
locked) and cannot be readjusted or released
even if the lever is moved back.
DIAGNOSIS AND TESTING - BRAKE LAMP
SWITCH
NOTE: Before proceeding with this diagnostic test,
verify the adjustment lever on the back of the
switch is in the adjusted position. If the lever is in
the non-adjusted (diagonal) position it may have
never been adjusted (Refer to 8 - ELECTRICAL/
LAMPS/LIGHTING - EXTERIOR/BRAKE LAMP
SWITCH - OPERATION). For adjustment, (Refer to 8
- ELECTRICAL/LAMPS/LIGHTING - EXTERIOR/
BRAKE LAMP SWITCH - INSTALLATION)
If the electrical circuit has been tested and the
brake lamp switch is suspected of being faulty, it can
be tested using the following method.
(1) Remove the switch from the vehicle. (Refer to 8
- ELECTRICAL/LAMPS/LIGHTING - EXTERIOR/
BRAKE LAMP SWITCH - REMOVAL)
(2) With the switch in the released position (plung-
er extended), use an ohmmeter to test each of the
three internal switches as shown (Fig. 1). You should
achieve the results as listed in the figure.
(3) Gently push the plunger on the brake lamp
switch in until it stops.
(4) With the switch in this depressed position
(plunger pushed in), use an ohmmeter to test each of
the three internal switches as shown (Fig. 2). You
should achieve the results as listed in the figure.
If you do not achieve the results as listed in both
figures, the switch is faulty and must be replaced.
Refer to Removal And Installation in this section.
If the switch is found to be operating properly, it
may be misadjusted. Do not reinstall the switch,
replace it. (Refer to 8 - ELECTRICAL/LAMPS/LIGHTING - EXTERIOR/BRAKE LAMP SWITCH -
INSTALLATION)
CAUTION: The switch can only be adjusted once.
That is during initial installation of the switch. If the
switch is not adjusted properly or has been
removed for any reason, a new switch must be
installed and adjusted.
REMOVAL
(1) Disconnect and isolate the battery negative
cable from its post on the battery.
(2) Remove silencer panel below steering column
and knee blocker.
(3) Remove the brake lamp switch by rotating the
switch in a counterclockwise direction approximately
30 degrees and pulling it out of the bracket (Fig. 3).
(4) Release the locking tab and disconnect the wir-
ing connector from the switch.
(5) Discard the brake lamp switch. It must not be
reused.
INSTALLATION
CAUTION: Do not reuse the original brake lamp
switch. The switch can only be adjusted once. That
is during initial installation of the switch. If the
switch is not adjusted properly or has been
removed for some service, a new switch must be
installed and adjusted.
(1) Mount and adjust the NEW brake lamp switch
using the following procedure:
(a) Connect the wiring connector to the switch
and latch the locking tab.Fig. 1 SWITCH TEST - RELEASED POSITION
Fig. 2 SWITCH TEST - DEPRESSED POSITION
RSLAMPS/LIGHTING - EXTERIOR8L-5
BRAKE LAMP SWITCH (Continued)
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(4) Disconnect CHMSL electrical connector from
bulb socket (Fig. 7).
INSTALLATION
(1) Connect electrical connector to CHMSL bulb
socket.
(2) Reconnect the rear window washer nozzle
assembly.
(3) Install the retaining screws.
(4) Reconnect the battery negative cable.
FRONT FOG LAMP
DIAGNOSIS AND TESTING - FRONT FOG LAMP
When a vehicle experiences problems with the
front fog lamp system, verify the condition of the bat-
tery connections, fuses, charging system, fog lamp
bulbs, wire connectors, relay, high beam switch, and
headlamp switch. Refer to the appropriate wiring
information.
Each vehicle is equipped with various lamp assem-
blies. A good ground is necessary for proper lighting
operation. Grounding is provided by the lamp socket
when it comes in contact with the metal body, or
through a separate ground wire.
When changing lamp bulbs check the socket for
corrosion. If corrosion is present, clean it with a wire
brush.
