2003 JEEP GRAND CHEROKEE Brake

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)

ADJUSTMENTS
ADJUSTMENT
(1) Press and hold brake pedal in applied position.
(2) Pull switch plunger all the way out to fully
extended position.
(3) Release brake pedal. Then pull pedal lightly
rearward. Pedal will set plunger to correct position
as pedal pushes plunger into switch body. Switch will
make ratcheting sound as it self adjusts.
CAUTION: Booster damage may occur if the pedal
pull exceeds 20 lbs.
CENTER HIGH MOUNTED
STOP LAMP
REMOVAL
REMOVAL - BULB
(1) Remove the screws attaching the lamp housing
to the liftgate.
(2) Rotate the bulb socket 1/4 turn and remove it
from the housing (Fig. 4).
(3) Remove the bulb from the socket.
REMOVAL - CHMSL
(1) Remove the screws attaching CHMSL to the
liftgate (Fig. 5).
(2) Disconnect the wire harness connector.
(3) Separate the CHMSL from the vehicle.
INSTALLATION
INSTALLATION - BULB
(1) Push the bulb into the socket.
(2) Position the socket in lamp and rotate 1/4 turn.
(3) Install the screws attaching the lamp housing
to liftgate.
Fig. 3 Brake Lamp
1 - SWITCH
2 - HARNESS CONNECTOR
Fig. 4 CHMSL Bulb
1 - CHMSL
2 - CHMSL BULB
Fig. 5 Center High Mounted Stop lamp
1 - PUSH-IN NUT
2 - CONNECTOR
3 - LIFTGATE
4 - CHSML
8L - 6 LAMPS/LIGHTING - EXTERIORWJ
BRAKE LAMP SWITCH (Continued)

Turn signal inputs that actuate the combination
flasher are low current grounds, each drawing a
maximum of 300 milliamperes.The hazard warning
signal input is a low current ground drawing a max-
imum of 600 milliamperes.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the steering column cover. (Refer to 23
- BODY/INSTRUMENT PANEL/STEERING COL-
UMN OPENING COVER - REMOVAL).
(3) Remove the combination flasher from the Junc-
tion Block (JB) (Fig. 8).
INSTALLATION
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Align the terminals of the combination flasher
with the terminal cavities in the JB. (Fig. 8)
(2) Push in firmly and evenly on the combination
flasher until the terminals are fully seated.
(3) Reinstall the steering column opening cover.
(Refer to 23 - BODY/INSTRUMENT PANEL/STEER-
ING COLUMN OPENING COVER - INSTALLA-
TION).
(4) Reconnect the battery negative cable.
DAYTIME RUNNING LAMP
MODULE
DESCRIPTION
The Daytime Running Lights (Headlamps) System
is installed on vehicles manufactured for sale in Can-
ada only. A separate module, mounted in the junction
block under the dash, controls the DRL.
OPERATION
The headlamps are illuminated at a reduced inten-
sity when the engine is running, headlamp switch
off, and the parking brake released.
REMOVAL
(1) Lower the junction block. (Refer to 8 - ELEC-
TRICAL/POWER DISTRIBUTION/JUNCTION
BLOCK - REMOVAL) for service procedures.
(2) Remove the module from the junction block.
INSTALLATION
(1) Position the module in the junction block and
press to secure.
(2) Install the junction block. (Refer to 8 - ELEC-
TRICAL/POWER DISTRIBUTION/JUNCTION
BLOCK - INSTALLATION) for service procedures.
Fig. 8 Combination Flasher
1 - COMBINATION FLASHER
2 - JUNCTION BLOCK
WJLAMPS/LIGHTING - EXTERIOR 8L - 9
COMBINATION FLASHER (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
FOG LAMPS DO NOT
ILLUMINATE1. Blown fuse for fog lamp. 1. Replace fuse. Refer to Electrical, Wiring
Information.
2. No Z1-ground at fog lamps. 2. Repair circuit ground. Refer to Electrical,
Wiring Information.
3. Faulty multifunction switch. 3. Refer to Electrical, Wiring Information.
4. Broken connector terminal or wire
splice in fog lamp circuit.4. Repair connector terminal or wire splice.
5. Defective or burned out bulb. 5. Replace bulb.
DAYTIME RUNNING LAMP
CONDITION POSSIBLE CAUSES CORRECTION
DAYTIME RUNNING LAMPS DO
NOT WORK1. Poor connection at DRL module. 1. Secure connector on DRL
module.
2. Parking brake engaged. 2. Disengage parking brake.
3. Parking brake circuit shorted to
ground.3. Check cluster telltale, refer to
Group 8W.
4. Headlamp circuit shorted to
ground.4. Refer to Group 8W.
5. Defective DRL relay. 5. Replace DRL relay.
6. Body controller not programed
with Canadian country code.6. Check country code.
7. DRL relay is missing. 7. Install DRL relay.
8. Blown fuse for DRL. 8. Replace fuse refer to Electrical,
Wiring Information.
Clicking or chattering when DRL is
on.1. Mechanical relay is installed in
the junction block.1. Ensure that the DRL relay is
installed in the proper socket in
junction block, and that no
mechanical relay exists in the low
beam socket.
DIAGNOSIS AND TESTING Ð HEADLAMP
WARNING: EYE PROTECTION SHOULD BE USED
WHEN SERVICING GLASS COMPONENTS. PER-
SONAL INJURY CAN RESULT.
CAUTION: Do not touch the glass of halogen bulbs
with fingers or other possibly oily surface, reduced
bulb life will result. Do not use bulbs other than
those indicated in the Bulb Application table. Dam-
age to lamp and/or Daytime Running Lamp Module
can result. Do not use fuses, circuit breakers or
relays having greater amperage value than indi-
cated on the fuse panel or in the Owners Manual.
Each vehicle is equipped with various lamp assem-
blies. A good power feed and ground are necessary forproper lighting operation. Grounding is provided by
the lamp socket when it comes in contact with the
metal body, or through a separate ground wire.
When changing lamp bulbs check the socket for
corrosion. If corrosion is present, clean it with a wire
brush and coat the inside of the socket lightly with
Mopar Multi-Purpose Grease or equivalent.
REMOVAL - BULB
(1) Remove the headlamp.
(2) Turn the bulb socket one quarter turn counter
clockwise.
(3) Remove the socket from lamp (Fig. 13).
(4) Remove the bulb from socket.
8L - 14 LAMPS/LIGHTING - EXTERIORWJ
HEADLAMP (Continued)

