2002 DODGE RAM steering

(2) Push the harness connector locks to release the
locks, (Fig. 11) then remove the connectors from the
CAB.
(3) Disconnect the pump motor connector (Fig. 12)
.
(4) Remove screws attaching CAB to the HCU
(Fig. 13) .
(5) Remove the CAB.
INSTALLATION
(1) Place the CAB onto the HCU.
NOTE: Insure the CAB seal is in position before
installation.
(2) Install the mounting screws and tighten to
4-4.7 N´m (36-42 in. lbs.).
(3) Connect the pump motor harness.
(4) Connect the harnesses to the CAB and lock the
connectors.
(5) Connect battery.
DATA LINK CONNECTOR
DESCRIPTION - DATA LINK CONNECTOR
The data link connector (DLC) is located at the
lower edge of the instrument panel near the steering
column.
OPERATION - DATA LINK CONNECTOR
The 16±way data link connector (diagnostic scan
tool connector) links the Diagnostic Readout Box
(DRB) scan tool or the Mopar Diagnostic System
(MDS) with the Powertrain Control Module (PCM).
Fig. 11 Harness Connector Locks
1 - CONNECTOR LOCK
2 - CAB
Fig. 12 Pump
1 - PUMP MOTOR
2 - PUMP CONNECTOR
Fig. 13 Controller Mounting Screws
1 - CAB
2 - MOUNTING LOCATIONS
8E - 12 ELECTRONIC CONTROL MODULESBR/BE
CONTROLLER ANTILOCK BRAKE (Continued)

the top of the battery. The eyelet terminals secured
to the ends of the battery cable wires opposite the
female battery terminal clamps provide secure and
reliable connection of the battery to the vehicle elec-
trical system.
GASOLINE ENGINE
The battery positive cable terminal clamp is
crimped onto the ends of two wires. One wire has an
eyelet terminal that connects the battery positive
cable to the B(+) terminal stud of the Power Distri-
bution Center (PDC), and the other wire has an eye-
let terminal that connects the battery positive cable
to the B(+) terminal stud of the engine starter motor
solenoid. The battery negative cable terminal clamp
is also crimped onto the ends of two wires. One wire
has an eyelet terminal that connects the battery neg-
ative cable to the vehicle powertrain through a stud
on the front of the left engine cylinder head. The
other wire has an eyelet terminal that connects the
battery negative cable to the vehicle body through a
ground screw on the left front fender inner shield,
just ahead of the battery. An additional ground wire
with two eyelet terminals is used to provide ground
to the vehicle frame. One eyelet terminal of this
ground wire is installed under the head of the bat-
tery negative cable terminal clamp pinch-bolt, and
the other eyelet terminal is secured with a ground
screw to the outer surface of the left frame rail,
below the battery.
DIESEL ENGINE
The left battery positive cable terminal clamp is
die cast onto the ends of two wires. One wire has an
eyelet terminal that connects the left battery positive
cable to the B(+) terminal stud of the Power Distri-
bution Center (PDC), and the other wire has an eye-
let terminal that connects the left battery positive
cable to the B(+) terminal stud of the engine starter
motor solenoid. The right battery positive cable ter-
minal clamp is die cast onto the end of a single wire.
The eyelet terminal on the other end of the right bat-
tery positive cable is connected to the stud on the
pinch-bolt of the left battery positive cable terminal
clamp. This stud also provides a connection point for
the eyelet terminals from the fuel heater relay and
intake air heater relay jumper harness take outs. All
of these eyelet terminals are secured to the left bat-
tery positive cable terminal clamp pinch-bolt stud
with a single hex nut.The left battery negative cable terminal clamp is
die cast onto the ends of two wires. One wire has an
eyelet terminal that connects the left battery nega-
tive cable to the vehicle powertrain through a ground
screw on the left side of the engine block, below the
power steering and vacuum pumps. The other wire
has an eyelet terminal that connects the left battery
negative cable to the vehicle body through a ground
screw on the left front fender inner shield, just ahead
of the left battery. An additional ground wire with
two eyelet terminals is used to provide ground to the
vehicle frame. One eyelet terminal of this ground
wire is installed under the nut of the left battery
negative cable terminal clamp pinch-bolt, and the
other eyelet terminal is secured with a ground screw
to the outer surface of the left frame rail, below the
left battery. The right battery negative cable terminal
is also die cast onto the ends of two wires. One wire
has an eyelet terminal that connects the right bat-
tery negative cable to the vehicle powertrain through
a ground screw on the right side of the engine block,
just forward of the right engine mount. The other
wire has an eyelet terminal that connects the right
battery negative cable to the vehicle body through a
ground screw on the right front fender inner shield,
just behind the right battery.
DIAGNOSIS AND TESTING - BATTERY CABLES
A voltage drop test will determine if there is exces-
sive resistance in the battery cable terminal connec-
tions or the battery cables. If excessive resistance is
found in the battery cable connections, the connec-
tion point should be disassembled, cleaned of all cor-
rosion or foreign material, then reassembled.
Following reassembly, check the voltage drop for the
battery cable connection and the battery cable again
to confirm repair.
When performing the voltage drop test, it is impor-
tant to remember that the voltage drop is giving an
indication of the resistance between the two points at
which the voltmeter probes are attached.EXAM-
PLE:When testing the resistance of the battery pos-
itive cable, touch the voltmeter leads to the battery
positive cable terminal clamp and to the battery pos-
itive cable eyelet terminal at the starter solenoid
B(+) terminal stud. If you probe the battery positive
terminal post and the battery positive cable eyelet
terminal at the starter solenoid B(+) terminal stud,
you are reading the combined voltage drop in the
battery positive cable terminal clamp-to-terminal
post connection and the battery positive cable.
BR/BEBATTERY SYSTEM 8F - 19
BATTERY CABLE (Continued)

