Power JEEP GRAND CHEROKEE 2002 WJ / 2.G Workshop Manual
[x] Cancel search | Manufacturer: JEEP, Model Year: 2002, Model line: GRAND CHEROKEE, Model: JEEP GRAND CHEROKEE 2002 WJ / 2.GPages: 2199, PDF Size: 76.01 MB
Page 532 of 2199

PASSENGER SIDE FRONT AND REAR WINDOWS
INOPERATIVE
If the driver side front and rear power windows
operate, but the passenger side front and rear do not,
use a DRB scan tool and the proper Diagnostic Pro-
cedures manual to check the PCI data bus for proper
operation.
ONE WINDOW INOPERATIVE
The window glass and regulator mechanism must
be free to slide up and down for the power window
motor to function properly. If the window glass and
regulator is not free to move up and down, the motor
will overload and trip the integral circuit breaker. To
determine if the window glass and regulator are free,
disconnect the regulator plate from the glass. Then
slide the window up and down by hand.
There is an alternate method to check if the win-
dow glass and regulator mechanism is free. Position
the glass between the up and down stops. Then,
shake the glass in the door. Check that the glass can
be moved slightly from side to side, front to rear, and
up and down. Then check that the glass is not bound
tight in the tracks.
If the window glass and regulator mechanism is
free, refer toDoor Modulein Electrical, Power Win-
dows. If the glass is not free, inspect the window
glass mounting and operating hardware for damage
or improperly installed components. Refer toBodyto
check for proper installation or damage of the win-
dow glass mounting and operating hardware.
DOOR MODULE
NOTE: The following tests may not prove conclu-
sive in the diagnosis of this component. The most
reliable, efficient, and accurate means to diagnose
this component requires the use of a DRB scan tool
and the proper Diagnostic Procedures manual.
If the problem being diagnosed is a rear door win-
dow that does not operate from the rear door switch,
but does operate from the master switch on the
driver side front door, (Refer to 8 - ELECTRICAL/
POWER WINDOWS/POWER WINDOW SWITCH -
DIAGNOSIS AND TESTING). If the problem is a
passenger side front or rear window that operates
from the switch on that door, but does not operate
from the master switch on the driver side front door,
use a DRB scan tool and the proper Diagnostic Pro-
cedures manual to diagnose the circuitry of both door
modules and the PCI data bus. For complete circuit
diagrams, refer to the appropriate wiring informa-
tion. The wiring information includes wiring dia-
grams, proper wire and connector repair procedures,
details of wire harness routing and retention, connec-tor pin-out information and location views for the
various wire harness connectors, splices and grounds.
(1) Disconnect and isolate the battery negative
cable. Remove the trim panel from the front door, but
do not disconnect the door wire harness connectors
from the door module. Go to Step 2.
(2) Check the 15-way door wire harness connector
for the door module to see that it is fully seated in
the door module connector receptacle. If OK, go to
Step 3. If not OK, properly connect the 15-way door
wire harness connector for the door module to the
door module connector receptacle.
(3) Disconnect the 15-way door wire harness con-
nector from the door module connector receptacle.
Check for continuity between the ground circuit cav-
ity of the 15-way door wire harness connector for the
door module and a good ground. There should be con-
tinuity. If OK, go to Step 4. If not OK, repair the
open ground circuit to ground as required.
(4) Connect the battery negative cable. Check for
battery voltage at the fused B(+) circuit cavity of the
15-way door wire harness connector for the door
module. If OK, go to Step 5. If not OK, repair the
open fused B(+) circuit to the fuse in the Power Dis-
tribution Center (PDC) as required.
(5) If the inoperative window is on a front door, go
to Step 6. If the inoperative window is on a rear door
go to Step 9.
