engine MERCEDES-BENZ SPRINTER 2005 Service Owners Manual

REAR SIDE MARKER LAMP BULB
REMOVAL.............................21
INSTALLATION.........................21
REAR TURN LAMP BULB
REMOVAL.............................21
INSTALLATION.........................22
REPEATER LAMP BULB
REMOVAL.............................22
INSTALLATION.........................22REPEATER LAMP UNIT
REMOVAL.............................22
INSTALLATION.........................23
TAIL LAMP UNIT
REMOVAL.............................23
INSTALLATION.........................23
TURN SIGNAL RELAY
REMOVAL.............................24
INSTALLATION.........................24
LAMPS/LIGHTING - EXTERIOR
DESCRIPTION
The exterior lighting system for this model
includes the following exterior lamps:
²Backup Lamps- The backup (or reverse) lamps
are integral to the tail lamp units mounted to the
back of the quarter panel on each side of the tailgate
at the rear of the vehicle.
²Brake Lamps- The brake (or stop) lamps
include a bulb and reflector that are integral to the
tail lamp units mounted to the back of the quarter
panel on each side of the tailgate opening, and the
Center High Mounted Stop Lamp (CHMSL) that is
centered on the rear edge of the roof panel above the
tailgate opening.
²Daytime Running Lamps- Vehicles manufac-
tured for sale in Canada have a Daytime Running
Lamps (DRL) relay that illuminates the low beam
headlamp bulbs whenever the engine is running.
²Fog Lamps- Fog lamp bulbs and reflectors are
included in both front lamp units of vehicles
equipped with this option.
²Hazard Warning Lamps- The hazard warning
lamps include all of the right and left turn signal and
repeater lamps.
²Headlamps- Separate low beam and high
beam headlamp bulbs are installed in the front lamp
unit on each side of the front grille opening. A head-
lamp leveling actuator motor is also integral to each
front lamp unit.
²Park Lamps- The park lamps include the front
park/side marker lamps and front position lamps
that are integral to the front lamp units mounted on
either side of the front grille opening, as well as the
rear park lamps and rear side marker lamps that are
integral to the tail lamp units mounted to the back of
the quarter panel on each side of the tailgate open-
ing. Included in the park lamps circuit are two rear
license plate lamp units mounted on the left rear
tailgate door. The park lamps may also include
optional clearance lamps, which are located on each
side of a vehicle that is so equipped.
²Turn Signal Lamps- The turn signal lamps
include the front turn lamps that are integral to the
front lamp units, the rear turn lamps that are inte-
gral to the tail lamp units, and a repeater lampmounted to each front fender just above the front
wheel opening.
Other components of the exterior lighting system
for this model include:
²Brake Lamp Switch- A plunger-type brake
lamp switch is located on the steering column sup-
port bracket under the instrument panel and actu-
ated by the brake pedal arm.
²Daytime Running Lamp Relays- Vehicles
manufactured for sale in Canada have two Daytime
Running Lamps (DRL) relays. Dedicated right and
left side relays illuminate the low beam headlamp
bulb installed in each front lamp unit whenever the
engine is running. These relays are located in dedi-
cated vehicle wire harness connectors within the
driver side front seat riser.
²Fog Lamp Relay- Vehicles equipped with the
optional fog lamps have a fog lamp relay located in a
dedicated vehicle wire harness connector within the
driver side front seat riser.
²Fog Lamp Switch- A fog lamp switch is
mounted in the instrument cluster bezel, below the
cluster and outboard of the steering column on vehi-
cles equipped with this option.
²Headlamp Leveling Motor- A headlamp lev-
eling actuator motor is located on the back of each
headlamp housing and adjusts both the low beam
headlamp, high beam headlamp, and fog lamp (if
equipped) reflector frames in unison.
²Headlamp Leveling Switch- A thumbwheel
actuated headlamp leveling switch is mounted in the
instrument cluster bezel, below the cluster and out-
board of the steering column.
