2002 JEEP GRAND CHEROKEE headlamp

(from rear of vehicle forward) to verify accuracy of
the line placement.
(4) Rock vehicle side-to-side three times to allow
suspension to stabilize.
(5) Jounce front suspension three times by pushing
downward on front bumper and releasing.
(6) Measure the distance from the center of head-
lamp lens to the floor. Transfer measurement to the
alignment screen (with tape). Use this line for
up/down adjustment reference.
(7) Measure distance from the centerline of the
vehicle to the center of each headlamp being aligned.
Transfer measurements to screen (with tape) to each
side of vehicle centerline. Use these lines for left/
right adjustment reference.
HEADLAMP ADJUSTMENT
A properly aimed low beam will project the top
edge of the beam intensity pattern on the screen
from 25 mm (1 in.) above to 75 mm (3 in.) below
headlamp centerline. The side-to-side left edge of the
beam intensity pattern should be from 50 mm (2 in.)
left to 50 mm (2 in.) right of headlamp centerline
(Fig. 17).
(1) Clean front of the headlamps.
(2) Place headlamps on LOW beam.(3) Cover front of the headlamp that is not being
adjusted.
(4) Turn adjustment screw (Fig. 18) and (Fig. 19)
until the top edge of the beam intensity pattern is
positioned within 25 mm (1 in.) above or 75 mm (3
in.) below the headlamp horizontal centerline.
(5) Cover front of the headlamp and adjust the
other headlamp beam as instructed below.
(6) Rotate the adjustment screw until the top edge
of the beam intensity pattern is positioned within 25
mm (1 in.) above or 75 mm (3 in.) below the head-
lamp horizontal centerline.
LICENSE PLATE LAMP
REMOVAL
REMOVAL - BULB
(1) Remove lamp assembly from liftgate lamp mod-
ule.
(2) Rotate bulb socket counterclockwise to discon-
nect bulb socket from lamp.
(3) Remove bulb from socket.
Fig. 16 Headlamp Alignment ScreenÐTypical
1 - CENTER OF VEHICLE TO CENTER OF HEADLAMP LENS
2 - FLOOR TO CENTER OF HEADLAMP LENS
3 - 7.62 METERS (25 FEET)4 - FRONT OF HEADLAMP
5 - VEHICLE CENTERLINE
WJLAMPS/LIGHTING - EXTERIOR 8L - 17
HEADLAMP UNIT (Continued)

REMOVAL - LAMP
(1) Remove the screws attaching lamp assembly to
liftgate. (Fig. 20).
(2) Pull the lamp assembly away from the sheet-
metal at extreme outboard edges to disengage the
push pins.
(3) Separate lamp assembly harness wiring con-
nector.
(4) Remove lamp.
INSTALLATION
INSTALLATION - BULB
(1) Install bulb in socket.
(2) Install socket and bulb assembly in lamp hous-
ing.
(3) Install lamp assembly in liftgate lamp module.
INSTALLATION - LAMP
(1) Connect bulb harness to lamp assembly.
(2) Position lamp assembly on liftgate and press
outboard fasteners in place.
(3) Install screws in lamp assembly.
LICENSE PLATE LAMP UNIT
REMOVAL
(1) Remove the screws retaining the lamp housing/
trim panel to the liftgate (Fig. 21).
(2) Disconnect the wire harness for the license
plate lamps and the flip up glass switch, if equipped.
(3) Remove the license plate lamps and the flip up
glass switch, if equipped.
(4) Remove the license plate lamp housing.
Fig. 17 Low Beam Pattern
1 - LOW BEAM INTENSITY PATTERN (ISO-CANDELA CURVE)
Fig. 18 Headlamp Beam Adjustment Screw
1 - ADJUSTMENT SCREW LOCATION
Fig. 19 Headlamp Beam Adjustment
Fig. 20 License Plate Lamp Housing
1 - LICENSE PLATE LAMP
2 - CONNECTOR
3 - LIFTGATE
8L - 18 LAMPS/LIGHTING - EXTERIORWJ
LICENSE PLATE LAMP (Continued)

INSTALLATION
(1) Install the license plate lamps, and the flip up
glass switch, if equipped.
(2) Connect the wire harnesses for the license
plate lamps and the flip up glass switch.