When it is necessary to remove components to ser-
vice another, it should not be necessary to apply
excessive force or bend a component to remove it.
Before damaging a trim component, verify hidden
fasteners or captured edges are not holding the com-
ponent in place.Fig. 6 REAR WASHER NOZZLE ASSEMBLY
1 - BARREL IN CHMSL
2 - NOZZLE ASSEMBLY
3 - SQUEEZE ARMS TO RELEASE NOZZLE ASSEMBLY
4 - HOSE
Fig. 7 CHMSL ELECTRICAL CONNECTOR
1 - CHMSL UNIT
2 - CHMSL ELECTRICAL CONNECTOR
RSLAMPS/LIGHTING - EXTERIOR8L-7
CENTER HIGH MOUNTED STOP LAMP UNIT (Continued)
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FRONT FOG LAMP DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
FOG LAMPS ARE DIM
WITH ENGINE IDLING
OR IGNITION TURNED
OFF.1. Loose or corroded battery
cables.1. Clean and secure battery cable clamps and
posts.
2. Loose or worn generator drive
belt.2. Adjust or replace generator drive belt.
3. Charging system output too low. 3. Test and repair charging system. Refer to
Electrical, Charging,
4. Battery has insufficient charge. 4. Test battery state-of-charge. Refer to
Electrical, Battery System.
5. Battery is sulfated or shorted. 5. Load test battery. Refer to Electrical, Battery
System.
6. Poor lighting circuit Z349/Z248
ground.6. Test for voltage drop across Z349/248
ground locations. Refer to Electrical, Wiring
Information.
FOG LAMP BULBS
BURN OUT
FREQUENTLY1. Charging system output too
high.1. Test and repair charging system. Refer to
Electrical, Charging.
2. Loose or corroded terminals or
splices in circuit.2. Inspect and repair all connectors and splices.
Refer to Electrical, Wiring Information.
FOG LAMPS ARE DIM
WITH ENGINE
RUNNING ABOVE IDLE1. Charging system output too low. 1. Test and repair charging system. Refer to
Electrical, Charging.
2. Poor lighting circuit Z349/Z248
ground.2. Test for voltage drop across Z349/Z248
ground locations. Refer to Electrical, Wiring
Information.
3. High resistance in fog lamp
circuit.3. Test amperage draw of fog lamp circuit.
FOG LAMPS FLASH
RANDOMLY1. Poor lighting circuit Z349/Z248
ground.1. Test for voltage drop across Z349/Z248
ground locations. Refer to Electrical, Wiring
Information.
2. Variable resistance in fog lamp
circuit.2. Test amperage draw of fog lamp circuit.
3. Faulty fog lamp switch (part of
headlamp switch).3. Replace headlamp switch.
4. Loose or corroded terminals or
splices in circuit.4. Inspect and repair all connectors and splices.
Refer to Electrical, Wiring Information.
5. Is relay engaging properly? 5. Verify function of fog lamp relay in IPM.
6. PCI Bus Communication. 6. Verify PCI bus message (fog lamp info)
transmitted from BCM and received by FCM.
FOG LAMPS DO NOT
ILLUMINATE1. Blown fuse for fog lamp. 1. Replace fuse. Refer to Electrical, Wiring
Information.
2. No Z349/Z248 ground at fog
lamps.2. Repair circuit ground. Refer to Electrical,
Wiring Information.
3. Faulty fog lamp switch (part of
headlamp switch).3. Replace headlamp switch.
4. Broken connector terminal or
wire splice in fog lamp circuit.4. Repair connector terminal or wire splice.
5. Faulty or burned out bulb. 5. Replace bulb.
6. Is relay engaging? 6. Verify function of fog lamp relay in IPM.
7. PCI Bus Communication. 7. Verify PCI bus message (fog lamp info)
transmitted from BCM and received by FCM.
8L - 8 LAMPS/LIGHTING - EXTERIORRS
FRONT FOG LAMP (Continued)
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Before damaging a trim component, verify hidden
fasteners or captured edges are not holding the com-
ponent in place.
