key MERCEDES-BENZ SPRINTER 2006 Repair Manual

Symptom:
P1610-ENGINE CONTROL RELAY SHUTS OFF TOO LATE
When Monitored and Set Condition:
P1610-ENGINE CONTROL RELAY SHUTS OFF TOO LATE
When Monitored: During after-run.
Set Condition: The internal ECM timer determines that the Engine Control Relay
remains on for more than 2.0 seconds after the ECM has turned off the Engine Control
Relay.
POSSIBLE CAUSES
CHECK FOR OTHER DTCS
INTERMITTENT CONDITION
SUBSTITUTE ENGINE CONTROL RELAY
ENGINE CONTROL RELAY CONTROL CIRCUIT SHORTED TO GROUND INTERMITTENTLY
ENGINE CONTROL RELAY OUTPUT CIRCUIT SHORTED TO VOLTAGE
ENGINE CONTROL MODULE
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRB, check for additional DTCs.
Are other DTCs present?All
Ye s!Refer to the Symptom List for diagnosis of the other DTCs before
continuing.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 2
2NOTE: If the ECM detects and stores a DTC, the ECM also stores the
engine/vehicle operating conditions under which the DTC was set. Some of
these conditions are displayed on the DRB at the same time the DTC is
displayed.
NOTE: Before erasing stored DTCs, record these conditions. Attempting to
duplicate these conditions may assist when checking for an active DTC.
Turn the ignition on.
With the DRB, erase ECM DTCs.
Perform several ignition key cycles, pausing for at least 10 seconds between each
cycle.
Turn the ignition on.
With the DRB, read ECM DTCs.
Did this DTC set again?All
Ye s!Go To 3
No!Go To 6
91
DRIVEABILITY - DIESEL

TEST ACTION APPLICABILITY
3 Turn the ignition off.
Install a substitute relay in place of the Engine Control Relay.
Turn the ignition on.
With the DRBIIIt, erase DTCs.
Perform several ignition key cycles, pausing for at least 10 seconds between each
cycle.
Turn the ignition on.
With the DRB, read ECM DTCs.
Did this DTC set again?All
Ye s!Go To 4
No!Replace the Engine Control Relay.
Perform ROAD TEST VERIFICATION - VER-2.
4 Turn the ignition off.
Remove the Engine Control Relay.
Disconnect the ECM harness connectors.
Measure the resistance between ground and the Engine Control Relay Control circuit
while wiggling the wiring harness and connectors.
Was the resistance below 1000.0 ohms at any time while wiggling the wiring harness
and connectors?All
Ye s!Repair the Engine Control Relay Control circuit for an intermit-
tent short to ground.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 5
5 Turn the ignition off.
Remove the Engine Control Relay.
Turn the ignition on.
Measure the voltage of the Engine Control Relay Output circuit.
Is the voltage below 0.5 volt?All
Ye s!Replace and program the Engine Control Module in accordance
with the Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
No!Repair the Engine Control Relay Output circuit for a short to
voltage.
Perform ROAD TEST VERIFICATION - VER-2.
92
DRIVEABILITY - DIESEL
P1610-ENGINE CONTROL RELAY SHUTS OFF TOO LATE ÐContinued

Symptom List:
P2025-INTAKE PRESSURE SENSOR SIGNAL VOLTAGE TOO HIGH
P2030-INTAKE PRESSURE SENSOR CIRCUIT FAULT
P2030-INTAKE PRESSURE SENSOR OPEN CIRCUIT
P2030-INTAKE PRESSURE SENSOR SIGNAL VOLTAGE TOO HIGH
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be P2025-INTAKE PRESSURE
SENSOR SIGNAL VOLTAGE TOO HIGH.
POSSIBLE CAUSES
INTERMITTENT CONDITION
INTAKE PRESSURE SENSOR GROUND CIRCUIT SHORTED TO VOLTAGE
INTAKE PRESSURE SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE
INTAKE PRESSURE SENSOR GROUND CIRCUIT OPEN
INTAKE PRESSURE SENSOR
ENGINE CONTROL MODULE (INTERNAL)
ENGINE CONTROL MODULE (SENSOR SIGNAL SHORTED TO VOLTAGE)
TEST ACTION APPLICABILITY
1NOTE: If the ECM detects and stores a DTC, the ECM also stores the
engine/vehicle operating conditions under which the DTC was set. Some of
these conditions are displayed on the DRB at the same time the DTC is
displayed.
