bulb JEEP LIBERTY 2002 KJ / 1.G Owner's Guide

ible when it is not illuminated. An amber Light
Emitting Diode (LED) behind the cutout in the
opaque layer of the overlay causes the ªTRANS
TEMPº text to appear in amber through the translu-
cent outer layer of the overlay when the indicator is
illuminated from behind by the LED, which is sol-
dered onto the instrument cluster electronic circuit
board. The transmission over-temperature indicator
is serviced as a unit with the instrument cluster.
OPERATION
The transmission over-temperature indicator gives
an indication to the vehicle operator when the trans-
mission fluid temperature is excessive, which may
lead to accelerated transmission component wear or
failure. This indicator is controlled by a transistor on
the instrument cluster electronic circuit board based
upon the cluster programming and electronic mes-
sages received by the cluster from the Powertrain
Control Module (PCM) over the Programmable Com-
munications Interface (PCI) data bus. The transmis-
sion over-temperature indicator Light Emitting Diode
(LED) is completely controlled by the instrument
cluster logic circuit, and that logic will only allow
this indicator to operate when the instrument cluster
receives a battery current input on the fused ignition
switch output (run-start) circuit. Therefore, the LED
will always be off when the ignition switch is in any
position except On or Start. The LED only illumi-
nates when it is provided a path to ground by the
instrument cluster transistor. The instrument cluster
will turn on the transmission over-temperature indi-
cator for the following reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position the transmission over-tem-
perature indicator is illuminated for about three sec-
onds as a bulb test.
²Trans Over-Temp Lamp-On Message- Each
time the cluster receives a trans over-temp lamp-on
message from the PCM indicating that the transmis-
sion fluid temperature is 135É C (275É F) or higher,
the indicator will be illuminated. The indicator
remains illuminated until the cluster receives a trans
over-temp lamp-off message from the PCM, or until
the ignition switch is turned to the Off position,
whichever occurs first.
²Actuator Test- Each time the cluster is put
through the actuator test, the trans over-temp indi-
cator will be turned on, then off again during the
bulb check portion of the test to confirm the function-
ality of the LED and the cluster control circuitry.
The PCM continually monitors the transmission
temperature sensor to determine the transmission
operating condition. The PCM then sends the proper
trans over-temp lamp-on and lamp-off messages to
the instrument cluster. If the instrument clusterturns on the transmission over-temperature indicator
due to a high transmission oil temperature condition,
it may indicate that the transmission and/or the
transmission cooling system are being overloaded or
that they require service. For further diagnosis of the
transmission over-temperature indicator or the
instrument cluster circuitry that controls the indica-
tor, (Refer to 8 - ELECTRICAL/INSTRUMENT
CLUSTER - DIAGNOSIS AND TESTING). For
proper diagnosis of the transmission temperature
sensor, the PCM, the PCI data bus, or the electronic
message inputs to the instrument cluster that control
the transmission over-temperature indicator, a
DRBIIItscan tool is required. Refer to the appropri-
ate diagnostic information.
TURN SIGNAL INDICATOR
DESCRIPTION
Two turn signal indicators, one right and one left,
are standard equipment on all instrument clusters.
The turn signal indicators are located near the upper
edge of the instrument cluster, between the speedom-
eter and the tachometer. Each turn signal indicator
consists of a stencil-like cutout of the International
Control and Display Symbol icon for ªTurn Warningº
in the opaque layer of the instrument cluster overlay.
The dark outer layer of the overlay prevents these
icons from being clearly visible when they are not
illuminated. A green Light-Emitting Diode (LED)
behind each cutout in the opaque layer of the cluster
overlay causes the indicator to appear in green
through the translucent outer layer of the overlay
when it is illuminated from behind by the LED,
which is soldered onto the instrument cluster elec-
tronic circuit board. The turn signal indicators are
serviced as a unit with the instrument cluster.
OPERATION
The turn signal indicators give an indication to the
vehicle operator that the turn signal (left or right
indicator flashing) or hazard warning (both left and
right indicators flashing) have been selected and are
operating. These indicators are controlled by two
individual hard wired inputs from the combination
flasher circuitry within the hazard switch to the
instrument cluster electronic circuit board. Each turn
signal indicator Light Emitting Diode (LED) is
grounded on the instrument cluster electronic circuit
board at all times; therefore, these indicators remain
functional regardless of the ignition switch position.
Each LED will only illuminate when it is provided
battery current by the combination flasher circuitry
of the hazard switch.
