1998 DODGE RAM 1500 Vin tag

²Exterior Lighting Fail-safe- In the absence of
a headlamp switch input, the EMIC will turn on the
cluster illumination lamps and provide electronic
headlamp low beam and park lamp request messages
to the Front Control Module (FCM) located on the
Integrated Power Module (IPM) for default exterior
lamp operation. The FCM will also provide default
park lamp and headlamp low beam operation and the
EMIC will turn on the cluster illumination lamps if
there is a failure of the electronic data bus commu-
nication between the EMIC and the FCM.
²Heated Seat Control- The EMIC monitors
inputs from the ignition switch and electronic engine
speed messages from the Powertrain Control Module
(PCM) to control a high side driver output to the
heated seat switch Light Emitting Diode (LED) indi-
cators. This input allows the heated seat switches to
wake up the heated seat module if the switch is actu-
ated. The EMIC will de-energize the heated seat
switch LED indicators, which deactivates the heated
seat system, if the ignition switch is turned to any
position except On or Start, or if the engine speed
message indicates zero. (Refer to 8 - ELECTRICAL/
HEATED SEATS - DESCRIPTION).
²Interior Lamp Load Shedding- The EMIC
provides a battery saver feature which will automat-
ically turn off all interior lamps that remain on after
a timed interval of about fifteen minutes.
²Interior Lamps - Enhanced Accident
Response- The EMIC monitors inputs from the Air-
bag Control Module (ACM) and the Powertrain Con-
trol Module (PCM) to automatically turn on the
interior lighting after an airbag deployment event
ten seconds after the vehicle speed is zero. The inte-
rior lighting remains illuminated until the key is
removed from the ignition switch lock cylinder, at
which time the interior lighting returns to normal
operation and control. This feature, like all other
enhanced accident response features, is dependent
upon a functional vehicle electrical system following
the vehicle impact event.
²Interior Lighting Control- The EMIC moni-
tors inputs from the interior lighting switch, the door
ajar switches, the cargo lamp switch, the reading
lamp switches, and the Remote Keyless Entry (RKE)
module to provide courtesy lamp control. This
includes support for timed illuminated entry with
theater-style fade-to-off and courtesy illumination
defeat features.
²Lamp Out Indicator Control- The EMIC
monitors electronic lamp outage messages from the
Front Control Module (FCM) located on the Inte-
grated Power Module (IPM) in order to provide lamp
out indicator control for the headlamps (low and high
beams), turn signal lamps, and the brake lamps
(excluding CHMSL).²Panel Lamps Dimming Control- The EMIC
provides a hard wired 12-volt Pulse-Width Modulated
(PWM) output that synchronizes the dimming level
of all hard wired panel lamps dimmer controlled
lamps with that of the cluster illumination lamps.
²Parade Mode- The EMIC provides a parade
mode (also known as funeral mode) that allows all
Vacuum-Fluorescent Display (VFD) units in the vehi-
cle to be illuminated at full (daytime) intensity while
driving during daylight hours with the exterior
lamps turned on.
²Power Locks- The EMIC monitors inputs from
the power lock switches and the Remote Keyless
Entry (RKE) receiver module (optional) to provide
control of the power lock motors through high side
driver outputs to the power lock motors. This
includes support for rolling door locks (also known as
automatic door locks), automatic door unlock, a door
lock inhibit mode, and central locking (with the
optional Vehicle Theft Security System only). (Refer
to 8 - ELECTRICAL/POWER LOCKS - DESCRIP-
TION).
²Remote Keyless Entry- The EMIC supports
the optional Remote Keyless Entry (RKE) system fea-
tures, including support for the RKE Lock, Unlock
(with optional driver-door-only unlock, and unlock-
all-doors), Panic, audible chirp, optical chirp, illumi-
nated entry modes, an RKE programming mode, as
well as optional Vehicle Theft Security System
(VTSS) arming (when the proper VTSS arming con-
ditions are met) and disarming.
²Remote Radio Switch Interface- The EMIC
monitors inputs from the optional remote radio
switches and then provides the appropriate electronic
data bus messages to the radio to select the radio
operating mode, volume control, preset station scan
and station seek features.