NOTE: Before erasing stored DTCs, record these conditions. Attempting to
duplicate these conditions may assist when checking for an active DTC.
NOTE: Ensure all turbocharger inlet and outlet tubes are connected prop-
erly, without damage and restriction before continuing with this test. Also
ensure the Boost Pressure Servo Motor and Servo Motor rod are attached
and functioning properly.
Turn the ignition on.
With the DRB, erase ECM DTCs.
Cycle the ignition key on and off several times, leaving the key on for at least 10
seconds at a time.
With the DRB, read ECM DTCs.
Did this DTC set again?All
Ye s!Go To 2
No!Go To 7
128
DRIVEABILITY - DIESEL

Symptom List:
P2025-INTAKE PRESSURE SENSOR SIGNAL VOLTAGE TOO LOW
P2030-INTAKE PRESSURE SENSOR SIGNAL VOLTAGE TOO LOW
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be P2025-INTAKE PRESSURE
SENSOR SIGNAL VOLTAGE TOO LOW.
POSSIBLE CAUSES
INTERMITTENT CONDITION
INTAKE PRESSURE SENSOR 5 VOLT SUPPLY
INTAKE PRESSURE SENSOR
INTAKE PRESSURE SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
INTAKE PRESSURE SENSOR SIGNAL AND GROUND CIRCUITS SHORTED TOGETHER
ENGINE CONTROL MODULE
INTAKE PRESSURE SENSOR SIGNAL CIRCUIT OPEN
TEST ACTION APPLICABILITY
1NOTE: If the ECM detects and stores a DTC, the ECM also stores the
engine/vehicle operating conditions under which the DTC was set. Some of
these conditions are displayed on the DRB at the same time the DTC is
displayed.
NOTE: Before erasing stored DTCs, record these conditions. Attempting to
duplicate these conditions may assist when checking for an active DTC.
NOTE: Ensure all turbocharger inlet and outlet tubes are connected prop-
erly, without damage and restriction before continuing with this test. Also
ensure the Boost Pressure Servo Motor and Servo Motor rod are attached
and functioning properly.
Turn the ignition on.
With the DRB, erase ECM DTCs.
Cycle the ignition key on and off several times, leaving the key on for at least 10
seconds at a time.
With the DRB, read ECM DTCs.
Did this DTC set again?All
Ye s!Go To 2
No!Go To 7
2 Turn the ignition off.
Disconnect the Intake Pressure Sensor harness connector.
Turn the ignition on.
Measure the voltage between ground and the Intake Pressure Sensor 5 Volt Supply
circuit.
Is the voltage above 4.8 volts?All
Ye s!Go To 3
No!Repair the Intake Pressure Sensor 5 Volt Supply circuit for an
open.
Perform ROAD TEST VERIFICATION - VER-2.
131
DRIVEABILITY - DIESEL

NO START VERIFICATION - VER-1 APPLICABILITY
1. NOTE: IMPORTANT! If the Engine Control Module or Sentry Key Immobilizer
Module has been replaced, ensure the programming procedure for the module has
been performed in accordance with the Service Information.
2. Inspect the vehicle to ensure that all engine components are properly installed and
connected. Reassemble and reconnect components as necessary.
3. Inspect the engine oil for contamination. If it is contaminated, change the oil and filter.
4. With the DRB, erase all diagnostic trouble codes (DTCs).
5. Turn the ignition off for at least 10 seconds.
6. Attempt to start the engine.
7. If the engine is unable to start, look for any Technical Service Bulletins (TSBs) that may
relate to this condition. Return to the Symptom List if necessary.
8. If the engine starts and continues to run, the repair is now complete.
Are any DTCs or symptoms remaining?All
Ye s!Repair is not complete, refer to appropriate symptom.
No!Repair is complete.
ROAD TEST VERIFICATION - VER-2 APPLICABILITY
1. Inspect the vehicle to ensure that all engine components are properly installed and
connected. Reassemble and reconnect components as necessary.
2. If this verification procedure is being performed after a non-DTC test, perform steps 3 and
4. If not, proceed to step 5.
3. Check to see if the initial symptom still exists. If there are no trouble codes and the symptom
no longer exists, the repair was successful and testing is now complete.
4. If the initial or another symptom exists, the repair is not complete. Check all pertinent
Technical Service Bulletins (TSBs) and return to the Symptom List if necessary.
