diagram DODGE RAM 1500 1998 2.G Owner's Manual

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
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 ground. 6. Test for voltage drop across ground circuits,
refer to Electrical, Wiring Diagram Information.
HEADLAMP BULBS
BURN OUT
FREQUENTLY1. Integrated Control Module (ICM)
not controlling voltage.1. Test and repair Integrated Control 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 IDLE1. Charging system output too low. 1. Test and repair charging system, refer to
Electrical, Wiring Information.
2. Poor lighting circuit ground. 2. Test for voltage drop across ground circuits,
refer to Electrical, Wiring Information.
3. High resistance in headlamp
circuit.3. Test amperage draw of headlamp circuit.
HEADLAMPS FLASH
RANDOMLY1. Poor lighting circuit ground. 1. Test for voltage drop across 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.
5. Front Control Module
Malfunction.5. Refer to appropriate ICM/FCM diagnostics.
8L - 4 LAMPS/LIGHTING - EXTERIORDR
LAMPS/LIGHTING - EXTERIOR (Continued)

ment of the vehicle. The front fog lamp relay is a
conventional International Standards Organization
(ISO) micro relay (Fig. 9). Relays conforming to the
ISO specifications have common physical dimensions,
current capacities, terminal patterns, and terminal
functions. The relay is contained within a small, rect-
angular, molded plastic housing and is connected to
all of the required inputs and outputs by five integral
male spade-type terminals that extend from the bot-
tom of the relay base.
The front fog lamp relay cannot be adjusted or
repaired and, if faulty or damaged, the unit must be
replaced.
OPERATION
The front fog lamp relay is an electromechanical
switch that uses a low current input from the Front
Control Module (FCM) to control a high current out-
put to the front fog lamps. The movable common feed
contact point is held against the fixed normally
closed contact point by spring pressure. When the
relay coil is energized, an electromagnetic field is
produced by the coil windings. This electromagnetic
field draws the movable relay contact point away
from the fixed normally closed contact point, and
holds it against the fixed normally open contact
point. When the relay coil is de-energized, spring
pressure returns the movable contact point back
against the fixed normally closed contact point. A
resistor is connected in parallel with the relay coil in
the relay, and helps to dissipate voltage spikes and
electromagnetic interference that can be generated as
the electromagnetic field of the relay coil collapses.
The front fog lamp relay terminals are connected
to the vehicle electrical system through a connector
receptacle in the Power Distribution Center (PDC).
The inputs and outputs of the front fog lamp relay
include:
²Common Feed Terminal- The common feed
terminal (30) receives battery voltage at all times
from a fuse in the PDC through a fused B(+) circuit.
²Coil Ground Terminal- The coil ground termi-
nal (85) is connected to a control output of the Front
Control Module (FCM) through a front fog lamp relay
control circuit. The FCM controls front fog lamp oper-
ation by controlling a ground path through this cir-
cuit.
²Coil Battery Terminal- The coil battery ter-
minal (86) receives battery voltage at all times from
a fuse in the PDC through a fused B(+) circuit.
²Normally Open Terminal- The normally open
terminal (87) is connected to the front fog lamps
through a front fog lamp relay output circuit and
provides battery voltage to the front fog lamps when-
ever the relay is energized.²Normally Closed Terminal- The normally
closed terminal (87A) is not connected in this appli-
cation.
The front fog lamp relay can be diagnosed using
conventional diagnostic tools and methods. Refer to
the appropriate wiring information for diagnosis and
testing of the front fog lamp micro-relay and for com-
plete wiring diagrams.
REMOVAL
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.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the cover for the Power Distribution
Center (PDC).
(3) Remove the front fog lamp relay by grasping it
firmly and pulling it straight out from the receptacle
in the PDC.
INSTALLATION
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.
DRLAMPS/LIGHTING - EXTERIOR 8L - 13
FOG LAMP RELAY (Continued)

REMOVAL - TAILGATE MARKER LAMP
(1) Remove the two screws that secure the lens
assembly to the tailgate (Fig. 15).
(2) Turn the bulb sockets counterclockwise a quar-
ter turn and remove the bulb sockets from the lens
assembly.
INSTALLATION
INSTALLATION - FENDER MARKER LAMP
(1) Install the bulb socket to the lens assembly.
Turn the bulb socket a quarter turn clockwise.
(2) Position the lens assembly against the fender.