²Multi-Function Switch- The multi-function
switch is located on the top of the steering column,
just below the steering wheel. The multi-function
switch is connected directly to the fuse block located
below the steering column through an integral inter-
face connector. Only the left (lighting), right (wiper)
control stalks and the hazard warning switch button
for the multi-function switch are visible, the remain-
der of the switch is concealed beneath the steering
column shrouds. The multi-function switch includes a
left (lighting) control stalk and a right (wiper) control
stalk. The left control stalk is dedicated to providing
almost all of the driver controls for the exterior light-
ing system.
8L - 2 LAMPS/LIGHTING - EXTERIORVA

²Trailer Tow Connector- Vehicles equipped
with a factory-approved, field-installed trailer towing
electrical package have a heavy duty 7-way trailer
tow connector installed in a bracket on the trailer
hitch receiver. This package includes a 7-way to
4-way connector adapter unit.
²Trailer Tow Control Module- Vehicles
equipped with a factory-approved, field-installed
trailer towing electrical package have a trailer tow
brake/turn control module located within the driver
side front seat riser that controls the brake lamp and
turn signal lamp outputs to the trailer lighting cir-
cuits.
²Turn Signal Relay- A turn signal relay is
installed in the fuse block located on the underside of
the steering column behind a fuse access panel in the
steering column opening cover on the instrument
panel. The electronic circuitry of the wipers, turn sig-
nals and engine start control module within the fuse
block controls the turn signal relay.
²Wipers, Turn Signals, Engine Start Control
Module- The wipers, turn signals and engine start
control module is integral to the fuse block located on
the underside of the steering column behind a fuse
access panel in the steering column opening cover on
the instrument panel. This module includes active
electronic elements that control the operation of the
turn signal relay based upon inputs from the multi-
function switch and feedback from the turn signal
circuits. (Refer to 8 - ELECTRICAL/POWER DISTRI-
BUTION/FUSE BLOCK - DESCRIPTION).
Hard wired circuitry connects the exterior lighting
system components to the electrical system of the
vehicle. These hard wired circuits are integral to sev-
eral wire harnesses, which are routed throughout the
vehicle and retained by many different methods.
These circuits may be connected to each other, to the
vehicle electrical system and to the exterior lighting
system components through the use of a combination
of soldered splices, splice block connectors, and many
different types of wire harness terminal connectors
and insulators. Refer to the appropriate wiring infor-
mation. The wiring information includes wiring dia-
grams, proper wire and connector repair procedures,
further details on wire harness routing and reten-
tion, as well as pin-out and location views for the
various wire harness connectors, splices and grounds.
OPERATION
Following are paragraphs that briefly describe the
operation of each of the major exterior lighting sys-
tems. The hard wired circuits and components of the
exterior lighting systems may be diagnosed and
tested using conventional diagnostic tools and proce-
dures. However, conventional diagnostic methods
may not prove conclusive in the diagnosis of the wip-ers, turn signals and engine start control module
located within the fuse block underneath the steering
column, the ElectroMechanical Instrument Cluster
(EMIC), the Engine Control Module (ECM), or the
Controller Area Network (CAN) data bus network.
The most reliable, efficient, and accurate means to
diagnose the electronic module within the fuse block,
the EMIC, the ECM, and the CAN data bus network
inputs and outputs related to the various exterior
lighting systems requires the use of a DRBIIItscan
tool. Refer to the appropriate diagnostic information.
BACKUP LAMPS
The backup (or reverse) lamps have a path to
ground received at all times through the vehicle wire
harness from a ground point located on the frame
near the left end of the tailgate sill. The backup
lamps receive battery current on the backup lamp
supply circuit only when the backup lamp switch cir-
cuit of the Transmission Range Sensor (TRS) integral
to the gear shifter assembly is closed by the gear
shifter mechanism.
BRAKE LAMPS
The brake (or stop) lamps have a path to ground at
all times through the vehicle wire harness from a
ground point located on the frame near the left end
of the tailgate sill. The Center High Mounted Stop
Lamp (CHMSL) has a path to ground at all times
through the vehicle wire harness from a ground point
on the left side of the dash panel. The brake lamps
and CHMSL receive battery current on the brake
lamp switch output circuit when the brake lamp
switch is closed by the brake pedal arm.
