2002 JEEP LIBERTY connectors

HORN SYSTEM DIAGNOSIS TABLE
CONDITION POSSIBLE CAUSES CORRECTION
BOTH HORNS
INOPERATIVE1. Faulty fuse. 1. Check the fuse in the Junction Block (JB).
Replace the fuse and repair the shorted circuit or
component, if required.
2. Faulty horn relay. 2. Refer to horn relay for the proper diagnosis
and testing procedures. Replace the horn relay or
repair the open horn relay circuit, if required.
3. Faulty horn switch. 3. Refer to horn switch for the proper diagnosis
and testing procedure. Replace the horn switch or
repair the open horn switch circuit, if required.
4. Faulty horns. 4. Refer to horn for the proper diagnosis and
testing procedure. Replace the horns or repair the
open horn circuit, if required.
ONE HORN INOPERATIVE 1. Faulty horn. 1. Refer to horn for the proper diagnosis and
testing procedures. Replace the horn or repair the
open horn circuit, if required.
HORN SOUNDS
CONTINUOUSLY1. Faulty horn relay. 1. Refer to horn relay for the proper diagnosis
and testing procedure. Replace the horn relay or
repair the shorted horn relay control circuit, if
required.
2. Faulty horn switch. 2. Refer to horn switch for the proper diagnosis
and testing procedure. Replace the horn switch or
repair the shorted horn switch circuit, if required.
HORN
DIAGNOSIS AND TESTING - HORN
WARNING: DISABLE THE AIRBAG SYSTEM
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, SEAT BELT TENSIONER, SIDE
AIRBAG, 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.
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 har-
ness connectors, splices and grounds.(1) Disconnect the wire harness connector from the
horn. Measure the resistance between the horn
ground circuit cavity of the wire harness connector
and a good ground. There should be no measurable
resistance. If OK, go to Step 2. If not OK, replace
wiring as necessary.
(2) Check for battery voltage at the horn relay out-
put circuit cavity of the wire harness connector for
the horn. There should be zero volts. If OK, go to
Step 3. If not OK, refer to horn relay and horn relay
circuit for the proper diagnosis and testing proce-
dures.
(3) Depress the horn switch. There should now be
battery voltage at the horn relay output circuit cavity
of the wire harness connector for the horn. If OK, but
the horn does not sound, replace the faulty horn. If
not OK, refer to horn relay and horn relay circuit for
the proper diagnosis and testing procedures.
8H - 2 HORNKJ
HORN SYSTEM (Continued)

REMOVAL
(1)Disconnect and isolate the battery negative cable.
(2) Disconnect the electrical harness connector
from the horns.
(3) Remove the mounting bolt (Fig. 2).
(4) Remove the horns.
INSTALLATION
(1) Install the horns.
(2) Install the mounting bolt. Tighten bolt to 25
N´m (19 lb. ft.).
(3) Connect the electrical harness connector to the
horns
(4) Connect the battery negative cable.
HORN RELAY
DIAGNOSIS AND TESTING - HORN RELAY
(1) Remove horn relay (Refer to 8 - ELECTRICAL/
HORN/HORN RELAY - REMOVAL).
(2) Using ohmmeter, test between relay connector
terminals 85 to 86 for 75   8 ohms resistance. If
resistance not OK, replace relay (Fig. 3).
(3) Test for continuity between ground and termi-
nal 85 of horn relay.
(a) When the horn switch is not depressed, no
continuity should be present.
(b) Continuity to ground when horn switch is
depressed.
(c) If continuity is not correct replace horn
switch or wiring as necessary, refer to the appro-
priate wiring information. The wiring information
includes wiring diagrams, proper wire and connec-
tor repair procedures, details of wire harness rout-ing and retention, connector pin-out information
and location views for the various wire harness
connectors, splices and grounds.
(4) Using voltmeter, test voltage at:
(a) Terminals 30 and 86 of the horn relay to
body ground.
(b) If NO voltage check fuse 3 of the Junction
Block (JB).
