
STEP IS NOT DONE A DIAGONSTIC TROUBLE
CODE (DTC) MAY BE SET.
VACUUM RESERVOIR
The reservoir contains a one-way check valve to
trap engine vacuum in the reservoir. When engine
vacuum drops, as in climbing a grade while driving,
the reservoir supplies the vacuum needed to main-
tain proper speed control operation. The vacuum res-
ervoir cannot be repaired and must be replaced if
faulty.
VEHICLE SPEED AND DISTANCE
The 4 speed automatic Transmission Control Mod-
ule (TCM) supplies the speed input to the PCM. The
PCM determines acceleration rates. The speed con-
trol software in the PCM uses vehicle speed and
acceleration to control to the set speed.
Vehicles with a 3 speed automatic or manual trans-
mission have a vehicle speed sensor (VSS) mounted
to an adapter near the transmission output shaft.
The sensor is driven through the adapter by a speed-
ometer pinion gear. The VSS pulse signal is moni-
tored by the PCM to determine vehicle speed and to
maintain speed control set speed. Refer to the appro-
priate Powertrain Diagnostic Procedures manual for
diagnosis and testing of this component. Refer to
group 14, Fuel System for Removal/Installation
DIAGNOSIS AND TESTING
ROAD TEST
Perform a vehicle road test to verify reports of
speed control system malfunction. The road test
should include attention to the speedometer. Speed-
ometer operation should be smooth and without flut-
ter at all speeds.
Flutter in the speedometer indicates a problem
which might cause surging in the speed control sys-
tem. The cause of any speedometer problems should
be corrected before proceeding. Refer to Group 8E,
Instrument Panel and Gauges for speedometer diag-
nosis.
If a road test verifies a surge following a set and
the speedometer operates properly see ªOvershoot/
Undershoot on speed control setº.
If a road test verifies an inoperative system, and
the speedometer operates properly, check for:
²A Diagnostic Trouble Code (DTC). If a DTC
exists, conduct tests per the Powertrain Diagnostic
Procedures service manual.
²A misadjusted brake (stop) lamp switch. This
could also cause an intermittent problem.
²Loose or corroded electrical connections at the
servo. Corrosion should be removed from electricalterminals and a light coating of Mopar Multipurpose
Grease, or equivalent, applied.
²Leaking vacuum reservoir.
²Loose or leaking vacuum hoses or connections.
²Defective one-way vacuum check valve.
²Secure attachment at both ends of the speed
control servo cable.
²Smooth operation of throttle linkage and throttle
body air valve.
²Conduct electrical test at PCM.
²Failed speed control servo. Do the servo vacuum
test.
CAUTION: When test probing for voltage or conti-
nuity at electrical connectors, care must be taken
not to damage connector, terminals or seals. If
these components are damaged, intermittent or
complete system failure may occur.
OVERSHOOT/UNDERSHOOT FOLLOWING SPEED
CONTROL SET
If the operator repeatedly presses and releases the
set button with their foot off of the accelerator (a ªlift
foot setº to begin speed control operation), the vehicle
may accelerate and exceed the desired set speed by
up to 5 MPH (8 km/h) and then decelerate to less
than the desired set speed before finally achieving
the desired set speed.
The Speed Control has an adaptive strategy that
compensates for vehicle-to-vehicle variations in speed
control cable lengths. When the speed control is set
with the vehicle operators foot off of the accelerator
pedal, the speed control thinks there is excessive
speed control cable slack and adapts. If the lift foot
sets are continually used, the speed control over-
shoot/undershoot condition will develop.
To ªunlearnº the overshoot/undershoot condition,
the vehicle operator has to press and release the set
button while maintaining the desired set speed with
the accelerator pedal (not decelerating or accelerat-
ing), and then turn the cruise control switch to the
OFF position (or press the CANCEL button if
equipped) after waiting 10 seconds. This procedure
must be performed approximately 10±15 times to
completely unlearn the overshoot/undershoot condi-
tion.
CHECKING FOR DIAGNOSTIC CODES
When trying to verify a speed control system elec-
tronic malfunction: Connect a DRB scan tool if avail-
able to the data link connector. The connector is
located at left side of the steering column, and at
lower edge of the panel.
(1) A speed control malfunction may occur without
a diagnostic code being indicated.