8J - 34 INSTRUMENT CLUSTERKJ
TRANS TEMP INDICATOR (Continued)

The turn signal indicators are connected in parallel
with the other turn signal circuits. This arrangement
allows the turn signal indicators to remain func-
tional, regardless of the condition of the other cir-
cuits in the turn signal and hazard warning systems.
The combination flasher outputs of the hazard switch
to the instrument cluster turn signal indicator inputs
can be diagnosed using conventional diagnostic tools
and methods. (Refer to 8 - ELECTRICAL/LAMPS/
LIGHTING - EXTERIOR/HAZARD SWITCH -
DESCRIPTION) for more information on the combi-
nation flasher and hazard switch operation.
WAIT-TO-START INDICATOR
DESCRIPTION
A wait-to-start indicator is only found in the
instrument clusters of vehicles equipped with an
optional diesel engine. The wait-to-start indicator is
located above the fuel gauge and to the left of the
tachometer in the instrument cluster. The wait-to-
start indicator consists of a stencil-like cutout of the
International Control and Display Symbol icon for
ªDiesel Preheatº in the opaque layer of the instru-
ment cluster overlay. The dark outer layer of the
overlay prevents the indicator from being clearly vis-
ible when it is not illuminated. An amber Light
Emitting Diode (LED) behind the cutout in the
opaque layer of the overlay causes the icon to appear
in amber through the translucent outer layer of the
overlay when it is illuminated from behind by the
LED, which is soldered onto the instrument cluster
electronic circuit board. The wait-to-start indicator is
serviced as a unit with the instrument cluster.
OPERATION
The wait-to-start indicator gives an indication to
the vehicle operator when the diesel engine glow
plugs are energized in their pre-heat operating mode.
This indicator is controlled by a transistor on the
instrument cluster electronic circuit board based
upon the cluster programming and electronic mes-
sages received by the cluster from the Powertrain
Control Module (PCM) over the Programmable Com-
munications Interface (PCI) data bus. The wait-to-
start indicator Light Emitting Diode (LED) is
completely controlled by the instrument cluster logic
circuit, and that logic will only allow this indicator to
operate when the instrument cluster receives a bat-
tery current input on the fused ignition switch out-
put (run-start) circuit. Therefore, the LED will
always be off when the ignition switch is in any posi-
tion except On or Start. The LED only illuminates
when it is provided a path to ground by the instru-
ment cluster transistor. The instrument cluster willturn on the wait-to-start indicator for the following
reasons:
²Wait-To-Start Lamp-On Message- Each time
the cluster receives a wait-to-start lamp-on message
from the PCM indicating the glow plugs are heating
and the driver must wait to start the engine, the
wait-to-start indicator will be illuminated. The indi-
cator remains illuminated until the cluster receives a
wait-to-start lamp-off message, or until the ignition
switch is turned to the Off position, whichever occurs
first.
²Actuator Test- Each time the cluster is put
through the actuator test, the wait-to-start indicator
will be turned on, then off again during the bulb
check portion of the test to confirm the functionality
of the LED and the cluster control circuitry.
The PCM continually monitors the ambient tem-
perature and the glow plug pre-heater circuits to
determine how long the glow plugs must be heated in
the pre-heat operating mode. The PCM then sends
the proper wait-to-start lamp-on and lamp-off mes-
sages to the instrument cluster. For further diagnosis
of the wait-to-start indicator or the instrument clus-
ter circuitry that controls the indicator, (Refer to 8 -
ELECTRICAL/INSTRUMENT CLUSTER - DIAGNO-
SIS AND TESTING). For proper diagnosis of the
glow plug pre-heater control circuits, the PCM, the
PCI data bus, or the electronic message inputs to the
instrument cluster that control the wait-to-start indi-
cator, a DRBIIItscan tool is required. Refer to the
appropriate diagnostic information.
WASHER FLUID INDICATOR
DESCRIPTION
A washer fluid indicator is standard equipment on
all instrument clusters. The washer fluid indicator
consists of the text ªlowashº, which appears in place
of the odometer/trip odometer information in the Vac-
uum-Fluorescent Display (VFD) of the instrument
cluster. The VFD is part of the cluster electronic cir-
cuit board, and is visible through a cutout located
near the lower edge of the speedometer dial face in
the instrument cluster. The dark outer layer of the
overlay prevents the VFD from being clearly visible
when it is not illuminated. The text message
ªlowashº appears in the same blue-green color and at
the same lighting level as the odometer/trip odometer
information through the translucent outer layer of
the overlay when it is illuminated by the instrument
cluster electronic circuit board. The washer fluid
indicator is serviced as a unit with the instrument
cluster.
