Brake JEEP GRAND CHEROKEE 2003 WJ / 2.G Workshop Manual

(4) Turn the ignition switch to the Off position.
Check for continuity between the ground circuit cav-
ity of the overhead wire harness connector for the
automatic day/night mirror and a good ground. There
should be continuity. If OK, go to Step 5. If not OK,
repair the open ground circuit to ground as required.
(5) Turn the ignition switch to the On position. Set
the parking brake. Place the transmission gear selec-
tor lever in the Reverse position. Check for battery
voltage at the backup lamp switch output circuit cav-
ity of the overhead wire harness connector for the
automatic day/night mirror. If OK, reconnect the
overhead wire harness connector to the automatic
day/night mirror connector receptacle and go to Step
6. If not OK, repair the open backup lamp switch
output circuit as required.
(6) Place the transmission gear selector lever in
the Neutral position. Place the automatic day/night
mirror switch in the Auto (LED next to the switch is
lighted) position (Fig. 1). Cover the forward facing
ambient photocell sensor to keep out any ambient
light.
NOTE: The ambient photocell sensor must be cov-
ered completely, so that no light reaches the sen-
sor. Use a finger pressed tightly against the sensor,
or cover the sensor completely with electrical tape.
(7) Shine a light into the rearward facing head-
lamp photocell sensor. The automatic day/night mir-
ror should darken. If OK, go to Step 8. If not OK,
replace the faulty automatic day/night mirror unit.
(8) With the mirror darkened, place the transmis-
sion gear selector lever in the Reverse position. The
automatic day/night mirror should return to its nor-
mal reflectance. If not OK, replace the faulty auto-
matic day/night mirror unit.POWER FOLD-AWAY MIRROR -
EXPORT
DESCRIPTION
Some vehicles are equipped with Power Fold-Away
Side View Mirrors. This feature allows both the
driver and passenger side view mirrors to fold
inward (retract) on demand. This feature is con-
trolled by an additional switch located on the power
mirror switch.
The fold-away side view mirror is attached to the
vehicle's door in the same manner as mirrors without
the fold-away option. The fold-away mirrors unique
option is the internal motor which allows the mirrors
to fold inward on demand. the fold-away mirror
motor is not serviceable separately, and if a motor is
found to be faulty the entire side view mirror must
be replaced.
OPERATION
When the mirror retract switch is depressed, both
of the side view mirrors will fold inward, thus mak-
ing the overall width of the vehicle the smallest pos-
sible. This can be very helpful where parking space is
an absolute minimum.
DIAGNOSIS AND TESTING - POWER
FOLD-AWAY MIRROR - EXPORT
The most reliable, efficient and accurate means to
diagnose the power mirror system requires the use of
a DRB scan tool and the proper Diagnostic Proce-
dures manual. The DRB scan tool can provide confir-
mation that the PCI data bus is functional, that all
of the electronic modules are sending and receiving
the proper messages on the PCI data bus, that the
power mirror motors are being sent the proper hard
wired outputs, and that the mirror position potenti-
ometers are returning the proper outputs to the door
modules for them to perform their power mirror sys-
tem functions.
REMOVAL
The fold-away mirror motor is not serviceable sep-
arately, and if a motor is found to be faulty the entire
side view mirror must be replaced. (Refer to 8 -
ELECTRICAL/POWER MIRRORS/SIDEVIEW MIR-
ROR - REMOVAL).
Fig. 1 Automatic Day/Night Mirror
1 - LED INDICATOR
2 - SWITCH
3 - HEADLAMP SENSOR
8N - 14 POWER MIRRORSWJ
AUTOMATIC DAY/NIGHT MIRROR (Continued)

ACTIVE RESTRAINTS
The active restraints for this model include:
²Front Seat Belts- Both front seating positions
are equipped with three-point seat belt systems
employing a lower B-pillar mounted inertia latch-
type retractor, height-adjustable upper B-pillar
mounted turning loops, a fixed lower seat belt anchor
secured to the lower B-pillar, and a fixed end-release
seat belt buckle secured to the side of the floor panel
transmission tunnel. Both front seat belt buckles
include an integral Hall-effect seat belt switch that
detects whether its respective seat belt has been fas-
tened.