²Rolling Door Locks- The EMIC provides sup-
port for the power lock system rolling door locks fea-
ture (also known as automatic door locks). This
feature will automatically lock all unlocked doors
each time the vehicle speed reaches twenty-four kilo-
meters-per-hour (fifteen miles-per-hour). Following
an automatic lock event, if the driver side front door
is opened first after the ignition is turned to the Off
position, all doors will be automatically unlocked.
²Turn Signal & Hazard Warning Lamp Con-
trol- The EMIC provides electronic turn and hazard
lamp request messages to the Front Control Module
(FCM) located on the Integrated Power Module (IPM)
for turn and hazard lamp control. The EMIC also
provides an audible click at one of two rates to emu-
late normal and bulb out turn or hazard flasher oper-
ation based upon electronic lamp outage messages
from the FCM, and provides an audible turn signal
on chime warning if a turn is signalled continuously
8J - 4 INSTRUMENT CLUSTERDR
INSTRUMENT CLUSTER (Continued)

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 individual ser-
vice replacement.
OPERATION
The ElectroMechanical Instrument Cluster (EMIC)
in this model also includes the hardware and soft-
ware necessary to serve as the electronic body control
module and is sometimes referred to as the Cab
Compartment Node or CCN. The following informa-
tion deals primarily with the instrument cluster
functions of this unit. Additional details of the elec-
tronic body control functions of this unit may be
found within the service information for the system
or component that the EMIC controls. For example:
Additional details of the audible warning functions ofthe EMIC are found within the Chime/Buzzer service
information.
The EMIC is designed to allow the vehicle operator
to monitor the conditions of many of the vehicle com-
ponents and operating systems. The gauges and indi-
cators in the EMIC provide valuable information
about the various standard and optional powertrains,
fuel and emissions systems, cooling systems, lighting
systems, safety systems and many other convenience
items. The EMIC is installed in the instrument panel
so that all of these monitors can be easily viewed by
the vehicle operator when driving, while still allow-
ing relative ease of access for service. The micropro-
cessor-based EMIC hardware and software uses
various inputs to control the gauges and indicators
visible on the face of the cluster. Some of these
inputs are hard wired, but most are in the form of
electronic messages that are transmitted by other
electronic modules over the Programmable Communi-
cations Interface (PCI) data bus network. (Refer to 8
Fig. 3 Gauges & Indicators - Gasoline Engine
1 - MALFUNCTION INDICATOR LAMP 13 - ELECTRONIC THROTTLE CONTROL (ETC) INDICATOR
2 - VOLTAGE GAUGE 14 - ENGINE TEMPERATURE GAUGE
3 - LEFT TURN INDICATOR 15 - SECURITY INDICATOR
4 - TACHOMETER 16 - GEAR SELECTOR INDICATOR DISPLAY (INCLUDES
CRUISE & UPSHIFT INDICATORS)
5 - AIRBAG INDICATOR 17 - CHECK GAUGES INDICATOR
6 - HIGH BEAM INDICATOR 18 - BRAKE INDICATOR
7 - SEATBELT INDICATOR 19 - ABS INDICATOR
8 - SPEEDOMETER 20 - ODOMETER/TRIP ODOMETER DISPLAY (INCLUDES
ENGINE HOURS, WASHER FLUID, LAMP OUTAGE, TOW/HAUL
& SERVICE 4x4 INDICATORS)
9 - RIGHT TURN INDICATOR 21 - ODOMETER/TRIP ODOMETER SWITCH BUTTON
10 - OIL PRESSURE GAUGE 22 - FUEL GAUGE
11 - CARGO LAMP INDICATOR 23 - LOW FUEL INDICATOR
12 - DOOR AJAR INDICATOR 24 - TRANSMISSION OVERTEMP INDICATOR
8J - 6 INSTRUMENT CLUSTERDR
INSTRUMENT CLUSTER (Continued)

CAUTION: Instrument clusters used in this model
automatically configure themselves for compatibil-
ity with the features and optional equipment in the
vehicle in which they are initially installed. The
instrument cluster is programmed to do this by
embedding the Vehicle Identification Number (VIN)
and other information critical to proper cluster
operation into electronic memory. This embedded
information is learned through electronic messages
received from other electronic modules in the vehi-
cle over the Programmable Communications Inter-
face (PCI) data bus, and through certain hard wired
inputs received when the cluster is connected to
the vehicle electrically. Once configured, the instru-
ment cluster memory may be irreparably damaged
and certain irreversible configuration errors may
occur if the cluster is connected electrically to
another vehicle; or, if an electronic module from
another vehicle is connected that provides data to
the instrument cluster (including odometer values)
that conflicts with that which was previously
learned and stored. Therefore, the practice of
exchanging (swapping) instrument clusters and
other electronic modules in this vehicle with those
removed from another vehicle must always be
avoided. Failure to observe this caution may result
in instrument cluster damage, which is not reim-
bursable under the terms of the product warranty.