DAYTIME RUNNING LAMPS
Vehicles manufactured for sale in Canada illumi-
nate the low beam headlamp bulb when the engine is
running and the exterior lamps are turned off. This
feature is enabled by the right and left Daytime Run-
ning Lamps (DRL) relays. When the DRL relays are
de-energized, they provide fused battery current from
the circuit K26 relay to the headlamp low beams.
When the headlamps are turned On using the left
(lighting) control stalk of the multi-function switch
the DRL relays are energized, which returns control
of the headlamps to the headlamp switch circuitry of
the multi-function switch. The circuit K26 relay is
energized by the Electro-Mechanical Instrument
Cluster (EMIC) whenever it receives an electronic
message from the Engine Control Module (ECM) over
the Controller Area Network (CAN) data bus indicat-
ing that the engine is running. The DRL and circuit
K26 relays are installed in a relay bracket located
below the forward edge of the driver side front seat
cushion within the driver side front seat riser.
VALAMPS/LIGHTING - EXTERIOR 8L - 3
LAMPS/LIGHTING - EXTERIOR (Continued)

FRONT FOG LAMPS
Vehicles equipped with optional front fog lamps
have a front fog lamp relay installed in a relay
bracket located below the forward edge of the driver
side front seat cushion within the driver side front
seat riser, a fog lamp switch installed in the cluster
bezel on the instrument panel outboard of the steer-
ing column, and a fog lamp bulb installed in each of
the two front lamp units. The front fog lamps have a
path to ground at all times through their connection
to the vehicle wire harness. The headlamp switch cir-
cuitry of the left (lighting) control stalk of the multi-
function switch controls front fog lamp operation by
providing battery current to the front fog lamp relay
only when the low beam headlamps are selected. The
fog lamp switch controls front fog lamp operation by
energizing or de-energizing the front fog lamp relay
control coil.
HAZARD WARNING LAMPS
With the hazard switch in the On position, the
hazard switch button illuminates and the right and
left turn signal indicators as well as the right and
left turn signal lamps begin to flash on and off. When
the hazard warning system is activated, the hazard
switch circuitry within the multi-function switch and
the wipers, turn signals and engine start control
module electronic circuitry within the fuse block will
repeatedly energize and de-energize the turn signal
relay located in the fuse block. The turn signal relay
switches battery current from a fused B(+) fuse in
the fuse block to the turn signal indicators and the
turn signal lamps. The flashing of the hazard switch
button illumination lamp is also controlled by the
output from the turn signal relay.
HEADLAMPS
The headlamp system includes the exterior lighting
switches integral to the left (lighting) control stalk of
the multi-function switch as well as the low and high
beam bulbs installed in the right and left front lamp
units (Fig. 1). The headlamp bulbs have a path to
ground at all times through the vehicle wire harness.
The exterior lighting switches control headlamp oper-
ation by providing battery current to the selected low
or high beam bulbs. Each front lamp unit includes
two integral adjustment screws to be used for static
horizontal and vertical aiming of the headlamp beam
reflectors.
HEADLAMP LEVELING
The headlamp leveling system includes a leveling
actuator motor integral to each front lamp unit, and
a rotary thumbwheel actuated headlamp leveling
switch in the cluster bezel on the instrument panel
outboard of the steering column. The headlamp lev-eling system allows the headlamp beam reflectors to
be adjusted to one of four vertical positions to com-
pensate for changes in inclination caused by the load-
ing of the vehicle suspension. The actuator motors
are mechanically connected through an integral
pushrod to an adjustable headlamp reflector. The
headlamp leveling switch is a resistor multiplexed
unit that provides one of four voltage outputs to the
headlamp leveling motors. The headlamp leveling
motors will move the headlamps to the selected posi-
tion based upon the voltage input received from the
switch. The headlamp leveling motors and switch
have a path to ground at all times. The headlamp
leveling components operate on battery current
received through the park lamps circuit so that the
system will only operate when the exterior lighting is
turned on.
PARK LAMPS
The park lamps system includes the exterior light-
ing switches integral to the left (lighting) control
stalk of the multi-function switch (Fig. 1), the front
park/side marker lamps, the front position lamps, the
rear park lamps, the rear side marker lamps, the
optional clearance lamps, and the license plate
lamps. Each of these lamps are provided with a path
to ground at all times through the vehicle wire har-
ness. The exterior lighting switches control the park
lamp operation by providing battery current through
the park lamps circuit to the appropriate lamp bulbs.