²Rear Seat Belts- Both outboard rear seating
positions are equipped with three-point seat belt sys-
tems. The outboard seating position belts employ a
lower C-pillar mounted inertia latch-type retractor,
height-adjustable upper C-pillar mounted turning
loops, and a fixed lower seat belt anchor secured to
the floor panel. The center rear seating position of
vehicles manufactured for sale in North America has
a lap belt that is anchored to the rear floor panel
with the right outboard seat belt buckle. Vehicles
manufactured for sale outside of North America are
equipped with a three-point seat belt in the rear seat
center seating position. This seat belt has an inertia
latch-type retractor that is integral to the rear seat
back panel, and the lower belt anchor is secured to
the rear floor panel with the right outboard seat belt
buckle. A cable from the seat back latch locks the
center belt retractor spool unless the seat back is
fully latched. All three rear seat belts have fixed end-
release seat belt buckles secured to the rear floor
panel, a single buckle unit on the right side and a
double buckle unit on the left side.
²Child Seat Tether Anchors- All vehicles are
equipped with three, fixed-position, child seat upper
tether anchors and two lower anchors. Two upper
anchors are integral to the back of the right rear seat
back panel, and one is integral to the left rear seat
back panel. The two lower anchors are integral to the
outboard rear seat back brackets.
PASSIVE RESTRAINTS
The passive restraints available for this model
include the following:
²Dual Front Airbags- Multistage driver and
front passenger airbags are available for this model.
This airbag system is a passive, inflatable, Supple-
mental Restraint System (SRS) and vehicles with
this equipment can be readily identified by the ªSRS
- AIRBAGº logo molded into the driver airbag trim
cover in the center of the steering wheel and also
into the passenger airbag door area of the instru-
ment panel top pad above the glove box (Fig. 2).
Vehicles with the airbag system can also be identifiedby the airbag indicator, which will illuminate in the
instrument cluster for about seven seconds as a bulb
test each time the ignition switch is turned to the On
position.
²Side Curtain Airbags- Optional side curtain
airbags are available for this model when it is also
equipped with dual front airbags. This airbag system
is a passive, inflatable, Supplemental Restraint Sys-
tem (SRS) and vehicles with this equipment can be
readily identified by a molded identification trim but-
ton with the ªSRS - AIRBAGº logo located on the
headliner above each B-pillar (Fig. 2).
The supplemental restraint system includes the
following major components, which are described in
further detail elsewhere in this service information:
²Airbag Control Module- The Airbag Control
Module (ACM) is also sometimes referred to as the
Occupant Restraint Controller (ORC). The ACM is
located on a mount on the floor panel transmission
tunnel near the park brake release mechanism,
under the center floor console.
²Airbag Indicator- The airbag indicator is inte-
gral to the ElectroMechanical Instrument Cluster
(EMIC), which is located on the instrument panel in
front of the driver.
²Clockspring- The clockspring is located near
the top of the steering column, directly beneath the
steering wheel.
²Driver Airbag- The driver airbag is located in
the center of the steering wheel, beneath the driver
airbag trim cover.
²Driver Knee Blocker- The driver knee blocker
is a structural unit secured to the back side of and
integral to the instrument panel steering column
opening cover.
²Front Impact Sensor- Two front impact sen-
sors are used on vehicles equipped with dual front
airbags, one left side and one right side. One sensor
is located on a bracket on the lower inboard side of
each vertical member of the radiator support.
Fig. 2 SRS Logo
WJRESTRAINTS 8O - 3
RESTRAINTS (Continued)

(4) Check to be certain that nobody is in the vehi-
cle, then reconnect the battery negative cable.
(5) Using the DRBIIIt, read and record the active
(current) Diagnostic Trouble Code (DTC) data.
(6) Next, use the DRBIIItto read and record any
stored (historical) DTC data.