Service replacement instrument clusters are pro-
vided with the correct VIN, and the certified odom-
eter and engine hours values embedded into cluster
memory, but will otherwise be automatically config-
ured for compatibility with the features and optional
equipment in the vehicle in which they are initially
installed.
NOTE: Certain indicators in this instrument cluster
are automatically configured. This feature allows
those indicators to be activated or deactivated for
compatibility with certain optional equipment. If the
problem being diagnosed involves improper illumi-
nation of the cruise indicator, the electronic throttle
control indicator, the service four-wheel drive indi-
cator, the tow/haul indicator, the transmission over-
temp indicator, the upshift indicator, the security
indicator or the gear selector indicator, disconnect
and isolate the battery negative cable. After about
five minutes, reconnect the battery negative cable
and turn the ignition switch to the On position. The
instrument cluster should automatically relearn the
equipment in the vehicle and properly configure the
configurable indicators accordingly.PRELIMINARY DIAGNOSIS
WARNING: TO AVOID PERSONAL INJURY OR
DEATH, ON VEHICLES EQUIPPED WITH AIRBAGS,
DISABLE THE SUPPLEMENTAL RESTRAINT SYS-
TEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, AIRBAG, SEAT BELT
TENSIONER, IMPACT SENSOR, OR INSTRUMENT
PANEL COMPONENT DIAGNOSIS OR SERVICE.
DISCONNECT AND ISOLATE THE BATTERY NEGA-
TIVE (GROUND) CABLE, THEN WAIT TWO MINUTES
FOR THE SYSTEM CAPACITOR TO DISCHARGE
BEFORE PERFORMING FURTHER DIAGNOSIS OR
SERVICE. THIS IS THE ONLY SURE WAY TO DIS-
ABLE THE SUPPLEMENTAL RESTRAINT SYSTEM.
FAILURE TO TAKE THE PROPER PRECAUTIONS
COULD RESULT IN ACCIDENTAL AIRBAG DEPLOY-
MENT.
(1) Check the fused B(+) fuse (Fuse 51 - 20
ampere) 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) Check for battery voltage at the fused B(+) fuse
(Fuse 51 - 20 ampere) in the IPM. If OK, go to Step
3. If not OK, repair the open fused B(+) circuit
between the IPM and the battery as required.
(3) Disconnect and isolate the battery negative
cable. Remove the instrument cluster. Reconnect the
battery negative cable. Check for battery voltage at
the fused B(+) circuit cavity of the instrument panel
wire harness connector (Connector C1) for the instru-
ment cluster. If OK, go to Step 4. If not OK, repair
the open fused B(+) circuit between the instrument
cluster and the IPM as required.
(4) Check for continuity between the signal ground
circuit cavity of the instrument panel wire harness
connector (Connector C1) for the instrument cluster
and a good ground. There should be continuity. If
OK, refer to ACTUATOR TEST. If not OK, repair the
open ground circuit to ground (G202) as required.
DRINSTRUMENT CLUSTER 8J - 11
INSTRUMENT CLUSTER (Continued)

INSTRUMENT CLUSTER FAILURE MESSAGE
Fault Code Description Correction
07 Wait to start indicator circuit shorted. Refer to the appropriate diagnostic information.
08 Wait to start indicator circuit open. Refer to the appropriate diagnostic information.
0B BTSI output circuit shorted or open. Refer to the appropriate diagnostic information.
22 Headlamp switch input circuit shorted. Refer to the appropriate diagnostic information.
23 Headlamp switch input circuit open. Refer to the appropriate diagnostic information.
24 Turn hazard switch input circuit shorted. Refer to the appropriate diagnostic information.
25 Turn hazard swiitch inpot circuit open. Refer to the appropriate diagnostic information.
27 Courtesy/dome output circuit shorted or open. Refer to the appropriate diagnostic information.
28 Glovebox/map lamp output circuit shorted or
open.Refer to the appropriate diagnostic information.