HEADLAMP DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
HEADLAMPS ARE DIM
WITH ENGINE IDLING
OR IGNITION TURNED
OFF.1. Loose or corroded battery
cables.1. Clean and secure battery cable clamps and
posts.
2. Loose or worn generator drive
belt.2. Adjust or replace generator drive belt.
3. Charging system output too low. 3. Test and repair charging system, refer to
Electrical, Charging
4. Battery has insufficient charge. 4. Test battery state-of-charge, refer to
Electrical, Battery System.
5. Battery is sulfated or shorted. 5. Load test battery, refer to Electrical, Battery
System.
6. Poor lighting circuit Z343/Z344-
ground.6. Test for voltage drop across Z343/Z344-
ground locations, refer to Electrical, Wiring
Diagram Information.
HEADLAMP BULBS
BURN OUT
FREQUENTLY.1. Integrated Power Module (IPM)
not controlling voltage.1. Test and repair Integrated Power Module.
2. Loose or corroded terminals or
splices in circuit.2. Inspect and repair all connectors and splices.
Refer to Electrical, Wiring Information.
HEADLAMPS ARE DIM
WITH ENGINE
RUNNING ABOVE IDLE.1. Charging system output too low. 1. Test and repair charging system, refer to
Electrical, Wiring Information.
2. Poor lighting circuit Z343/Z344-
ground.2. Test for voltage drop across Z343/Z344-
ground locations, refer to Electrical, Wiring
Information.
3. High resistance in headlamp
circuit.3. Test amperage draw of headlamp circuit.
HEADLAMPS FLASH
RANDOMLY1. Poor lighting circuit Z343/Z344-
ground.1. Test for voltage drop across Z343/Z344-
ground locations, refer to Electrical, Wiring
Information.
2. Variable resistance in headlamp
circuit.2. Test amperage draw of headlamp circuit.
3. Loose or corroded terminals or
splices in circuit.3. Inspect and repair all connectors and splices,
refer to Electrical, Wiring Information.
4. Faulty headlamp switch. 4. Replace headlamp switch.
8L - 12 LAMPS/LIGHTING - EXTERIORRS
HEADLAMP (Continued)
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CONDITION POSSIBLE CAUSES CORRECTION
HEADLAMPS DO NOT
ILLUMINATE.1. No voltage to headlamps. 1. Repair open headlamp circuit, refer to
Electrical, Wiring Information.
2. No Z343/Z344-ground at
headlamps.2. Repair circuit ground, refer to Electrical,
Wiring Information.
3. Broken connector terminal or
wire splice in headlamp circuit.3. Repair connector terminal or wire splice.
4. Faulty or burned out bulb. 4. Replace headlamp bulb(s).
5. Body Control Module
malfunction.5. Refer to appropriate Body Control Module
diagnostics.
6. PCI Bus Communication 6. Verify messages being transmitted by BCM
and received by FCM.
7. IPM/FCM Malfunction. 7. Refer to appropriate IPM/FCM diagnostics.
HEADLAMPS ON WITH
IGNITION IN RUN, WITH
HEADLAMP SWITCH
OFF.1. Faulty headlamp switch. 1. Replace headlamp switch (review BCM
logged faults).
2. Diagnostic tool indicates (4.7 -
5.0V) on headlamp switch input to
BCM.2. Inspect and repair terminals, connectors and
open circuits.
3. PCI Bus Communication. 3. Verify messages being transmitted by BCM
and received by FCM.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove headlamp unit retaining screws.
(3) Remove headlamp unit to expose back of unit.
(4) Remove wiring connector from bulb.
(5) Rotate headlamp bulb retaining ring counter-
clockwise.
(6) Pull headlamp bulb and remove from headlamp
unit (Fig. 13).
INSTALLATION
(1) Install headlamp bulb to the headlamp unit.
(2) Install headlamp bulb retaining ring.
(3) Connect wiring connector to bulb.
(4) Install the headlamp unit.