(3) Install the lamp housing/trim panel on the lift-
gate.
LEFT MULTI-FUNCTION
SWITCH
DESCRIPTION
The left multi-function switch, its mounting provi-
sions, and its electrical connections are all concealed
beneath the steering column shrouds, just below the
steering wheel (Fig. 22).
A single connector with eleven terminal pins is
located on the back of the switch housing and con-
nects the switch to the vehicle electrical system. The
left multi-function switch supports the following exte-
rior lighting functions:
²Auto Headlamps
²Front Fog Lamps
²Hazard Warning Control
²Headlamps
²Headlamp Beam Selection
²Headlamp Optical Horn
²Park Lamps
²Rear Fog Lamps
²Turn Signal Control
The left multi-function switch also supports the fol-
lowing interior lighting functions:
²Panel Lamps Dimming
²Interior Lamps Defeat²Interior Lamps On
²Parade Mode
The left multi-function switch cannot be adjusted
or repaired. If any function of the switch is faulty, or
if the switch is damaged, the entire switch unit must
be replaced.
OPERATION
The left multi-function switch uses a combination
of resistor multiplexed and conventionally switched
outputs to control the many functions and features it
provides using a minimal number of hard wired cir-
cuits. The switch is grounded to the chassis beneath
the center floor console, just forward of the Airbag
Control Module (ACM). Following are descriptions of
the how the left multi-function switch operates to
control the many exterior lighting functions and fea-
tures it provides:
²Auto Headlamps- The automatic headlamps
feature is provided by the Body Control Module
(BCM), which monitors an input from a photodiode
sensor located on the top of the instrument panel to
detect ambient light levels whenever the ignition
switch is in the On position. Based upon the multi-
plexed input from the left multi-function switch and
the input of the photodiode sensor, the BCM controls
outputs to the park lamp and headlamp relays to
illuminate or extinguish all exterior lighting.
²Front Fog Lamps- The Body Control Module
(BCM) monitors the left multi-function switch then,
based upon that switched ground input, controls an
output to the front fog lamp relay to illuminate or
extinguish the front fog lamps.
Fig. 21 License Plate Lamp Housing
1 - LICENSE PLATE LAMP
2 - CONNECTOR
3 - LIFTGATE
Fig. 22 Left (Lighting) Multi-Function Switch
1 - EXTERIOR LIGHTING CONTROL
2 - INTERIOR LIGHTING CONTROL
3 - CONTROL STALK
4 - HAZARD WARNING BUTTON
5 - CANCEL ACTUATOR
6 - LEFT (LIGHTING) MULTI-FUNCTION SWITCH
WJLAMPS/LIGHTING - EXTERIOR 8L - 19
LICENSE PLATE LAMP UNIT (Continued)

²Hazard Warning Control- The hazard warn-
ing push button is pressed down to activate the haz-
ard warning system, and pressed down again to turn
the system off. The left multi-function switch pro-
vides a ground to the hazard warning sense input of
the combination flasher to control activation of the
hazard warning lamps.
²Headlamps- The Body Control Module (BCM)
monitors the left multi-function switch then, based
upon that multiplexed input, controls an output to
the headlamp low or high beam relays to illuminate
or extinguish the headlamps.
²Headlamp Beam Selection- The Body Control
Module (BCM) monitors the left multi-function
switch then, based upon that switched ground input,
controls an output to the headlamp low or high beam
relays to activate the selected headlamp beam.
²Headlamp Optical Horn- The Body Control
Module (BCM) monitors the left multi-function
switch then, based upon that switched ground input,
controls an output to the headlamp high beam relay
to activate the headlamp high beams.
²Park Lamps- The Body Control Module (BCM)
monitors the left multi-function switch then, based
upon that multiplexed input, controls an output to
the park lamp relay to illuminate or extinguish the
parking lamps.
²Rear Fog Lamps- The Body Control Module
(BCM) monitors the left multi-function switch then,
based upon that multiplexed input, controls an out-
put to the rear fog lamp relay to illuminate or extin-
guish the rear fog lamps.
²Turn Signal Control- The left multi-function
switch control stalk actuates the turn signal switch.
The Body Control Module (BCM) monitors the left
multi-function switch then, based upon that multi-
plexed input, provides a variable voltage output to
control the lighting of the turn signals.