(6) Disconnect and isolate the battery negative
cable. Disconnect the door wire harness connector
from the inoperative power window motor wire har-
ness connector. Check for continuity between the
front window driver up circuit cavity of the 15-way
door wire harness connector for the door module and
a good ground. Repeat the check for the front window
driver down circuit. In each case there should be no
continuity. If OK, go to Step 7. If not OK, repair the
shorted front window driver up or down circuit as
required.
(7) Check for continuity between the front window
driver up circuit cavities of the 15-way door wire har-
ness connector for the door module and the door wire
harness connector for the power window motor.
Repeat the check for the front window driver down
circuit. In each case there should be continuity. If
OK, go to Step 8. If not OK, repair the open front
window driver up or down circuit as required.
(8) Reconnect the 15-way door wire harness con-
nector back into the door module connector recepta-
cle. Connect the battery negative cable. Connect the
probes of a reversible DC digital voltmeter to the
door wire harness connector for the power window
motor. Observe the voltmeter while actuating the
switch for that window in the up and down direc-
tions. There should be battery voltage for as long as
the switch is held in both the up and down positions,
WJPOWER WINDOWS 8N - 35
POWER WINDOWS (Continued)
Page 533 of 2199

and no voltage in the neutral position. If OK,(Refer
to 8 - ELECTRICAL/POWER WINDOWS/WINDOW
MOTOR - DIAGNOSIS AND TESTING). If not OK,
replace the faulty door module.
(9) Check the rear door power window switch con-
tinuity. (Refer to 8 - ELECTRICAL/POWER WIN-
DOWS/POWER WINDOW SWITCH - DIAGNOSIS
AND TESTING). If OK, go to Step 10. If not OK,
replace the faulty rear door power window switch.
(10) Disconnect and isolate the battery negative
cable. Reconnect the door wire harness connector to
the rear door power window switch. Disconnect the
door wire harness connector from the inoperative
power window motor wire harness connector. Check
for continuity between the rear window driver up cir-
cuit cavity of the 15-way door wire harness connector
for the door module and a good ground. Repeat the
check for the rear window driver down circuit. In
each case there should be no continuity. If OK, go to
Step 11. If not OK, repair the shorted rear window
driver up or down circuit as required.
(11) Check for continuity between the rear window
driver up circuit cavities of the 15-way door wire har-
ness connector for the door module and the power
window motor wire harness connector. Repeat the
check for the rear window driver down circuit. In
each case there should be continuity. If OK, go to
Step 12. If not OK, repair the open rear window
driver up or down circuit as required.
NOTE: The door module feeds battery current to
both terminals of the rear door power window
motors when the power window lockout switch is in
the Unlock position, until the master window switch
on the driver side front door is actuated. The door
module feeds ground to both terminals of the rear
door power window motor when the power window
lockout switch is in the Lock position, until the
master window switch on the driver side front door
is actuated.
(12) Reconnect the 15-way door wire harness con-
nector for the door module to the door module con-
nector receptacle. Connect the battery negative cable.
Check for battery voltage at each cavity in the door
wire harness connector for the power window motor.
Each cavity should have battery voltage when the
power window switch is in the neutral position. Each
cavity should also have battery voltage in one other
switch position, either up or down, and zero volts
with the switch in the opposite position. If OK, (Refer
to 8 - ELECTRICAL/POWER WINDOWS/WINDOW
MOTOR - DIAGNOSIS AND TESTING). If not OK,
replace the faulty door module.POWER WINDOW SWITCH
DESCRIPTION
The power window motors are controlled by a two-
way momentary switch mounted on the trim panel of
each passenger door, and four two-way momentary
switches on the driver side front door trim panel. The
driver side front door trim panel also has a two-posi-
tion power window lockout switch. Each power win-
dow switch, except the lockout switch, is illuminated
by a Light-Emitting Diode (LED) that is integral to
the switch paddle.