(5) Install headlamp unit retaining screws.
(6) Reconnect the battery negative cable.
HEADLAMP - EXPORT
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the headlamp unit.
(3) Remove the cover (high beam lamp) or rubber
boot (low beam lamp) to access bulbs (Fig. 14).
(4) Disconnect the wire harness connector.
(5) Disengage spring clip from headlamp.
(6) Pull headlamp bulb from back of headlamp
unit.
INSTALLATION
(1) Insert headlamp bulb into headlamp unit.
(2) Engage spring clip to headlamp.
(3) Connect wire harness connector.
(4) Install the cover (high beam lamp) or rubber
boot (low beam lamp) to headlamp unit.
(5) Install the headlamp unit.
(6) Connect the battery negative cable.
Fig. 13 HEADLAMP
1 - HEADLAMP
2 - HEADLAMP UNIT
RSLAMPS/LIGHTING - EXTERIOR8L-13
HEADLAMP (Continued)
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HEADLAMP LEVELING MOTOR
- EXPORT
DIAGNOSIS AND TESTING - HEADLAMP
LEVELING MOTOR - EXPORT
HEADLAMP LEVELING MOTOR DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
ONE MOTOR DOES NOT
OPERATE.1. Poor electrical connection at
motor1. Check for proper electrical connection at
motor
2. No voltage at motor 2. Repair no voltage condition. Refer to
Wiring Diagrams
3. No ground at motor 3. Repair no ground condition. Refer to
Wiring Diagrams
4. Defective motor 4. Replace leveling motor
BOTH MOTORS DO NOT
OPERATE1. No voltage at or from headlamp
leveling switch1. Repair no voltage condition. Check for
proper headlamp leveling switch operation
2. No voltage at leveling motors 2. Repair no voltage condition. Refer to
Wiring Diagrams
3. No ground at leveling motors 3. Repair no ground condition. Refer to
Wiring Diagrams
4. Both motors defective 4. Replace both motors
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove headlamp unit.(3) Disconnect electrical connector from headlamp
leveling motor.
(4) Remove the two mounting screws.
(5) Gently pry motor from headlamp unit (Fig. 15).
Fig. 14 HEADLAMP UNIT
1 - HIGH BEAM LAMP
2 - HEADLAMP LEVELING MOTOR
3 - LOW BEAM LAMP
4 - TURN LAMP
8L - 14 LAMPS/LIGHTING - EXTERIORRS
HEADLAMP - EXPORT (Continued)
ProCarManuals.com

INSTALLATION
(1) Press motor into position.
(2) Install the two mounting screws.
(3) Connect the electrical connector to motor.
(4) Install the headlamp unit.
(5) Connect the battery negative cable.
HEADLAMP LEVELING
SWITCH - EXPORT
DESCRIPTION
Some vehicles are equipped with a remote head-
lamp leveling system. This system allows the driver
to adjust the vertical headlamp aim from the interior
of the vehicle to compensate for passenger or cargo
load.
The headlamp leveling switch is located next to the
headlamp switch on the instrument panel (Fig. 16).
If the headlamp leveling switch is faulty or damaged,
the headlamp switch must be replaced.
DIAGNOSIS AND TESTING - HEADLAMP
LEVELING SWITCH - EXPORT
The headlamp leveling switch is located next to the
headlamp switch on the instrument panel. (Refer to 8
- ELECTRICAL/LAMPS/LIGHTING - EXTERIOR/
HEADLAMP SWITCH - DIAGNOSIS AND TEST-
ING) for diagnosis of the headlamp leveling switch. If
the headlamp leveling switch is faulty, the headlamp
switch must be replaced.
HEADLAMP SWITCH
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - HEADLAMP
SWITCH
Using a Digital Multi-meter, perform the HEAD-
LAMP SWITCH CONTINUITY test and refer to (Fig.
17).
If the Headlamp Switch is not within specifications
replace the switch.