Using firm pressure, push the lens assembly into the
fender.
INSTALLATION - TAILGATE MARKER LAMP
(1) Install the bulb sockets into the lens assembly.
Turn the bulb sockets a quarter turn clockwise.(2) Position the lens assembly to the tailgate.
Install and tighten the two screws securely.
MULTI-FUNCTION SWITCH
DESCRIPTION - TURN SIGNAL SYSTEM
The multi-function switch is a resistive MUX
switch that is monitored by the Instrument Cluster.
The turn signals are actuated with the lever on
Multi-Function Switch. The signals are automatically
turned off by a canceling cam (two lobes molded to
the back of the clock spring mechanism). The cam
comes in contact with the cancel actuator on the turn
signal (multi-function) switch assembly. Either cam
lobe, pushing on the cancel actuator, returns the
switch to the OFF position.
OPERATION - TURN SIGNAL SYSTEM
The Instrument Cluster monitors the multiplexed
multifunction switch. In a turning event the Instru-
ment Cluster senses a change in the turn signal
lever and illuminates the appropriate turn signal
indicator. At the same time, the Instrument Cluster
will send a J1850 message on the PCI bus to the
Front Control Module (FCM). The FCM will respond
by activating the appropriate relay in the Power Dis-
tribution Center.
A chime will sound after the turn is completed if
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 the turn signal, headlamp beam select and
optical 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 TESTS table.
MULTI-FUNCTION SWITCH TESTS
EXTERIOR LIGHTING FUNCTIONS
SWITCH POSITION CONNECTOR PINS RESISTANCE (OHMS)
Off 1 - 2 Open
Headlamp High Beams On 1 - 2 518 - 575
Hazard 3 - 2 115 - 128
Fig. 15 Tailgate Marker Lamp Housing
1 - RETAINING NUT (2)
2 - TAILGATE
3 - WIRING HARNESS AND BULB SOCKET
4 - SCREW (2)
5 - LENS ASSEMBLY
8L - 18 LAMPS/LIGHTING - EXTERIORDR
MARKER LAMP UNIT (Continued)

The compass unit also will compensate for magne-
tism the body of the vehicle may acquire during nor-
mal use. However, avoid placing anything magnetic
directly on the roof of the vehicle. Magnetic mounts
for an antenna, a repair order hat, or a funeral pro-
cession flag can exceed the compensating ability of
the compass unit if placed on the roof panel. Mag-
netic bit drivers used on the fasteners that hold the
overhead console assembly to the roof header can
also affect compass operation. If the vehicle roof
should become magnetized, the demagnetizing and
calibration procedures found in this section may be
required to restore proper compass operation.
TEMPERATURE DISPLAY
All the available overhead consoles on this model
include Temperature information. The temperature
displays the outside ambient temperature in whole
degrees. The temperature display can be toggled
from Fahrenheit to Celsius by selecting the desired
U.S./Metric option from the customer programmable
features. The displayed temperature is not an instant
reading of conditions, but an average temperature. It
may take the temperature display several minutes to
respond to a major temperature change, such as driv-
ing out of a heated garage into winter temperatures.
When the ignition switch is turned to the Off posi-
tion, the last displayed temperature reading stays in
the electronic control modules, (CMTC, EVIC) mem-
ory. When the ignition switch is turned to the On
position again, the electronic module will display the
memory temperature for one minute; then update the
display to the current average temperature reading
within five minutes.The temperature function is supported by an ambi-
ent temperature sensor. This sensor is mounted out-
side the passenger compartment near the front and
center of the vehicle, and is hard wired to the Front
Control Module (FCM). The FCM sends temperature
status messages to the module over the J1850 PCI
data bus circuit. For more information on the ambi-
ent temperature sensor, refer to Ambient Tempera-
ture Sensor later in this section.
Following are general descriptions of the major
components used in the overhead console. Refer to
Wiring Diagrams for complete circuit schematics.
OPERATION
Refer to the vehicle Owner's Manual for specific
operation of each overhead console and its systems.