5. For previously read DTCs that have not been dealt with, return to the Symptom List and
follow the diagnostic path for that DTC; otherwise, continue.
6. If the Engine Control Module (ECM) has not been changed, perform steps 7 and 8, otherwise,
continue with step 9.
7. With the DRB IIIt, erase all diagnostic trouble codes (DTCs), then disconnect the DRB IIIt.
8. Turn the ignition off for at least 10 seconds.
9. If equipped with a Transfer Case Position Switch, perform step 10, otherwise, continue with
step 11.
10. With the ignition switch on, place the Transfer Case Shift Lever in each gear position,
stopping for 15 seconds in each position.
11. Ensure no DTCs remain by performing steps 12 through 15.
12. Road test the vehicle. For some of the road test, go at least 64 km/h (40 MPH). If this test
is for an A/C Relay Control Circuit, drive the vehicle for at least 5 minutes with the A/C on.
13. At some point, stop the vehicle and turn the engine off for at least 10 seconds, then restart
the engine and continue.
14. Upon completion of the road test, turn the engine off and check for DTCs with the DRB IIIt.
15. If the repaired DTC has set again, the repair is not complete. Check for any pertinent
Technical Service Bulletins (TSBs) and return to the Symptom List. If there are no DTCs, the
repair was successful and is now complete.
Are any DTCs or symptoms remaining?All
Ye s!Repair is not complete, refer to appropriate symptom.
No!Repair is complete.
247
VERIFICATION TESTS
Verification Tests ÐContinued

(6) Start the engine in the vehicle which has the
booster battery, let the engine idle a few minutes,
then start the engine in the vehicle with the dis-
charged battery.
CAUTION: Do not crank starter motor on disabled
vehicle for more than 15 seconds, starter will over-
heat and could fail.
(7) Allow battery in disabled vehicle to charge to
at least 12.4 volts (75% charge) before attempting to
start engine. If engine does not start within 15 sec-
onds, stop cranking engine and allow starter to cool
(15 min.), before cranking again.
DISCONNECT CABLE CLAMPS AS FOLLOWS:
²Disconnect BLACK cable clamp from engine
ground on disabled vehicle.
²When using a Booster vehicle, disconnect
BLACK cable clamp from battery negative terminal.
Disconnect RED cable clamp from battery positive
terminal.
²Disconnect RED cable clamp from battery posi-
tive terminal on disabled vehicle.
TOWING
STANDARD PROCEDURE - TOWING
WARNING: Do not tow the vehicle if the key cannot
be turned in the ignition lock. If the key cannot be
turned, the ignition lock remains locked and the
vehicle cannot be steered. With the engine not run-
ning there is no power assistance for the braking
and steering systems. In this case, it is important to
keep in mind that a considerably higher degree of
effort is necessary to brake and steer the vehicle.
The vehicle must not be towed with the front axle
raised and the key in position 2 in the ignition lock
as the drive wheels could then lock due to the
acceleration skid control (ASR)
If the Engine is Damaged
For towing distances up to 30 miles (about 50
km)
²Shift selector lever in ªNº position.
²Do not exceed a towing speed of 30 m.p.h. (50
km/h).
For towing distances greater than 30 mile
(about 50 km)
²Remove the propeller shafts leading to the drive
axles. The vehicle can be towed without restriction.
If the Transmission is Damaged
²Remove the propeller shafts leading to the drive
axles. The vehicle can be towed without restriction.
If the Front Axle is Damaged
²Raise the front axle.
²Observe the same towing restrictions as for
engine damage.
If the Rear Axle is Damaged
²Raise the rear axle.
NOTE: Comply with local legal regulations regard-
ing towing vehicles.
SAFETY PRECAUTIONS
NOTE: The following safety precautions must be
observed when towing a vehicle.
²Secure loose and protruding parts.
²Always use a safety chain system that is inde-
pendent of the lifting and towing equipment.
²Do not allow towing equipment to contact the
disabled vehicle's fuel tank.
²Do not allow anyone under the disabled vehicle
while it is lifted by the towing device.
²Do not allow passengers to ride in a vehicle
being towed.
²Always observe state and local laws regarding
towing regulations.
²Do not tow a vehicle in a manner that could
jeopardize the safety of the operator, pedestrians or
other motorists.
²Do not attach tow chains, T-hooks, J-hooks, or a
tow sling to a bumper, steering linkage, drive shafts
or a non-reinforced frame hole.
