2002 JEEP LIBERTY Headlamp fuse relay

NOTE: If three attempts are made to enter secured
access mode using an incorrect PIN, secured
access mode will be locked out for one hour. To
exit this lockout mode, turn the ignition switch to
the ON position for one hour, then enter the correct
PIN. (Ensure all accessories are turned off. Also
monitor the battery state and connect a battery
charger if necessary).
(6) Press ENTER to transfer the secret key (the
SKIM will send the secret key to the PCM).
(7) Press PAGE BACK to get to the Select System
menu and select ENGINE, MISCELLANEOUS, and
SRI MEMORY CHECK.
(8) The DRBIIItwill ask, ªIs odometer reading
between XX and XX?º Select the YES or NO button
on the DRBIIIt. If NO is selected, the DRBIIItwill
read, ªEnter Odometer Reading (From I.P. odome-
ter)º. Enter the odometer reading from the instru-
ment cluster and press ENTER.
PROGRAMMING THE SKIM
(1) Turn the ignition switch to the On position
(transmission in Park/Neutral).
(2) Use the DRBIIItand select THEFT ALARM,
SKIM, then MISCELLANEOUS.
(3) Select PCM REPLACED (GAS ENGINE).
(4) Program the vehicle four-digit PIN into SKIM.
(5) Select COUNTRY CODE and enter the correct
country.
NOTE: Be sure to enter the correct country code. If
the incorrect country code is programmed into
SKIM, it cannot be changed and the SKIM must be
replaced.
(6) Select YES to update VIN (the SKIM will learn
the VIN from the PCM).
(7) Press ENTER to transfer the secret key (the
PCM will send the secret key to the SKIM).
(8) Program ignition keys to the SKIM.
NOTE: If the PCM and the SKIM are replaced at the
same time, all vehicle ignition keys will need to be
replaced and programmed to the new SKIM.
PROGRAMMING IGNITION KEYS TO THE SKIM
(1) Turn the ignition switch to the On position
(transmission in Park/Neutral).
(2) Use the DRBIIItand select THEFT ALARM,
SKIM, then MISCELLANEOUS.
(3) Select PROGRAM IGNITION KEY'S.
(4) Enter secured access mode by entering the
vehicle four-digit PIN.NOTE: A maximum of eight keys can be learned to
each SKIM. Once a key is learned to a SKIM it (the
key) cannot be transferred to another vehicle.
(5) Obtain ignition keys to be programmed from
the customer (8 keys maximum).
(6) Using the DRBIIIt, erase all ignition keys by
selecting MISCELLANEOUS, and ERASE ALL CUR-
RENT IGN. KEYS.
(7) Program all of the ignition keys.
If ignition key programming is unsuccessful, the
DRBIIItwill display one of the following messages:
²Programming Not Attempted- The DRBIIIt
attempts to read the programmed key status and
there are no keys programmed into SKIM memory.
²Programming Key Failed (Possible Used
Key From Wrong Vehicle)- SKIM is unable to pro-
gram an ignition key transponder due to one of the
following:
²The ignition key transponder is faulty.
²The ignition key transponder is or has been
already programmed to another vehicle.
²8 Keys Already Learned, Programming Not
Done- The SKIM transponder ID memory is full.
²Learned Key In Ignition- The ID for the igni-
tion key transponder currently in the ignition lock
cylinder is already programmed in SKIM memory.
BODY CONTROL MODULE
DESCRIPTION
A Body Control Module (BCM) is concealed behind
the driver side end of the instrument panel in the
passenger compartment, where it is secured to the
fuse panel side of the Junction Block (JB) with four
screws (Fig. 1). The JB is the interface between the
body, the instrument panel, and the headlamp and
dash wire harnesses. The JB also contains the fuses
and relays used for the interior electrical system of
the vehicle. The BCM is enclosed in a molded plastic
housing with two integral external connector recepta-
cles that connect it to the vehicle electrical system
through two take outs with connectors from the
instrument panel wire harness (Fig. 2). The BCM
also has an integral interface connector concealed on
the back side of the unit that joins it through a con-
nector receptacle that is integral to the JB housing to
the circuitry within the JB. This connector is referred
to as the JB-BCM connector. The combined BCM and
JB are sometimes referred to as the Junction Block
Module (JBM).