29 Cargo lamp output circuit shorted or open. Refer to the appropriate diagnostic information.
40 Wiper switch input circuit shorted. Refer to the appropriate diagnostic information.
41 Wiper switch input circuit open. Refer to the appropriate diagnostic information.
42 Wash/beam input circuit shorted. Refer to the appropriate diagnostic information.
60 Passenger door lock switch input circuit
shorted.Refer to the appropriate diagnostic information.
61 Passenger door lock switch input circuit open. Refer to the appropriate diagnostic information.
62 Passenger door lock switch input circuit stuck. Refer to the appropriate diagnostic information.
63 Driver door lock switch input circuit shorted. Refer to the appropriate diagnostic information.
64 Driver door lock switch input circuit open. Refer to the appropriate diagnostic information.
65 Driver door lock switch input circuit stuck. Refer to the appropriate diagnostic information.
66 All door lock output circuit shorted to ground
or voltage.Refer to the appropriate diagnostic information.
67 All door unlock output circuit shorted to
ground or voltage.Refer to the appropriate diagnostic information.
68 Driver door unlock output circuit shorted to
ground or voltage.Refer to the appropriate diagnostic information.
6C Driver cylinder lock switch input circuit
shorted.Refer to the appropriate diagnostic information.
6E Driver cylinder lock switch input circuit stuck. Refer to the appropriate diagnostic information.
80 Incorrect odometer value found. Refer to the appropriate diagnostic information.
81 Remote radio switch input circuit high. Refer to the appropriate diagnostic information.
82 Remote radio switch stuck. Refer to the appropriate diagnostic information.
A0 Internal module FLASH memory checksum
failure.Refer to the appropriate diagnostic information.
A1 Internal module bootloader failure. Refer to the appropriate diagnostic information.
A3 Battery voltage open. Refer to the appropriate diagnostic information.
A5 TCCM messages not received. Refer to the appropriate diagnostic information.
A7 VIN checksum error. Refer to the appropriate diagnostic information.
A8 VIN previously stored. Refer to the appropriate diagnostic information.
A9 PCI bus internal failure. Refer to the appropriate diagnostic information.
AA PCM messages not received. Refer to the appropriate diagnostic information.
AB TCM messages not received. Refer to the appropriate diagnostic information.
DRINSTRUMENT CLUSTER 8J - 13
INSTRUMENT CLUSTER (Continued)

Instrument Cluster transmits a message via J1850
informing the the FCM. The FCM will then turn off
the headlamps, park lamps and fog lamps. This fea-
ture (load shed) prevents the vehicle battery from
being discharged when the vehicle lights have been
left ON.
HEADLAMP TIME DELAY SYSTEM
The headlamp time delay system is activated by
turning the headlamps ON (high or low beam) while
the engine is running, turning the ignition switch
OFF, and then turning the headlamp switch OFF
within 45 seconds. The system will not activate if
more than 45 seconds elapse between ignition switch
OFF and headlamp switch OFF. The FCM will allow
the headlamps to remain ON for 60 seconds (config-
urable) before they automatically turn off (If the key
is in the ignition during the headlamp time delay
mode, then the headlamps including panel dimming
will be ON).
LAMP OUTAGE
If one or more of the following lamps (Low and/or
High beams, Brake and/or Turn Signal) are out, then
a ªlamps outº indicator located in the cluster will
illuminate.
OPTICAL HORN/HIGH BEAMS
When the multiplexed multifunction switch is
pulled to the first detent (optical horn) signal, the
headlamps are ON, the Instrument Cluster shall
send a message via J1850 to the FCM to turn on the
headlamps drivers to illuminate all four filaments
(Low and High beams). When the multifunction
switch is pulled to the second detent (high beam) sig-
nal and the headlamps are ON, the Instrument Clus-
ter shall send a message via J1850 to the FCM to
turn on the headlamps drivers. The High Beams are
illuminated and the Low Beams and Fog Lamps (if
ON) are extinguished. If the headlamps were in the
high beam configuration when power was removedfrom the headlamps, the headlamps will return to
their last state prior to being shut off.
