2005 MERCEDES-BENZ SPRINTER belt

OPERATION
The central timer module (CTM) monitors many
hard wired switch and sensor inputs as well as those
resources it shares with other modules in the vehicle
through its communication over the programmable
communications interface (PCI) data bus network.
The internal programming and all of these inputs
allow the CTM to determine the tasks it needs to
perform and their priorities, as well as both the stan-
dard and optional features that it should provide.
The CTM then performs those tasks and provides
those features through both PCI data bus communi-
cation with other modules and hard wired outputs
through a number of driver circuits, relays, and
actuators.These outputs allow the CTM the ability to
control numerous accessory systems in the vehicle.
The CTM monitors its own internal circuitry as
well as many of its input and output circuits, and
will store a Diagnostic Trouble Code (DTC) in elec-
tronic memory for any failure it detects. These DTCs
can be retrieved and diagnosed using a DRBIIItscan
tool. Refer to the appropriate diagnostic information.
HARD WIRED INPUTS
The hard wired inputs to the CTM include the fol-
lowing:
²Fused B(+)
²Fused ignition switch output (run-acc)
²Fused ignition switch output (run-start)
²Ground
²Key-in ignition switch sense
²Sliding door switch sense
²Passenger door switch sense
²Driver door switch sense
²PCI bus circuit
HARD WIRED OUTPUTS
The hard wired outputs of the CTM include the fol-
lowing:
²Door lock relay output
²Door unlock relay output
²VTSS indicator driver
MESSAGING
The CTM uses the following messages received
from other electronic modules over the PCI data bus:
²Airbag Deploy (ACM)
²Beep request (CMTC)
²Charging System Failure (PCM)
²Chime request (EMIC)
²Engine RPM (PCM)
²OK to Arm VTSS (PCM)
²Security indicator request (SKIM)
²System Voltage (PCM)
²Valid/Invalid Key (SKIM)
²Vehicle Distance (PCM)²Vehicle Speed (PCM)DIAGNOSIS AND TESTING - CENTRAL TIMER
MODULE
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, SEAT BELT TENSIONER, OR INSTRU-
MENT PANEL COMPONENT DIAGNOSIS OR SER-
VICE. DISCONNECT AND ISOLATE THE BATTERY
NEGATIVE (GROUND) CABLE, THEN WAIT TWO
MINUTES FOR THE AIRBAG SYSTEM CAPACITOR
TO DISCHARGE BEFORE PERFORMING FURTHER
DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE
WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE
TO TAKE THE PROPER PRECAUTIONS COULD
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
The hard wired inputs to and outputs from the
central timer module (CTM) may be diagnosed and
tested using conventional diagnostic tools and meth-
ods. Refer to the appropriate wiring information.
However, conventional diagnostic methods may not
prove conclusive in the diagnosis of the CTM. In
order to obtain conclusive testing of the CTM, the
programmable communications interface (PCI) data
bus network and all of the modules that provide
inputs to or receive outputs from the CTM must also
be checked. The most reliable, efficient, and accurate
means to diagnose the CTM, the PCI data bus net-
work, and the modules that provide inputs to, or
receive outputs from, the CTM requires the use of a
DRBIIItscan tool. Refer to the appropriate diagnos-
tic information.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Slide the driver seat to the full forward posi-
tion.
(3) Disconnect the wire harness connector for the
seat belt latch. (Fig. 1).
(4) Remove the screws that secure the closeout
panel beneathe the driver seat cushion and remove
the panel.
(5) Remove the screws that secure the central
timer module to the bracket.
(6) Disconnect the wire harness connectors from
the central timer module.
(7) Remove the central timer module from the
vehicle.
INSTALLATION
(1) Position the central timer module in the vehicle
8E - 2 ELECTRONIC CONTROL MODULESVA
CENTRAL TIMER MODULE (Continued)