(c) If incorrect voltage, repair as necessary. Refer
to the appropriate wiring information. The wiring
information includes wiring diagrams, proper wire
and connector repair procedures, details of wire
harness routing and retention, connector pin-out
information and location views for the various wire
harness connectors, splices and grounds.
(5) Insert a jumper wire between terminal 30 and
87 of the Junction Block (JB).
(a) If horn sounds replace relay.
(b) If the horn does not sound, install horn relay
and test horn (Refer to 8 - ELECTRICAL/HORN/
HORN - DIAGNOSIS AND TESTING).
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the instrument panel end cap.
(3) Locate and pull the horn relay from the Junc-
tion Block (JB).
INSTALLATION
(1) Locate proper connector, and press relay into
position.
(2) Install instrument panel end cap.
(3) Connect battery negative cable.
Fig. 2 HORN MOUNTING
1 - POWER DISTRIBUTION CENTER
2 - LOW NOTE HORN
3 - HIGH NOTE HORN
Fig. 3 Horn Relay
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
KJHORN 8H - 3
HORN (Continued)

HORN SWITCH
DESCRIPTION
The horn switch is molded into the driver airbag
assembly. The horn switch can not be serviced sepa-
rately. For service procedures, (Refer to 8 - ELEC-
TRICAL/RESTRAINTS/DRIVER AIRBAG -
REMOVAL).
DIAGNOSIS AND TESTING - HORN SWITCH
For complete circuit diagrams, refer to the appro-
priate wiring information. The wiring information
includes wiring diagrams, proper wire and connector
repair procedures, details of wire harness routing
and retention, connector pin-out information and
location views for the various wire harness connec-
tors, splices and grounds.
WARNING: DISABLE THE AIRBAG SYSTEM
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, SEAT BELT TENSIONER, SIDE
AIRBAG, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the steering column opening cover.
(3) Check for continuity between the metal steer-
ing column jacket and a good ground. There should
be continuity. If OK, go to Step 4. If not OK,(Refer to
19 - STEERING/COLUMN - INSTALLATION) for
proper installation of the steering column.
(4) Remove the driver side airbag module from the
steering wheel (Refer to 8 - ELECTRICAL/RE-
STRAINTS/DRIVER AIRBAG - REMOVAL). Discon-
nect the horn switch wire harness connectors from
the driver side airbag module (Fig. 4).
(5) Remove the horn relay from the Junction Block
(JB). Check for continuity between the steering col-umn half of the horn switch feed wire harness con-
nector and a good ground. There should be no
continuity. If OK, go to Step 6. If not OK, repair the
shorted horn relay control circuit to the horn relay in
the Junction Block as required.
(6) Check for continuity between the steering col-
umn half of the horn switch feed wire harness con-
nector and the horn relay control circuit cavity for
the horn relay in the Junction Block. There should be
continuity. If OK, go to Step 7. If not OK, repair the
open horn relay control circuit to the horn relay in
the Junction Block as required.
(7) Check for continuity between the horn switch
feed wire and the horn switch ground wire on the
driver side airbag module. There should be no conti-
nuity. If OK, go to Step 8. If not OK, replace the
faulty horn switch.
(8) Depress the center of the driver side airbag
module trim cover and check for continuity between
the horn switch feed wire and the horn switch
ground wire on the driver side airbag module. There
should now be continuity. If not OK, replace the
faulty horn switch (Refer to 8 - ELECTRICAL/RE-
STRAINTS/DRIVER AIRBAG - REMOVAL).