²Remove exhaust pipe tips that interfere with the
tow sling and crossbar
²Padding should be placed between the tow sling/
crossbar and any painted surfaces
²When placing tow hooks on the rear axle, posi-
tion them so they do not damage the brake tubing or
hoses
²Do not tow the vehicle by connecting to the front
or rear shock absorbers
²Do not tow a heavily loaded vehicle. Damage to
the vehicle may result. Use a flatbed device to trans-
port a loaded vehicle.
GROUND CLEARANCE
CAUTION: If vehicle is towed with wheels removed,
install lug nuts to retain brake drums.
A towed vehicle should be raised until lifted wheels
are a minimum 100 mm (4 in) from the ground. Be
sure there is adequate ground clearance at the oppo-
site end of the vehicle, especially when towing over
rough terrain, steep rises in the road or if the vehicle
is equipped with air dams, spoilers, and/or ground
VALUBRICATION & MAINTENANCE 0 - 7

effect panels. If necessary, remove the wheels from
the lifted end of the vehicle and lower the vehicle
closer to the ground, to increase the ground clearance
at the opposite end of the vehicle. Install lug nuts on
wheel attaching studs to retain brake drums.
RAMP ANGLE
If a vehicle with flat-bed towing equipment is used,
the approach ramp angle should not exceed 15
degrees.
TOWING WHEN KEYS ARE NOT AVAILABLE
When the vehicle is locked and keys are not avail-
able, use a flat bed hauler. A Wheel-lift or Sling-type
device can be used provided all the wheels are lifted
off the ground using tow dollies.
MAINTENANCE SCHEDULES
DESCRIPTION
The use of special lubricant additives is not recom-
mended. The use of such additives may affect the
warranty rights. With regard to legal stipulations
concerning emissions control, please note that
engines have to be serviced and adjusted in accor-
dance with special instructions and using special
measuring equipment. Modifications to or interfer-
ence with the emissions control systems are not per-
missible.
MAINTENANCE - WITHOUT ASSYST MAINTE-
NANCE COMPUTER
Maintenance Intervals
²Oil service ±Normal Operationevery 10,000
miles or 16,000 km or 12 months.
²Maintenance service every 30,000 miles or
48,000 km.
Additional work must be carried out at yearly
intervals.
MAINTENANCE - WITH ASSYST MAINTENANCE
COMPUTER
ASSYST provides information on the best possible
timing for maintenance work.
When the next maintenance service is due, this
will be indicated in the multi-function display with
the wrench icon symbol displayed in km/miles or
days.
²One wrench icon showing indicates Oil Service
is necessary.
²Two wrench icons showing indicates Mainte-
nance Service is necessary ± displayed in km/miles or
days.
If the display shows the number of days, a clock
symbol will also appear in the multi-function display.You should have the maintenance performed
within the stated period/distance.
The service indicator will be reset after an oil ser-
vice and/or maintenance service has been performed.
REGULAR CHECK - UPS
To maintain the safe operation of the vehicle, it is
recommended that the following tasks be performed
on a regular basis (i.e. weekly or whenever the vehi-
cle is refueled). Check:
²Engine oil level
²Brake system - fluid level
²Battery - acid level
²Windshield washer system and headlamp clean-
ing system - fluid level
²Mechanical assemblies (e.g. engine, transmis-
sion, etc.) - check for leaks
²Condition of tires and tires pressures
²All exterior lights
SPECIAL MAINTENANCE REQUIREMENTS
If bodies built by manufacturers other than
DaimlerChrysler Corporation are fitted to the vehi-
cle, the maintenance requirements and lubrication
intervals specified by the body manufacturer must be
adhered to, in addition to all standard maintenance
requirements.
Coolant
Corrosion inhibitor/antifreeze concentration in the
coolant should be checked before the onset of winter
(once year in countries with high prevailing temper-
atures).
Replace the coolant every five years or 100,000
miles.
Dust Filter for Heating / Ventilation Replacement
The dust filter and the tailgate interior filter are to
be renewed during routine maintenance service. If
operating conditions are dusty, these filters should be
renewed more frequently.
ENGINE OIL CHANGE AND FILTER REPLACEMENT
At a minimum, change the engine oil and oil filter
once a year ± even if the vehicle mileage per year is
extremely low. For standard oil service schedules
refer to the chapter oil service and maintenance ser-
vice.