(2) Connect the wire harness connectors to the
central timer module.
(3) Install the screws that secure the central timer
module. Tighten the screws securely.
(4) Route the seat belt latch wire lead through the
hole in the closeout panel and position the panel
beneath the driver seat cushion
(5) Install the screws that secure the closeout
panel beneath the driver seat cushion. Tighten the
screws securely.
(6) Connect the wire harness connector to the seat
belt latch connector.
(7) Slide the driver seat to back to its original posi-
tion.
(8) Reconnect the negative battery cable.
CONTROLLER ANTILOCK
BRAKE
DESCRIPTION
The Controler Antilock Brake (CAB) is mounted to
the Hydraulic Control Unit (HCU) and operates the
ABS system.
REMOVAL
(1) Remove the negative battery cable from the
battery.
(2) Pull up on the CAB harness connector release
and remove connector.
(3) Remove the CAB mounting bolts.
(4) Remove the CAB from the HCU.
INSTALLATION
(1) Install CAB to the HCU.
(2) Install mounting bolts. Tighten to 2 N´m (16 in.
lbs.).
(3) Install the wiring harness connector to the
CAB and push down on the release to secure the con-
nector.
(4) Install negative battery cable to the battery.
ENGINE CONTROL MODULE
DESCRIPTION
The electronic control module (ECM) is mounted to
the left lower dash panel and consists of an electronic
printed circuit board which is designed as a multi-
layer board assembly fitted on both sides. The rout-
ing of the five wiring harness connectors at the ECM
connectors are split into interfering cables and sensi-
tive cables in order to achieve improved electromag-
netic compatibility. The ECM stores engine specific
data, monitors the connected sensor and analyzes
their measurement (Fig. 2).
Its task consists in controlling the following sys-
tems in line with the analysis of the input signals:
²Fuel Supply System
²Injected Quantity Control
²Emission Control System
²Charge Pressure Control
²Cruise Control
²A/C Compressor Shut-Off
²Pre-Heating Output Relay for the Glow Plugs
²Vehicle Theft
²Air Bag
²Monitors inputs/outputs, checks plausibility and
stores faults
²Share information with other control modules
²Diagnosis
If a sensor should fail, provided the fault is not
serious, the ECM will continue to operate the engine
in Limp-Home Mode (emergency mode) using a
default value for the missing signal. The ECM
ensures that continuing to operate the engine will
not cause damage or effect safety,otherwise a Engine
shut-off process will be carried out.Fig. 1 Central Timer Module
1 - DRIVER SEAT
2 - WIRE HARNESS CONNECTOR
3 - SCREW (2)
4 - CLOSEOUT PANEL
5 - CENTRAL TIMER MODULE
6 - WIRE HARNESS CONNECTOR (2)
7 - SCREW (2)
VAELECTRONIC CONTROL MODULES 8E - 3
CENTRAL TIMER MODULE (Continued)

GENERATOR
DESCRIPTION
The generator is belt-driven by the engine using a
serpentine-type drive belt. It is serviced only as a
complete assembly. If the generator fails for any rea-
son, the entire assembly must be replaced.
On certain engines, the decoupler pulley may be
replaced separately.
OPERATION
As the energized rotor begins to rotate within the
generator, the spinning magnetic field induces a cur-
rent into the windings of the stator coil. Once the
generator begins producing sufficient current, it also
provides the current needed to energize the rotor.
The stator winding connections deliver the induced
AC current to 3 positive and 3 negative diodes for
rectification. From the diodes, rectified DC current is
delivered to the vehicle electrical system through the
generator battery terminal.
Although the generators appear the same exter-
nally, different generators with different output rat-
ings are used on this vehicle. Be certain that the
replacement generator has the same output rating
and part number as the original unit. Refer to Spec-
ifications and see Generator Ratings for amperage
ratings and part numbers.
Noise emitting from the generator may be caused
by: worn, loose or defective bearings; a loose or defec-
tive drive pulley (decoupler pulley); incorrect, worn,
damaged or misadjusted fan drive belt; loose mount-
ing bolts; a misaligned drive pulley or a defective sta-
tor or diode.
An instrument panel mounted, battery charge indi-
cator lamp is used. When the key is in the on posi-
tion, the lamp will be illuminated. This is done as a
bulb check. If this lamp remains illuminated while
the engine is running, a Diagnostic Trouble Code
(DTC) has been detected for the charging system.
REMOVAL
CAUTION: DISCONNECT NEGATIVE CABLE FROM
BATTERY BEFORE REMOVING BATTERY OUTPUT
WIRE FROM GENERATOR. FAILURE TO DO SO
CAN RESULT IN INJURY.
CAUTION: Never force a belt over a pulley rim
using a screwdriver. The synthetic fiber of the belt
can be damaged.
CAUTION: When installing a serpentine accessory
drive belt, the belt MUST be routed correctly. The
water pump will be rotating in the wrong direction ifthe belt is installed incorrectly, causing the engine
to overheat. Refer to belt routing label in engine
compartment, or refer to Belt Schematics in Cooling
System.
(1) Disconnect and isolate negative battery cable.
(2) Remove generator drive belt. Refer to Cooling
System for procedure.
(3) Raise and support vehicle.
(4) Remove protective plastic cover from B+ stud
at top of generator.
(5) Remove nut securing battery output cable to
B+ terminal at top of generator.
(6) Unplug field terminal connector at rear of gen-
erator.
(7) Remove 4 generator mounting bolts (Torx-style
#12 bit) (Fig. 1).
(8) Remove generator from lower side of vehicle.
INSTALLATION
(1) Raise and support vehicle.
(2) Position generator to engine.
(3) Install 4 generator mounting bolts (Fig. 1).
Refer to Torque Specifications.
Fig. 1 GENERATOR MOUNTING - 2.7L DIESEL
1 - GENERATOR
2 - DRIVE BELT
3 - MOUNTING BOLTS (4)
4 - GENERATOR WIRING HARNESS
8F - 18 CHARGING SYSTEMVA