(7) If any DTC is found in Step 5 or Step 6, refer
to the appropriate diagnostic information.
(8) Use the DRBIIItto erase the stored DTC data.
If any problems remain, the stored DTC data will not
erase. Refer to the appropriate diagnostic informa-
tion to diagnose any stored DTC that will not erase.
If the stored DTC information is successfully erased,
go to Step 9.
(9) Turn the ignition switch to the Off position for
about fifteen seconds, and then back to the On posi-
tion. Observe the airbag indicator in the instrument
cluster. It should light for six to eight seconds, and
then go out. This indicates that the supplemental
restraint system is functioning normally and that the
repairs are complete. If the airbag indicator fails to
light, or lights and stays on, there is still an active
supplemental restraint system fault or malfunction.
Refer to the appropriate diagnostic information to
diagnose the problem.
AIRBAG CONTROL MODULE
DESCRIPTION
The Airbag Control Module (ACM) is also some-
times referred to as the Occupant Restraint Control-
ler (ORC) (Fig. 6). The ACM is concealed underneath
the center floor console, where it is secured by four
screws to a stamped steel mounting bracket welded
onto the top of the floor panel transmission tunnel
just forward of the park brake mechanism in the pas-
senger compartment of the vehicle.
Concealed within a hollow in the center of the die
cast aluminum ACM housing is the electronic cir-
cuitry of the ACM which includes a microprocessor,
an electronic impact sensor, an electronic safing sen-
sor, and an energy storage capacitor. A stamped
metal cover plate is secured to the bottom of the
ACM housing with four screws to enclose and protect
the internal electronic circuitry and components. A
printed label on the top of the ACM housing provides
a visual verification of the proper orientation of the
unit, and should always be pointed toward the front
of the vehicle.
Two molded plastic electrical connector receptacles
exit the forward side of the ACM housing. These two
receptacles connect the ACM to the vehicle electrical
system through a dedicated take out and connector of
the instrument panel wire harness, and a dedicated
take out and connector of the airbag overlay wire
harness. For vehicles equipped with the optional side
curtain airbags, both ACM connector receptacles are
black in color and the ACM contains a second bi-di-
rectional safing sensor for the side airbags. For vehi-
cles not equipped with the optional side curtain
airbags, the ACM connector receptacles are both
gray.
The impact sensor and safing sensor internal to
the ACM are calibrated for the specific vehicle, and
are 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 other electronic modules in the vehicle as well
as with the DRBIIItscan tool using the Programma-
ble Communications Interface (PCI) data bus net-
work. This method of communication is used for
control of the airbag indicator in the ElectroMechani-
cal Instrument Cluster (EMIC) and for supplemental
restraint system diagnosis and testing through the
16-way data link connector located on the driver side
lower edge of the instrument panel. (Refer to 8 -
ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/COMMUNICATION - OPERATION).
Fig. 6 Airbag Control Module
1 - AIRBAG CONTROL MODULE
2 - ORIENTATION ARROW
3 - LABEL
4 - MOUNTING HOLES (4)
5 - CONNECTOR RECEPTACLE (2)
WJRESTRAINTS 8O - 9
RESTRAINTS (Continued)

WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, FRONT IMPACT SENSOR,
SIDE IMPACT SENSOR, SIDE CURTAIN AIRBAG, 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.
WARNING: THE AIRBAG CONTROL MODULE CON-
TAINS THE IMPACT SENSOR, WHICH ENABLES
THE SYSTEM TO DEPLOY THE SUPPLEMENTAL
RESTRAINTS. NEVER STRIKE OR DROP THE AIR-
BAG CONTROL MODULE, AS IT CAN DAMAGE THE
IMPACT SENSOR OR AFFECT ITS CALIBRATION. IF
AN AIRBAG CONTROL MODULE IS ACCIDENTALLY
DROPPED DURING SERVICE, THE MODULE MUST
BE SCRAPPED AND REPLACED WITH A NEW UNIT.