DIAGNOSIS AND TESTING - LAMPS/LIGHTING
- EXTERIOR
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 other than
those indicated in the Bulb Application table. Dam-
age to lamp and/or Daytime Running Lamp Module
can result. Do not use fuses, circuit breakers or
relays having greater amperage value than indi-
cated on the fuse panel or in the Owners Manual.
When a vehicle experiences problems with the
headlamp system, verify the condition of the battery
connections, fuses, charging system, headlamp bulbs,
wire connectors, relay, multifunction 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
loose pin connections and corrosion. Repair as neces-
sary.
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.
DRLAMPS/LIGHTING - EXTERIOR 8L - 3
LAMPS/LIGHTING - EXTERIOR (Continued)

Certain functions and features of the power lock
system rely upon resources shared with other elec-
tronic modules in the vehicle over the Programmable
Communications Interface (PCI) data bus network.
For proper diagnosis of these electronic modules or of
the PCI data bus network, the use of a DRB IIIt
scan tool and the appropriate diagnostic information
are required.
CENTRAL LOCKING/UNLOCKING
The instrument cluster will lock all doors when a
cylinder lock switch is activated in the ªlockº posi-
tion. When the instrument cluster receives an unlock
command from one of the cylinder lock switches, it
will unlock only that door. If the instrument cluster
receives a second command within a 5 second period,
it will unlock all the remaining doors. The illumi-
nated entry will activate during door unlock.
ENHANCED ACCIDENT RESPONSE
Upon detection of an airbag deployment by way of
the PCI bus, the instrument cluster will:
²Immediately disable the power door lock output.
²Unlock all doors by activating the door unlock
output for approximately 300 milliseconds.
²After actuating the door unlock output, allow
the door lock motors to be activated if the door lock
input has been inactive (not erratic) for 2 seconds
since the reception of the airbag deployment mes-
sage.
REMOTE KEYLESS ENTRY
A Radio Frequency (RF) type Remote Keyless
Entry (RKE) system is an available factory-installed
option on this model. The RKE system allows the use
of a remote battery-powered radio transmitter to sig-
nal the instrument cluster to actuate the power lock
system. The RKE receiver operates on non-switched
battery current through a fuse in the Integrated
Power Module (IPM), so that the system remains
operational, regardless of the ignition switch position.
The RKE transmitters are also equipped with a
Panic button. If the Panic button on the RKE trans-
mitter is depressed, the horn will sound and the
exterior lights will flash on the vehicle for about
three minutes, or until the Panic button is depressed
a second time. A vehicle speed of about 25.7 kilome-
ters-per-hour (15 miles-per-hour) will also cancel the
panic event.
The RKE system can also perform other functions
on this vehicle. If the vehicle is equipped with the
optional Vehicle Theft Security System (VTSS), the
RKE transmitter will arm the VTSS when the Lock
button is depressed, and disarm the VTSS when the
Unlock button is depressed.
The RKE system includes two transmitters when
the vehicle is shipped from the factory, but the system
can retain the vehicle access codes of up to a total of
four transmitters. The transmitter codes are retained
in the RKE module memory, even if the battery is dis-
connected. If an RKE transmitter is faulty or lost,
new transmitter vehicle access codes can be pro-
grammed into the system using a DRB IIItscan tool.
This vehicle also offers several customer program-
mable features, which allows the selection of several
optional electronic features to suit individual prefer-
ences. Customer programmable feature options
affecting the RKE system include:
²Remote Unlock Sequence- Allows the option
of having only the driver side front door unlock when
the RKE transmitter Unlock button is depressed the
first time. The remaining doors unlock when the but-
ton is depressed a second time within 5 seconds of
the first unlock press. Another option is having all
doors unlock upon the first depression of the RKE
transmitter Unlock button.
²Sound Horn on Lock- Allows the option of
having the horn sound a short chirp as an audible
verification that the RKE system received a valid
Lock request from the RKE transmitter, or having no
audible verification.
²Flash Lights with Lock and Unlock- Allows
the option of having the park lamps flash as an opti-
cal verification that the RKE system received a valid
Lock request or Unlock request from the RKE trans-
mitter, or having no optical verification.