The front door power window switches and the
power window lockout switch are integral to the
Driver Door Module (DDM) and Passenger Door
Module (PDM). The front door power window
switches and their lamps cannot be adjusted or
repaired and, if faulty or damaged, the entire DDM
or PDM unit must be replaced. The rear door power
window switches and their lamps cannot be adjusted
or repaired but, if faulty or damaged, only the
affected rear door power window switch must be
replaced. (Refer to 8 - ELECTRICAL/ELECTRONIC
CONTROL MODULES/DRIVER DOOR MODULE -
REMOVAL).
OPERATION
The front door power window switches provide an
up or down (or lock and unlock signal in the case of
the lockout switch) to the door module circuitry. The
Driver Door Module (DDM) circuitry controls the out-
put to the driver side front and rear door power win-
dow motors, and supplies electrical current as
required for the stand-alone operation of the driver
side rear door power window switch. The Passenger
Door Module (PDM) circuitry controls the output to
the passenger side front and rear door power window
motors, and supplies electrical current as required
for the stand-alone operation of the passenger side
rear door power window switch.
When a DDM-integrated master power window
switch for a passenger side window is actuated, or
when the power window lockout switch is actuated to
disable the passenger door power windows, the DDM
circuitry sends a message to the PDM over the Pro-
grammable Communications Interface (PCI) data bus
to control the output to that power window motor(s).
The power window switch for the driver side front
door power window has two detent positions in the
Down direction. The first detent provides normal
power window down operation. If this switch is
depressed to the second detent, the Auto Down cir-
cuitry of the DDM is activated. The Auto-Down cir-
cuitry will automatically move the driver side front
door window to its fully lowered position, even if the
power window switch is released. The Auto-Down
8N - 36 POWER WINDOWSWJ
POWER WINDOWS (Continued)
Page 534 of 2199

event will be automatically cancelled and the window
movement will be stopped if the DDM circuitry
detects a second input from the driver side front door
power window switch, in either direction.
Each power window switch, except the lockout
switch, is illuminated by a Light-Emitting Diode
(LED) when the ignition switch is turned to the On
position. However, when the lockout switch is placed
in the Lock position, the LED for the locked-out front
and rear passenger door power window switches is
turned off.
See the owner's manual in the vehicle glove box for
more information on the features, use and operation
of the power window switches.
DIAGNOSIS AND TESTING - POWER WINDOW
SWITCH
The diagnosis found here applies only to the rear
door power window switches. If the problem being
diagnosed is an inoperative power window switch
illumination lamp, but the power window switch
operates as designed, replace the faulty rear door
power window switch(verify the power lockout
switch is not actuated). For complete circuit dia-
grams, refer to the appropriate wiring information.
The wiring information includes wiring diagrams,
proper wire and connector repair procedures, details
of wire harness routing and retention, connector pin-
out information and location views for the various
wire harness connectors, splices and grounds.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the power window switch from the
rear door trim panel. (Refer to 8 - ELECTRICAL/
POWER WINDOWS/POWER WINDOW SWITCH -
REMOVAL).
(3) Check the rear door power window switch con-
tinuity as shown in the Rear Door Power Window
Switch Continuity chart (Fig. 1). If OK, (Refer to 8 -
ELECTRICAL/POWER WINDOWS/WINDOW
MOTOR - DIAGNOSIS AND TESTING). If not OK,
replace the faulty rear door power window switch.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the trim panel from the rear door.
(Refer to 23 - BODY/DOORS - REAR/TRIM PANEL -
REMOVAL) for the procedures.
(3) Using a trim stick or another suitable wide
flat-bladed tool, gently pry the sides of the switch
receptacle on the back of the rear door trim panel
away from the perimeter of the power window switch
to release the switch from the receptacle (Fig. 2).
(4) Remove the power window switch from the
rear door trim panel switch receptacle.