DIAGNOSIS AND TESTING - OVERHEAD
CONSOLE
If the problem with the overhead console is an
inaccurate or scrambled display, refer toSELF-DI-
AGNOSTIC TESTlater in this text. If the problem
with the overhead console is incorrect Vacuum Fluo-
rescent Display (VFD) dimming levels, use a DRB
IIItscan tool and the proper Diagnostic Procedures
manual to test for the correct dimming message
inputs being received from the Body Control Module
(BCM) or Front Control Module (FCM) over the
J1850 Programmable Communications Interface
(PCI) data bus circuit. If the problem is a no-display
condition, use the following procedure. For complete
circuit diagrams, refer toOverhead Consolein the
Wiring Diagrams section of the service manual.
(1) Remove the overhead console from the head-
liner (Refer to 8 - ELECTRICAL/OVERHEAD CON-
SOLE - REMOVAL).
(2) Check for battery voltage at the overhead con-
sole electrical connector. Refer to Wiring for connec-
tor information. If OK, go to Step 3. If not OK, Check
for battery voltage at the appropriate B(+) fuse in the
integrated power module, repair the open fused B(+)
circuit as required.
(3) Turn the ignition switch to the On position.
Check the fused ignition switch output circuit(s) at
the overhead console electrical connector. If OK, go to
Step 4. If not OK, repair the open or shorted circuit
as required.
(4) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Check for continuity between the ground circuit cav-
ity of the overhead console electrical connector and a
good ground. There should be continuity. If OK, refer
toSELF-DIAGNOSTIC TESTbelow for further
diagnosis of the electronics module and the J1850
PCI data bus circuit. If not OK, repair the open
ground circuit as required.
Fig. 1 DR OVERHEAD CONSOLE ± EVIC
8M - 2 MESSAGE SYSTEMSDR
OVERHEAD CONSOLE (Continued)

(2) Install the screws holding the EVIC module in
the overhead console.
(3) Connect the EVIC module electrical connector.
(4) Install the overhead console on the headlin-
er(Refer to 8 - ELECTRICAL/OVERHEAD CON-
SOLE - INSTALLATION).
(5) Connect the battery negative cable.
(6) Check EVIC module function.
NOTE: If a new EVIC module has been installed, the
compass will have to be calibrated and the variance
set. Refer to Compass Variation Adjustment and
Compass Calibration in the Standard Procedures
section of this group for the procedures.
AMBIENT TEMP SENSOR
DESCRIPTION
Ambient air temperature is monitored by the over-
head console. The ambient temperature messages are
received from the Front Control Module (FCM) over
the Programmable Communications Interface (PCI)
J1850 data bus circuit. The FCM receives a hard
wired input from the ambient temperature sensor
(Fig. 7). The ambient temperature sensor is a vari-
able resistor mounted to the underside of the hood,
in the engine compartment.
For more information on the front control module,
refer toFront Control Modulein the Electronic
Control Modules section of this manual. For complete
circuit diagrams, refer toWiring. The ambient tem-
perature sensor cannot be adjusted or repaired and,
if faulty or damaged, it must be replaced.
OPERATION
The ambient temperature sensor is a variable
resistor that operates on a five-volt reference signal
sent to it by the Front Control Module. The resis-
tance in the sensor changes as temperature changes,
changing the temperature sensor signal circuit volt-
age to the Front Control Module. Based upon the
resistance in the sensor, the Front Control Modulesenses a specific voltage on the temperature sensor
signal circuit, which it is programmed to correspond
to a specific temperature. The Front Control Module
then sends the proper ambient temperature mes-
sages to the EVIC, CMTC over the PCI J1850 data
bus.
The temperature function is supported by the
ambient temperature sensor, a wiring circuit, the
Front Control Module, the Programmable Communi-
cations Interface (PCI) data bus, and a portion of the
Electronics module. If any portion of the ambient
temperature sensor circuit fails, the Front Control
Module will self-diagnose the circuit.
For complete circuit diagrams, refer toWiring.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - AMBIENT
TEMPERATURE SENSOR
(1) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the ambient temperature sensor wire har-
ness connector.
(2) Measure the resistance of the ambient temper-
ature sensor. At 24É C (75É F), the sensor resistance
should be approximately 10.3 kilohms. At 30É C (86É
F), the sensor resistance should be approximately
7.57 kilohms. The sensor resistance should decrease
as the temperature rises. If OK, refer toDiagnosis
and Testing - Ambient Temperature Sensor Cir-
cuitin this group. If not OK, replace the faulty
ambient temperature sensor.
NOTE: The ambient temperature sensor is a very
sensitive device. When testing, be certain the tem-
perature sensor has had time to stabilize (room
temperature) before attempting to read the sensor
resistance. Failure to let the ambient temperature
sensor temperature stabilize could result in a mis-
leading test.