Fig. 4 Driver Airbag Housing
1 - HOUSING
2 - HORN SWITCH GROUND WIRE
3 - HORN SWITCH FEED WIRE
4 - INFLATOR
5 - TRIM COVER
8H - 4 HORNKJ

perform its many functions. The EMIC module incor-
porates a blue-green digital Vacuum Fluorescent Dis-
play (VFD) for displaying odometer and trip
odometer information, as well as several warning
messages and certain diagnostic information. In addi-
tion to instrumentation and indicators, the EMIC has
the hardware and software needed to provide the fol-
lowing features:
²Chime Warning Service- A chime tone gener-
ator on the EMIC electronic circuit board provides
audible alerts to the vehicle operator and eliminates
the need for a separate chime module. (Refer to 8 -
ELECTRICAL/CHIME WARNING SYSTEM -
DESCRIPTION).
²Panel Lamps Dimming Service- The EMIC
provides a hard wired 12-volt Pulse-Width Modulated
(PWM) output that synchronizes the dimming level
of the radio display, gear selector indicator, heater-air
conditioner control, and all other dimmable lighting
on the panel lamps dimmer circuit with that of the
cluster illumination lamps and VFD.
The EMIC houses four analog gauges and has pro-
visions for up to twenty-four indicators (Fig. 2). The
EMIC includes the following analog gauges:
²Coolant Temperature Gauge
²Fuel Gauge
²Speedometer
²Tachometer
Some of the EMIC indicators are automatically
configured when the EMIC is connected to the vehi-
cle electrical system for compatibility with certain
optional equipment or equipment required for regula-
tory purposes in certain markets. While each EMIC
may have provisions for indicators to support every
available option, the configurable indicators will not
be functional in a vehicle that does not have the
equipment that an indicator supports. The EMIC
includes provisions for the following indicators (Fig.
2):
²Airbag Indicator (with Airbag System only)
²Antilock Brake System (ABS) Indicator
(with ABS only)
²Brake Indicator
²Charging Indicator
²Coolant Low Indicator (with Diesel Engine
only)
²Cruise Indicator (with Speed Control Sys-
tem only)
²Four-Wheel Drive Full Time Indicator (with
Selec-Trac Transfer Case only)
²Four-Wheel Drive Low Mode Indicator
²Four-Wheel Drive Part Time Indicator
²Front Fog Lamp Indicator (with Front Fog
Lamps only)
²High Beam Indicator
²Low Fuel Indicator²Low Oil Pressure Indicator
²Malfunction Indicator Lamp (MIL)
²Overdrive-Off Indicator (with Automatic
Transmission only)
²Rear Fog Lamp Indicator (with Rear Fog
Lamps only)
²Seatbelt Indicator
²Security Indicator (with Vehicle Theft
Security System only)
²Sentry Key Immobilizer System (SKIS)
Indicator (with SKIS only)
²Transmission Overtemp Indicator (with
Automatic Transmission only)
²Turn Signal (Right and Left) Indicators
²Wait-To-Start Indicator (with Diesel Engine
only)
²Water-In-Fuel Indicator (with Diesel Engine
only)
Each indicator in the EMIC is illuminated by a
dedicated Light Emitting Diode (LED) that is sol-
dered onto the EMIC electronic circuit board. The
LEDs are not available for service replacement and,
if damaged or faulty, the entire EMIC must be
replaced. Cluster illumination is accomplished by
dimmable incandescent back lighting, which illumi-
nates the gauges for visibility when the exterior
lighting is turned on. Each of the incandescent bulbs
is secured by an integral bulb holder to the electronic
circuit board from the back of the cluster housing.
The incandescent bulb/bulb holder units are available
for service replacement.
Hard wired circuitry connects the EMIC to the
electrical system of the vehicle. These hard wired cir-
cuits are integral to several wire harnesses, which
are routed throughout the vehicle and retained by
many different methods. These circuits may be con-
nected to each other, to the vehicle electrical system
and to the EMIC 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.
The EMIC modules for this model are serviced only
as complete units. The EMIC module cannot be
adjusted or repaired. If a gauge, an LED indicator,
the VFD, the electronic circuit board, the circuit
board hardware, the cluster overlay, or the EMIC
housing are damaged or faulty, the entire EMIC mod-
ule must be replaced. The cluster lens, hood and
mask unit and the individual incandescent lamp
bulbs with holders are available for service replace-
ment.
