brake sensor JEEP GRAND CHEROKEE 2002 WJ / 2.G Owner's Guide

LAMPS
TABLE OF CONTENTS
page page
LAMPS/LIGHTING - EXTERIOR............... 1LAMPS/LIGHTING - INTERIOR............... 28
LAMPS/LIGHTING - EXTERIOR
TABLE OF CONTENTS
page page
LAMPS/LIGHTING - EXTERIOR
DESCRIPTION - TURN SIGNAL & HAZARD
WARNING SYSTEM.....................2
OPERATION - TURN SIGNAL & HAZARD
WARNING SYSTEM.....................2
DIAGNOSIS AND TESTING - TURN SIGNAL &
HAZARD WARNING SYSTEMS............3
SPECIFICATIONS
EXTERIOR LAMPS.....................4
AUTO HEADLAMP SENSOR
DIAGNOSIS AND TESTING - AUTO
HEADLAMP SENSOR (AHL)..............4
REMOVAL.............................4
INSTALLATION..........................4
BRAKE LAMP SWITCH
DESCRIPTION..........................5
OPERATION............................5
DIAGNOSIS AND TESTING Ð BRAKE LAMP
SWITCH.............................5
REMOVAL.............................5
INSTALLATION..........................5
ADJUSTMENTS
ADJUSTMENT.........................6
CENTER HIGH MOUNTED STOP LAMP
REMOVAL
REMOVAL - BULB......................6
REMOVAL - CHMSL....................6
INSTALLATION
INSTALLATION - BULB..................6
INSTALLATION - CHMSL.................7
COMBINATION FLASHER
DESCRIPTION..........................7
OPERATION............................7
REMOVAL.............................9
INSTALLATION..........................9
DAYTIME RUNNING LAMP MODULE
DESCRIPTION..........................9OPERATION............................9
REMOVAL.............................9
INSTALLATION..........................9
FOG LAMP
REMOVAL.............................10
INSTALLATION.........................10
FOG LAMP UNIT
REMOVAL.............................10
INSTALLATION.........................10
ADJUSTMENTS
FOG LAMP ADJUSTMENT...............10
HEADLAMP
DESCRIPTION.........................11
OPERATION...........................11
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING Ð HEADLAMP
SYSTEM............................12
DIAGNOSIS AND TESTING Ð HEADLAMP . . 14
REMOVAL - BULB.......................14
INSTALLATION - BULB...................15
HEADLAMP SWITCH
DESCRIPTION.........................15
OPERATION...........................15
DIAGNOSIS AND TESTING Ð HEADLAMP
SWITCH............................15
HEADLAMP UNIT
REMOVAL.............................16
INSTALLATION.........................16
ADJUSTMENTS........................16
LICENSE PLATE LAMP
REMOVAL
REMOVAL - BULB.....................17
REMOVAL - LAMP.....................18
INSTALLATION
INSTALLATION - BULB.................18
INSTALLATION - LAMP.................18
WJLAMPS 8L - 1