NSVEHICLE SPEED CONTROL SYSTEM 8H - 3
DESCRIPTION AND OPERATION (Continued)

LAMPS
CONTENTS
page page
BULB APPLICATION...................... 25
EXTERIOR LAMP BULB SERVICE............ 9
EXTERIOR LAMP SERVICE................. 14HEADLAMP ALIGNMENT................... 5
INTERIOR LAMPS........................ 18
LAMP DIAGNOSIS........................ 1
LAMP DIAGNOSIS
INDEX
page page
GENERAL INFORMATION
ELECTRONIC DAYTIME RUNNING LIGHT (DRL).1
GENERAL INFORMATION.................. 1SAFETY PRECAUTIONS................... 1
DIAGNOSIS AND TESTING
DIAGNOSTIC PROCEDURES................ 2
GENERAL INFORMATION
GENERAL INFORMATION
NS vehicles use lighting on the interior and exte-
rior of the vehicle for illuminating and indicating
purposes. Lighting circuits are protected by fuses.
Lighting circuits require an overload protected power
source, on/off device, lamps and body ground to oper-
ate properly. Plastic lamps require a wire in the har-
ness to supply body ground to the lamp socket.
Replace sockets and bulbs that are corroded.
Some of the interior and exterior lighting functions
are governed by the body controller. The headlamp,
dome, and the door ajar switches provide signals to
the body controller. The body controller in turn acti-
vates relay(s) in order to provide either a ground or
feed line to the appropriate lamp(s).
Wire connectors can make intermittent contact or
become corroded. Before coupling wire connectors,
inspect the terminals inside the connector. Male ter-
minals should not be bent or disengaged from the
insulator. Female terminals should not be sprung
open or disengaged from the insulator. Bent and
sprung terminals can be repaired using needle nose
pliers and pick tool. Corroded terminals appear
chalky or green. Corroded terminals should be
replaced to avoid recurrence of the problem symp-
toms.
Begin electrical system failure diagnosis by testing
related fuses in the fuse block and power distribution
center. Verify that bulbs are in good condition andtest continuity of the circuit ground. Refer to Group
8W, Wiring Diagrams, for component location and cir-
cuit information.SAFETY PRECAUTIONS
WARNING: EYE PROTECTION SHOULD BE USED
WHEN SERVICING GLASS COMPONENTS. PER-
SONAL INJURY CAN RESULT.
CAUTION: Do not touch the glass of halogen bulbs
with fingers or other possibly oily surface, reduced
bulb life will result.
Do not use bulbs with higher candle power than
indicated in the Bulb Application table at the end of
this group. Damage to lamp and/or Daytime Run-
ning Lamp Module can result.
Do not use fuses, circuit breakers or relays hav-
ing greater amperage value than indicated on the
fuse panel or in the Owners Manual.
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.
ELECTRONIC DAYTIME RUNNING LIGHT (DRL)
The Combination Flasher/DRL is a module provid-
ing turn signal, hazard warning, and daytime run-
NSLAMPS 8L - 1

HEADLAMP DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
HEADLAMPS ARE DIM
WITH ENGINE IDLING OR
IGNITION TURNED OFF1. 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
Group 8A.
4. Battery has insufficient charge. 4. Test battery state-of -charge. Refer to
Group 8A.
5. Battery is sulfated or shorted. 5. Load test battery. Refer to Group 8A.
6. Poor lighting circuit Z1-ground. 6. Test for voltage drop across Z1-ground
locations. Refer to Group 8W.
7. Low beam headlamp / foglamp fuse
blown.7. Locate cause of blown fuse and repair.
HEADLAMP BULBS BURN
OUT FREQUENTLY1. Charging system output too high. 1. Test and repair charging system. Refer to
Group 8A.
2. Loose or corroded terminals or
splices in circuit.2. Inspect and repair all connectors and
splices. Refer to Group 8W.
HEADLAMPS ARE DIM
WITH ENGINE RUNNING
ABOVE IDLE1. Charging system output too low. 1. Test and repair charging system. Refer to
Group 8A.
2. Poor lighting circuit Z1-ground. 2. Test for voltage drop across Z1-ground
locations. Refer to Group 8W.
3. High resistance in headlamp circuit. 3. Test amperage draw of headlamp circuit.
4. Low beam headlamp / fog lamp
fuse blown.4. Locate cause of blown fuse and repair.
HEADLAMPS FLASH
RANDOMLY1. Poor lighting circuit Z1-ground. 1. Test for voltage drop across Z1-ground
locations, refer to Group 8W.