FAILURE TO OBSERVE THIS WARNING COULD
RESULT IN ACCIDENTAL, INCOMPLETE, OR
IMPROPER SUPPLEMENTAL RESTRAINT DEPLOY-
MENT AND POSSIBLE OCCUPANT INJURIES.
(1) Disconnect and isolate the battery negative
cable. Wait two minutes for the system capacitor to
discharge before further service.
(2) Remove the center console from the top of the
floor panel transmission tunnel. (Refer to 23 - BODY/
INTERIOR/FLOOR CONSOLE - REMOVAL).
(3) Remove the two nuts that secure the center
console bracket to the studs on the floor panel trans-
mission tunnel just forward of the Airbag Control
Module (ACM) (Fig. 7).
(4) Remove the center console bracket from the
two studs on the floor panel transmission tunnel.
(5) Disconnect the airbag overlay wire harness
connector for the ACM from the ACM connector
receptacle (Fig. 8). To disconnect the airbag overlay
wire harness connector from the ACM:
(a) Slide the red Connector Position Assurance
(CPA) lock on the top of the connector toward the
front of the vehicle.
(b) Depress the forward edge of the CPA lock to
release the connector latch tab and pull the connec-
tor straight away from the ACM connector recepta-
cle.(6) Disconnect the instrument panel wire harness
connector for the ACM from the ACM connector
receptacle.
Fig. 7 Center Console Bracket Remove/Install
1 - SHIFTER
2 - NUT (2)
3 - BRACKET
4 - PARK BRAKE LEVER
5 - AIRBAG CONTROL MODULE
6 - FLOOR PANEL TRANSMISSION TUNNEL
7 - INSTRUMENT PANEL WIRE HARNESS
Fig. 8 Airbag Control Module Connector
1 - INSTRUMENT PANEL WIRE HARNESS CONNECTOR
2 - LATCH TAB
3 - CPA LOCK
4 - AIRBAG OVERLAY WIRE HARNESS CONNECTOR
5 - AIRBAG CONTROL MODULE
WJRESTRAINTS 8O - 11
AIRBAG CONTROL MODULE (Continued)

SPEED CONTROL
TABLE OF CONTENTS
page page
SPEED CONTROL
DESCRIPTION..........................1
OPERATION............................1
DIAGNOSIS AND TESTING - ROAD TEST.....2
SPECIFICATIONS
TORQUE - SPEED CONTROL.............3
CABLE
DESCRIPTION..........................3
OPERATION............................3
REMOVAL
REMOVAL - 4.0L.......................3
REMOVAL - 4.7L.......................3
INSTALLATION
INSTALLATION - 4.0L...................4
INSTALLATION - 4.7L...................4
SERVO
DESCRIPTION..........................5OPERATION............................5
REMOVAL.............................5
INSTALLATION..........................6
SWITCH
DESCRIPTION..........................7
OPERATION............................7
REMOVAL.............................7
INSTALLATION..........................7
VACUUM RESERVOIR
DESCRIPTION..........................8
OPERATION............................8
DIAGNOSIS AND TESTING - VACUUM
RESERVOIR..........................8
REMOVAL.............................8
INSTALLATION..........................9
SPEED CONTROL
DESCRIPTION
The speed control system is electronically con-
trolled and vacuum operated. Electronic control of
the speed control system is integrated into the Pow-
ertrain Control Module (PCM). The controls consist
of two steering wheel mounted switches. The
switches are labeled: ON/OFF, RES/ACCEL, SET,
COAST, and CANCEL.
The system is designed to operate at speeds above
30 mph (50 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 is selected by depressing the
ON switch, the PCM allows a set speed to be stored
in PCM RAM for speed control. To store a set speed,
depress the SET switch while the vehicle is moving
at a speed between 35 and 85 mph. 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
²Depressing the OFF switch
²Depressing the CANCEL switch.
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 PCM.
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)
WJSPEED CONTROL 8P - 1

²The speed signal decreases at a rate of 10 mph
per second (indicates that the vehicle may have
decelerated at an extremely high rate)
Once the speed control has been disengaged,
depressing the RES/ACCEL switch (when speed is
greater than 30 mph) restores the vehicle to the tar-
get speed that was stored in the PCM.