Fig. 1 Rear Door Power Window Switch Continuity
SWITCH POSITION CONTINUITY BETWEEN
LED 3 AND 6
OFF 1 AND 2
OFF 4 AND 5
FORWARD 1 AND 2
FORWARD 5 AND 6
REARWARD 2 AND 6
REARWARD 4 AND 5
Fig. 2 Rear Door Power Window Switch Remove/
Install
1 - REAR DOOR TRIM PANEL
2 - TRIM PANEL RECEPTACLE
3 - POWER WINDOW SWITCH
WJPOWER WINDOWS 8N - 37
POWER WINDOW SWITCH (Continued)
Page 535 of 2199

INSTALLATION
(1) Position the power window switch to the rear
door trim panel switch receptacle.
(2) Press firmly and evenly on the back of the
power window switch until it snaps into rear door
trim panel switch receptacle.
(3) Install the trim panel onto the rear door. (Refer
to 23 - BODY/DOORS - REAR/TRIM PANEL -
INSTALLATION) for the procedures.
(4) Reconnect the battery negative cable.
WINDOW MOTOR
DESCRIPTION
Power operated front and rear door windows are
standard equipment on this model. Each door has a
permanent magnet reversible electric motor with an
integral right angle gearbox mechanism that oper-
ates the window regulator. In addition, each power
window motor is equipped with an integral self-reset-
ting circuit breaker to protect the motor from over-
loads.
The power window motor gearbox housing is
secured to the window regulator drum housing with
screws. The window regulators used in all four doors
are single vertical post cable-and-drum type. A
molded plastic slider guided by the post is driven by
the regulator cables. The slider raises and lowers the
window glass through a steel lift plate attachment.
Front and rear glass channels within each door guide
and stabilize each end of the glass.
The power window motor and gearbox assembly
cannot be repaired and, if faulty or damaged, the
entire power window motor and gearbox unit must be
replaced. The window regulators are available for
service. (Refer to 23 - BODY/DOOR - FRONT/WIN-
DOW REGULATOR - REMOVAL) or (Refer to 23 -
BODY/DOORS - REAR/WINDOW REGULATOR -
REMOVAL) for the regulator service procedures.
OPERATION
A positive and negative battery connection to the
two motor terminals will cause the power window
motor to rotate in one direction. Reversing the cur-
rent through these same two connections will cause
the motor to rotate in the opposite direction.
When the power window motor operates, it rotates
the regulator cable drum through its gearbox. The
window regulator cable drum is connected through
two cables to the plastic slider on the vertical post.
As the cable drum rotates, it lets cable out on one
side of the drum, and takes cable in on the other side
of the drum. The changes in cable length move the
slider up or down the vertical post, raising or lower-
ing the window glass.If the window regulator or window glass bind,
encounter obstructions, or reach their travel limits it
overloads the power window motor. The overloading
condition causes the power window motor self-reset-
ting circuit breaker to open, which stops the motor
from running.
DIAGNOSIS AND TESTING - WINDOW MOTOR
Before you proceed with this diagnosis, confirm
proper switch operation. (Refer to 8 - ELECTRICAL/
ELECTRONIC CONTROL MODULES/DRIVER
DOOR MODULE - OPERATION) or (Refer to 8 -
ELECTRICAL/POWER WINDOWS/POWER WIN-
DOW SWITCH - OPERATION). For complete circuit
diagrams, refer to the appropriate wiring informa-
tion. The wiring information includes wiring dia-
grams, proper wire and connector repair procedures,
details of wire harness routing and retention, connec-
tor pin-out information and location views for the
various wire harness connectors, splices and grounds.
(1) Remove the trim panel from the door with the
inoperative power window. (Refer to 23 - BODY/
DOOR - FRONT/TRIM PANEL - REMOVAL) or
(Refer to 23 - BODY/DOORS - REAR/TRIM PANEL -
REMOVAL) for the procedures.
(2) Disconnect the door wire harness connector
from the power window motor wire harness connec-
tor. Apply battery current to one cavity of the power
window motor wire harness connector, and apply
ground to the other cavity of the connector. The
power window motor should operate in one direction.
Remember, if the window is in the full up or full
down position, the motor will not operate in that
direction by design. If OK, go to Step 3. If not OK,
replace the faulty power window motor.