2. High 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 Group 8W.
HEADLAMPS DO NOT
ILLUMINATE1. No voltage to headlamps. 1. Repair open headlamp circuit. Refer to
Group 8W.
2. No Z1-ground at headlamps. 2. Repair circuit ground. Refer to Group 8W.
3. Faulty headlamp switch. 3. Replace headlamp switch.
4. Faulty headlamp dimmer (multi-
function) switch.4. Replace multi-function switch.
5. Broken connector terminal or wire
splice in headlamp circuit.5. Repair connector terminal or wire splice.
6. Defective or burned out bulb. 6. Replace bulb.
7. Body controller malfunction. 7. Refer to appropriate body controller
diagnostics.
NSLAMPS 8L - 3
DIAGNOSIS AND TESTING (Continued)

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 Group 8A,
4. Battery has insufficient charge. 4. Test battery state-of -charge.
Refer to Group 8A.
5. Battery is sulfated or shorted. 5. Load test battery. Refer to Group
8A.
6. Poor lighting circuit Z1-ground. 6. Test for voltage drop across
Z1-ground locations. Refer to Group
8W.
FOG LAMP BULBS BURN OUT
FREQUENTLY1. Charging system output too high. 1. Test and repair charging system.
Refer to Group 8A.
2. Loose or corroded terminals or
splices in circuit.2. Inspect and repair all connectors
and splices. Refer to Group 8W.
FOG LAMPS ARE DIM WITH
ENGINE RUNNING ABOVE IDLE1. Charging system output too low. 1. Test and repair charging system.
Refer to Group 8A.
2. Poor lighting circuit Z1-ground. 2. Test for voltage drop across
Z1-ground locations. Refer to Group
8W.
3. High resistance in fog lamp
circuit.3. Test amperage draw of fog lamp
circuit.
FOG LAMPS FLASH RANDOMLY 1. Poor lighting circuit Z1-ground. 1. Test for voltage drop across
Z1-ground locations. Refer to Group
8W.
2. High resistance in fog lamp
circuit.2. Test amperage draw of fog lamp
circuit.
3. Faulty fog lamp switch. 3. Replace fog lamp switch.
4. Loose or corroded terminals or
splices in circuit.4. Inspect and repair all connectors
and splices. Refer to Group 8W.
FOG LAMPS DO NOT ILLUMINATE 1. Blown fuse for fog lamp. 1. Replace fuse. Refer to Group
8W.
2. No Z1-ground at fog lamps. 2. Repair circuit ground. Refer to
Group 8W.
3. Faulty fog lamp switch. 3. Replace fog lamp switch.
4. Broken connector terminal or
wire splice in fog lamp circuit.4. Repair connector terminal or wire
splice.
5. Defective or burned out bulb. 5. Replace bulb.
8L - 4 LAMPSNS
DIAGNOSIS AND TESTING (Continued)

BULB APPLICATION
INDEX
page page
GENERAL INFORMATION
INTRODUCTION......................... 25SPECIFICATIONS
EXTERIOR LAMP BULBS.................. 25
INTERIOR LAMP BULBS.................. 25
GENERAL INFORMATION
INTRODUCTION
The following Bulb Application Tables list the lamp
title on the left side of the column and trade number
or part number on the right.
CAUTION: Do not use bulbs that have a higher
candle power than the bulb listed in the Bulb Appli-
cation Table. Damage to lamp can result.
Do not touch halogen bulbs with fingers or other
possibly oily surfaces. Bulb life will be reduced.
If a halogen bulb is contaminated with oil, clean
bulb with denatured alcohol or ammonia based sol-
vent.