Once a Year
Select the viscosity of the engine oil (SAE classes)
according to the outside air temperature.
Only use engine oil approved by DaimlerChrysler
Corporation if following the ASSYST system guide-
lines.
0 - 8 LUBRICATION & MAINTENANCEVA

the status of the driver side front seat belt. This
audible warning occurs independent of the visual
warning provided by the EMIC ªSeatbeltº indicator.
²Lights-On Warning- The EMIC chime tone
generator will generate repetitive chime tones at a
fast rate when either front door is opened with the
ignition switch in any position except On, and the
exterior lights are turned On. The EMIC uses inter-
nal programming and hard wired inputs from the left
(lighting) control stalk of the multi-function switch,
the ignition switch, and both front door jamb
switches to determine the current status of these
switches. This chime will continue to sound until the
exterior lighting is turned Off, until the ignition
switch is turned to the On position, or until both
front doors are closed, whichever occurs first.
²Key-In-Ignition Warning- The EMIC chime
tone generator will generate repetitive chime tones at
a fast rate when the key is in the ignition lock cylin-
der, the ignition switch is in any position except On,
and either front door is opened. The EMIC uses
internal programming and hard wired inputs from
the key-in ignition switch, the ignition switch, and
both front door jamb switches to determine the cur-
rent status of these switches. The chime will con-
tinue to sound until the key is removed from the
ignition lock cylinder, until the ignition switch is
turned to the On position, or until both front doors
are closed, whichever occurs first.
²Audible Turn Signal/Hazard Warning Sup-
port- The EMIC contactless relay will generate
repetitive clicks at a slow rate during normal turn
signal/hazard warning operation, or at a fast rate
when a turn signal lamp bulb or circuit is inopera-
tive, in concert with the operation of the turn signal
indicators in the cluster. These clicks are designed to
emulate the sound of the opening and closing of the
contact points in a conventional electromechanical
turn signal or hazard warning flasher. The EMIC
uses a hard wired input received from the turn sig-
nal relay in the fuse block beneath the steering col-
umn through the turn signal or hazard warning
switch circuitry of the multi-function switch to deter-
mine when to flash the turn signal indicators and
activate the contactless relay on the cluster electronic
circuit board. The turn signal clicks will continue to
sound until the turn signal switch is turned Off, or
until the ignition switch is turned to the Off position,
whichever occurs first. The hazard warning clicks
will continue to sound until the hazard warning
switch is turned Off.
The EMIC provides chime service for all available
features in the chime warning system. The EMIC relies
upon its internal programming and hard wired inputs
from the front door ajar switches, the key-in ignition
switch, the ignition switch, the seat belt switch, and the
turn signal/hazard warning (multi-function) switches.
The EMIC relies upon electronic message inputsreceived from other electronic modules over the CAN
data bus network to provide chime service for the low
engine oil level warning. Upon receiving the proper
inputs, the EMIC activates the chime tone generator or
the contactless relay to provide the audible warning to
the vehicle operator. The internal programming of the
EMIC determines the priority of each chime request
input that is received, as well as the rate and duration
of each tone that is to be generated. See the owner's
manual in the vehicle glove box for more information on
the features provided by the chime warning system.
The hard wired chime warning system inputs to
the EMIC, as well as other hard wired circuits for
this system may be diagnosed and tested using con-
ventional diagnostic tools and procedures. However,
conventional diagnostic methods may not prove con-
clusive in the diagnosis of the EMIC, the CAN data
bus network, or the electronic message inputs used
by the EMIC to provide chime warning system ser-
vice. The most reliable, efficient, and accurate means
to diagnose the EMIC, the CAN data bus network,
and the electronic message inputs for the chime
warning system requires the use of a diagnostic scan
tool. Refer to the appropriate diagnostic information.
DIAGNOSIS AND TESTING - CHIME WARNING
SYSTEM
WARNING: To avoid personal injury or death, on
vehicles equipped with airbags, disable the supple-
mental restraint system before attempting any
steering wheel, steering column, airbag, seat belt
tensioner, or instrument panel component diagno-
sis or service. Disconnect and isolate the battery
negative (ground) cable, then wait two minutes for
the system capacitor to discharge before perform-
ing further diagnosis or service. This is the only
sure way to disable the supplemental restraint sys-
tem. Failure to take the proper precautions could
result in accidental airbag deployment.