8E - 2 ELECTRONIC CONTROL MODULESKJ
ELECTRONIC CONTROL MODULES (Continued)

flip-up glass ajar switch, the hood ajar switch (in
required markets only), and the Remote Keyless
Entry (RKE) module to control the features of the
optional Vehicle Theft Security System (VTSS).
Hard wired circuitry connects the BCM to the elec-
trical system of the vehicle. These hard wired circuits
are integral to several wire harnesses, which are
routed throughout the vehicle and retained by many
different methods. These circuits may be connected to
each other, to the vehicle electrical system and to the
BCM through the use of a combination of soldered
splices, splice block connectors, and many different
types of wire harness terminal connectors and insu-
lators. Refer to the appropriate wiring information.
The wiring information includes wiring diagrams,
proper wire and connector repair procedures, further
details on wire harness routing and retention, as well
as pin-out and location views for the various wire
harness connectors, splices and grounds.
Many of the electronic features in the vehicle con-
trolled or supported by the BCM are programmable
using a customer programming procedure or the
DRBIIItscan tool. In addition, the BCM software is
Flash compatible, which means it can be repro-
grammed using Flash reprogramming procedures.
However, if any of the BCM hardware components is
damaged or faulty, the entire BCM unit must be
replaced.
OPERATION
The microprocessor-based Body Control Module
(BCM) monitors many hard wired switch and sensor
inputs as well as those resources it shares with other
electronic modules in the vehicle through its commu-
nication over the Programmable Communications
Interface (PCI) data bus network. The internal pro-
gramming and all of these inputs allow the BCM
microprocessor to determine the tasks it needs to
perform and their priorities, as well as both the stan-
dard and optional features that it should provide.
The BCM programming then performs those tasks
and provides those features through both PCI data
bus communication with other electronic modules
and through hard wired outputs through a number of
driver circuits, relays, and actuators. These outputs
allow the BCM the ability to control numerous acces-
sory systems in the vehicle.
The BCM operates on battery current received
through a fuse in the Junction Block (JB) on a non-
switched fused B(+) circuit, through another fuse in
the JB on a fused ignition switch output (run-start)
circuit, and through a third fuse in the JB on a fused
ignition switch output (run-acc) circuit. This arrange-
ment allows the BCM to provide some features
regardless of the ignition switch position, while other
features will operate only with the ignition switch inthe On, Start, and/or Accessory positions. All of the
battery current circuits are connected to the BCM
through the JB/BCM connector. The BCM receives
ground through five separate circuits. Three of these
circuits are connected to the BCM through a connec-
tor and take out of the instrument panel wire har-
ness on three separate ground circuits, while the
other two circuits are connected to the BCM through
the JB/BCM connector. All of these circuits are
grounded through a splice block located in the instru-
ment panel wire harness with an eyelet terminal con-
nector that is secured by a nut to a ground stud on
the driver side instrument panel end bracket near
the JB.
The BCM monitors its own internal circuitry as
well as many of its input and output circuits, and
will store a Diagnostic Trouble Code (DTC) in elec-
tronic memory for any failure it detects. These DTCs
can be retrieved and diagnosed using a DRBIIItscan
tool. Refer to the appropriate diagnostic information.
HARD WIRED INPUTS The hard wired inputs to
the BCM include the following:
²A/C on/off control
²Ambient temperature sensor signal
²Body control module flash enable
²Door lock switch mux
²Driver door ajar switch sense
²Flip-up glass ajar switch sense
²Flip-up glass release switch sense
²Fog lamp switch sense
²Front wiper park switch sense
²Front wiper switch mux
²Front washer pump driver
²Fused B(+)
²Fused ignition switch output (run-acc)
²Fused ignition switch output (run-start)
²Headlamp switch mux
²High beam switch sense
²Hood ajar switch sense - premium with
VTSS - in markets where required only
²Key-in ignition switch sense
²Left cylinder lock switch sense - premium
with VTSS only - omitted in some markets as
required
²Panel lamps dimmer switch mux
²Passenger doors ajar switch sense (input
from three ajar switches connected in parallel)
²Radio control mux - premium with remote
radio switches only
²Rear courtesy lamp control
²Rear window defogger control
²Rear wiper intermittent driver
²Rear wiper on driver
²Right cylinder lock switch sense - premium
with VTSS only - omitted in some markets as
required
KJELECTRONIC CONTROL MODULES 8E - 5
BODY CONTROL MODULE (Continued)

eter/trip odometer switch button that extends
through the lower edge of the cluster lens, just right
of the speedometer. Actuating this switch momen-
tarily with the ignition switch in the On position will
toggle the VFD between the odometer and trip odom-
eter modes. Depressing the switch button for about
two seconds while the VFD is in the trip odometer
mode will reset the trip odometer value to zero. Hold-
ing this switch depressed while turning the ignition
switch from the Off position to the On position will
initiate the EMIC self-diagnostic actuator test. The
VFD will also display the cluster software version
level near the completion of the EMIC self-diagnostic
actuator test. Refer to the appropriate diagnostic
information for additional details on this VFD func-
tion.