SPECIFICATIONS
EXTERIOR LAMP BULBS
LAMP BULB
Back-up...............................3057
CHMSL................................921
Fog Lamp...............................H3
FogLamp±T&C ........................9040
Headlamp..............................9007
Headlamp high beam ± T&C...............9005
Headlamp low beam ± T&C............9005 SLL
License Plate............................168
Parking/Turn Signal/Front Side Marker. . . .3157NA
Parking/Turn Signal ± T&C............4157NAK
Tail, Stop, Turn Signal and Side Marker......3057
Front Side Marker......................194NA
INTERIOR LAMP BULBS
LAMP BULB
ABS.................................PC194
AirBag ..............................PC194
Alarm Set (Security)....................PC194
Brake Warning.........................PC194
Center/Rear Reading Lamps.................578
Center/Rear Dome Lamps...................579
Check Engine Ind.......................PC194
Front Door Courtesy.......................567
Door Ajar Ind..........................PC194
Front Header Reading Lamp................567
Glove Box Lamp..........................194
High Beam Ind.........................PC194
Instrument Cluster.....................PC194
IP Bin/Ash Tray..........................161
Liftgate Flood Lamps......................567
Liftgate Ajar Ind.........................PC74
Low Fuel Ind..........................PC194
Oil Pressure Ind........................PC194
O/H Console Reading Lamps................579
Seat Belt Ind...........................PC74
Engine Temp Ind.......................PC194
Turn Signal...........................PC194
Engine Compartment Lamps................579
Visor Vanity Lamp....................6501966
Low Washer Fluid.......................PC74
Low Volts Warning.......................PC74
Cruise Indicator........................PC194
NSLAMPS 8L - 25

LAMPS
CONTENTS
page page
BULB APPLICATION..................... 17
HEADLAMP ALIGNMENT.................. 5
LAMP BULB SERVICE.................... 8LAMP DIAGNOSIS....................... 1
LAMP SERVICE........................ 13
LAMP DIAGNOSIS
INDEX
page page
GENERAL INFORMATION
HEADLAMP LEVELING MOTOR............. 2
INTRODUCTION........................ 1SAFETY PRECAUTIONS.................. 1
DIAGNOSIS AND TESTING
DIAGNOSTIC PROCEDURES.............. 2
GENERAL INFORMATION
INTRODUCTION
GS vehicles use lighting on the interior and exte-
rior of the vehicle for illuminating and indicating
purposes. Lighting circuits are protected by fuses.
Lighting circuits require an overload protected power
source, on/off device, lamps and body ground to oper-
ate properly. Plastic lamps require a wire in the har-
ness to supply body ground to the lamp socket.
Replace sockets and bulbs that are corroded.
Some of the interior and exterior lighting functions
are governed by the body controller. The headlamp,
dome, and the door ajar switches provide signals to
the body controller. The body controller in turn acti-
vates relay(s) in order to provide either a ground or
feed line to the appropriate lamp(s).
Wire connectors can make intermittent contact or
become corroded. Before coupling wire connectors,
inspect the terminals inside the connector. Male ter-
minals should not be bent or disengaged from the
insulator. Female terminals should not be sprung
open or disengaged from the insulator. Bent and
sprung terminals can be repaired using needle nose
pliers and pick tool. Corroded terminals appear
chalky or green. Corroded terminals should be
replaced to avoid recurrence of the problem symp-
toms.Begin electrical system failure diagnosis by testing
related fuses in the fuse block and power distribution
center. Verify that bulbs are in good condition and
test continuity of the circuit ground. Refer to Group
8W, Wiring Diagrams, for component location and cir-
cuit information.
SAFETY PRECAUTIONS
WARNING: EYE PROTECTION SHOULD BE USED
WHEN SERVICING GLASS COMPONENTS. PER-
SONAL INJURY CAN RESULT.
CAUTION: Do not touch the glass of halogen bulbs
with fingers or other possibly oily surface, reduced
bulb life will result.
Do not use bulbs with higher candle power than
indicated in the Bulb Application table at the end of
this group. Damage to lamp and/or Daytime Run-
ning Lamp Module can result.
Do not use fuses, circuit breakers or relays hav-
ing greater amperage value than indicated on the
fuse panel or in the Owners Manual.
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.
NS/GSLAMPS 8L - 1

HEADLAMP LEVELING MOTOR
This vehicle is equipped with a remote headlamp
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. A headlamp leveling switch is located in the
instrument panel and controls the headlamp leveling
motor found on the back of the headlamp module.
DIAGNOSIS AND TESTING
DIAGNOSTIC PROCEDURES
When a vehicle experiences problems with the head-
lamp system, verify the condition of the battery connec-
tions, charging system, headlamp bulbs, wire
connectors, relay, high beam dimmer switch and head-
lamp switch. Refer to Group 8W, Wiring Diagrams, for
component locations and circuit information.
HEADLAMP DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
HEADLAMPS ARE DIM
WITH ENGINE IDLING OR
IGNITION TURNED OFF1. Loose or corroded battery cables. 1. Clean and secure battery cable clamps
and posts.