While the speed control is engaged, the driver can
increase the vehicle speed by depressing the RES/AC-
CEL switch. The new target speed is stored in the
PCM when the RES/ACCEL is released. The PCM
also has a9tap-up9feature in which vehicle speed
increases at a rate of approximately 2 mph for each
momentary switch activation of the RES/ACCEL
switch.
A ªtap downº feature is used to decelerate without
disengaging the speed control system. To decelerate
from an existing recorded target speed, momentarily
depress the COAST switch. For each switch activa-
tion, speed will be lowered approximately 1 mph.
OVERSHOOT/UNDERSHOOT
If the vehicle operator repeatedly presses and
releases the SET button with their foot off of the
accelerator (referred to as a ªlift foot setº), the vehicle
may accelerate and exceed the desired set speed by
up to 5 mph (8 km/h). It may also decelerate to less
than the desired set speed, before finally achieving
the desired set speed.
The Speed Control System has an adaptive strat-
egy that compensates for vehicle-to-vehicle variations
in speed control cable lengths. When the speed con-
trol is set with the vehicle operators foot off of the
accelerator pedal, the speed control thinks there is
excessive speed control cable slack and adapts
accordingly. If the ªlift foot setsº are continually used,
a speed control overshoot/undershoot condition will
develop.
To ªunlearnº the overshoot/undershoot condition,
the vehicle operator has to press and release the set
button while maintaining the desired set speed using
the accelerator pedal (not decelerating or accelerat-
ing), and then turning the cruise control switch to
the OFF position (or press the CANCEL button if
equipped) after waiting 10 seconds. This procedure
must be performed approximately 10±15 times to
completely unlearn the overshoot/undershoot condi-
tion.DIAGNOSIS AND TESTING - ROAD TEST
Perform a vehicle road test to verify reports of
speed control system malfunction. The road test
should include attention to the speedometer. Speed-
ometer operation should be smooth and without flut-
ter at all speeds.
Flutter in the speedometer indicates a problem
which might cause surging in the speed control sys-
tem. The cause of any speedometer problems should
be corrected before proceeding. Refer to Group 8J,
Instrument Cluster for speedometer diagnosis.
If a road test verifies a system problem and the
speedometer operates properly, check for:
²A Diagnostic Trouble Code (DTC). If a DTC
exists, conduct tests per the Powertrain Diagnostic
Procedures service manual.
²A misadjusted brake (stop) lamp switch. This
could also cause an intermittent problem.
²Loose, damaged or corroded electrical connec-
tions at the servo. Corrosion should be removed from
electrical terminals and a light coating of Mopar
MultiPurpose Grease, or equivalent, applied.
²Leaking vacuum reservoir.
²Loose or leaking vacuum hoses or connections.
²Defective one-way vacuum check valve.
²Secure attachment of both ends of the speed con-
trol servo cable.
²Smooth operation of throttle linkage and throttle
body air valve.
²Failed speed control servo. Do the servo vacuum
test.
CAUTION: When test probing for voltage or conti-
nuity at electrical connectors, care must be taken
not to damage connector, terminals or seals. If
these components are damaged, intermittent or
complete system failure may occur.
8P - 2 SPEED CONTROLWJ
SPEED CONTROL (Continued)

(8) Connect negative battery cable at battery.
(9) Before starting engine, operate accelerator
pedal to check for any binding.
SERVO
DESCRIPTION
The servo unit consists of a solenoid valve body,
and a vacuum chamber. The solenoid valve body con-
tains three solenoids:
²Vacuum
²Vent
²Dump
The vacuum chamber contains a diaphragm with a
cable attached to control the throttle linkage.
OPERATION
The Powertrain Control Module (PCM) controls the
solenoid valve body. The solenoid valve body controls
the application and release of vacuum to the dia-
phragm of the vacuum servo. The servo unit cannot
be repaired and is serviced only as a complete assem-
bly.