Following are descriptions of the how the left
multi-function switch operates to control the many
interior lighting functions and features it provides:
²Panel Lamps Dimming- The Body Control
Module (BCM) monitors the left multi-function
switch then, based upon that multiplexed input, pro-
vides a variable voltage output through several panel
lamps driver circuits to control the lighting of many
incandescent panel lamps. The BCM also sends panel
lamps dimming messages over the Programmable
Communications Interface (PCI) data bus to other
modules to control Display lighting levels in those
modules.²Interior Lamps Defeat- The Body Control
Module (BCM) monitors the left multi-function
switch then, based upon that multiplexed input,
internally disables the function the BCM normally
provides to control the illumination of the interior
lamps.
²Interior Lamps On- The Body Control Module
(BCM) monitors the left multi-function switch then,
based upon that multiplexed input, provides a control
output to activate all of the interior lamp circuits.
²Parade Mode- The Body Control Module
(BCM) monitors the left multi-function switch then,
based upon that multiplexed input, provides a volt-
age output through several panel lamps driver cir-
cuits to control the lighting of many incandescent
panel lamps. The BCM also sends panel lamps dim-
ming messages over the Programmable Communica-
tions Interface (PCI) data bus to other modules on
the bus to control lighting levels in those modules.
DIAGNOSIS AND TESTING - LEFT MULTI -
FUNCTION SWITCH
Refer to the appropriate wiring information.
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. Disconnect the instrument panel wire harness
connector from the multi-function switch connector.
(2) Using an ohmmeter, perform the continuity
and resistance tests at the terminals in the multi-
function switch connector as shown in the Left Multi-
Function Switch Test chart (Fig. 23).
8L - 20 LAMPS/LIGHTING - EXTERIORWJ
LEFT MULTI-FUNCTION SWITCH (Continued)

LEFT (LIGHTING) MULTI-FUNCTION SWITCH
TURN SIGNAL AND HAZARD WARNING SWITCH TESTS
SWITCH POSITION CONTINUITY
BETWEEN
TURN HAZARD
Neutral Off No Related Continuity
Left Off Pins2&8
Right Off Pins2&7
Neutral On Pins2&9
EXTERIOR LIGHTING SWITCH TESTS
SWITCH POSITION CONTINUITY
BETWEENRESISTANCE
BETWEENRESISTANCE RANGE (OHMS)
Off - Pins4&113743 - 3824
Park Lamps On - Pins4&11 901-926
Head Lamps On - Pins4&11 345-358
Auto Headlamps On - Pins4&11 74-81
Fog Lamps Pins1&2 - -
Optical Horn Pins2&5 - -
High Beam Pins2&6 - -
INTERIOR LIGHTING SWITCH TESTS
Dome Lamp Disable
On- Pins4&9 63-70
Panel Lamps
Dimming Position 1- Pins4&9 198-208
Dimming Position 2 - Pins4&9 551-569
Dimming Position 3 - Pins4&9 905-929
Dimming Position 4 - Pins4&91258 - 1290
Dimming Position 5 - Pins4&9 1611-1651
Dimming Position 6 - Pins4&91965 - 2011
Parade Mode On - Pins4&93534 - 3611
Dome Lamp Enable
On- Pins4&9 7811-7974
Fig. 23 Left Multi -Function Switch Test
WJLAMPS/LIGHTING - EXTERIOR 8L - 21
LEFT MULTI-FUNCTION SWITCH (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)

PROGRAMMABLE FEATURES
²LANGUAGE?-The options include English,
Francaise, Deutsch, Italiana, or Espanol. The default is
English. All EVIC display nomenclature, including the
trip computer functions, warning messages and the pro-
grammable features appear in the selected language.
²DISPLAY U.S. OR METRIC?- The options
include U.S. and M. The default is U.S. This feature
toggles the trip computer temperature, fuel economy
and odometer display readings between U.S. and
metric units of measure. It also changes the odome-
ter display in the instrument cluster.
²AUTO DOOR LOCKS?- The options include
Yes and No. The default is Yes. When Yes is selected,
all doors and the liftgate lock automatically when
vehicle speed reaches 25 kilometers-per-hour (15
miles-per-hour). If YES is selected, a second program-
mable feature appears,AUTO UNLOCK ON EXIT?