DIAGNOSIS AND TESTING - AMBIENT
TEMPERATURE SENSOR CIRCUIT
(1) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the ambient temperature sensor wire har-
ness connector and the Front Control Module wire
harness connector.
(2) Connect a jumper wire between the two termi-
nals of the ambient temperature sensor wire harness
connector.
(3) Check for continuity between the sensor return
circuit and the ambient temperature sensor signal
circuit cavities of the Front Control Module wire har-
Fig. 7 Ambient Temperature Sensor - Typical
8M - 10 MESSAGE SYSTEMSDR
ELECTRONIC VEHICLE INFO CENTER (Continued)

ness connector. There should be continuity. If OK, go
to Step 4. If not OK, repair the open sensor return or
signal circuit as required.
(4) Remove the jumper wire from the ambient tem-
perature sensor wire harness connector. Check for
continuity between the sensor return circuit cavity of
the Front Control Module wire harness connector
and a good ground. There should be no continuity. If
OK, go to Step 5. If not OK, repair the shorted sen-
sor return circuit as required.
(5) Check for continuity between the ambient tem-
perature sensor signal circuit cavity of the Front
Control Module wire harness connector and a good
ground. There should be no continuity. If OK, refer to
Diagnosis and Testing - Overhead Consolein
this group. If not OK, repair the shorted ambient
temperature sensor signal circuit as required.
REMOVAL
(1) Open the hood.
(2) Disconnect and isolate the battery negative
cable.
(3) Working on the underside of the hood, remove
screw holding sensor to hood panel.
(4) Disconnect the sensor electrical connector and
remove sensor from vehicle.
INSTALLATION
(1) Connect the sensor electrical connector.
(2) Working on the underside of the hood, install
screw holding sensor to hood panel.
(3) Connect the battery negative cable.
(4) Close the hood.
UNIVERSAL TRANSMITTER
DESCRIPTION
Some DR models are equipped with a universal
transmitter transceiver. The universal transmitter is
integral to the Electronic Vehicle Information Center
(EVIC) and the Compass Mini-Trip Computer
(CMTC), which is located in the overhead console.
The only visible component of the universal transmit-
ter are the three transmitter push buttons centered
between the modules push buttons located just rear-
ward of the display screen in the overhead console.
The three universal transmitter push buttons are
identified with one, two or three light indicators so
that they be easily identified.
Each of the three universal transmitter push but-
tons control an independent radio transmitter chan-
nel. Each of these three channels can be trained to
transmit a different radio frequency signal for the
remote operation of garage door openers, motorized
gate openers, home or office lighting, security sys-tems or just about any other device that can be
equipped with a radio receiver in the 286 to 399
MegaHertz (MHz) frequency range for remote opera-
tion. The universal transmitter is capable of operat-
ing systems using either rolling code or non-rolling
code technology.
The electronics module displays messages and a
small house-shaped icon with one, two or three dots
corresponding to the three transmitter buttons to
indicate the status of the universal transmitter. The
EVIC messages are:
²Clearing Channels- Indicates that all of the
transmitter codes stored in the universal transmitter
have been successfully cleared.
²Channel ªXº Training- Indicates that the uni-
versal transmitter is in its transmitter learning
mode.
²Channel ªXº Trained- Indicates that the uni-
versal transmitter has successfully acquired a new
transmitter code.
²Channel ªXº Transmitting- Indicates that a
trained universal transmitter button has been
depressed and that the universal transmitter is
transmitting.
The universal transmitter cannot be repaired, and
is available for service only as a unit with the EVIC
or CMTC modules. If any part of the universal trans-
mitter is faulty or damaged, the complete EVIC or
CMTC module must be replaced.
OPERATION
The universal transmitter operates on a non-
switched source of battery current so the unit will
remain functional, regardless of the ignition switch
position. For more information on the features, pro-
gramming procedures and operation of the universal
transmitter, see the owner's manual in the vehicle
glove box.