²Programming Additional Transmitters-
Allows up to a total of four transmitter vehicle access
codes to be stored in the receiver memory.
Certain functions and features of the RKE system
rely upon resources shared with other electronic
modules in the vehicle over the Programmable Com-
munications Interface (PCI) data bus network. For
diagnosis of these electronic modules or of the PCI
data bus network, the use of a DRB IIItscan tool
and the appropriate diagnostic information are
required.
OPERATION
POWER LOCKS
The instrument cluster locks or unlocks the doors
when an actuation input signal from a door lock
switch or Remote Keyless Entry Module (RKE) is
received. The instrument cluster turns on the output
drivers and provides a voltage level to the door lock
motor for a specified time. All passenger doors can be
locked or unlocked using a mechanical button
mounted on the door trim panel. The front passenger
doors can be locked or unlocked by using the key cyl-
inder.
8N - 2 POWER LOCKSDR
POWER LOCKS (Continued)

POWER MIRRORS
TABLE OF CONTENTS
page page
POWER MIRRORS
DESCRIPTION.........................10
OPERATION...........................10
DIAGNOSIS AND TESTING - POWER
MIRRORS...........................10
AUTOMATIC DAY / NIGHT MIRROR
DESCRIPTION.........................11
OPERATION...........................11
DIAGNOSIS AND TESTING - AUTOMATIC DAY
/ NIGHT MIRROR......................11REMOVAL.............................12
POWER MIRROR SWITCH
DIAGNOSIS AND TESTING - POWER MIRROR
SWITCH............................12
REMOVAL.............................12
SIDEVIEW MIRROR
REMOVAL.............................12
POWER MIRRORS
DESCRIPTION
AUTOMATIC DAY/NIGHT MIRROR
The automatic day/night mirror system is able to
automatically change the reflectance of the inside
rear view mirror in order to reduce the glare of head-
lamps approaching the vehicle from the rear. The
automatic day/night rear view mirror receives bat-
tery current through a fuse in the Integrated Power
Module (IPM) only when the ignition switch is in the
On position.
OUTSIDE REAR VIEW MIRROR
The power operated outside rear view mirrors
allow the driver to adjust both outside mirrors elec-
trically from the driver side front seat position by
operating a switch on the driver side front door trim
panel. The power mirrors receive a non-switched bat-
tery feed through a fuse in the Integrated Power
Module (IPM) so that the system will remain opera-
tional, regardless of the ignition switch position.
OPERATION
AUTOMATIC DAY/NIGHT MIRROR
A switch located on the bottom of the automatic
day/night mirror housing allows the vehicle operator
to select whether the automatic dimming feature is
operational. When the automatic day/night mirror is
turned on, the mirror switch is lighted by an integral
Light-Emitting Diode (LED). The mirror will auto-
matically disable its self-dimming feature whenever
the vehicle is being driven in reverse.
OUTSIDE REAR VIEW MIRROR
The heated mirrors include an electric heating grid
behind the mirror glass in each outside mirror, which
can clear the mirror glass of ice, snow, or fog. (Refer
to 8 - ELECTRICAL/HEATED MIRRORS -
DESCRIPTION) for more information.
DIAGNOSIS AND TESTING - POWER MIRRORS
WIRING VOLTAGE TEST
The following wiring test determines whether or
not voltage is continuous through the body harness
to switch.
(1) Remove the power mirror switch (Refer to 8 -
ELECTRICAL/POWER LOCKS/DOOR MODULE -
REMOVAL).
(2) Disconnect wire harness connector from back of
power mirror switch.
(3) Connect the clip end of a 12 volt test light to
Pin 5 in the mirror switch harness connector. Touch
the test light probe to Pin 3.
If the test light illuminates, the wiring circuit
between the battery and switch is OK.
If the lamp does not illuminate, first check fuse in
the Integrated Power Module (IPM). If fuse is OK,
then check for a broken wire.
Refer to the appropriate wiring information.
POWER MIRROR MOTOR TEST
If the power mirror switch is receiving proper cur-
rent and ground and mirrors do not operate, proceed
with power mirror motor test. Refer to the appropri-
ate wiring information.
(1) Remove the power mirror switch (Refer to 8 -
ELECTRICAL/POWER LOCKS/DOOR MODULE -
REMOVAL).