KJINSTRUMENT CLUSTER 8J - 3
INSTRUMENT CLUSTER (Continued)

fluid level is not low), or until the ignition switch is
turned to the Off position, whichever occurs first.
²Brake Fluid Level Switch Input Fault- The
brake fluid level switch also features a 1 kilohm
diagnostic resistor connected in parallel between the
switch input and output to provide the cluster with
verification that the red brake warning indicator
driver circuit is not open. If the cluster does not see a
proper input on the red brake warning indicator
driver circuit, it will turn on the brake indicator. The
indicator remains illuminated until the red brake
warning indicator driver circuit fault is resolved, or
until the ignition switch is turned to the Off position,
whichever occurs first.
²Actuator Test- Each time the instrument clus-
ter is put through the actuator test, the brake 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 park brake switch on the park brake pedal
mechanism provides a hard wired ground input to
the instrument cluster circuitry through the park
brake switch sense circuit whenever the park brake
is applied or not fully released. The brake fluid level
switch on the brake master cylinder reservoir pro-
vides a hard wired ground input to the instrument
cluster circuitry through the red brake warning indi-
cator driver circuit whenever the fluid level in the
reservoir becomes low. On models equipped with the
optional ABS, the CAB sends the proper lamp-on or
lamp-off messages to the instrument cluster. If the
CAB sends a lamp-on message after the bulb test, it
indicates that the CAB has detected a brake hydrau-
lic system malfunction and/or that the ABS system
has become inoperative. The CAB will store a Diag-
nostic Trouble Code (DTC) for any malfunction it
detects.
For further diagnosis of the brake indicator or the
instrument cluster circuitry that controls the LED,
(Refer to 8 - ELECTRICAL/INSTRUMENT CLUS-
TER - DIAGNOSIS AND TESTING). The park brake
switch input to the instrument cluster can be diag-
nosed using conventional diagnostic tools and meth-
ods. For proper diagnosis of the brake fluid level
switch input to the instrument cluster, the antilock
brake system, the CAB, the PCI data bus, or the
electronic message inputs to the instrument cluster
that control the brake indicator, a DRBIIItscan tool
is required. Refer to the appropriate diagnostic infor-
mation.
DIAGNOSIS AND TESTING - BRAKE INDICATOR
The diagnosis found here addresses an inoperative
brake indicator condition. If there are problems with
several indicators in the instrument cluster, (Refer to
8 - ELECTRICAL/INSTRUMENT CLUSTER - DIAG-NOSIS AND TESTING). If the brake indicator stays
on with the ignition switch in the On position and
the park brake released, or comes on while driving,
(Refer to 5 - BRAKES - DIAGNOSIS AND TEST-
ING). If no brake system problem is found, the fol-
lowing procedures will help to locate a shorted or
open circuit, or a faulty park brake switch input.
Refer to the appropriate wiring information. The wir-
ing information includes wiring diagrams, proper
wire and connector repair procedures, details of wire
harness routing and retention, connector pin-out
information and location views for the various wire
harness connectors, splices and grounds.
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.
INDICATOR ILLUMINATES DURING BULB TEST, BUT DOES
NOT WHEN PARK BRAKE APPLIED
(1) Disconnect and isolate the battery negative
cable. Disconnect the front body wire harness connec-
tor for the park brake switch from the switch termi-
nal. Apply the parking brake. Check for continuity
between the park brake switch terminal and a good
ground. There should be continuity. If OK, go to Step
2. If not OK, replace the faulty park brake switch.
(2) Disconnect the instrument panel wire harness
connector for the instrument cluster from the cluster
connector receptacle. Check for continuity between
the park brake switch sense circuit cavities of the
front body wire harness connector for the park brake
switch and the instrument panel wire harness con-
nector for the instrument cluster. There should be
continuity. If not OK, repair the open park brake
switch sense circuit between the park brake switch
and the instrument cluster as required.