KJINSTRUMENT CLUSTER 8J - 35
TURN SIGNAL INDICATOR (Continued)

ity of the headlamp and dash wire harness connector
for the washer fluid level switch and a good ground.
There should be continuity. If OK, go to Step 2. If not
OK, repair the open ground circuit to ground (G111)
as required.
(2) Remove the instrument cluster from the instru-
ment panel. Check for continuity between the washer
fluid sense circuit cavities of the headlamp and dash
wire harness connector for the washer fluid level
switch and the instrument panel wire harness con-
nector (Connector C2) for the instrument cluster. If
OK, replace the faulty washer fluid level switch. If
not OK, repair the open washer fluid switch sense
circuit between the washer fluid level switch and the
instrument cluster as required.
INDICATOR STAYS ILLUMINATED WITH WASHER
RESERVOIR FULL
(1) Disconnect and isolate the battery negative
cable. Disconnect the headlamp and dash wire har-
ness connector for the washer fluid level switch from
the washer fluid level switch connector receptacle.
Check for continuity between the ground circuit ter-
minal and the washer fluid sense terminal in the
washer fluid level switch connector receptacle. There
should be no continuity. If OK, go to Step 2. If not
OK, replace the faulty washer fluid level switch.
(2) Remove the instrument cluster from the instru-
ment panel. Check for continuity between the washer
fluid sense circuit cavity of the headlamp and dash
wire harness connector for the washer fluid level
switch and a good ground. There should be no conti-
nuity. If not OK, repair the shorted washer fluid
switch sense circuit between the washer fluid level
switch and the instrument cluster as required.
WATER-IN-FUEL INDICATOR
DESCRIPTION
A water-in-fuel indicator is only found in the
instrument clusters of vehicles equipped with an
optional diesel engine. The water-in-fuel indicator is
located above the coolant temperature gauge and to
the right of the speedometer in the instrument clus-
ter. The water-in-fuel indicator consists of a stencil-
like cutout of the International Control and Display
Symbol icon for ªWater In Fuelº in the opaque layer
of the instrument cluster overlay. The dark outer
layer of the overlay prevents the indicator from being
clearly visible when it is not illuminated. A red Light
Emitting Diode (LED) behind the cutout in the
opaque layer of the overlay causes the icon to appear
in red through the translucent outer layer of the
overlay when the indicator is illuminated from
behind by the LED, which is soldered onto the
instrument cluster electronic circuit board. Thewater-in-fuel indicator is serviced as a unit with the
instrument cluster.
OPERATION
The water-in-fuel indicator gives an indication to
the vehicle operator when there is excessive water in
the fuel system. This indicator is controlled by a
transistor on the instrument cluster electronic circuit
board based upon cluster programming and elec-
tronic messages received by the cluster from the
Powertrain Control Module (PCM) over the Program-
mable Communications Interface (PCI) data bus. The
water-in-fuel indicator Light Emitting Diode (LED) is
completely controlled by the instrument cluster logic
circuit, and that logic will only allow this indicator to
operate when the instrument cluster receives a bat-
tery current input on the fused ignition switch out-
put (run-start) circuit. Therefore, the LED will
always be off when the ignition switch is in any posi-
tion except On or Start. The LED only illuminates
when it is provided a path to ground by the instru-
ment cluster transistor. The instrument cluster will
turn on the water-in-fuel indicator for the following
reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position the water-in-fuel indicator
is illuminated for about three seconds as a bulb test.
²Water-In-Fuel Lamp-On Message- Each time
the cluster receives a water-in-fuel lamp-on message
from the PCM indicating there is excessive water in
the diesel fuel system, the water-in-fuel indicator will
be illuminated. The indicator remains illuminated
until the cluster receives a water-in-fuel lamp-off
message, or until the ignition switch is turned to the
Off position, whichever occurs first.
²Actuator Test- Each time the cluster is put
through the actuator test, the water-in-fuel indicator
will be turned on, then off again during the bulb
check portion of the test to confirm the functionality
of the LED and the cluster control circuitry.
The PCM continually monitors the water-in-fuel
sensor to determine whether there is excessive water
in the diesel fuel. The PCM then sends the proper
water-in-fuel lamp-on and lamp-off messages to the
instrument cluster. For further diagnosis of the
water-in-fuel indicator or the instrument cluster cir-
cuitry that controls the indicator, (Refer to 8 - ELEC-
TRICAL/INSTRUMENT CLUSTER - DIAGNOSIS
AND TESTING). For proper diagnosis of the water-
in-fuel-sensor, the PCM, the PCI data bus, or the
electronic message inputs to the instrument cluster
that control the water-in-fuel indicator, a DRBIIIt
scan tool is required. Refer to the appropriate diag-
nostic information.