Power is supplied to the servo's by the PCM
through the brake switch. The PCM controls the
ground path for the vacuum and vent solenoids.The dump solenoid is energized anytime it receives
power. If power to the dump solenoid is interrupted,
the solenoid dumps vacuum in the servo. This pro-
vides a safety backup to the vent and vacuum sole-
noids.
The vacuum and vent solenoids must be grounded
at the PCM to operate. When the PCM grounds the
vacuum servo solenoid, the solenoid allows vacuum
to enter the servo and pull open the throttle plate
using the cable. When the PCM breaks the ground,
the solenoid closes and no more vacuum is allowed to
enter the servo. The PCM also operates the vent sole-
noid via ground. The vent solenoid opens and closes a
passage to bleed or hold vacuum in the servo as
required.
The PCM duty cycles the vacuum and vent sole-
noids to maintain the set speed, or to accelerate and
decelerate the vehicle. To increase throttle opening,
the PCM grounds the vacuum and vent solenoids. To
decrease throttle opening, the PCM removes the
grounds from the vacuum and vent solenoids. When
the brake is released, if vehicle speed exceeds 30
mph to resume, 35 mph to set, and the RES/ACCEL
switch has been depressed, ground for the vent and
vacuum circuits is restored.
REMOVAL
The speed control servo is attached to a bracket.
The bracket and servo assembly are located below
the battery tray.
(1) Disconnect negative battery cable at battery.
(2) Disconnect positive battery cable at battery.
(3) Remove air cleaner housing at top of throttle
body and disconnect servo cable at throttle body.
Refer to Servo Cable Removal/Installation.
(4) Remove battery from battery tray.
(5) Disconnect wiring at battery tray.
(6) Disconnect positive battery cable at Power Dis-
tribution Center (PDC).
(7) Loosen PDC at battery tray.
(8) Remove 4 battery tray bolts. One of these bolts
attaches to speed control bracket flange that sup-
ports battery tray. While removing battery tray, dis-
connect battery temperature sensor electrical
connector at sensor.
(9) Disconnect vacuum line at servo vacuum hose
fitting (Fig. 5) .
(10) Disconnect electrical connector at servo (Fig.
5) .
If servo and mounting bracket are being removed
as one assembly, remove two mounting nuts (Fig. 5) .
These are located above right-front tire. Remove
inner fender clips and pry inner fender back slightly
to gain access to mounting nuts.
Fig. 4 Speed Control Cable at BracketÐ4.7L V-8
Engine
1 - PLASTIC CABLE MOUNT
2 - SPEED CONTROL CABLE
3 - BRACKET
4 - SLIDE FOR REMOVAL
WJSPEED CONTROL 8P - 5
CABLE (Continued)

SWITCH
DESCRIPTION
There are two separate switch pods that operate
the speed control system. The steering-wheel-
mounted switches use multiplexed circuits to provide
inputs to the PCM for ON, OFF, RESUME, ACCEL-
ERATE, SET, DECEL and CANCEL modes. Refer to
the owner's manual for more information on speed
control switch functions and setting procedures.
The individual switches cannot be repaired. If one
switch fails, the entire switch module must be
replaced.
OPERATION
When speed control is selected by depressing the
ON, OFF switch, the PCM allows a set speed to be
stored in its RAM for speed control. To store a set
speed, depress the SET switch while the vehicle is
moving at a speed between approximately 35 and 85
mph. 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
²Depressing the OFF switch
²Depressing the CANCEL switch.
The speed control can be disengaged also by any of
the following conditions:
²An indication of Park or Neutral
²The VSS signal increases at a rate of 10 mph
per second (indicates that the co-efficient of friction
between the road surface and tires is extremely low)
²Depressing the clutch pedal.
²Excessive engine rpm (indicates that the trans-
mission may be in a low gear)
²The VSS signal decreases at a rate of 10 mph
per second (indicates that the vehicle may have
decelerated at an extremely high rate)
²If the actual speed is not within 20 mph of the
set speed
The previous disengagement conditions are pro-
grammed for added safety.