The VFD is diagnosed using the EMIC self-diag-
nostic actuator test. (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER - DIAGNOSIS AND
TESTING). Proper testing of the PCI data bus and
the electronic data bus message inputs to the EMIC
that control some of the VFD functions requires the
use of a DRBIIItscan tool. Refer to the appropriate
diagnostic information. Specific operation details for
the odometer, the trip odometer, and the various
warning message functions of the VFD may be found
elsewhere in this service information.
INDICATORS Indicators are located in various
positions within the EMIC and are all connected to
the EMIC circuit board. The turn signal indicators,
security indicator, washer fluid indicator, and coolant
low indicator (diesel engine only) use hard wired
inputs to the EMIC. The brake indicator is controlled
by PCI data bus messages from the Controller
Antilock Brake (CAB) as well as by hard wired park
brake switch and brake fluid level switch inputs to
the EMIC. The Malfunction Indicator Lamp (MIL) is
normally controlled by PCI data bus messages from
the Powertrain Control Module (PCM); however, if
the EMIC loses PCI data bus communication, the
EMIC circuitry will automatically turn the MIL on
until PCI data bus communication is restored. The
EMIC uses PCI data bus messages from the Body
Control Module (BCM), the PCM, the Airbag Control
Module (ACM), and the CAB to control all of the
remaining indicators.
The various indicators are controlled by different
strategies; some receive fused ignition switch output
from the EMIC circuitry and have a switched ground,
others are grounded through the EMIC circuitry and
have a switched battery feed, while still others are
completely controlled by the EMIC microprocessor
based upon various hard wired and electronic mes-
sage inputs. Some indicators are illuminated at a
fixed intensity, while the illumination intensity ofothers is synchronized with that of the EMIC general
illumination lamps.
In addition, certain indicators in this instrument
cluster are automatically configured or self-config-
ured. This feature allows the configurable indicators
to be enabled by the EMIC circuitry for compatibility
with certain optional equipment. The ABS indicator,
airbag indicator, SKIS indicator are automatically
configured by PCI data bus messages received by the
EMIC from the CAB, ACM, or Sentry Key Immobi-
lizer Module (SKIM) after the EMIC is installed in
the vehicle. Once these configuration settings are
learned by the EMIC, the DRBIIItscan tool must be
used to remove these settings from the EMIC non-
volatile memory. The self-configured indicators
remain latent in each EMIC at all times and will be
activated only when the EMIC receives the appropri-
ate PCI message inputs for the optional system or
equipment.
The hard wired indicators are diagnosed using con-
ventional diagnostic methods. The EMIC and PCI
bus message controlled indicators are diagnosed
using the EMIC self-diagnostic actuator test. (Refer
to 8 - ELECTRICAL/INSTRUMENT CLUSTER -
DIAGNOSIS AND TESTING). Proper testing of the
PCI data bus and the electronic data bus message
inputs to the EMIC that control each indicator
require the use of a DRBIIItscan tool. Refer to the
appropriate diagnostic information. Specific details of
the operation for each indicator may be found else-
where in this service information.