KJINSTRUMENT CLUSTER 8J - 37
WASHER FLUID INDICATOR (Continued)

LAMPS
TABLE OF CONTENTS
page page
LAMPS/LIGHTING - EXTERIOR............... 1LAMPS/LIGHTING - INTERIOR............... 65
LAMPS/LIGHTING - EXTERIOR
TABLE OF CONTENTS
page page
LAMPS/LIGHTING - EXTERIOR
DESCRIPTION..........................2
OPERATION............................5
DIAGNOSIS AND TESTING - LAMPS/
LIGHTING - EXTERIOR..................7
SPECIFICATIONS - LAMPS/LIGHTING -
EXTERIOR...........................15
BACKUP LAMP SWITCH
DESCRIPTION.........................15
OPERATION...........................15
DIAGNOSIS AND TESTING - BACKUP LAMP
SWITCH............................15
BRAKE LAMP SWITCH
DESCRIPTION.........................16
OPERATION...........................16
DIAGNOSIS AND TESTING - BRAKE LAMP
SWITCH............................17
REMOVAL.............................17
INSTALLATION.........................18
CENTER HIGH MOUNTED STOP LAMP BULB
REMOVAL.............................18
INSTALLATION.........................19
CENTER HIGH MOUNTED STOP LAMP UNIT
REMOVAL.............................19
INSTALLATION.........................19
COMBINATION FLASHER
DESCRIPTION.........................19
OPERATION...........................19
DAYTIME RUNNING LAMP RELAY
DESCRIPTION.........................20
OPERATION...........................20
REMOVAL.............................21
INSTALLATION.........................21
FRONT FOG LAMP BULB
REMOVAL.............................21
INSTALLATION.........................22FRONT FOG LAMP RELAY
DESCRIPTION.........................22
OPERATION...........................22
DIAGNOSIS AND TESTING - FRONT FOG
LAMP RELAY.........................23
REMOVAL.............................24
INSTALLATION.........................24
FRONT FOG LAMP UNIT
REMOVAL.............................25
INSTALLATION.........................25
ADJUSTMENTS
ADJUSTMENT - FRONT FOG LAMP UNIT . . . 25
FRONT LAMP BULB
REMOVAL.............................26
INSTALLATION.........................27
FRONT LAMP UNIT
REMOVAL.............................27
INSTALLATION.........................28
FRONT POSITION LAMP BULB
REMOVAL.............................28
INSTALLATION.........................28
HAZARD SWITCH
DESCRIPTION.........................29
OPERATION...........................29
REMOVAL.............................30
INSTALLATION.........................30
HEADLAMP BULB
REMOVAL.............................31
INSTALLATION.........................32
HEADLAMP HIGH BEAM RELAY
DESCRIPTION.........................33
OPERATION...........................33
DIAGNOSIS AND TESTING - HEADLAMP
HIGH BEAM RELAY....................34
REMOVAL.............................34
INSTALLATION.........................35
KJLAMPS 8L - 1

HEADLAMP LEVELING MOTOR
DESCRIPTION.........................35
OPERATION...........................36
REMOVAL.............................36
INSTALLATION.........................36
HEADLAMP LEVELING SWITCH
DESCRIPTION.........................37
OPERATION...........................37
DIAGNOSIS AND TESTING - HEADLAMP
LEVELING SWITCH....................37
REMOVAL.............................38
INSTALLATION.........................38
HEADLAMP LOW BEAM RELAY
DESCRIPTION.........................39
OPERATION...........................39
DIAGNOSIS AND TESTING - HEADLAMP LOW
BEAM RELAY........................40
REMOVAL.............................40
INSTALLATION.........................41
HEADLAMP UNIT
REMOVAL.............................41
INSTALLATION.........................42
ADJUSTMENTS
ADJUSTMENT - HEADLAMP UNIT........42
LICENSE PLATE LAMP BULB
REMOVAL.............................44
INSTALLATION.........................45
LICENSE PLATE LAMP UNIT
REMOVAL.............................45
INSTALLATION.........................46
MULTI-FUNCTION SWITCH
DESCRIPTION.........................46
OPERATION...........................48
DIAGNOSIS AND TESTING - MULTI-
FUNCTION SWITCH...................50
REMOVAL.............................53
INSTALLATION.........................53
PARK LAMP RELAY
DESCRIPTION.........................54OPERATION...........................54
DIAGNOSIS AND TESTING - PARK LAMP
RELAY..............................55
REMOVAL.............................55
INSTALLATION.........................56
REAR FOG LAMP RELAY
DESCRIPTION.........................56
OPERATION...........................57
DIAGNOSIS AND TESTING - REAR FOG
LAMP RELAY.........................57
REMOVAL.............................58
INSTALLATION.........................58
REAR LAMP BULB
REMOVAL.............................58
INSTALLATION.........................59
REAR LAMP UNIT
REMOVAL.............................59
INSTALLATION.........................60