TURN SIGNAL LAMPS
When the left (lighting) control stalk of the multi-
function switch is activated (Fig. 1), the turn signal
Fig. 1 Lighting Switch
1 - LEFT TURN SIGNAL
2 - RIGHT TURN SIGNAL
3 -EXTERIOR LIGHTING
4 - BEAM SELECT (DIMMER)
5 - OPTICAL HORN
8L - 4 LAMPS/LIGHTING - EXTERIORVA
LAMPS/LIGHTING - EXTERIOR (Continued)

system illuminates the selected right or left turn sig-
nal indicator and the turn signal lamps begin to
flash. The turn signal lamps include a bulb integral
to each front lamp unit and each tail lamp unit, as
well as a repeater lamp bulb located on each front
fender above the front wheels. When the turn signal
system is activated, the turn signal switch circuitry
within the multi-function switch and the electronic
circuitry of the wipers, turn signals and engine start
control module within the fuse block will repeatedly
energize and de-energize the turn signal relay
located in the fuse block. The turn signal relay
switches battery current from a fused ignition switch
output fuse in the fuse block to the appropriate turn
signal indicator and turn signal lamps.
The ElectroMechanical Instrument Cluster (EMIC)
contactless relay will generate repetitive, audible
turn signal ªclickº sounds to emulate the sounds of a
conventional electro-mechanical turn signal flasher
at one of two rates to coincide with the flashing of
the turn signals. The slow rate emulates normal turn
signal operation, while the fast rate emulates ªbulb
outº turn signal operation.
SPECIFICATIONS - LAMPS/LIGHTING -
EXTERIOR
BULB SPECIFICATIONS
LAMP BULB
Backup P21W - 12V 21W
Brake & Rear Park P21/5W - 12V 21/5W
Center High Mounted
StopP21W - 12V 21W
Clearance W3W - 12V 3W
Front Fog H1 - 12V 55W
Front Position W5W - 12V 5W
Front Turn, Park & Side
Marker3457 NA - 12V 28/7.5W
Amber Glass
Low Beam Headlamp H7 - 12V 55W
High Beam Headlamp H1 - 12V 55W
License Plate C5W - 12V 5W
Rear Side Marker R5W - 12V 5W
Rear Turn P21W - 12V 21W
Side Repeater W5W - 12V 3W
BACKUP LAMP BULB
REMOVAL
(1) Disconnect and isolate the battery negative
cable.(2) If the vehicle is so equipped, remove the trim
from the inside of the right or left rear corner pillar.
(3) From inside the vehicle, use hand pressure to
push the two latch tabs toward the center of the tail
lamp unit socket plate and pull the socket plate
straight out from the inner rear pillar (Fig. 2).
(4) Pull the socket plate away from the inner rear
pillar far enough to access the backup lamp bulb
(Fig. 3).
(5) Remove the backup lamp bulb from the tail
lamp socket plate.
Fig. 2 Tail Lamp Socket Plate Remove/Install
1 - SOCKET PLATE
2 - INNER REAR PILLAR
3 - LATCH TAB (2)
Fig. 3 Tail Lamp Bulb Remove/Install
1 - BRAKE/PARK LAMP BULB
2 - BACKUP LAMP BULB
3 - TURN SIGNAL LAMP BULB
4 - SIDE MARKER LAMP BULB
5 - TAIL LAMP SOCKET PLATE
VALAMPS/LIGHTING - EXTERIOR 8L - 5
LAMPS/LIGHTING - EXTERIOR (Continued)

(3) From the back of the cluster bezel, squeeze the
two latches on the fog lamp switch body and push
the switch out through the face of the bezel (Fig. 17).
(4) Remove the fog lamp switch from the face of
the cluster bezel.
INSTALLATION
(1) Position the fog lamp switch to the proper
mounting hole on the face of the cluster bezel (Fig.
16).
(2) Using hand pressure, push the fog lamp switch
firmly and evenly into the switch mounting hole of
the cluster bezel until both of the latches on the
switch body are fully engaged.