CLUSTER ILLUMINATION The EMIC has several
illumination lamps that are illuminated when the
exterior lighting is turned on with the headlamp
(multi-function) switch. The illumination intensity of
these lamps is adjusted by a 12-volt Pulse Width
Modulated (PWM) output of the EMIC when the
interior lighting control ring on the left control stalk
of the multi-function switch is rotated (down to dim,
up to brighten) to one of six available minor detent
positions. The BCM provides electronic dimming
level messages based upon internal programming
and inputs it receives from the control knob and con-
trol ring on the left (lighting) control stalk of the
multi-function switch on the steering column, then
provides a control output to energize or de-energize
the park lamp relay as appropriate. The energized
park lamp relay provides battery current to the
EMIC on the hard wired fused park lamp relay out-
put circuit, and the BCM provides the electronic dim-
ming level message to the EMIC over the PCI data
bus. The EMIC electronic circuitry provides the
proper PWM output to the cluster illumination lamps
and the VFD on the EMIC circuit board, then pro-
vides a synchronized PWM output on the hard wired
8J - 6 INSTRUMENT CLUSTERKJ
INSTRUMENT CLUSTER (Continued)

sage inputs to the instrument cluster that control the
glass ajar indicator, a DRBIIItscan tool is required.
Refer to the appropriate diagnostic information.
HIGH BEAM INDICATOR
DESCRIPTION
A high beam indicator lamp is standard equipment
on all instrument clusters. The high beam indicator
is located near the upper edge of the instrument clus-
ter overlay, between the tachometer and the speed-
ometer. The high beam indicator consists of a stencil-
like cutout of the International Control and Display
Symbol icon for ªHigh Beamº in the opaque layer of
the instrument cluster overlay. The dark outer layer
of the overlay prevents the indicator from being
clearly visible when the it is not illuminated. A blue
Light Emitting Diode (LED) behind the cutout in the
opaque layer of the overlay causes the icon to appear
in blue 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 high beam indicator is
serviced as a unit with the instrument cluster.
OPERATION
The high beam indicator gives an indication to the
vehicle operator whenever the headlamp high beams
are illuminated. This indicator is controlled by a
transistor on the instrument cluster electronic circuit
board based upon the cluster programming and elec-
tronic messages received by the cluster from the
Body Control Module (BCM) over the Programmable
Communications Interface (PCI) data bus. The high
beam indicator Light Emitting Diode (LED) is com-
pletely controlled by the instrument cluster logic cir-
cuit, and that logic will allow this indicator to
operate whenever the instrument cluster receives a
battery current input on the fused B(+) circuit.
Therefore, the LED can be illuminated regardless of
the ignition switch position. 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 high beam indicator for the following
reasons:
²High Beam Headlamps-On Message- Each
time the cluster receives a high beam headlamps-on
message from the BCM indicating the headlamp high
beams are turned On, the high beam indicator will
be illuminated. The indicator remains illuminated
until the cluster receives a high beam headlamps-off
message from the BCM.
²Actuator Test- Each time the cluster is put
through the actuator test, the high beam indicator
will be turned on, then off again during the bulbcheck portion of the test to confirm the functionality
of the LED and the cluster control circuitry.
The BCM continually monitors the exterior light-
ing (multi-function) switch to determine the proper
outputs to the headlamp low beam and high beam
relays. The BCM then sends the proper high beam
indicator lamp-on and lamp-off messages to the
instrument cluster. For further diagnosis of the high
beam indicator or the instrument cluster circuitry
that controls the indicator, (Refer to 8 - ELECTRI-
CAL/INSTRUMENT CLUSTER - DIAGNOSIS AND
TESTING). For proper diagnosis of the headlamp
system, the BCM, the PCI data bus, or the electronic
message inputs to the instrument cluster that control
the high beam indicator, a DRBIIItscan tool is
required. Refer to the appropriate diagnostic infor-
mation.
LOW FUEL INDICATOR
DESCRIPTION
A low fuel indicator is standard equipment on all
instrument clusters. The low fuel indicator is located
above the fuel gauge and to the left of the tachometer
in the instrument cluster. The low fuel indicator con-
sists of a stencil-like cutout of the International Con-
trol and Display Symbol icon for ªFuelº 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. 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 clus-
ter electronic circuit board. The low fuel indicator is
serviced as a unit with the instrument cluster.
OPERATION
The low fuel indicator gives an indication to the
vehicle operator when the level of fuel in the fuel
tank becomes low. 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
low 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
8J - 22 INSTRUMENT CLUSTERKJ
GLASS AJAR INDICATOR (Continued)

trols for both the exterior and interior lighting sys-
tems.