REPEATER LAMP BULB
REMOVAL.............................60
INSTALLATION.........................60
REPEATER LAMP UNIT
REMOVAL.............................60
INSTALLATION.........................61
TRAILER TOW CONNECTOR
REMOVAL.............................61
INSTALLATION.........................61
TRAILER TOW RELAY
DESCRIPTION.........................61
OPERATION...........................62
DIAGNOSIS AND TESTING - TRAILER TOW
RELAY..............................62
REMOVAL.............................63
INSTALLATION.........................64
TRAILER TOW WIRING
DESCRIPTION.........................64
LAMPS/LIGHTING - EXTERIOR
DESCRIPTION
The exterior lighting system for this model
includes the following exterior lamps (Fig. 1):
²Backup Lamps- The backup (or reverse) lamps
are integral to the rear lamp units mounted to the
back of the quarter panel on each side of the tailgate
at the rear of the vehicle.
²Brake Lamps- The brake (or stop) lamps
include a lamp that is integral to the rear lamp units
mounted to the back of the quarter panel on each
side of the tailgate, and the Center High Mounted
Stop Lamp (CHMSL) that is centered on the rear
edge of the roof panel above the flip-up glass opening
at the rear of the vehicle.²Daytime Running Lamps- Vehicles manufac-
tured for sale in Canada illuminate the high beam
filament in each headlamp bulb serves as the Day-
time Running Lamps (DRL).
²Front Fog Lamps- Optional front fog lamps
include a single round front fog lamp unit with an
adjustable reflector and a removable bulb that is
secured behind a dedicated opening on each forward-
facing end of the front bumper fascia.
²Hazard Warning Lamps- The hazard warning
lamps include all of the right and left turn signal
lamps.
²Headlamps- A single round headlamp housing
with a fixed lens, an adjustable reflector, and a single
removable halogen bulb is secured to the grille open-
ing panel on each side of the grille opening at the
8L - 2 LAMPS/LIGHTING - EXTERIORKJ

DRL relay is energized, it provides battery current
from a fused B(+) fuse in the JB to the headlamp
high beam filament through the DRL relay output
circuit.
FRONT FOG LAMPS
Vehicles equipped with optional front fog lamps
have a premium Body Control Module (BCM), a front
fog lamp relay installed in the Junction Block (JB),
and a front fog lamp switch integral to the left (light-
ing) control stalk of the multi-function switch. The
front fog lamps have a path to ground at all times
through their connection to the front fascia wire har-
ness from two take outs of the headlamp and dash
wire harness with eyelet terminal connectors that
are secured by ground screws to the left inner fender
shield in the engine compartment. The BCM controls
front fog lamp operation by monitoring the exterior
lighting switch input from the multi-function switch,
then energizing or de-energizing the front fog lamp
relay control coil; and, by sending the appropriate
electronic message to the instrument cluster over the
Programmable Communications Interface (PCI) data
bus to turn the front fog lamp indicator on or off.
When the front fog lamp relay is energized, it pro-
vides battery current from a fused B(+) fuse in the
JB to the front fog lamps through the front fog lamp
relay output circuit. The BCM provides a battery
saver (load shedding) feature for the front fog lamps,
which will turn these lamps off if they are left on for
more than about eight minutes with the ignition
switch in the Off position. In certain markets where
required, the front fog lamps are also turned off by
the BCM whenever the headlamp high beams are
selected. Each front fog lamp includes an integral
adjustment screw to be used for static aiming the fog
lamp beams.
HAZARD WARNING LAMPS
With the hazard switch in the On position, the
hazard warning system is activated causing the haz-
ard switch button illumination lamp, the right and
left turn signal indicators, and the right and left turn
signal lamps to flash on and off. When the hazard
warning system is activated, the circuitry within the
hazard switch and electronic combination flasher
unit will repeatedly energize and de-energize two
internal relays that switch battery current from a
fused B(+) fuse in the Junction Block (JB) to the
right side and left side turn signal indicators, and
turn signal lamps through the right and left turn sig-
nal circuits. The flashing of the hazard switch button
illumination lamp is performed internally by the haz-
ard switch and combination flasher unit circuit
board. The hazard warning lamps can also be ener-
gized by the Body Control Module (BCM) through ahazard lamp control circuit input to the hazard
switch and combination flasher unit.