DIAGNOSIS AND TESTING - UNIVERSAL
TRANSMITTER
If the Universal Transmitter is inoperative, but the
Electronic Vehicle Information Center (EVIC) is oper-
ating normally, see the owner's manual in the vehicle
glove box for instructions on training the Transmit-
ter. Retrain the Transmitter with a known good
transmitter as instructed in the owner's manual and
test the Transmitter operation again. If the unit is
still inoperative, test the universal transmitter with
Radio Frequency Detector special tool. If both the
Transmitter and the EVIC module are inoperative,
refer toElectronic Vehicle Information Center
Diagnosis and Testingin this group for further
diagnosis. For complete circuit diagrams, refer to
Wiring Diagrams. (Fig. 8) as described below:
DRMESSAGE SYSTEMS 8M - 11
AMBIENT TEMP SENSOR (Continued)

(2) Disconnect wire harness connector to power
mirror switch (Fig. 1).
(3) Using two jumper wires:
²Connect one to a 12 volt source
²Connect the other to a good body ground
²Refer to the Mirror Motor Test Chart for proper
wire connections at the switch connector
MIRROR MOTOR TEST CHART
12 VOLTS GROUND MIRROR REACTION
SWITCH CONNECTOR RIGHT LEFT
PIN 1 PIN 2 - UP
PIN 6 PIN 2 - LEFT
PIN 2 PIN 1 - DOWN
PIN 2 PIN 6 - RIGHT
PIN 7 PIN 2 UP -
PIN 4 PIN 2 LEFT -
PIN 2 PIN 7 DOWN -
PIN 2 PIN 4 RIGHT -
(4) If results shown in table are not obtained,
check for open or shorted circuit. Replace mirror
assembly as necessary.
AUTOMATIC DAY / NIGHT
MIRROR
DESCRIPTION
The automatic day/night mirror uses a thin layer
of electrochromic material between two pieces of con-
ductive glass to make up the face of the mirror.
When the mirror switch is in the On position, two
photocell sensors are used by the mirror circuitry to
monitor external light levels and adjust the reflec-
tance of the mirror.
OPERATION
The ambient photocell sensor is located on the for-
ward-facing (windshield side) of the rear view mirror
housing, and detects the ambient light levels outside
of the vehicle. The headlamp photocell sensor is
located inside the rear view mirror housing behind
the mirror glass and faces rearward, to detect the
level of the light being received at the rear window
side of the mirror. When the circuitry of the auto-
matic day/night mirror detects that the difference
between the two light levels is too great (the light
level received at the rear of the mirror is much
higher than that at the front of the mirror), it begins
to darken the mirror.
The automatic day/night mirror circuitry also mon-
itors the transmission using an input from the
backup lamp circuit. The mirror circuitry is pro-
grammed to automatically disable its self-dimming
feature whenever it senses that the transmission
backup lamp circuit is energized.
The automatic day/night mirror is a completely
self-contained unit and cannot be repaired. If faulty
or damaged, the entire mirror assembly must be
replaced.
DIAGNOSIS AND TESTING - AUTOMATIC DAY /
NIGHT MIRROR
For complete circuit diagrams, refer to the appro-
priate wiring information.
(1) Check the fuse in the Integrated Power Module
(IPM). If OK, go to Step 2. If not OK, repair the
shorted circuit or component as required and replace
the faulty fuse.
(2) Turn the ignition switch to the On position.
Check for battery voltage at the fuse in the IPM. If
OK, go to Step 3. If not OK, repair the open circuit to
the ignition switch as required.
(3) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Unplug the wire harness connector from the auto-
matic day/night mirror (Fig. 2). Connect the battery
negative cable. Turn the ignition switch to the On
position. Check for battery voltage at the fused igni-
tion switch output (run/start) circuit cavity of the
automatic day/night mirror wire harness connector. If
OK, go to Step 4. If not OK, repair the open circuit to
the IPM as required.
(4) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Check for continuity between the ground circuit cav-
ity of the automatic day/night mirror wire harness
connector and a good ground. There should be conti-
nuity. If OK, go to Step 5. If not OK, repair the cir-
cuit to ground as required.