(3) Reverse the battery and ground connections to
the two cavities of the power window motor wire har-
ness connector. The power window motor should now
operate in the other direction. Remember, if the win-
dow is in the full up or full down position, the motor
will not operate in that direction by design. If OK, go
to Step 4. If not OK, replace the faulty power window
motor.
(4) If the power window motor operates in both
directions, check the operation of the window glass
and regulator mechanism through its complete up
and down travel. There should be no binding or stick-
ing of the window glass or regulator mechanism
through the entire travel range. If not OK, (Refer to
23 - BODY/DOOR - FRONT/WINDOW REGULATOR
- REMOVAL) or (Refer to 23 - BODY/DOORS -
REAR/WINDOW REGULATOR - REMOVAL) to
check for proper installation or damage of the win-
dow glass mounting and operating hardware.
8N - 38 POWER WINDOWSWJ
POWER WINDOW SWITCH (Continued)
Page 536 of 2199

REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the window regulator from the door.
(Refer to 23 - BODY/DOOR - FRONT/WINDOW
REGULATOR - REMOVAL) or (Refer to 23 - BODY/
DOORS - REAR/WINDOW REGULATOR -
REMOVAL) for the procedures.
(3) Place the window regulator on a suitable work
surface and remove the screws that secure the power
window motor to the window regulator.
(4) Remove the power window motor from the win-
dow regulator.
INSTALLATION
(1) Position the power window motor onto the win-
dow regulator.
(2) Install and tighten the screws that secure the
power window motor to the window regulator.
Tighten the screws to 9 N´m (80 in. lbs.).
(3) Install the window regulator onto the door.
(Refer to 23 - BODY/DOOR - FRONT/WINDOW
REGULATOR - INSTALLATION) or(Refer to 23 -
BODY/DOORS - REAR/WINDOW REGULATOR -
INSTALLATION) for the procedures.
(4) Reconnect the battery negative cable.
WJPOWER WINDOWS 8N - 39
WINDOW MOTOR (Continued)
Page 566 of 2199

WARNING: DURING AND FOLLOWING ANY SEAT
BELT SERVICE, CAREFULLY INSPECT ALL SEAT
BELTS, BUCKLES, MOUNTING HARDWARE, AND
RETRACTORS FOR PROPER INSTALLATION,
OPERATION, OR DAMAGE. REPLACE ANY BELT
THAT IS CUT, FRAYED, OR TORN. STRAIGHTEN
ANY BELT THAT IS TWISTED. TIGHTEN ANY
LOOSE FASTENERS. REPLACE ANY BELT THAT
HAS A DAMAGED OR INOPERATIVE BUCKLE OR
RETRACTOR. REPLACE ANY BELT THAT HAS A
BENT OR DAMAGED LATCH PLATE OR ANCHOR
PLATE. NEVER ATTEMPT TO REPAIR A SEAT BELT
COMPONENT. ALWAYS REPLACE DAMAGED OR
FAULTY SEAT BELT COMPONENTS WITH THE COR-
RECT, NEW AND UNUSED REPLACEMENT PARTS
LISTED IN THE MOPAR PARTS CATALOG.
(1) Move the front seat to its most forward position
for easiest access to the front seat belt buckle lower
anchor screw.
(2) Disconnect and isolate the battery negative
cable. Wait two minutes for the system capacitor to
discharge before further service.
(3) Disconnect the seat belt switch pigtail wire
connector from the body wire harness connector for
the seat belt switch with manual seats, or from the
power seat wire harness connector for the seat belt
switch with power seats (Fig. 30).
(4) Remove the screw that secures the front seat
belt buckle lower anchor to the side of the floor panel
transmission tunnel.(5) Remove the front seat belt buckle from the
floor panel transmission tunnel.