2. Loose or worn alternator drive
belt.2. Adjust or replace alternator drive belt.
3. Charging system output too low. 3. Test and repair charging system. Refer
to Group 8A.
4. Battery has insufficient charge. 4. Test battery state-of -charge. Refer to
Group 8A.
5. Battery is sulfated or shorted. 5. Load test battery. Refer to Group 8A.
6. Poor lighting circuit Z1-ground. 6. Test for voltage drop across Z1-ground
locations. Refer to Group 8W.
HEADLAMP BULBS BURN
OUT FREQUENTLY1. Charging system output too high. 1. Test and repair charging system. Refer
to Group 8A.
2. Loose or corroded terminals or
splices in circuit.2. Inspect and repair all connectors and
splices. Refer to Group 8W.
HEADLAMPS ARE DIM
WITH ENGINE RUNNING
ABOVE IDLE1. Charging system output too low. 1. Test and repair charging system. Refer
to Group 8A.
2. Poor lighting circuit Z1-ground. 2. Test for voltage drop across Z1-ground
locations. Refer to Group 8W.
3. High resistance in headlamp
circuit.3. Test amperage draw of headlamp circuit.
HEADLAMPS FLASH
RANDOMLY1. Poor lighting circuit Z1-ground. 1. Test for voltage drop across Z1-ground
locations, refer to Group 8W.
2. High 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 Group 8W.
HEADLAMPS DO NOT
ILLUMINATE1. No voltage to headlamps. 1. Repair open headlamp circuit. Refer to
Group 8W.
2. No Z1-ground at headlamps. 2. Repair circuit ground. Refer to Group
8W.
3. Faulty headlamp switch. 3. Replace headlamp switch.
4. Faulty headlamp dimmer
(multi-function) switch.4. Replace multi-function switch.
5. Broken connector terminal or wire
splice in headlamp circuit.5. Repair connector terminal or wire splice.
6. Defective or burned out bulb. 6. Replace bulb.
7. Body controller malfunction. 7. Refer to appropriate body controller
diagnostics.
8L - 2 LAMPSNS/GS
GENERAL INFORMATION (Continued)

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 alternator drive
belt.2. Adjust or replace alternator drive
belt.
3. Charging system output too low. 3. Test and repair charging system.
Refer to Group 8A,
4. Battery has insufficient charge. 4. Test battery state-of -charge.
Refer to Group 8A.
5. Battery is sulfated or shorted. 5. Load test battery. Refer to Group
8A.
6. Poor lighting circuit Z1-ground. 6. Test for voltage drop across
Z1-ground locations. Refer to Group
8W.
FOG LAMP BULBS BURN OUT
FREQUENTLY1. Charging system output too high. 1. Test and repair charging system.
Refer to Group 8A.
2. Loose or corroded terminals or
splices in circuit.2. Inspect and repair all connectors
and splices. Refer to Group 8W.
FOG LAMPS ARE DIM WITH
ENGINE RUNNING ABOVE IDLE1. Charging system output too low. 1. Test and repair charging system.
Refer to Group 8A.
2. Poor lighting circuit Z1-ground. 2. Test for voltage drop across
Z1-ground locations. Refer to Group
8W.
3. High resistance in fog lamp
circuit.3. Test amperage draw of fog lamp
circuit.
FOG LAMPS FLASH RANDOMLY 1. Poor lighting circuit Z1-ground. 1. Test for voltage drop across
Z1-ground locations. Refer to Group
8W.
2. High resistance in fog lamp
circuit.2. Test amperage draw of fog lamp
circuit.
3. Faulty fog lamp switch. 3. Replace fog lamp switch.
4. Loose or corroded terminals or
splices in circuit.4. Inspect and repair all connectors
and splices. Refer to Group 8W.
FOG LAMPS DO NOT
ILLUMINATE1. Blown fuse for fog lamp. 1. Replace fuse. Refer to Group 8W.
2. No Z1-ground at fog lamps. 2. Repair circuit ground. Refer to
Group 8W.
3. Faulty fog lamp switch. 3. Replace fog lamp switch.
4. Broken connector terminal or wire
splice in fog lamp circuit.4. Repair connector terminal or wire
splice.
5. Defective or burned out bulb. 5. Replace bulb.
NS/GSLAMPS 8L - 3
DIAGNOSIS AND TESTING (Continued)