HEADLAMPS
The headlamp system includes the Body Control
Module (BCM), a low beam relay installed in the
Junction Block (JB), a high beam relay installed in
the JB (except Canada), a solid state Daytime Run-
ning Lamps (DRL) relay installed in the JB (Canada
only), and the exterior lighting (headlamp and dim-
mer) switches integral to the left (lighting) control
stalk of the multi-function switch. The headlamp
bulbs have a path to ground at all times through
their connection to the grille opening reinforcement
wire harness from two take outs of the headlamp and
dash wire harness with eyelet terminal connectors
that are secured by ground screws to the left inner
fender shield in the engine compartment. The BCM
controls the headlamp operation by monitoring the
exterior lighting switch inputs from the multi-func-
tion switch, then energizing or de-energizing the con-
trol coils of the low beam relay, the high beam relay,
or the solid state circuitry of the DRL relay; and, by
sending the appropriate electronic message to the
instrument cluster over the Programmable Commu-
nications Interface (PCI) data bus to turn the high
beam indicator on or off. When each respective relay
is energized, it provides battery current from a fused
B(+) fuse in the Power Distribution Center (PDC)
through a relay (low beam, high beam, or DRL) out-
put circuit and four separate fuses in the JB through
individual fused right and left, low and high beam
output circuits to the appropriate headlamp bulb fil-
aments. The BCM provides a battery saver (load
shedding) feature for the headlamps, which will turn
these lamps off if they are left on for more than
about eight minutes with the ignition switch in the
Off position; and, a headlamp delay feature with a
DRBIIItscan tool programmable delay interval.
Each headlamp includes an integral adjustment
screw to be used for static aiming of the headlamp
beams.
HEADLAMP LEVELING
In certain markets where required, a headlamp
leveling system is provided on the vehicle. The head-
lamp leveling system includes unique headlamp units
equipped with a headlamp leveling actuator motor,
and a rotary thumbwheel actuated headlamp leveling
switch on the instrument panel. The headlamp level-
ing system allows the headlamp beams to be
adjusted to one of four vertical positions to compen-
sate for changes in inclination caused by the loading
of the vehicle suspension. The actuator motors are
mechanically connected through an integral pushrod
to an adjustable headlamp reflector. The headlamp
8L - 6 LAMPS/LIGHTING - EXTERIORKJ
LAMPS/LIGHTING - EXTERIOR (Continued)

leveling switch is a resistor multiplexed unit that
provides one of four voltage outputs to the headlamp
leveling motors. The headlamp leveling motors will
move the headlamps to the selected position based
upon the voltage input received from the switch. The
headlamp leveling motors and switch have a path to
ground at all times. The headlamp leveling compo-
nents operate on battery current received through
the fused park lamp relay output circuit so that the
system will only operate when the exterior lighting is
turned on.
PARK LAMPS
The park lamps system includes the Body Control
Module (BCM), a park lamp relay installed in the
Junction Block (JB), and the exterior lighting switch
integral to the left (lighting) control stalk of the
multi-function switch. The front park lamp and side
marker or, if equipped, the front position lamp bulbs
each have a path to ground at all times through their
connections to the grille opening reinforcement wire
harness from two take outs of the headlamp and
dash wire harness with eyelet terminal connectors
that are secured by ground screws to the left inner
fender shield in the engine compartment. The rear
park lamp bulbs and license plate lamp have a path
to ground at all times through their connection to the
rear lighting wire harness from a take out of the rear
body wire harness with an eyelet terminal connector
that is secured by a ground screw to the base of the
right D-pillar behind the quarter trim panel. The
BCM controls the park lamp operation by monitoring
the exterior lighting switch inputs from the multi-
function switch, then energizing or de-energizing the
control coil of the park lamp relay. When the park
lamp relay is energized, it provides battery current
from a fused B(+) fuse in the Power Distribution
Center (PDC) through a park lamp relay output cir-
cuit and a separate fuse in the JB through a fused
park lamp relay output circuit to the appropriate
lamp bulb filaments. The BCM provides a battery
saver (load shedding) feature for the park lamps,
which will turn these lamps off if they are left on for
more than about eight minutes with the ignition
switch in the Off position.
REAR FOG LAMPS
Rear fog lamps are installed on vehicles manufac-
tured for certain markets where they are required.