INSTALLATION
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG, PAS-
SENGER 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 PRECAU-
TIONS COULD RESULT IN ACCIDENTAL AIRBAG
DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
WARNING: DURING AND FOLLOWING ANY SEAT
BELT SERVICE, CAREFULLY INSPECT ALL SEAT
BELTS, BUCKLES, MOUNTING HARDWARE, AND
RETRACTORS FOR PROPER INSTALLATION,
OPERATION, OR DAMAGE. REPLACE ANY BELT
THAT IS CUT, FRAYED, OR TORN. STRAIGHTEN
ANY BELT THAT IS TWISTED. TIGHTEN ANY
LOOSE FASTENERS. REPLACE ANY BELT THAT
HAS A DAMAGED OR INOPERATIVE BUCKLE OR
RETRACTOR. REPLACE ANY BELT THAT HAS A
BENT OR DAMAGED LATCH PLATE OR ANCHOR
PLATE. NEVER ATTEMPT TO REPAIR A SEAT BELT
COMPONENT. ALWAYS REPLACE DAMAGED OR
FAULTY SEAT BELT COMPONENTS WITH THE COR-
RECT, NEW AND UNUSED REPLACEMENT PARTS
LISTED IN THE MOPAR PARTS CATALOG.
(1) Position the front seat belt buckle to the side of
the floor panel transmission tunnel (Fig. 30).
(2) Install and tighten the screw that secures the
front seat belt buckle lower anchor to the side of the
floor panel transmission tunnel. Tighten the screw to
43 N´m (32 ft. lbs.).
(3) Reconnect the seat belt switch pigtail wire con-
nector to the body wire harness connector for the
seat belt switch with manual seats, or to the power
seat wire harness connector for the seat belt switch
with power seats.
(4) Do not reconnect the battery negative cable at
this time. The supplemental restraint system verifi-
cation test procedure should be performed following
service of any supplemental restraint system compo-
nent. (Refer to 8 - ELECTRICAL/RESTRAINTS -
STANDARD PROCEDURE - VERIFICATION TEST).
Fig. 30 Front Seat Belt Buckle
1 - SEAT BELT BUCKLE
2 - SEAT BELT SWITCH PIGTAIL WIRE
3 - SCREW
WJRESTRAINTS 8O - 29
FRONT SEAT BELT BUCKLE (Continued)
Page 574 of 2199

NOTE: Vehicles equipped with a three-point center
seat belt have the center seat belt lower anchor
secured to the right buckle anchor plate with a
screw instead of the center lap belt. (Refer to 8 -
ELECTRICAL/RESTRAINTS/REAR CENTER SEAT
BELT & RETRACTOR - INSTALLATION).
(3) Fold the rear seat cushion back into the seat-
ing position.
SEAT BELT SWITCH
DESCRIPTION
The seat belt switch for this model is actually a
Hall Effect-type sensor. This sensor consists of a
fixed-position, Hall Effect Integrated Circuit (IC) chip
and a small permanent magnet that are integral to
each front seat belt buckle. The front seat belt buck-
les are each located on a stamped steel stanchion
within a molded plastic scabbard and secured with a
screw to the floor panel transmission tunnel on the
inboard side of each front seat cushion (Fig. 40). Theseat belt switches are connected to the vehicle elec-
trical system through a two-lead pigtail wire and
connector on the seat belt buckle-half, which is con-
nected to a wire harness connector and take out of
the body wire harness on vehicles with manual seat
adjusters, or to a connector and take out of the power
seat wire harness on vehicles with power seat adjust-
ers. A radio noise suppression capacitor is connected
in parallel with the IC where the two pigtail wire
leads connect to the IC pins.
The seat belt switch cannot be adjusted or repaired
and, if faulty or damaged, the entire seat belt buckle-
half unit must be replaced.