Once the speed control has been disengaged,
depressing the ACCEL switch restores the vehicle to
the target speed that was stored in the PCM's RAM.
NOTE: Depressing the OFF switch will erase the set
speed stored in the PCM's RAM.
If, while the speed control is engaged, the driver
wishes to increase vehicle speed, the PCM is pro-
grammed for an acceleration feature. With the
ACCEL switch held closed, the vehicle accelerates
slowly to the desired speed. The new target speed is
stored in the PCM's RAM when the ACCEL switch isreleased. The PCM also has a9tap-up9feature in
which vehicle speed increases at a rate of approxi-
mately 2 mph for each momentary switch activation
of the ACCEL switch.
The PCM also provides a means to decelerate with-
out disengaging speed control. To decelerate from an
existing recorded target speed, depress and hold the
COAST switch until the desired speed is reached.
Then release the switch. The ON, OFF switch oper-
ates two components: the PCM's ON, OFF input, and
the battery voltage to the brake switch, which powers
the speed control servo.
Multiplexing
The PCM sends out 5 volts through a fixed resistor
and monitors the voltage change between the fixed
resistor and the switches. If none of the switches are
depressed, the PCM will measure 5 volts at the sen-
sor point (open circuit). If a switch with no resistor is
closed, the PCM will measure 0 volts (grounded cir-
cuit). Now, if a resistor is added to a switch, then the
PCM will measure some voltage proportional to the
size of the resistor. By adding a different resistor to
each switch, the PCM will see a different voltage
depending on which switch is pushed.
Another resistor has been added to the 'at rest cir-
cuit' causing the PCM to never see 5 volts. This was
done for diagnostic purposes. If the switch circuit
should open (bad connection), then the PCM will see
the 5 volts and know the circuit is bad. The PCM will
then set an open circuit fault.
REMOVAL
WARNING: BEFORE BEGINNING ANY AIRBAG SYS-
TEM COMPONENT REMOVAL OR INSTALLATION,
REMOVE AND ISOLATE THE NEGATIVE (-) CABLE
FROM THE BATTERY. THIS IS THE ONLY SURE
WAY TO DISABLE THE AIRBAG SYSTEM. THEN
WAIT TWO MINUTES FOR SYSTEM CAPACITOR TO
DISCHARGE BEFORE FURTHER SYSTEM SERVICE.
FAILURE TO DO THIS COULD RESULT IN ACCIDEN-
TAL AIRBAG DEPLOYMENT AND POSSIBLE
INJURY.
(1) Disconnect and isolate negative battery cable.
(2) Remove airbag module. Refer to Group 8M,
Passive Restraint Systems.
(3) Remove electrical connector at switch.
(4) Remove switch-to-steering wheel mounting
screw (Fig. 7) .
(5) Remove switch.
INSTALLATION
(1) Install switch and mounting screw.
(2) Tighten screw to 1.5 N´m (15 in. lbs.) torque.
(3) Install electrical connector to switch.
