:
;
The brake valve uses exhaust back pressure
to increase braking power. The constant
throttle
OM 904 LA/OM 924 LA constant throttle valve
:
Constant throttle valve
;
Pneumatically-actuated line
compression pressure in the power stroke
(third stroke), whilst the compression (second stroke) is not significantly affected.
The constant throttle valve is an additional
valve in the cylinder head. When open, the
constant throttle valve establishes a connection between the combustion chamber and
4
Off-highway: vehicles without MOT approval.
1
Symbols may vary depending on the vehicle/equipment version.
2
In addition, a warning tone may sound.
Constant throttle valve
Hydraulically-actuated line
valves
bring about a reduction of the
General information
27
exhaust port. This brings about the desired
decompression during the power stroke.
When the engine brake is activated, the constant throttle valves are opened. For
OM 904/OM 924 engines, the actuation is
pneumatic. For OM 906/OM 926
engines,
the actuation is hydraulic. The brake valve on
the exhaust gas turbocharger is also closed.
The engine brake is actuated by the FR (drive
control) unit (Y page 23) or the ADM.
The engine brake is always deactivated below
900 rpm. This prevents the engine from stalling. The engine brake is automatically deactivated even if the position sensor (e.g. accelerator pedal) is in use.
i
In emergency mode (constant engine
speed), the engine brake can only be activated in overrun mode at increased engine
speed. Once the constant engine speed is
reached, the engine brake is automatically
deactivated again.
Cold-start aid
The cold-start
aid makes it easier to start the
engine at low outside temperatures (below
–15 †); it is activated when the outside temperature falls below –4 †.
Environmental note
H
At outside temperatures below about –4 †
the cold-start aid minimises emissions (after
starting
load on the starter motor and batteries and
enables the engine to be started more rapidly.
For this reason you should only start the
engine after the % indicator lamp goes out.
engine). In addition, it reduces the
the
The cold-start aid is automatically deactivated if:
R
the engine
is not started within 30 seconds
of the % indicator lamp going out.
R
the engine is started while the % indicator lamp is still lit.
R
the coolant temperature reaches around
0 † while the engine is running.
At a coolant temperature above approximately –4 †, the % indicator lamp goes
out after approximately 2 seconds (function
check). At a coolant temperature below
approximately –4 †, the % indicator lamp
goes out after approximately 20 seconds.
Have the cold-start aid checked and repaired
at a qualified specialist workshop. MercedesBenz recommends that you use a MercedesBenz or MTU Service Centre for this purpose
(Y page 11). Work relevant to safety or on
safety-related systems must be carried out at
a qualified specialist workshop.
At a glance
X
To activate the cold-start aid: turn the
vehicle key
to the drive position in the igni-
tion lock.
The % indicator lamp lights up in the
instrument panel.
X
After the % indicator lamp goes out,
start the engine within 30
seconds.
Z
28
Loading...