nector for the multi-function switch. There should be
continuity. If OK, go to Step 11. If not OK, repair the
open hazard switch sense circuit between the multi-
function switch and the combination flasher.
(11) Check for continuity between the turn switch
sense circuit of the instrument panel wire harness
connector for the multi-function switch and a good
ground. There should be no continuity. If OK, go to
Step 12. If not OK, repair the shorted left turn
switch sense circuit between the multi-function
switch and the combination flasher.
(12) Check for continuity between the left turn
switch sense circuit of the JB for the combination
flasher and the instrument panel wire harness con-
nector for the multi-function switch. There should be
continuity. If OK, go to Step 13. If not OK, repair the
open left turn switch sense circuit between the multi-
function switch and the combination flasher.
(13) Check for continuity between the right turn
switch sense circuit of the instrument panel wire
harness connector for the left multi-function switch
and a good ground. There should be no continuity. If
OK, go to Step 14. If not OK, repair the shorted right
turn switch sense circuit between the left multi-func-
tion switch and the combination flasher.
(14) Check for continuity between the right turn
switch sense circuit of the JB for the combination
flasher and the instrument panel wire harness con-
nector for the multi-function switch. There should be
continuity. If OK, test the left multi-function switch.
(Refer to 8 - ELECTRICAL/LAMPS/LIGHTING -
EXTERIOR/LEFT MULTI-FUNCTION SWITCH -
DIAGNOSIS AND TESTING). If not OK, repair the
open right turn switch sense circuit between the
multi-function switch and the combination flasher as
required.
SPECIFICATIONS
EXTERIOR LAMPS
CAUTION: Do not use bulbs other than the bulbs
listed in the Bulb Application Table. Damage to
lamp can result. Do not touch halogen bulbs with
fingers or other oily surfaces. Bulb life will be
reduced.
LAMP BULB TYPE
BACK-UP 3157
CENTER HIGH
MOUNTED STOP LAMP921
FOG LAMP 9005
FRONT SIDE MARKER 194/194NA
LAMP BULB TYPE
FRONT TURN SIGNAL 3157/3157NA
HIGH BEAM 9005XS
LOW BEAM 9006XS
LICENSE PLATE 168
TAIL/BRAKE 3157
REAR TURN SIGNAL 3157
UNDERHOOD LAMP 561
AUTO HEADLAMP SENSOR
DIAGNOSIS AND TESTING - AUTO HEADLAMP
SENSOR (AHL)
The auto headlamp sensor needs real sunlight to
properly register the light level. When auto head-
lamps are enabled indoors, the headlamps may be
turned on. The sensor is located in the center of the
defroster grille at the base of the windshield. There
are no faults set in the Body Control Module (BCM)
for a inoperative or missing AHL Sensor. Symptom of
a missing sensor or unconnected sensor would be
that the Headlamps and Parklamps turn on when
the vehicle is started and there is a high level of
ambient light present (ie. daytime). Auto headlamps
should not function in the presence of daylight.
REMOVAL
(1) Remove the instrument panel top cover. (Refer
to 23 - BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL TOP COVER - REMOVAL) for service proce-
dures.
(2) Remove the screw attaching auto headlamp
sensor to instrument panel (Fig. 1).
(3) Disengage the harness connector from auto
headlamp sensor.
(4) Separate the auto headlamp sensor from
instrument panel.
INSTALLATION
(1) Position the auto headlamp sensor on instru-
ment panel.
(2) Engage the harness connector to auto head-
lamp sensor.
(3) Install the screw attaching auto headlamp sen-
sor to instrument panel.
(4) Install the instrument panel top cover. (Refer
to 23 - BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL TOP COVER - INSTALLATION) for service
procedures.
8L - 4 LAMPS/LIGHTING - EXTERIORWJ
LAMPS/LIGHTING - EXTERIOR (Continued)