- The options again include Yes and No. The default
is No. When Yes is selected, following each Auto Door
Lock event all doors and the liftgate will automati-
cally unlock when the driver door is opened, if the
vehicle is stopped and the transmission gear selector
is in Park or Neutral. The Auto Door Unlock event
will only occur once following each Auto Door Lock
event.
²REMOTE UNLOCK- The options include
Driver Door 1st and All Doors. The default is Driver
Door 1st. When Diver Door 1st is selected, only the
driver door unlocks when the Unlock button of the
Remote Keyless Entry (RKE) transmitter is
depressed once. The Unlock button of the RKE trans-
mitter must be depressed twice to unlock all doors
and the liftgate. When All Doors is selected, all doors
and the liftgate unlock when the Unlock button of
the RKE transmitter is depressed once.
²REMOTE LINKED TO MEMORY?- This pro-
grammable feature only applies to vehicles equipped
with the optional memory system. The options
include Yes and No. The default is No. When Yes is
selected, the memory system will recall the Driver 1
or Driver 2 memory settings assigned to the RKE
transmitter being used to unlock the vehicle. When
No is selected, the memory system will only recall
memory settings when the Driver 1 or Driver 2 push
buttons of the memory switch on the driver side front
door trim panel are depressed.
²SOUND HORN ON LOCK?- The options
include Yes and No. The default is No. When Yes is
selected, a short horn chirp will provide an audible
confirmation when the RKE receiver recognizes a
valid Lock signal from an RKE transmitter. When No
is selected, no horn chirp will occur with the RKE
Lock event. This feature may be selected indepen-
dent of theFLASH LIGHTS WITH LOCKS?pro-
grammable feature.²FLASH LIGHTS WITH LOCKS?- The options
include Yes and No. The default is Yes. When Yes is
selected, a single flash of the hazard warning lamps
will provide an optical confirmation when the RKE
receiver recognizes a valid Lock signal from an RKE
transmitter, and two flashes of the same lamps will
occur when the RKE receiver recognizes a valid
Unlock signal from an RKE transmitter. When No is
selected, no lamp flash will occur with the RKE Lock
or Unlock event. This feature may be selected inde-
pendent of theSOUND HORN ON LOCK?pro-
grammable feature.
²HEADLAMP DELAY =- The options include
Off, 30 Sec, 60 Sec, and 90 Sec. The default is 90 Sec.
When a time interval is selected, the headlamps will
remain on for that length of time when the head-
lamps are turned off after the ignition is turned off,
or if the Auto mode is selected on vehicles with the
Auto Headlamps option. When Off is selected, the
headlamp delay feature is disabled.
²HEADLAMPS ON WITH WIPERS?- This pro-
grammable feature only applies to vehicles equipped
with the optional Auto Headlamps. The options
include Yes and No. The default is No. When Yes is
selected, the headlamps will turn on automatically
when the windshield wipers are turned on. The head-
lamps will turn off when the wipers are turned off,
as long as the headlamp switch is in the Auto or Off
positions. When No is selected, the headlamps will
only turn on if manually selected or if the Auto mode
is selected and the outside ambient light levels dic-
tate that they should be on.
²SERVICE INTV. =- The options include from
1000 to 12000 kilometers in 1000 kilometer incre-
ments (2000 to 7500 miles in 500 mile increments).
The default is 12000 kilometers (7500 miles). The
selected distance becomes the interval at which the
Perform Service warning message will be displayed
by the EVIC. If a new distance is selected, a second
programmable feature appears,RESET SERVICE
DISTANCE?- The options include No and Yes. The
default is Yes. When Yes is selected, the accumulated
distance since the last previous Perform Service
warning message will be reset to zero because the
service interval has been changed. When No is
selected, the distance until the next Perform Service
warning message is reduced by the accumulated dis-
tance since the last previous message.
²LOW FUEL CHIME?- The options include Yes
and No. The default is Yes. When Yes is selected, a
single chime will sound as an audible alert whenever
the instrument cluster low fuel warning lamp lights.
The chime will sound only once per ignition cycle.
When No is selected, only the low fuel warning lamp
in the instrument cluster will light and no chime will
sound.