The hard wired chime warning system inputs to
the ElectroMechanical Instrument Cluster (EMIC),
as well as other hard wired circuits for this system
may be diagnosed and tested using conventional
diagnostic tools and procedures. However, conven-
tional diagnostic methods may not prove conclusive
in the diagnosis of the EMIC, the Controller Area
Network (CAN) data bus network, or the electronic
message inputs used by the EMIC to provide chime
warning system service. The most reliable, efficient,
and accurate means to diagnose the EMIC, the CAN
data bus network, and the electronic message inputs
for the chime warning system requires the use of a
diagnostic scan tool. Refer to the appropriate diag-
nostic information.
8B - 2 CHIME/BUZZERVA

ELECTRONIC CONTROL MODULES
TABLE OF CONTENTS
page page
CENTRAL TIMER MODULE
DESCRIPTION..........................1
OPERATION............................1
DIAGNOSIS AND TESTING - CENTRAL TIMER
MODULE.............................2
REMOVAL.............................2
INSTALLATION..........................3
CONTROLLER ANTILOCK BRAKE
DESCRIPTION..........................3
REMOVAL.............................3INSTALLATION..........................3
ENGINE CONTROL MODULE
DESCRIPTION..........................3
REMOVAL.............................6
INSTALLATION..........................6
TRANSMISSION CONTROL MODULE
DESCRIPTION..........................6
OPERATION............................7
STANDARD PROCEDURE - TCM ADAPTATION . 10
CENTRAL TIMER MODULE
DESCRIPTION
The central timer module (CTM) is located beneath
the driver seat. The CTM uses information carried on
the programmable communications interface (PCI)
data bus network along with many hard wired inputs
to monitor many sensor and switch inputs. In
response to those inputs, the circuitry and program-
ming of the CTM allow it to supply the vehicle occu-
pants with audible and visual information, and to
control and integrate many functions and features of
the vehicle through both hard wired outputs and the
transmission of message outputs to other modules in
the vehicle over the PCI data bus.
The features that the CTM supports or controls
include the following:
²Central Locking- The CTM on vehicles
equipped with the optional Vehicle Theft Security
System (VTSS) includes a central locking/unlocking
feature.
²Enhanced Accident Response- The CTM pro-
vides an optional enhanced accident response fea-
ture. This is a programmable feature.
²Panic Mode- The CTM provides support for
the optional RKE system panic mode including horn,
headlamp, and park lamp flash features.
²Power Lock Control- The CTM provides the
optional power lock system features, including sup-
port for the automatic door lock and door lock inhibit
modes.
²Programmable Features- The CTM provides
support for certain programmable features.
²Remote Keyless Entry- The CTM provides
the optional Remote Keyless Entry (RKE) system fea-
tures, including support for the RKE Lock (with
optional horn and park lamps flash), Unlock (with
park lamps flash, driver-door-only unlock, andunlock-all-doors), Panic, and illuminated entry
modes, as well as the ability to be programmed to
recognize up to four RKE transmitters. The RKE
horn, driver-door-only unlock, and unlock-all-doors
features are programmable.
²Vehicle Theft Security System- The CTM
provides control of the optional Vehicle Theft Secu-
rity System (VTSS) features, including support for
the central locking/unlocking mode and control of the
Security indicator in the instrument cluster.
Hard wired circuitry connects the CTM to the elec-
trical system of the vehicle. Refer to the appropriate
wiring information.
Many of the features in the vehicle controlled or
supported by the CTM are programmable using the
DRBIIItscan tool. However, if any of the CTM hard-
ware components are damaged or faulty, the entire
CTM unit must be replaced. The hard wired inputs
or outputs of all CTM versions can be diagnosed
using conventional diagnostic tools and methods;
however, for diagnosis of the CTM or the PCI data
bus, the use of a DRBIIItscan tool is required. Refer
to the appropriate diagnostic information.
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
VAELECTRONIC CONTROL MODULES 8E - 1

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: To avoid personal injury or death, on
vehicles equipped with airbags, disable the supple-
mental restraint system before attempting any
steering wheel, steering column, airbag, seat belt
tensioner, or instrument panel component diagno-
sis or service. Disconnect and isolate the battery
negative (ground) cable, then wait two minutes for
the system capacitor to discharge before perform-
ing further diagnosis or service. This is the only
sure way to disable the supplemental restraint sys-tem. Failure to take the proper precautions could
result in accidental airbag deployment.
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.
8E - 2 ELECTRONIC CONTROL MODULESVA