(3) Reinstall the cluster bezel onto the instrument
panel. (Refer to 23 - BODY/INSTRUMENT PANEL/
CLUSTER BEZEL - INSTALLATION).
(4) Reconnect the battery negative cable.
FRONT LAMP UNIT
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the front grille from the vehicle. (Refer
to 23 - BODY/EXTERIOR/GRILLE - REMOVAL).
(3) Remove the two screws that secure the cover at
the inboard side of the front lamp unit (Fig. 18).
(4) Remove the cover from the front lamp unit.
(5) From the engine compartment, disconnect the
vehicle wire harness connector from the connector
receptacle for the front lamp unit.
(6) Remove the four screws that secure the front
lamp unit to the front of the vehicle.(7) Remove the front lamp unit from the front of
the vehicle.
INSTALLATION
(1) Position the front lamp unit to the front of the
vehicle (Fig. 18).
(2) Install and tighten the four screws that secure
the front lamp unit to the front of the vehicle.
(3) From the engine compartment, reconnect the
vehicle wire harness connector to the connector
receptacle for the front lamp unit.
(4) Position the cover to the front lamp unit.
(5) Install and tighten the two screws that secure
the cover at the inboard side of the front lamp unit.
(6) Reinstall the front grille onto the vehicle.
(Refer to 23 - BODY/EXTERIOR/GRILLE - INSTAL-
LATION).
(7) Reconnect the battery negative cable.
(8) Check and adjust the front lamp alignment as
required. (Refer to 8 - ELECTRICAL/LAMPS/LIGHT-
ING - EXTERIOR/FRONT LAMP UNIT - ADJUST-
MENTS).
ADJUSTMENTS
ADJUSTMENT - FRONT LAMP UNIT
VEHICLE PREPARATION FOR FRONT LAMP UNIT
ALIGNMENT
(1) Verify headlamp dimmer (multi-function)
switch, fog lamp switch (if equipped), and high beam
indicator operation.
(2) Verify that the headlamp leveling switch is in
the ª0º position.
Fig. 17 Fog Lamp Switch Remove/Install
1 - FOG LAMP SWITCH
2 - LATCH (2)
3 - CLUSTER BEZEL
Fig. 18 Front Lamp Unit Remove/Install
1 - SCREW (2)
2 - COVER
3 - SCREW (4)
4 - LAMP UNIT
5 - WIRE HARNESS CONNECTOR
8L - 12 LAMPS/LIGHTING - EXTERIORVA
FOG LAMP SWITCH (Continued)

TURN SIGNAL RELAY
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS,
DISABLE THE SUPPLEMENTAL RESTRAINT SYSTEM
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, DRIVER AIRBAG, PASSENGER
AIRBAG, SEAT BELT TENSIONER, OR INSTRUMENT
PANEL COMPONENT DIAGNOSIS OR SERVICE. DIS-
CONNECT AND ISOLATE THE BATTERY NEGATIVE
(GROUND) CABLE, THEN WAIT TWO MINUTES FOR
THE SYSTEM CAPACITOR TO DISCHARGE BEFORE
PERFORMING FURTHER DIAGNOSIS OR SERVICE.
THIS IS THE ONLY SURE WAY TO DISABLE THE SUP-
PLEMENTAL RESTRAINT SYSTEM. FAILURE TO TAKE
THE PROPER PRECAUTIONS COULD RESULT IN
ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the fuse access panel from the steering
column opening cover below the steering column on
the instrument panel.
(3) Reach through and below the inboard side of
the fuse access opening to access the turn signal
relay (Fig. 47).(4) Remove the turn signal relay by grasping it
firmly, releasing the latches and pulling it straight
down from the receptacle on the bottom of the fuse
block.
INSTALLATION
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER, OR
INSTRUMENT PANEL COMPONENT DIAGNOSIS OR
SERVICE. DISCONNECT AND ISOLATE THE BAT-
TERY NEGATIVE (GROUND) CABLE, THEN WAIT
TWO MINUTES FOR THE SYSTEM CAPACITOR TO
DISCHARGE BEFORE PERFORMING FURTHER
DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE
WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
(1) Position the turn signal relay to the receptacle
on the bottom of the fuse block (Fig. 47).