BRAKE LAMP SWITCH
DESCRIPTION
The brake lamp switch is mounted on a bracket
attached to the brake pedal support. The switch is
adjustable.
OPERATION
The brake lamp switch is used for the brake lamp,
speed control and brake sensor circuits.
DIAGNOSIS AND TESTING Ð BRAKE LAMP
SWITCH
Brake lamp switch operation can be tested with an
ohmmeter. The ohmmeter is used to check continuity
between the pin terminals at different plunger posi-
tions (Fig. 2).
SWITCH CIRCUIT IDENTIFICATION
²Terminals 1 and 2: brake sensor circuit
²Terminals 3 and 4: speed control circuit
²Terminals 5 and 6: brake lamp circuit
SWITCH CONTINUITY TEST
NOTE: Disconnect switch harness before testing
continuity.
With the switch plunger retracted, attach the test
leads to terminal pins 1 and 2. Replace switch if
meter indicates no continuity.
With the switch plunger retracted, attach the test
leads to terminal pins 3 and 4. Replace switch if
meter indicates no continuity.With the switch plunger extended, attach the test
leads to terminal pins 5 and 6. Replace switch if
meter indicates no continuity.
REMOVAL
(1) Remove the steering column cover and lower
trim panel.
(2) Press the brake pedal downward to fully
applied position.
(3) Rotate the switch approximately 30É in coun-
terclockwise direction to unlock the switch retainer.
Pull switch rearward and out of bracket.
(4) Disconnect switch harness and remove switch
from vehicle (Fig. 3).
INSTALLATION
(1) Pull the switch plunger all the way out to fully
extended position.
(2) Connect the harness wires to switch.
(3) Press and hold brake pedal in applied position.
(4) Install the switch as follows: Align the tab on
the switch with the notch in the switch bracket.
Insert the switch in the bracket and turn it clockwise
about 30É to lock it in place.
(5) Release the brake pedal. Then pull the pedal
lightly rearward. The pedal will set the plunger to
the correct position as the pedal pushes the plunger
into switch body. The switch will make ratcheting
sound as it self adjusts.
CAUTION: Booster damage may occur if the pedal
pull exceeds 20 lbs.
Fig. 1 Auto Headlamp Sensor
1 - AUTO HEADLAMP SENSOR
2 - I/P ASSEMBLY
3 - CONNECTOR
Fig. 2 Brake Lamp Switch Terminal Identification
1 - TERMINAL PINS
2 - PLUNGER TEST POSITIONS
WJLAMPS/LIGHTING - EXTERIOR 8L - 5
AUTO HEADLAMP SENSOR (Continued)

(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)

(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)

8W-02 COMPONENT INDEX
Component Page
A/C Compressor Clutch................. 8W-42
A/C Pressure Transducer................ 8W-42
Accelerator Pedal Position Sensor......... 8W-30
Accessory Delay Relay.................. 8W-64
Adjustable Pedals..................... 8W-30
Airbags............................. 8W-43
Ambient Temperature Sensor............ 8W-45
Antennas............................ 8W-47
Ash Receiver Lamp.................... 8W-44
Auto Shut Down Relay................. 8W-30
Automatic Day/Night Mirror............. 8W-49
Automatic Headlamp Light Sensor/VTSS
LED.............................. 8W-39
Automatic Zone Control Module.......... 8W-42
Back-Up Lamp Relay................... 8W-51
Battery Temperature Sensor............. 8W-30
Battery............................. 8W-20
Blend Door Motor/Actuator.............. 8W-42
Blower Motor......................... 8W-42
Body Control Module................... 8W-45
Boost Pressure Sensor.................. 8W-30
Brake Lamp Switch.................... 8W-33
Camshaft Position Sensor............... 8W-30
Capacitors........................... 8W-30
Cargo Lamp.......................... 8W-44
Center High Mounted Stop Lamp......... 8W-51
Cigar Lighter......................... 8W-41
Circuit Breakers...................... 8W-12
Clockspring.................. 8W-33, 41, 43, 47
Coil On Plugs......................... 8W-30
Coil Rail............................. 8W-30
Combination Flasher................... 8W-52
Compact Disc Changer.................. 8W-47
Controller Antilock Brake............... 8W-35
Coolant Level Sensor................... 8W-45
Courtesy Lamps....................... 8W-44
Crankcase Heater..................... 8W-30
Crankshaft Position Sensor.............. 8W-30
Cylinder Lock Switches................. 8W-61
Data Link Connector................... 8W-18
Diagnostic Junction Port................ 8W-18
EGR Solenoid......................... 8W-30
Electric Brake........................ 8W-54
Electronic Speed Control Servo........... 8W-33
Engine Control Module................. 8W-30
Engine Coolant Temperature Sensor...... 8W-30
Engine Oil Pressure Sensor.............. 8W-30
Engine Starter Motor................... 8W-21
EVAP/Purge Solenoid................... 8W-30
Fog Lamps........................ 8W-50, 51
Fuel Injectors......................... 8W-30
Fuel Pressure Sensor................... 8W-30Component Page
Fuel Pressure Solenoid................. 8W-30
Fuel Pump........................... 8W-30
Fuel Tank Module..................... 8W-30
Fuses............................ 8W-10, 12
Fusible Link....................... 8W-10, 20
Grounds............................. 8W-15
Generator......................... 8W-20, 30
Glove Box Lamp...................... 8W-44
Glow Plugs........................... 8W-30
Headlamp Leveling Motor............... 8W-50
Heated Seats......................... 8W-63
High Beam Headlamps................. 8W-50
Hood Ajar Switch...................... 8W-39
Horns............................... 8W-41
Hydraulic Cooling Module............ 8W-30, 42
Idle Air Control Motor.................. 8W-30
Ignition Switch....................... 8W-10
Impact Sensors....................... 8W-43
Input Speed Sensor.................... 8W-31
Instrument Cluster.................... 8W-40
Intake Air Temperature Sensor........... 8W-30
Intake Port Swirl Actuator.............. 8W-30
Intrusion Transceiver Module............ 8W-49
Junction Block........................ 8W-12
Knock Sensor......................... 8W-30
Lamp Assemblies................... 8W-51, 52
Leak Detection Pump.................. 8W-30
License Lamps........................ 8W-51
Liftgate............................. 8W-61
Line Pressure Sensor................... 8W-31
Low Beam Headlamps.................. 8W-50
Low Beam Relay...................... 8W-50
Low Beam/Daytime Running Lamp Relay . . . 8W-50
Lumbar Motor........................ 8W-63
Lumbar Switch....................... 8W-63
Manifold Absolute Pressure Sensor........ 8W-30
Manual Temperature Control............. 8W-42
Mass Air Flow Sensor.................. 8W-30
Memory Set Switch................. 8W-62, 63
Mode Door Motor/Actuator............... 8W-42
Multi-Function Switch............... 8W-50, 53
Output Speed Sensor................... 8W-31
Overhead Map/Courtesy Lamp........... 8W-44
Oxygen Sensors....................... 8W-30
Park Brake Switch..................... 8W-40
Park Lamp........................... 8W-50
Park/Neutral Position Switch............ 8W-31
Park/Turn Signal Lamps................ 8W-50
Power Amplifier....................... 8W-47
Power Connector...................... 8W-41
Power Distribution Center............... 8W-10
Power Mirrors........................ 8W-62
WJ8W-02 COMPONENT INDEX 8W - 02 - 1