The rear fog lamp system includes a premium Body
Control Module (BCM), a rear fog lamp relay
installed in the Junction Block (JB), and a rear fog
lamp switch integral to the left (lighting) control
stalk of the multi-function switch. The rear fog lamps
have a path to ground at all times through their con-
nection to the rear lighting wire harness from a takeout of the rear body wire harness with an eyelet ter-
minal connector that is secured by a ground screw to
the base of the right D-pillar behind the quarter trim
panel. The BCM controls rear fog lamp operation by
monitoring the exterior lighting switch input from
the multi-function switch, then energizing or de-ener-
gizing the rear fog lamp relay control coil; and, by
sending the appropriate electronic message to the
instrument cluster over the Programmable Commu-
nications Interface (PCI) data bus to turn the rear
fog lamp indicator on or off. When the rear fog lamp
relay is energized, it provides battery current from a
fused B(+) fuse in the JB to the rear fog lamps
through the rear fog lamp relay output circuit. The
BCM provides a battery saver (load shedding) feature
for the rear fog lamps, which will turn these lamps
off if they are left on for more than about eight min-
utes with the ignition switch in the Off position.
TURN SIGNAL LAMPS
When the left control stalk of the multi-function
switch is moved up (right turn) or down (left turn),
the turn signal system is activated causing the
selected right or left turn signal indicator, and right
or left turn signal lamps to flash on and off. When
the turn signal system is activated, the circuitry
within the turn signal switch and the hazard switch/
electronic combination flasher unit will repeatedly
energize and de-energize one of two internal relays
that switch battery current from a fused ignition
switch output (run) fuse in the Junction Block (JB) to
the right side or left side turn signal indicators and
turn signal lamps through the right or left turn sig-
nal circuits. The ElectroMechanical Instrument Clus-
ter (EMIC) chime tone generator will generate an
audible turn signal cancel warning each time the
vehicle is driven for a distance of about 3.2 kilome-
ters (about two miles) with a turn signal indicator
flashing. The EMIC uses Programmable Communica-
tions Interface (PCI) data bus distance messages
from the Powertrain Control Module (PCM) and a
hard wired input from the turn signal switch cir-
cuitry of the multi-function switch to determine when
to sound the turn signal cancel warning.
DIAGNOSIS AND TESTING - LAMPS/LIGHTING
- EXTERIOR
The hard wired circuits and components of the
exterior lighting systems may be diagnosed and
tested using conventional diagnostic tools and proce-
dures. However, conventional diagnostic methods
may not prove conclusive in the diagnosis of the Body
Control Module (BCM), the ElectroMechanical
Instrument Cluster (EMIC), the Powertrain Control
Module (PCM), or the Programmable Communica-
tions Interface (PCI) data bus network. The most
KJLAMPS/LIGHTING - EXTERIOR 8L - 7
LAMPS/LIGHTING - EXTERIOR (Continued)

reliable, efficient, and accurate means to diagnose
the BCM, the EMIC, the PCM, and the PCI data bus
network inputs and outputs related to the various
exterior lighting systems requires the use of a
DRBIIItscan tool. Refer to the appropriate diagnos-
tic information.
When diagnosing the exterior lighting circuits,
remember that high generator output can burn out
bulbs rapidly and repeatedly; and, that dim or flick-
ering bulbs can be caused by low generator output or
poor battery condition. If one of these symptoms is a
problem on the vehicle being diagnosed, be certain to
diagnose and repair the battery and charging system
as required. Also keep in mind that a good ground is
necessary for proper lighting operation. If a lighting
problem is being diagnosed that involves multiple
symptoms, systems, or components the problem can
often be traced to a loose, corroded, or open ground.
For complete circuit diagrams, refer to the appropri-
ate wiring information. The wiring information
includes wiring diagrams, proper wire and connectorrepair procedures, details of wire harness routing
and retention, connector pin-out information and
location views for the various wire harness connec-
tors, splices and grounds.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER 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.
BACKUP LAMPS
CONDITION POSSIBLE CAUSES CORRECTION
BACKUP LAMP DOES
NOT ILLUMINATE1. Faulty or missing fuse. 1. Test and replace backup lamp fuse as
required.
2. Faulty or missing bulb. 2. Test and replace backup lamp bulb as
required.
3. Faulty switch. 3. Test and replace backup lamp switch
(manual transmission) or transmission
range sensor (automatic transmission) as
required.
4. Faulty ground circuit. 4. Test and repair backup lamp ground
circuit as required.