(4) Connect field terminal connector at rear of gen-
erator.
(5) Install battery output cable and nut to B+ ter-
minal at top of generator. Refer to Torque Specifica-
tions.
(6) Install protective plastic cover to B+ stud at
top of generator.
(7) Lower vehicle.
CAUTION: Never force a belt over a pulley rim
using a screwdriver. The synthetic fiber of the belt
can be damaged.
CAUTION: When installing a serpentine accessory
drive belt, the belt MUST be routed correctly. The
water pump will be rotating in the wrong direction if
the belt is installed incorrectly, causing the engine
to overheat. Refer to belt routing label in engine
compartment, or refer to Belt Schematics in Cooling
System.
(8) Install generator drive belt. Refer to Cooling
System for procedure.
(9) Connect negative battery cable.
(10) Check charging system for proper operation.
GENERATOR DECOUPLER
PULLEY
DESCRIPTION
The generator decoupler is used only with
certain engines.The decoupler is used in place of
the standard generator drive pulley (Fig. 2).
OPERATION
The generator decoupler is used only with
certain engines.The decoupler (Fig. 2) is a one-way
clutch designed to help reduce belt tension fluctua-
tion, vibration, reduce fatigue loads, improve belt life,
reduce hubloads on components, and reduce noise.
Dry operation is used (no grease or lubricants). The
decoupler is not temperature sensitive and also has a
low sensitivity to electrical load. The decoupler is a
non-serviceable item and is to be replaced as an
assembly.
DIAGNOSIS AND TESTING - GENERATOR DECOUPLER
CONDITION POSSIBLE CAUSES CORRECTION
Does not drive generator
(generator not charging)Internal failure Replace decoupler
Noise coming from
decouplerInternal failure Replace decoupler
Fig. 2 GENERATOR DECOUPLER PULLEY
VACHARGING SYSTEM 8F - 19
GENERATOR (Continued)

REMOVAL
The generator decoupler is used only with
certain engines.
Two different type generator decoupler pulleys are
used. One can be identified by the use of machined
splines (Fig. 3). The other can be identified by a hex
opening (Fig. 4) and will not use splines.
Different special tools are required to service each
different decoupler. Refer to following procedure.INA Decoupler
(1) Disconnect negative battery cable.
(2) Remove generator and accessory drive belt.
Refer to Generator Removal.
(3) Position Special Tool #8823 (VM.1048) into
decoupler (Fig. 5).
(4) Determine if end of generator shaft is hex
shaped (Fig. 6) or is splined (Fig. 7). If hex is used,
Fig. 5 #8823 TOOL AND INA DECOUPLER
1 - INA DECOUPLER
2 - TOOL #8823 (VM.1048)
Fig. 6 END OF GENERATOR SHAFT (HEX)
1 - GENERATOR SHAFT
2 - HEX
Fig. 3 GENERATOR DECOUPLER PULLEY (INA)
1 - GENERATOR
2 - DECOUPLER (INA)
3 - MACHINED SPLINES
Fig. 4 GENERATOR DECOUPLER PULLEY (LITENS)
1 - DECOUPLER (LITENS)
2 - HEX OPENING
8F - 20 CHARGING SYSTEMVA
GENERATOR DECOUPLER PULLEY (Continued)