Component Page
Power Outlet......................... 8W-41
Power Seats.......................... 8W-63
Power Windows....................... 8W-60
Powertrain Control Module.............. 8W-30
Radio............................... 8W-47
Rain Sensor.......................... 8W-49
Recirculation Door Motor/Actuator........ 8W-42
Red Brake Warning Indicator Switch....... 8W-35
Remote Keyless Module................. 8W-39
Remote Radio Switches................. 8W-47
Splices.............................. 8W-10
Seat Belt Switch...................... 8W-43
Seat Module.......................... 8W-63
Sentry Key Immobilizer Module.......... 8W-39
Shifter Assembly...................... 8W-31
Side Impact Sensors................... 8W-43
Side Marker Lamps.................... 8W-50
Side Repeater Lamps................... 8W-52
Siren............................... 8W-49
Speakers............................ 8W-47Component Page
Speed Control Switches................. 8W-33
Sunroof............................. 8W-64
Temperature Valve Actuator............. 8W-42
Throttle Position Sensor................ 8W-30
Trailer Tow.......................... 8W-54
Transfer Case Position Sensor............ 8W-31
Transmission......................... 8W-31
Turn Signal Lamps.................... 8W-52
Underhood Lamp...................... 8W-44
Vehicle Information Center.............. 8W-49
Viscous/Cabin Heater................... 8W-30
Visor/Vanity Lamps.................... 8W-44
Washer Fluid Level Switch.............. 8W-53
Wastegate Solenoid.................... 8W-30
Water In Fuel Sensor................... 8W-30
Wheel Speed Sensors................... 8W-35
Window Defogger...................... 8W-48
Wiper High/Low Relay.................. 8W-53
Wiper Motor.......................... 8W-53
Washer Pump......................... 8W-5
8W - 02 - 2 8W-02 COMPONENT INDEXWJ