WJMESSAGE SYSTEMS 8M - 3
OVERHEAD CONSOLE (Continued)

AMBIENT TEMP SENSOR
DESCRIPTION
Ambient air temperature is monitored by the Elec-
tronic Vehicle Information Center (EVIC) through
ambient temperature messages received from the
Body Control Module (BCM) over the Programmable
Communications Interface (PCI) data bus network.
The BCM receives a hard wired input from the ambi-
ent temperature sensor. The ambient temperature
sensor is a variable resistor mounted to a bracket
that is secured with a screw to the right side of the
headlamp mounting module grille opening, behind
the radiator grille and in front of the engine compart-
ment.
Refer toBody Control Modulein Electronic Con-
trol Modules. For complete circuit diagrams, refer to
the appropriate wiring information. The ambient
temperature sensor cannot be adjusted or repaired
and, if faulty or damaged, it must be replaced.
OPERATION
The ambient temperature sensor is a variable
resistor that operates on a five-volt reference signal
sent to it by the BCM. The resistance in the sensor
changes as temperature changes, changing the tem-
perature sensor signal circuit voltage to the BCM.
Based upon the resistance in the sensor, the BCM
senses a specific voltage on the temperature sensor
signal circuit, which it is programmed to correspond
to a specific temperature. The BCM then sends the
proper ambient temperature messages to the EVIC
over the PCI data bus.
The temperature function is supported by the
ambient temperature sensor, a wiring circuit, the
Body Control Module (BCM), the Programmable
Communications Interface (PCI) data bus, and a por-
tion of the Electronic Vehicle Information Center
(EVIC) module. If any portion of the ambient temper-
ature sensor circuit fails, the BCM will self-diagnose
the circuit. A temperature reading of 130É F will
appear in the EVIC display in place of the tempera-
ture when the sensor circuit is shorted. A tempera-
ture reading of ±40É F will appear in the EVIC
display in place of the temperature when the sensor
circuit is open.
The ambient temperature sensor circuit can also be
diagnosed by referring toDiagnosis and Testing -
Ambient Temperature Sensor, and Diagnosis
and Testing - Ambient Temperature Sensor Cir-
cuit. If the temperature sensor and circuit are con-
firmed to be OK, but the temperature display is
inoperative or incorrect, refer toDiagnosis and
Testing - Electronic Vehicle Information Center
in this group. For complete circuit diagrams, refer to
the appropriate wiring information.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - AMBIENT
TEMPERATURE SENSOR
(1) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the ambient temperature sensor wire har-
ness connector.
(2) Measure the resistance of the ambient temper-
ature sensor. At ±40É C (±40É F), the sensor resis-
tance is 336.6 kilohms. At 60É C (140É F), the sensor
resistance is 2.49 kilohms. The sensor resistance
should read between these two values. If OK, refer to
Diagnosis and Testing - Ambient Temperature
Sensor Circuitin this group. If not OK, replace the
faulty ambient temperature sensor.
DIAGNOSIS AND TESTING - AMBIENT
TEMPERATURE SENSOR CIRCUIT
(1) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the 2-way ambient temperature sensor
wire harness connector and the 22-way Body Control
Module (BCM) wire harness connector.
(2) Connect a jumper wire between the two termi-
nals in the body half of the 2-way ambient tempera-
ture sensor wire harness connector.
(3) Check for continuity between the sensor return
circuit and the ambient temperature sensor signal
circuit cavities of the 22-way BCM wire harness con-
nector. There should be continuity. If OK, go to Step
4. If not OK, repair the open sensor return circuit or
ambient temperature sensor signal circuit to the
ambient temperature sensor as required.
(4) Remove the jumper wire from the body half of
the 2-way ambient temperature sensor wire harness
connector. Check for continuity between the sensor
return circuit cavity of the 22-way BCM wire harness
connector and a good ground. There should be no
continuity. If OK, go to Step 5. If not OK, repair the
shorted sensor return circuit as required.
(5) Check for continuity between the ambient tem-
perature sensor signal circuit cavity of the 22-way
BCM wire harness connector and a good ground.
There should be no continuity. If OK, refer toDiag-
nosis and Testing - Electronic Vehicle Informa-
tion Centerin this group. If not OK, repair the
shorted ambient temperature sensor signal circuit as
required.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
8M - 12 MESSAGE SYSTEMSWJ