insert a 10MM deep socket into tool #8823 (VM.1048)
(Fig. 8). If splined, insert a 5/16º 6-point hex driver,
or a 10MM 12-point triple square driver into tool
#8823 (VM.1048) (Fig. 9).
(5) The generator shaft uses conventional right-
hand threads to attach decoupler. To break decoupler
loose from generator threads, rotate end of tool clock-
wise (Fig. 8) or, (Fig. 9).
(6) After breaking loose with tool, unthread decou-
pler by hand from generator.
Litens Decoupler
(1) Disconnect negative battery cable.
(2) Remove generator and accessory drive belt.
Refer to Generator Removal.
(3) Position Special Tool #8433 (Fig. 10) into
decoupler. Align to hex end of generator shaft.
(4) The generator shaft uses conventional right-
hand threads to attach decoupler. To break decoupler
loose from generator threads, rotate end of tool clock-
wise (Fig. 11).
(5) After breaking loose with tool, unthread decou-
pler by hand from generator.
INSTALLATION
INA Decoupler
(1) Thread decoupler pulley onto generator shaft
by hand (right-hand threads).
(2) Position Special Tool #8823 (VM.1048) into
decoupler (Fig. 5).
(3) Determine if end of generator shaft is hex
shaped (Fig. 6) or is splined (Fig. 7). If hex is used,
insert a 10MM deep socket into tool #8823 (VM.1048)
(Fig. 12). If splined, insert a 5/16º 6-point hex driver,
or a 10MM 12-point triple square driver into tool
#8823 (VM.1048) (Fig. 13).
Fig. 7 END OF GENERATOR SHAFT (SPLINED)
1 - GENERATOR SHAFT
2 - SPLINES
Fig. 8 DECOUPLER REMOVAL (INA-HEX)
1 - DEEP 10 MM SOCKET
2 - TOOL #8823 (VM.1048)
Fig. 9 DECOUPLER REMOVAL (INA-SPLINED)
1 - DRIVER
2 - TOOL #8823 (VM.1048)
3 - 17 MM WRENCH
VACHARGING SYSTEM 8F - 21
GENERATOR DECOUPLER PULLEY (Continued)

(4)Do not use an adjustable, ratcheting ªclick
typeº torque wrench. Most ªclick typeº
wrenches will only allow torque to be applied
in a clockwise rotation. Use a dial-type or
beam-type wrench.Tighten in counter-clockwise
rotation (Fig. 12) or, (Fig. 13). Refer to torque speci-
fications.
(5) Install accessory drive belt, and generator.
Refer to Generator Installation.
(6) Connect negative battery cable.Litens Decoupler
(1) Thread decoupler pulley onto generator shaft
by hand (right-hand threads).
Fig. 10 # 8433 TOOL AND LITENS DECOUPLER
Fig. 11 DECOUPLER REMOVAL (LITENS)
Fig. 12 DECOUPLER INSTALLATION (INA-HEX)
1 - 10MM DEEP SOCKET
2 - TOOL # 8823 (VM.1048)
Fig. 13 DECOUPLER INSTALLATION (INA SPLINED)
1 - DRIVER
2 - TOOL # 8823 (VM.1048)
8F - 22 CHARGING SYSTEMVA
GENERATOR DECOUPLER PULLEY (Continued)

(2) Position Special Tool 8433 (Fig. 10) into decou-
pler. Align tool to hex end of generator shaft.
(3)Do not use an adjustable, ratcheting ªclick
typeº torque wrench. Most ªclick typeº
wrenches will only allow torque to be applied
in a clockwise rotation. Use a dial-type or
beam-type wrench.Tighten in counter-clockwise
rotation (Fig. 14). Refer to torque specifications.
(4) Install accessory drive belt, and generator.
Refer to Generator Installation.
(5) Connect negative battery cable.VOLTAGE REGULATOR
DESCRIPTION
The electronic voltage regulator is attached to the
back of the generator. It is not serviced as a separate
component. If replacement is necessary, the generator
must be replaced.
Fig. 14 DECOUPLER INSTALLATION (Litens)
VACHARGING SYSTEM 8F - 23
GENERATOR DECOUPLER PULLEY (Continued)