5. Faulty feed circuit. 5. Test and repair open back-up lamp feed
circuit as required.
BACKUP LAMP DOES
NOT EXTINGUISH1. Faulty switch. 1. Test and replace backup lamp switch
(manual transmission) or transmission
range sensor (automatic transmission) as
required.
2. Faulty feed circuit. 2. Test and repair shorted back-up lamp
feed circuit as required.
8L - 8 LAMPS/LIGHTING - EXTERIORKJ
LAMPS/LIGHTING - EXTERIOR (Continued)

BRAKE LAMPS
CONDITION POSSIBLE CAUSES CORRECTION
BRAKE LAMP DOES NOT
ILLUMINATE1. Faulty or missing fuse. 1. Test and replace brake lamp fuse as
required.
2. Faulty or missing bulb. 2. Test and replace brake lamp bulb as
required.
3. Faulty switch. 3. Test and replace brake lamp switch as
required.
4. Faulty ground circuit. 4. Test and repair brake lamp ground circuit
as required.
5. Faulty feed circuit. 5. Test and repair open brake lamp switch
output circuit as required.
BRAKE LAMP DOES NOT
EXTINGUISH1. Faulty switch. 1. Test and replace brake lamp switch as
required.
2. Faulty feed circuit. 2. Test and repair shorted brake lamp
switch output circuit as required.
DAYTIME RUNNING LAMPS
Before performing the following tests, determine
whether the headlamp low and high beams operate.If the headlamp high and low beams are also inoper-
ative, diagnose and repair that problem before
attempting to repair the Daytime Running Lamps.
CONDITION POSSIBLE CAUSES CORRECTION
DAYTIME RUNNING
LAMPS WILL NOT
ILLUMINATE1. High beam relay installed. 1. Remove high beam relay as required.
2. Faulty or missing DRL relay. 2. Replace DRL relay with a known good
unit and check operation. Replace DRL
relay as required.
3. Incorrect BCM programming. 3. Use a DRBIIITscan tool to check and
program correct country code into BCM as
required.
4. Faulty BCM inputs or outputs. 4. Use a DRBIIITscan tool to test the BCM
inputs or outputs. Refer to the appropriate
diagnostic information.
KJLAMPS/LIGHTING - EXTERIOR 8L - 9
LAMPS/LIGHTING - EXTERIOR (Continued)

FRONT FOG LAMPS
CONDITION POSSIBLE CAUSES CORRECTION
FRONT FOG LAMP DOES
NOT ILLUMINATE1. Faulty or missing fuse. 1. Test and replace front fog lamp fuse as
required.
2. Faulty or missing bulb. 2. Test and replace front fog lamp bulb as
required.
3. Faulty or missing relay. 3. Test and replace front fog lamp relay as
required.
4. Faulty switch. 4. Test and replace multi-function switch as
required.
5. Faulty ground circuit. 5. Test and repair front fog lamp ground
circuit as required.
6. Faulty feed circuit. 6. Test and repair open front fog lamp relay
output circuit as required.
7. Faulty BCM inputs or outputs. 7. Use a DRBIIITscan tool to test the BCM
inputs and outputs. Refer to the appropriate
diagnostic information.
FRONT FOG LAMP DOES
NOT EXTINGUISH1. Faulty relay. 1. Test and replace front fog lamp relay as
required.
2. Faulty switch. 2. Test and replace multi-function switch as
required.
3. Faulty feed circuit. 3. Test and repair shorted front fog lamp
relay output circuit as required.
4. Faulty BCM inputs or outputs. 4. Use a DRBIIITscan tool to test the BCM
inputs and outputs. Refer to the appropriate
diagnostic information.
HAZARD WARNING LAMPS
Before performing the following tests, confirm
whether the left and right turn signals operate satis-
factorily. If the turn signals are inoperative or oper-ate improperly, diagnose and repair that problem
before attempting to repair the Hazard Warning
Lamps.
CONDITION POSSIBLE CAUSES CORRECTION
HAZARD WARNING
LAMPS DO NOT FLASH1. Faulty or missing fuse. 1. Test and replace hazard warning fuse as
required.
2. Faulty ground circuit. 2. Test and repair hazard switch ground
circuit as required.
3. Faulty feed circuit. 3. Test and repair open hazard switch fused
B(+) circuit as required.
4. Faulty switch/flasher. 4. Replace hazard switch/combination
flasher with a known good unit and check
operation. Replace hazard switch/
combination flasher unit if required.
8L - 10 LAMPS/LIGHTING - EXTERIORKJ
LAMPS/LIGHTING - EXTERIOR (Continued)