(2) Align the turn signal relay terminals with the
terminal cavities in the fuse block receptacle.
(3) Push firmly and evenly on the top of the turn
signal relay until the terminals are fully seated in
the terminal cavities in the receptacle of the fuse
block and both latches are fully engaged.
(4) Reinstall the fuse access panel onto the steer-
ing column opening cover below the steering column
on the instrument panel.
(5) Reconnect the battery negative cable.
Fig. 47 Turn Signal Relay
1 - STEERING COLUMN OPENING COVER
2 - FUSE BLOCK
3 - LOWER INSTRUMENT PANEL
4 - TURN SIGNAL RELAY
5 - ENGINE CONTROL MODULE RELAY
6 - WIPER RELAY
8L - 24 LAMPS/LIGHTING - EXTERIORVA

POWER SYSTEMS
TABLE OF CONTENTS
page page
POWER LOCKS............................ 1
POWER MIRRORS......................... 3POWER WINDOWS......................... 5
POWER LOCKS
TABLE OF CONTENTS
page page
POWER LOCKS
DESCRIPTION..........................1
DOOR LOCK MOTOR
REMOVAL.............................1
INSTALLATION..........................1
REMOTE KEYLESS ENTRY TRANSMITTER
DESCRIPTION..........................2MASTER LOCK SWITCH
DESCRIPTION..........................2
DIAGNOSIS AND TESTING - MASTER LOCK
SWITCH.............................2
REMOVAL.............................2
INSTALLATION..........................2
POWER LOCKS
DESCRIPTION
CENTRAL LOCKING
The central locking system locks all vehicle doors if
any door is locked from the inside or mechanically
locked with the key from the outside. the master door
lock switch on the instrument panel enables the
operator to lock/unlock all doors.
REMOTE KEYLESS ENTRY
The SKREEM is a combination of the Remote Key-
less Entry (RKE) module and the Sentry Key Immo-
bilizer (SKIM) module. It is located behind the
instrument cluster and has an antenna that mounts
to the A-pillar.
AUTO DOOR LOCKS
Whenever the engine is started, the CTM receivers
a message to lock all doors except the drivers door.
This is accomplished through a relay. The relay is
controlled by the Instrument Cluster which receives
a command from the ECM.
ACCIDENT RESPONSE
The CTM is hardwired to the Airbag Control Mod-
ule through the Enhanced Accident Report Driver cir-
cuit. Anytime the vehicles airbags are deployed, the
CTM will unlock all doors and a ªcrashº DTC will be
stored in memory. The door locks will be inoperative
until that code is cleared.
DOOR LOCK MOTOR
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the door trim panel.
(3) Remove the door lock.
(4) Remove the door lock motor from the door lock.
INSTALLATION
(1) Install the door lock motor to the door lock.
(2) Install the door lock.
(3) Install the door trim panel.
(4) Connect the battery negative cable.
VAPOWER SYSTEMS 8N - 1

an electronic impact sensor, and an energy storage
capacitor. The ACM housing has three integral
mounting tabs. A stamped metal cover plate is per-
manently secured to the bottom of the ACM housing
to enclose and protect the internal electronic circuitry
and components. An arrow printed on a label on the
top of the ACM housing near the rear provides a
visual verification of the proper orientation of the
unit, and should always be pointed toward the front
of the vehicle. A molded plastic electrical connector
receptacle containing numerous terminal pins is inte-
gral to the left facing side of the ACM housing. These
terminal pins connect the ACM to the vehicle electri-
cal system through a dedicated take out and connec-
tor of the vehicle wire harness.
The impact sensor internal to the ACM is cali-
brated for the specific vehicle, and is only serviced as
a unit with the ACM. The ACM cannot be repaired or
adjusted and, if damaged or faulty, it must be
replaced.