OPERATION
The seat belt switches are designed to provide a
status signal to the seat belt switch sense inputs of
the Airbag Control Module (ACM) indicating whether
the front seat belts are fastened. The ACM uses the
seat belt switch inputs as a factor in determining
what level of force with which it should deploy the
multistage driver and passenger airbags. In addition,
the ACM sends electronic messages to the ElectroMe-
chanical Instrument Cluster (EMIC) to control the
seat belt indicator based upon the status of the
driver side front seat belt switch. A spring-loaded
slide with a small window-like opening is integral to
the buckle latch mechanism. When a seat belt tip-
half is inserted and latched into the seat belt buckle,
the slide is pushed downward and the window of the
slide exposes the Hall Effect Integrated Circuit (IC)
chip within the buckle to the field of the permanent
magnet, which induces a current within the chip.
The chip provides this induced current as an output
to the ACM, which monitors the current to determine
the status of the front seat belts. When the seat belt
is unbuckled, the spring-loaded slide moves upward
and shields the IC from the field of the permanent
magnet, causing the output current from the seat
belt switch to be reduced.
The seat belt switch receives a supply current from
the ACM, and the ACM senses the status of the front
seat belts through its pigtail wire connection to the
airbag overlay wire harness. The ACM monitors the
condition of the seat belt switch circuits and will illu-
minate the airbag indicator in the EMIC then store a
Diagnostic Trouble Code (DTC) for any fault that is
detected in either seat belt switch circuit. For proper
diagnosis of the seat belt switches, a DRBIIItscan
tool is required. Refer to the appropriate diagnostic
information.
Fig. 40 Front Seat Belt Buckle
1 - SEAT BELT BUCKLE
2 - SEAT BELT SWITCH PIGTAIL WIRE
3 - SCREW
WJRESTRAINTS 8O - 37
REAR SEAT BELT BUCKLE (Continued)
Page 583 of 2199

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)
Page 586 of 2199

(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)
Page 587 of 2199

(11) If servo is being removed from its mounting
bracket, remove 2 mounting nuts holding servo cable
sleeve to bracket (Fig. 6) .
(12) Pull speed control cable sleeve and servo away
from servo mounting bracket to expose cable retain-
ing clip (Fig. 6) and remove clip. Note: The servo
mounting bracket displayed in (Fig. 6) is a typical
bracket and may/may not be applicable to this model
vehicle.
(13) Remove servo from mounting bracket or,
remove servo and mounting bracket as one assembly.
INSTALLATION
(1) Position servo to mounting bracket.
(2) Align hole in cable connector with hole in servo
pin. Install cable-to-servo retaining clip.
(3) Insert servo mounting studs through holes in
servo mounting bracket.
(4) Install servo cable mounting nuts (Fig. 6) and
tighten to 8.5 N´m (75 in. lbs.) torque. If servo and
bracket is being installed as one assembly, install 2
mounting nuts (Fig. 5) and tighten to 28 N´m 6 N´m
(250 in. lbs. 50 in. lbs.) torque.
(5) Connect vacuum line at servo.
(6) Connect electrical connector at servo.
(7) Connect servo cable to throttle body. Refer to
Servo Cable Removal/Installation.
(8) Install battery tray and battery temperature
sensor.
(9) Connect wiring to battery tray.
(10) Install battery to battery tray.
(11) Connect positive battery cable to Power Distri-
bution Center (PDC).
(12) Connect positive battery cable to battery.
(13) Connect negative battery cable to battery.
(14) Before starting engine, operate accelerator
pedal to check for any binding.
Fig. 5 Speed Control
1 - VACUUM HOSE FITTING
2 - SPEED CONTROL SERVO
3 - SERVO CABLE
4 - RIGHT INNER FENDER
5 - SERVO MOUNTING NUTS (2)
6 - SERVO MOUNTING BRACKET
7 - ELEC. CONNECTOR
Fig. 6 Servo Cable Clip Remove/InstallÐTypical
1 - SERVO MOUNTING NUTS (2)
2 - SERVO
3 - CABLE RETAINING CLIP
4 - SERVO CABLE AND SLEEVE
8P - 6 SPEED CONTROLWJ
SERVO (Continued)