INDICATOR REMAINS ILLUMINATED - BRAKE SYSTEM
CHECKS OK
(1) Disconnect and isolate the battery negative
cable. Disconnect the front body wire harness connec-
8J - 14 INSTRUMENT CLUSTERKJ
BRAKE/PARK BRAKE INDICATOR (Continued)

OPERATION
The washer fluid indicator gives an indication to
the vehicle operator that the fluid level in the washer
reservoir is low. This indicator is controlled by the
instrument cluster electronic circuit board based
upon cluster programming and a hard wired input
received by the cluster from the washer fluid level
switch mounted on the washer reservoir. The washer
fluid indicator function of the Vacuum Fluorescent
Display (VFD) is completely controlled by the instru-
ment 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 instrument
cluster will turn on the washer fluid indicator for the
following reasons:
²Washer Fluid Level Switch Input- Each time
the cluster detects ground on the low washer fluid
sense circuit (washer fluid level switch closed =
washer fluid level low) the cluster applies an algo-
rithm to confirm that the input is correct and not the
result of fluid sloshing in the washer reservoir. The
cluster tests the status of the circuit about seven mil-
liseconds after ignition On, and about once every sec-
ond thereafter, then uses an internal counter to
count up or down. When the counter accumulates
thirty ground inputs on the circuit, the washer fluid
indicator will be illuminated. If the vehicle is not
moving when the washer fluid level switch input
counter reaches thirty, the VFD will repeatedly and
sequentially cycle its indication in two second inter-
vals with the odometer/trip odometer information,
the low washer fluid warning, and any other active
warnings including: door ajar, gate ajar, and glass
ajar. If the vehicle is moving, or once the cluster of a
non-moving vehicle receives an electronic vehicle
speed message from the Powertrain Control Module
(PCM) indicating a speed greater than zero, the
warning sequence will consist of three complete dis-
play cycles, then revert to only the odometer/trip
odometer display. Once the washer fluid indicator
warning has completed, the washer fluid indicator is
extinguished and will not repeat until the ignition
switch is cycled.
The instrument cluster continually monitors the
washer fluid level switch in the washer reservoir to
determine the status of the washer fluid level. For
further diagnosis of the washer fluid indicator or the
instrument cluster circuitry that controls the indica-
tor, (Refer to 8 - ELECTRICAL/INSTRUMENT
CLUSTER - DIAGNOSIS AND TESTING). The
washer fluid level switch and circuits can be diag-
nosed using conventional diagnostic tools and meth-
ods. The washer fluid level switch also features a 3.3kilohm diagnostic resistor connected in parallel
between the switch input and output to provide the
cluster with verification that the low washer fluid
sense circuit is not open or shorted. This input can
be monitored using a DRBIIItscan tool. Refer to the
appropriate diagnostic information.
DIAGNOSIS AND TESTING - WASHER FLUID
INDICATOR
The diagnosis found here addresses an inoperative
washer fluid indicator condition. If the problem being
diagnosed is related to indicator accuracy, be certain
to confirm that the problem is with the indicator or
washer fluid level switch input and not with a dam-
aged or empty washer fluid reservoir, or inoperative
instrument cluster indicator control circuitry. Inspect
the washer fluid reservoir for proper fluid level and
signs of damage or distortion that could affect
washer fluid level switch performance and perform
the instrument cluster actuator test before you pro-
ceed with the following diagnosis. If no washer fluid
reservoir or instrument cluster control circuitry prob-
lem is found, the following procedure will help to
locate a short or open in the washer fluid switch
sense circuit. Refer to the appropriate wiring infor-
mation. The wiring information includes wiring dia-
grams, proper wire and connector repair procedures,
details of wire harness routing and retention, connec-
tor pin-out information and location views for the
various wire harness connectors, splices and grounds.
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.
INDICATOR DOES NOT ILLUMINATE WITH WASHER
RESERVOIR EMPTY
(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 cav-
8J - 36 INSTRUMENT CLUSTERKJ
WASHER FLUID 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)