Fig. 1 POWER MIRROR SWITCH CONNECTOR
DRPOWER MIRRORS 8N - 11
POWER MIRRORS (Continued)

POWER SEATS
TABLE OF CONTENTS
page page
POWER SEATS
DESCRIPTION.........................13
OPERATION...........................13
DIAGNOSIS AND TESTING - POWER SEAT
SYSTEM............................13
DRIVER SEAT SWITCH
DESCRIPTION.........................14
OPERATION...........................14
DIAGNOSIS AND TESTING - DRIVER SEAT
SWITCH............................14
REMOVAL.............................15
INSTALLATION.........................15
PASSENGER SEAT SWITCH
DESCRIPTION.........................15
OPERATION...........................15
DIAGNOSIS AND TESTING - PASSENGER
SEAT SWITCH........................16REMOVAL.............................16
INSTALLATION.........................16
POWER SEAT TRACK
DESCRIPTION.........................16
OPERATION...........................16
DIAGNOSIS AND TESTING - POWER SEAT
TRACK.............................17
REMOVAL.............................17
INSTALLATION.........................17
LUMBAR CONTROL SWITCH
DESCRIPTION.........................17
OPERATION...........................18
REMOVAL.............................18
LUMBAR MOTOR
DESCRIPTION.........................18
OPERATION...........................18
DIAGNOSIS AND TESTING - LUMBAR MOTOR . 18
POWER SEATS
DESCRIPTION
The power seat system option allows the driver or
passenger to electrically adjust the seat position for
optimum control and comfort using the power seat
switches located on the outboard seat cushion side
shield. The power seat system allows the seating
position to be adjusted forward, rearward, front up,
front down, rear up, or rear down. The power seat
system receives battery current through a fuse in the
Integrated Power Module, regardless of the ignition
switch position. The power seat system includes the
following components:
²Driver Power Seat Switch
²Passenger Power Seat Switch
²Driver Power Seat Track
²Passenger Power Seat Track
²Power Lumbar Adjuster(s)
Some models equipped with the power seat option
also feature a power operated lumbar support in the
seat back. The power lumbar support allows the user
to inflate or deflate a bladder located in the lower
seat back to achieve optimum comfort and support in
the lower lumbar region of the spinal column. The
power lumbar support shares the battery feed circuit
of the power seat system.
Following are general descriptions of the major
components in the power seat system. Refer to
Heated Seat Systemfor information on the individ-ually controlled heated front seats. Refer to the own-
er's manual in the vehicle glove box for more
information on the features, use and operation of the
power seat system.
OPERATION
The power seat system allows the driver and/or
front passenger seating positions to be adjusted elec-
trically and independently using the separate power
seat switches found on the outboard seat cushion
side shield of each front seat. See the owner's manual
in the vehicle glove box for more information on the
features, use and operation of the power seat system.
DIAGNOSIS AND TESTING - POWER SEAT
SYSTEM
Before any testing of the power seat system is
attempted, the battery should be fully-charged and
all wire harness connections and pins checked to
ensure proper continuity and grounds. For circuit
descriptions and diagrams, refer to Wiring Diagrams.
With the dome lamp on, apply the power seat
switch in the direction of the failure. If the dome
lamp dims, the seat may be jamming. Check under
and behind the seat for binding or obstructions. If
the dome lamp does not dim, proceed with testing of
the individual components and circuits.
DRPOWER SEATS 8N - 13

DRIVER SEAT SWITCH
DESCRIPTION
The power seat on this model can be adjusted in
eight different directions, up, down, front up, front
down, rear up, rear down, rearward and forward.
The power seat switch (Fig. 1) on this model has an
additional switch knob for adjusting the power lum-
bar support. The power seat switch is located on the
outboard side of the seat cushion on the seat cushion
side shield. Refer to the owner's manual in the vehi-
cle glove box for more information on the power seat
switch functions and the seat adjusting procedures.
The individual switches in the power seat switch
assembly cannot be repaired. If one switch is dam-
aged or faulty, the entire power seat switch assembly
must be replaced.
OPERATION
When a power switch control knob or knobs are
actuated, a battery feed and a ground path are
applied through the switch contacts to the power seat
track or recliner adjuster motor. The selected
adjuster motor operates to move the seat track or
recliner through its drive unit in the selected direc-
tion until the switch is released, or until the travel
limit of the adjuster is reached. When the switch ismoved in the opposite direction, the battery feed and
ground path to the motor are reversed through the
switch contacts. This causes the adjuster motor to
run in the opposite direction.
No power seat switch should be held applied in any
direction after the adjuster has reached its travel
limit. The power seat adjuster motors each contain a
self-resetting circuit breaker to protect them from
overload. However, consecutive or frequent resetting
of the circuit breaker must not be allowed to con-
tinue, or the motor may be damaged.