MULTI-FUNCTION SWITCH - INSTALLATION -
LEFT MULTI-FUNCTION SWITCH).
(6) Reinstall the clockspring onto the multi-func-
tion switch housing. (Refer to 8 - ELECTRICAL/RE-
STRAINTS/CLOCKSPRING - INSTALLATION).
(7) Reconnect the battery negative cable.
PARK/TURN SIGNAL LAMP
REMOVAL - BULBS
(1) Remove the headlamp module.
(2) Rotate the turn signal bulb socket 1/4 turn
counter clockwise.
(3) Remove the bulb socket from module.
(4) Remove the bulb from socket.
INSTALLATION - BULBS
(1) Press the bulb into socket.
(2) Position the bulb socket in module.
(3) Rotate the turn signal bulb socket 1/4 turn
clockwise.
(4) Install the headlamp module.
TAIL LAMP
DESCRIPTION
The taillamp module contains a housing, lens, and
three bulbs. A dual filament bulb is used for tail and
stop functions. A single filament bulb is used for turn
signal operations. A separate bulb is used for back-up
illumination.
OPERATION
All exterior lighting function are controlled by the
multifunction switch. Stop lamp functions are con-
trolled by the stoplamp switch. The back-up lamps
are controlled by the back-up lamp switch.
REMOVAL
REMOVAL - BULBS
The brake, turn signal, back-up, and side marker
lamp bulbs are incorporated into the tail lamp.
(1) Remove the tail lamp.
(2) Rotate the bulb socket counterclockwise.
(3) Separate the socket from the lamp
(4) Remove the bulb from the socket (Fig. 32).
REMOVAL - LAMP
The brake, turn signal, back-up, and side marker
lamps are incorporated in the tail lamp.
(1) Remove the screws attaching the lamp to body
(Fig. 33).
(2) Disengage the lamp from the alignment pin.
(3) Disconnect lamp wire harness connector.
(4) Separate lamp from vehicle.
Fig. 31 Multi-Function Switch Mounting Housing
Screw Remove/Install
1 - CLOCK SPRING
2 - SCREW
3 - MULTI-FUNCTION SWITCH MOUNTING HOUSING
Fig. 32 Tail Lamp Bulbs
1 - TAIL/STOP BULB
2 - TAIL LAMP
3 - BACK-UP BULB
4 - TURN SIGNAL BULB
WJLAMPS/LIGHTING - EXTERIOR 8L - 25
LEFT MULTI-FUNCTION SWITCH (Continued)

INSTALLATION
INSTALLATION - BULBS
(1) Position the bulb in socket and push into place.
(2) Position the bulb socket in the lamp and rotate
clockwise.
(3) Install the lamp.
INSTALLATION - LAMP
The brake, turn signal, back-up, and side marker
lamps are incorporated in the tail lamp.
(1) Position the lamp.
(2) Connect the lamp wire harness connector.
(3) Align the pin with the retainer and press the
lamp inward to engage.
(4) Install the screws attaching the lamp to body.
TURN SIGNAL CANCEL CAM
DESCRIPTION
The turn signal cancel cam is concealed within the
multi-function switch housing below the steering
wheel and the clockspring mechanism. The turn sig-
nal cancel cam consists of a disc unit with two inte-
gral lobes. The upper lobe of the cam has an
alignment hole that is used to align it with another
hole in the back of the multi-function switch mount-
ing housing. The upper surface of the turn signal
cancel cam features three holes, two round and one
oblong. These holes engage and key the cancel cam to
three matching pins in the hub of the clockspring
mechanism. The hub of the clockspring and the turn
signal cancel cam rotate with the steering wheel. The
centered clockspring housing is then secured to the
multi-function switch mounting housing over the top
of the turn signal cancel cam.
The turn signal cancel cam is serviced as a assem-
bly with the multi-function switch housing. The turn
signal cancel cam cannot be repaired and, if faulty or
damaged, the multi-function switch mounting hous-
ing unit must be replaced. (Refer to 8 - ELECTRI-
CAL/LAMPS/LIGHTING - EXTERIOR/LEFT MULTI-
FUNCTION SWITCH - REMOVAL - MULTI-
FUNCTION SWITCH MOUNTING HOUSING).
OPERATION
The turn signal cancel cam has two lobes. When
the turn signals are activated by moving the left
multi-function switch control stalk to a detent posi-
tion, a turn signal cancel actuator is extended from
the inside surface of the multi-function switch hous-
ing toward the center of the steering column and the
turn signal cancel cam. When the steering wheel is
rotated during a turning maneuver, one of the two
turn signal cancel cam lobes will contact the turn sig-
nal cancel actuator. The cancel actuator latches
against the cancel cam rotation in the direction oppo-
site that which is signaled.
Fig. 33 Tail Lamp
1 - CONNECTOR
2 - RETAINER
3 - TAILLAMP (STOP, TURN, BACK-UP, SIDE MARKER)
4 - PIN
8L - 26 LAMPS/LIGHTING - EXTERIORWJ
TAIL LAMP (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)