Fig. 15 HEADLAMP LEVELING MOTOR - EXPORT
1 - HIGH BEAM HEADLAMP
2 - HEADLAMP LEVELING MOTOR
3 - LOW BEAM HEADLAMP
Fig. 16 HEADLAMP LEVELING SWITCH
1 - POWER MIRROR SWITCH
2 - HEADLAMP SWITCH
3 - INTERIOR DIMMER
4 - HEADLAMP LEVELING SWITCH
Fig. 17 HEADLAMP SWITCH CONNECTOR
RSLAMPS/LIGHTING - EXTERIOR8L-15
HEADLAMP LEVELING MOTOR - EXPORT (Continued)
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MULTI-FUNCTION SWITCH
DESCRIPTION - TURN SIGNAL SYSTEM
The turn signals are actuated with a lever on
Multi-Function Switch, located on the left side of the
steering wheel. The signals are automatically turned
off by a canceling cam (two lobes molded to the clock
spring mechanism). The cam comes in contact with
the cancel actuator on the turn signal (multi-func-
tion) switch assembly. Either cam lobe, pushing on
the cancel actuator, returns the switch to the OFF
position. The multi-function switch is a resistive
MUX switch that feeds inputs to the BCM.
OPERATION - TURN SIGNAL SYSTEM
Lane change signaling is actuated by applying par-
tial turn signal stalk movement toward the direction
desired until the indicator lamps flashes in the
instrument cluster. When the switch stalk is released
the stalk will spring back into the neutral position
turning OFF the turn signal.
With the ignition switch ON and the turn signal
switch stalk actuated left or right, current flows
through the:
²Multi-function switch
²Body Control Module
²Integrated Power Module (IPM)
²Turn indicator lamp
²Front and rear turn signal bulbs.
A chime will sound after the vehicle has traveled a
distance of approximately 1.0 mile and a speed of 15
mph, with the turn signal ON.
DIAGNOSIS AND TESTING - MULTI-FUNCTION
SWITCH
To test turn signal, headlamp beam select and opti-
cal horn portion of the multi-function switch:(1) Remove the multi-function switch, refer to
Electrical, Lamps/Lighting - Exterior, Multi-Function
Switch, Removal, and Installation.
(2) Using an ohmmeter check the resistance read-
ings between multi-function switch pins. Refer to
Wiring Diagrams for proper pin numbers and the
MULTI-FUNCTION SWITCH RESISTANCE table.
MULTI-FUNCTION SWITCH RESISTANCE
SWITCH
POSITIONPIN NUMBER RESISTANCE
LEFT 2 AND 3 2.7V 5%
RIGHT 2 AND 3 1KV 5%
OPTICAL
HORN2 AND 4 1.7KV 5%
HI BEAM 2 AND 4 2.32KV 5%
REMOVAL
(1) Disconnect and isolate battery negative cable.
(2) Remove upper and lower steering column
shrouds. Refer to Steering, Column, Shroud,
Removal.
(3) Disconnect wire connector from back of multi-
function switch.
(4) Remove screws holding multi-function switch to
steering column adapter collar.
(5) Remove the multi-function switch.
INSTALLATION
(1) Position the switch on to the steering column.
(2) Install the two retaining screws.
(3) Connect the wire harness connector.
(4) Install the upper and lower steering column
shrouds. Refer to Steering, Column, Shroud, Installa-
tion.
(5) Connect the battery negative cable.
PARK/TURN SIGNAL LAMP
REMOVAL
(1) Disconnect and isolate battery negative cable.
(2) Remove headlamp retaining screws.
(3) Twist socket counter - clockwise and remove
(Fig. 27).
(4) Pull bulb from socket.
INSTALLATION
(1) Push bulb into socket.
(2) Twist socket into headlamp.
(3) Install headlamp retaining screws.
(4) Reconnect battery negative cable.
Fig. 26 LICENSE PLATE LAMP - REMOVE/INSTALL
1 - LICENSE PLATE LAMP UNIT
2 - BULB
RSLAMPS/LIGHTING - EXTERIOR8L-21
LICENSE LAMP (Continued)
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