OPERATION
The microprocessor in the Airbag Control Module
(ACM) contains the supplemental restraint system
logic circuits and controls all of the supplemental
restraint system components. The ACM uses
On-Board Diagnostics (OBD) and can communicate
with the DRBIIItscan tool using a diagnostic Serial
Communication Interface (SCI) data bus line for sup-
plemental restraint system programming or diagno-
sis and testing through the 16-way Data Link
Connector (DLC) located on the dash panel below the
driver side end of the instrument panel. A hard wired
output from the ACM is used for control of the airbag
indicator in the ElectroMechanical Instrument Clus-
ter (EMIC). (Refer to 8 - ELECTRICAL/INSTRU-
MENT CLUSTER/AIRBAG INDICATOR -
OPERATION).
The ACM microprocessor continuously monitors all
of the supplemental restraint system electrical cir-
cuits to determine the system readiness. If the ACM
detects a monitored system fault, it sets an appropri-
ate Diagnostic Trouble Code (DTC) and sends an out-
put to the EMIC to turn on the airbag indicator. The
ACM illuminates the indicator for about four seconds
each time the ignition switch is turned to the On
position as a bulb test. If the indicator remains illu-
minated for about ten seconds after the ignition
switch is turned to the On position, the ACM has
detected a non-critical fault that poses no danger to
the vehicle occupants. If the airbag indicator illumi-
nates solid (not flashing) while driving or stays on
longer than ten seconds following the bulb test, the
ACM has detected a critical fault that may cause the
airbags not to deploy when required or to deploy
when not required. An active fault only remains forthe duration of the fault, or in some cases, for the
duration of the current ignition switch cycle, while a
stored fault causes a DTC to be stored in memory by
the ACM.
The ACM receives battery current through a fused
ignition switch output circuit. The ACM receives
ground through a ground circuit and take out of the
vehicle wire harness. This take out has an eyelet ter-
minal connector secured by a nut to a ground stud on
the floor panel directly below the ACM within the
driver side seat riser. A case ground is also provided
for the ACM through a ground circuit and eyelet ter-
minal connector secured under the left rear ACM
mounting screw. These connections allow the ACM to
be operational whenever the ignition switch is in the
On position. The ACM also contains an energy-stor-
age capacitor. When the ignition switch is in the On
position, this capacitor is continually being charged
with enough electrical energy to deploy the supple-
mental restraint components for up to one second fol-
lowing a battery disconnect or failure. The purpose of
the capacitor is to provide backup supplemental
restraint system protection in case there is a loss of
battery current supply to the ACM during an impact.
An electronic impact sensor is contained within the
ACM. The electronic impact sensor is an accelerome-
ter that senses the rate of vehicle deceleration, which
provides verification of the direction and severity of
an impact. A pre-programmed decision algorithm in
the ACM microprocessor determines when the decel-
eration rate as signaled by the impact sensor indi-
cates an impact that is severe enough to require
supplemental restraint system protection. When the
programmed conditions are met, the ACM sends the
proper electrical signals to deploy the seat belt ten-
sioners and front airbags.
The ACM also provides a hard wired electrical
crash signal output following a supplemental
restraint deployment event. This output is used to
signal other electronic modules in the vehicle to pro-
vide their enhanced accident response features,
which include automatically disabling the engine
from running and unlocking all of the doors. How-
ever, these responses are each dependent upon the
circuits, components, and modules controlling these
features remaining intact from collateral damage
incurred during the vehicle impact.
A single ACM is used for all variations of the sup-
plemental restraint system available in this vehicle.
This ACM is programmable and in order to function
properly it must be programmed for the correct vehi-
cle supplemental restraint system equipment using
an initialization procedure. The initialization proce-
dure requires the use of a DRBIIItscan tool. Refer to
the appropriate diagnostic information. The hard
wired inputs and outputs for the ACM may be diag-
VARESTRAINTS 8O - 9
AIRBAG CONTROL MODULE (Continued)

SPEED CONTROL
TABLE OF CONTENTS
page page
SPEED CONTROL
DESCRIPTION..........................1
OPERATION............................1
SPECIFICATIONS
TORQUE.............................2
CABLE
DESCRIPTION..........................3SERVO
DESCRIPTION..........................3
SWITCH
REMOVAL.............................3
INSTALLATION..........................3
SPEED CONTROL
DESCRIPTION
The speed control system is electronically con-
trolled by the Engine Control Module (ECM).A
cable and a vacuum controlled servo are not
used. This is a servo-less system.Control of the
system is accomplished by a 4-position, instrument
panel mounted switch (Fig. 1).