8N - 10 POWER MIRRORSDR

shield that helps to shroud it from unintentional
actuation when entering or leaving the vehicle.
The power lumbar switches cannot be adjusted or
repaired and, if faulty or damaged, the seat switch
assembly must be replaced.
OPERATION
When the power lumbar switch paddle is actuated,
a battery feed and a ground path are applied through
the switch contacts to the power lumbar adjuster
motor. The motor operates to move the lumbar
adjuster 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 is
moved in the opposite direction, the battery feed and
ground path to the motor are reversed through the
switch contacts. This causes the motor to run in the
opposite direction.
The power lumbar switch should not be held
applied in either direction after the adjuster has
reached its travel limit. The power lumbar adjuster
motor contains a self-resetting circuit breaker to pro-
tect it from overload. However, consecutive or fre-
quent resetting of the circuit breaker must not be
allowed to continue, or the motor may be damaged.
REMOVAL
The power lumbar switch is integral with the other
power seat switches. Refer to the appropriate driver
or passenger power front seat switch removal and/or
installation procedure.
LUMBAR MOTOR
DESCRIPTION
The power lumbar seat option includes an electri-
cally operated lumbar support mechanism. The only
visible evidence of this option is the separate power
lumbar switch control paddle that is located on the
outboard seat cushion switch bezel, next to the other
power seat switch control knobs. The power lumbar
adjuster and motor are concealed beneath the seat
back trim cover and padding, where they are secured
to a molded plastic back panel and to the seat back
frame.
The power lumbar adjuster cannot be repaired, and
is serviced only as a unit with the seat back frame. If
the power lumbar adjuster or the seat back frame
are damaged or faulty, the entire seat back frame
unit must be replaced (Refer to 23 - BODY/SEATS/
SEAT BACK - REMOVAL).
OPERATION
The power lumbar adjuster mechanism includes a
reversible electric motor that is secured to theinboard side of the seat back panel and is connected
to a worm-drive gearbox. The motor and gearbox
operate the lumbar adjuster mechanism in the center
of the seat back driving a nut up or down a fixed
drive screw. The action of this nut extends or con-
tracts the plastic lumbar support band. The more
this band is contracted, the more outward pressure is
applied against the center of the seat back padding,
providing additional lumbar support.
DIAGNOSIS AND TESTING - LUMBAR MOTOR
Actuate the power lumbar switch to move the
power lumbar adjuster in each direction. The power
lumbar adjuster should move in both directions. It
should be noted that the power lumber adjuster nor-
mally operates very quietly and exhibits little visible
movement. If the power lumbar adjuster fails to oper-
ate in only one direction, move the adjuster a short
distance in the opposite direction and test again to be
certain that the adjuster is not at its travel limit. If
the power lumbar adjuster fails to operate in only
one direction, Test the appropriate power seat switch
as described in this group. If the power lumbar
adjuster fails to operate in either direction, perform
the following tests. For complete circuit diagrams,
refer toWiring.
(1) Check the power seat circuit breaker. If OK, go
to Step 2. If not OK, replace the faulty power seat
circuit breaker.
(2) Check for battery voltage at the power seat cir-
cuit breaker. If OK, go to Step 3. If not OK, repair
the open fused B(+) circuit to the fuse in the Inte-
grated Power Module as required.
(3) Remove the outboard seat cushion side shield
from the seat. Disconnect the seat wire harness con-
nector from the power lumbar switch connector
receptacle. Check for battery voltage at the fused
B(+) circuit cavity of the power seat wire harness
connector for the power lumbar switch. If OK, go to
Step 4. If not OK, repair the open fused B(+) circuit
to the power seat as required.
(4) Check for continuity between the ground cir-
cuit cavity of the power seat wire harness connector
for the power lumbar switch and a good ground.
There should be continuity. If OK, go to Step 5. If not
OK, repair the open ground circuit to ground as
required.
(5) Test the power lumbar switch. . If the switch
tests OK, test the circuits of the power seat wire har-
ness between the power lumbar adjuster motor and
the power lumbar switch for shorts or opens. If the
circuits check OK, replace the faulty seat back frame
assembly. If the circuits are not OK, repair the power
seat wire harness as required.
8N - 18 POWER SEATSDR
LUMBAR CONTROL SWITCH (Continued)