WJSPEED CONTROL 8P - 7

WIRING
TABLE OF CONTENTS
page page
WIRING DIAGRAM INFORMATION....... 8W-01-1
COMPONENT INDEX.................. 8W-02-1
POWER DISTRIBUTION............... 8W-10-1
JUNCTION BLOCK.................... 8W-12-1
GROUND DISTRIBUTION.............. 8W-15-1
BUS COMMUNICATIONS.............. 8W-18-1
CHARGING SYSTEM.................. 8W-20-1
STARTING SYSTEM.................. 8W-21-1
FUEL/IGNITION SYSTEM.............. 8W-30-1
TRANSMISSION CONTROL SYSTEM..... 8W-31-1
VEHICLE SPEED CONTROL............ 8W-33-1
ANTILOCK BRAKES................... 8W-35-1
VEHICLE THEFT SECURITY SYSTEM..... 8W-39-1
INSTRUMENT CLUSTER............... 8W-40-1
HORN/CIGAR LIGHTER/POWER OUTLET . . 8W-41-1
AIR CONDITIONING-HEATER........... 8W-42-1
AIRBAG SYSTEM.................... 8W-43-1
INTERIOR LIGHTING.................. 8W-44-1
BODY CONTROL MODULE............. 8W-45-1AUDIO SYSTEM..................... 8W-47-1
REAR WINDOW DEFOGGER............ 8W-48-1
OVERHEAD CONSOLE................. 8W-49-1
FRONT LIGHTING.................... 8W-50-1
REAR LIGHTING..................... 8W-51-1
TURN SIGNALS...................... 8W-52-1
WIPERS............................ 8W-53-1
TRAILER TOW....................... 8W-54-1
POWER WINDOWS................... 8W-60-1
POWER DOOR LOCKS................ 8W-61-1
POWER MIRRORS................... 8W-62-1
POWER SEATS...................... 8W-63-1
POWER SUNROOF................... 8W-64-1
SPLICE INFORMATION................ 8W-70-1
CONNECTOR PIN-OUT................ 8W-80-1
CONNECTOR/GROUND/SPLICE
LOCATION........................ 8W-91-1
POWER DISTRIBUTION............... 8W-97-1 WJWIRING 8W - 1

DESCRIPTION - CIRCUIT FUNCTIONS
All circuits in the diagrams use an alpha/numeric
code to identify the wire and it's function. To identify
which circuit code applies to a system, refer to the
Circuit Identification Code Chart. This chart shows
the main circuits only and does not show the second-
ary codes that may apply to some models.
CIRCUIT IDENTIFICATION CODE CHART
CIRCUIT FUNCTION
A BATTERY FEED
B BRAKE CONTROLS
C CLIMATE CONTROLS
D DIAGNOSTIC CIRCUITS
E DIMMING ILLUMINATION
CIRCUITS
F FUSED CIRCUITS
G MONITORING CIRCUITS
(GAUGES)
H OPEN
I NOT USED
J OPEN
K POWERTRAIN CONTROL
MODULE
L EXTERIOR LIGHTING
M INTERIOR LIGHTING
N NOT USED
O NOT USED
P POWER OPTION (BATTERY
FEED)
Q POWER OPTIONS (IGNITION
FEED)
R PASSIVE RESTRAINT
S SUSPENSION/STEERING
T TRANSMISSION/TRANSAXLE/
TRANSFER CASE
U OPEN
V SPEED CONTROL, WIPER/
WASHER
W OPEN
X AUDIO SYSTEMS
Y OPEN
Z GROUNDS
DESCRIPTION - SECTION IDENTIFICATION AND
INFORMATION
The wiring diagrams are grouped into individual
sections. If a component is most likely found in a par-
ticular group, it will be shown complete (all wires,
connectors, and pins) within that group. For exam-
ple, the Auto Shutdown Relay is most likely to be
found in Group 30, so it is shown there complete. It
can, however, be shown partially in another group if
it contains some associated wiring.
Splice diagrams in Section 8W-70 show the entire
splice and provide references to other sections the
splices serves. Section 8W-70 only contains splice dia-
grams that are not shown in their entirety some-
where else in the wiring diagrams.
Section 8W-80 shows each connector and the cir-
cuits involved with that connector. The connectors
are identified using the name/number on the dia-
gram pages.
WIRING SECTION CHART
GROUP TOPIC
8W-01 thru
8W-09General information and Diagram
Overview
8W-10 thru
8W-19Main Sources of Power and
Vehicle Grounding
8W-20 thru
8W-29Starting and Charging
8W-30 thru
8W-39Powertrain/Drivetrain Systems
8W-40 thru
8W-49Body Electrical items and A/C
8W-50 thru
8W-59Exterior Lighting, Wipers and
Trailer Tow
8W-60 thru
8W-69Power Accessories
8W-70 Splice Information
8W-80 Connector Pin Outs
8W-91 Connector, Ground and Splice
Locations
8W - 01 - 6 8W-01 WIRING DIAGRAM INFORMATIONWJ
WIRING DIAGRAM INFORMATION (Continued)