Switch settings (Fig. 2) are:
²1. Set / Accelerate
²2. Resume Set Speed
²3. Set / Decelerate
²4. Off
The system is designed to operate at speeds above
25 mph (40 km/h).
WARNING: THE USE OF SPEED CONTROL IS NOT
RECOMMENDED WHEN DRIVING CONDITIONS DO
NOT PERMIT MAINTAINING A CONSTANT SPEED,
SUCH AS IN HEAVY TRAFFIC OR ON ROADS THAT
ARE WINDING, ICY, SNOW COVERED, OR SLIP-
PERY.
OPERATION
When speed control operation is selected by the
speed control switch, the ECM (Engine Control Mod-
ule) allows a set speed to be stored in its RAM for
speed control. To store a set speed, press either of the
SET switch functions while the vehicle is moving,
and above 25 mph (40 km/h). In order for the speed
control to engage, the brakes cannot be applied, nor
can the gear selector be indicating the transmission
is in Park or Neutral.
The speed control can be disengaged manually by:
²Stepping on the brake pedal
²Pressing the speed control switch to OFF
²Depressing the clutch pedal (if equipped).NOTE: Depressing the OFF switch or turning off the
ignition switch will erase the set speed stored in
the ECM.
For added safety, the speed control system is pro-
grammed to disengage for any of the following condi-
tions:
²An indication of Park or Neutral
²A rapid increase rpm (indicates that the clutch
has been disengaged)
²Excessive engine rpm (indicates that the trans-
mission may be in a low gear)
²The speed signal increases at a rate of 10 mph
per second (indicates that the coefficient of friction
between the road surface and tires is extremely low)
²The speed signal decreases at a rate of 10 mph
per second (indicates that the vehicle may have
decelerated at an extremely high rate)
Fig. 1 INSTRUMENT CLUSTER
1 - COVER
2 - BEZEL
3 - INSTRUMENT CLUSTER
4 - STEERING WHEEL
5 - MULTI-FUNCTION SWITCH
6 - SPEED CONTROL SWITCH
VASPEED CONTROL 8P - 1

CABLE
DESCRIPTION
A cable and a vacuum controlled servo are not used
with this package. This is a cable-less, servo-less sys-
tem. The speed control system is electronically con-
trolled by the Engine Control Module (ECM).
SERVO
DESCRIPTION
A vacuum controlled servo and control cable are
not used with this package. This is a cable-less, ser-
vo-less system. The speed control system is electron-
ically controlled by the Engine Control Module
(ECM).
SWITCH
REMOVAL
The speed control switch is mounted to the back of
the multi-function switch (Fig. 3). The multi-function
switch must be removed first to gain access to the
speed control switch mounting screw.
(1) Remove and isolate negative battery cable from
battery.
(2) Remove multi-function switch. Refer to Multi-
Function Switch Removal/Installation.
(3) Remove switch mounting screw (Fig. 4).
(4) Remove speed control switch from multi-func-
tion switch.
(5) Unplug pigtail electrical connector (Fig. 3) from
instrument panel wiring harness.
INSTALLATION
The speed control switch is mounted to the back of
the multi-function switch (Fig. 3).
(1) Position speed control switch to back of multi-
function switch.
(2) Install switch mounting screw (Fig. 4). Refer to
Torque Specifications.
Install multi-function switch. Refer to Multi-Func-
tion Switch Removal/Installation.
(3) Plug pigtail electrical connector (Fig. 3) into
instrument panel wiring harness. Be sure wires are
not pinched.
(4) Install negative battery cable to battery.
Fig. 3 SPEED CONTROL SWITCH LOCATION
1 - SWITCH HANDLE
2 - PIGTAIL ELECTRICAL CONNECTOR
3 - MULTI-FUNCTION SWITCH
Fig. 4 SPEED CONTROL SWITCH REMOVAL /
INSTALLATION
1 - SWITCH MOUNTING SCREW (1)
2 - SPEED CONTROL SWITCH
3 - SWITCH HANDLE
4 - MULTI-FUNCTION SWITCH
VASPEED CONTROL 8P - 3