²Park Lamp Relay- A park lamp relay is
located in the Junction Block (JB) of all vehicles.
²Rear Fog Lamp Relay- Vehicles manufac-
tured for certain markets where rear fog lamps are
required equipment have a rear fog lamp relay
located in the Junction Block (JB).
²Trailer Tow Adapter- Vehicles equipped with
a factory-installed trailer towing package have an
adapter provided that adapts the factory-installed
heavy duty 7-way trailer tow connector to a conven-
tional 4-way light duty connector.
²Trailer Tow Connector- Vehicles equipped
with a factory-installed trailer towing package have a
heavy duty 7-way trailer tow connector installed in a
bracket on the trailer hitch receiver.
²Trailer Tow Relays- Vehicles equipped with a
factory-installed trailer towing package have a con-
nector bank containing four relays located behind the
right quarter trim panel and over the right rear
wheel housing. The four relays are used to supply
fused ignition switch output (run), brake lamps, right
turn signal, and left turn signal outputs to a trailer
through the trailer tow wiring and connectors.
Hard wired circuitry connects the exterior lighting
system components to the electrical system of the
vehicle. These hard wired circuits are integral to sev-
eral wire harnesses, which are routed throughout the
vehicle and retained by many different methods.
These circuits may be connected to each other, to the
vehicle electrical system and to the exterior lighting
system components through the use of a combination
of soldered splices, splice block connectors, and many
different types of wire harness terminal connectors
and insulators. Refer to the appropriate wiring infor-
mation. The wiring information includes wiring dia-
grams, proper wire and connector repair procedures,
further details on wire harness routing and reten-
tion, as well as pin-out and location views for the
various wire harness connectors, splices and grounds.
OPERATION
Following are paragraphs that briefly describe the
operation of each of the major exterior lighting sys-
tems. 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
reliable, efficient, and accurate means to diagnose
the BCM, the EMIC, the PCM, and the PCI data busnetwork inputs and outputs related to the various
exterior lighting systems requires the use of a
DRBIIItscan tool. Refer to the appropriate diagnos-
tic information.
BACKUP LAMPS
The backup (or reverse) lamps 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
backup lamps receive battery current from a fused
ignition switch output (run) fuse in the Junction
Block (JB) on the back-up lamp feed circuit only
when the backup lamp switch (manual transmission),
or backup lamp switch circuit of the Transmission
Range Sensor (TRS - electronic automatic transmis-
sion) is closed by the gearshift mechanism within the
transmission.
BRAKE LAMPS
The brake (or stop) lamps have a path to ground at
all times through their connection to the rear light-
ing wire harness from a take out of the rear body
wire harness with an eyelet terminal connector that
is secured by a screw to the base of the right D-pillar
behind the quarter trim panel. The Center High
Mounted Stop Lamp (CHMSL) has a path to ground
at all times through its connection to the rear body
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 driver side D-pillar
(left side D-pillar for left-hand drive, right side D-pil-
lar for right-hand drive) behind the quarter trim
panel. The brake lamps and CHMSL receive battery
current from a fused B(+) fuse in the Junction Block
(JB) on the brake lamp switch output circuit only
when the brake lamp switch circuit of the brake
lamp switch is closed by the brake pedal arm.
DAYTIME RUNNING LAMPS
Vehicles manufactured for sale in Canada illumi-
nate the high beam filament at a reduced intensity
when the engine is running and the exterior lamps
are turned off. This feature is enabled by the Body
Control Module (BCM) and a solid state Daytime
Running Lamps (DRL) relay, which is installed in the
Junction Block (JB) and the high beam relay is omit-
ted. When the BCM monitors an engine speed signal
of greater than 450 RPM and the status of the exte-
rior lighting switch input from the multi-function
switch is Off, the BCM duty cycles the DRL relay to
produce illumination of the headlamp high beam fil-
aments at a reduced intensity. The BCM also pro-
vides normal headlamp high beam operation through
the DRL relay on vehicles so equipped. When the
KJLAMPS/LIGHTING - EXTERIOR 8L - 5
LAMPS/LIGHTING - EXTERIOR (Continued)

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)

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)