DIAGNOSIS AND TESTING - DRIVER SEAT
SWITCH
For circuit descriptions and diagrams, refer to Wir-
ing.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the power seat switch from the power
seat.
(3) Use an ohmmeter to test the continuity of the
power seat switches in each position. See the Power
Seat Switch Continuity chart (Fig. 2). If OK, refer to
Power Seat Track Diagnosis and Testing in this
group. If not OK, replace the faulty power seat
switch.
DRIVER POWER SEAT SWITCH TEST TABLE
DRIVER SWITCH
POSITIONCONTINUITY BETWEEN
OFF B-N, B-J, B-M
B-E, B-L, B-K
VERTICAL UP A-E, A-M, B-N, B-J
VERTICAL DOWN A-J, A-N, B-M, B-E
Fig. 1 DR Power Seat Switch
1 - POWER SEAT SWITCH ASSEMBLY
2 - FRONT SEAT CUSHION ADJUSTMENT BUTTON
3 - COMPLETE SEAT ADJUSTMENT BUTTON
4 - REAR SEAT CUSHION ADJUSTMENT BUTTON
5 - LUMBAR ADJUSTMENT BUTTON
Fig. 2 Testing Driver Power Seat Switch
8N - 14 POWER SEATSDR

DIAGNOSIS AND TESTING - PASSENGER SEAT
SWITCH
For circuit descriptions and diagrams, refer to Wir-
ing.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the power seat switch from the power
seat.
(3) Use an ohmmeter to test the continuity of the
power seat switches in each position. See the Power
Seat Switch Continuity chart (Fig. 4). If OK, refer to
Power Seat Track Diagnosis and Testing in this
group. If not OK, replace the faulty power seat
switch.
PASSENGER SEAT SWITCH TEST TABLE
PASSENGER SWITCH
POSITIONCONTINUITY BETWEEN
OFF B-N, B-J, B-M
B-E, B-L, B-K
VERTICAL DOWN A-E, A-M, B-N, B-E
VERTICAL UP A-J, A-N, B-M, B-E
HORIZONTAL
FORWARDA-L, B-K
HORIZONTAL
REARWARDA-K, B-L
FRONT TILT DOWN A-M, B-N
FRONT TILT UP A-N, B-M
REAR TILT DOWN A-E, B-J
REAR TILT UP A-J, B-E
LUMBAR OFF O-P, O-R, P-R
LUMPAR UP (DEFLATE) O-P, Q-R
LUMBAR DOWN
(INFLATE)O-R, P-Q
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the seat cushion side shield from the
seat. Refer to the Body section of the service manual
for the procedure.
(3) Pull the switch bezel or side shield unit out
from the seat far enough to access the switch wire
harness connector. Gently pry the locking tabs of the
switch away from the wire harness connector and
carefully unplug the connector from the power seat
switch module.
(4) Remove the screws that secure the power seat
switch.
INSTALLATION
(1) Position the power seat switch on the seat
cushion bezel and install the screws that secure the
power seat switch to seat cushion side bezel.
(2) Connect the electrical connector.
(3) Install the seat cushion switch bezel on the
seat. Refer to the Body section of the service manual
for the procedure.
(4) If equipped, install the screw that secures the
recliner lever to the recliner mechanism release shaft
on the outboard side of the front seat.
(5) Connect the battery negative cable.
POWER SEAT TRACK
DESCRIPTION
The eight-way power seat option includes a power
seat track assembly located under each front seat
(Fig. 5). The power seat track assembly replaces the
standard manually operated seat tracks. The lower
half of the power seat track is secured at the front
with two bolts to the floor panel seat cross member,
and at the rear with two bolts to the floor panel.
Four nuts secure the bottom of the seat cushion
frame to the upper half of the power seat track unit.
The power seat track assembly cannot be repaired,
and is serviced only as a complete assembly. If any
component in this assembly is faulty or damaged, the
entire power seat track must be replaced.
OPERATION
The power seat track unit includes three reversible
electric motors that are secured to the upper half of
the track unit. Each motor moves the seat adjuster
through a combination of worm-drive gearboxes and
screw-type drive units.
The front and rear of the seat are operated by two
separate vertical adjustment motors. These motors
can be operated independently of each other, tilting
the entire seat assembly forward or rearward; or,
Fig. 4 Testing Passenger Power Seat Switch
8N - 16 POWER SEATSDR
PASSENGER SEAT SWITCH (Continued)