(4) Disconnect the starter motor signal wire har-
ness connector, located on the PDC housing.
(5) Disengage wire harness assembly pushpin
retainers.
(6) From under the vehicle, disengage wire har-
ness assembly pushpin retainers.
(7) Remove the positive battery cable from the
starter motor B+ terminal stud.
(8) Remove the starter motor trigger wire from the
starter motor.
(9) Remove the positive cable wire harness assem-
bly from the vehicle.
NEGATIVE CABLE REMOVAL - GASOLINE
ENGINE
Both the battery negative cable and the battery
positive cable are serviced in the battery wire har-
ness. If either battery cable is damaged or faulty, the
battery wire harness unit must be replaced.
(1) Turn the ignition switch to the Off position. Be
certain that all electrical accessories are turned off.
(2) Loosen the battery negative cable terminal
clamp pinch-bolt hex nut.
(3) Disconnect the battery negative cable terminal
clamp from the battery negative terminal post. If
necessary, use a battery terminal puller to remove
the terminal clamp from the battery post.
(4) Remove the negative cable jumper from the left
side of the radiator closure panel.
(5) Remove the negative cable jumper from the left
side of the frame assembly.
(6) Remove the PDC cover and remove the gener-
ator output wire from the PDC.
(7) Following the wire, remove the pushpin retain-
ers holding the wire assembly in place.
(8) Remove the negative cable eyelet from the
power steering pump pivot bolt.
(9) Remove the generator output wire from the
generator.
(10) Remove the negative battery cable assembly,
by fishing out from under the compressor mounting
bracket, if equipped.
INSTALLATION
POSITIVE CABLE INSTALLATION - GASOLINE
ENGINE
(1) Position the battery wire harness into the
engine compartment.
(2) Install the positive battery cable on the battery.
(3) Install the positive battery cable on the PDC.
(4) Install the cover on the PDC.
(5) Connect the starter motor signal wire harness
connector, located on the PDC housing.(6) Install wire harness assembly pushpin retain-
ers in their original position.
(7) From under the vehicle, install wire harness
assembly pushpin retainers.
(8) Install and tighten the nut that secures the
battery positive cable eyelet terminal to the B(+) ter-
minal stud on the starter solenoid. Tighten the nut to
10 N´m (90 in. lbs.).
(9) Connect the starter motor trigger wire on the
starter motor.
(10) Reconnect the battery positive cable terminal
clamp to the battery positive terminal post. Tighten
the terminal clamp pinch-bolt hex nut to 4 N´m (35
in. lbs.).
(11) Apply a thin coating of petroleum jelly or
chassis grease to the exposed surfaces of the battery
cable terminal clamps and the battery terminal
posts.
NEGATIVE CABLE INSTALLATION - GASOLINE
ENGINE
(1) Position the battery wire harness into the
engine compartment and under the compressor
mounting bracket, if equipped.
(2) Install and tighten the nut that secures the
battery negative cable ground eyelet terminal to the
stud on the power steering pump pivot bolt.
(3) Install the generator output cable eyelet termi-
nal onto the generator output terminal stud.
(4) Install and tighten the nut that secures the
generator output cable eyelet terminal to the genera-
tor output terminal stud. Tighten the nut to 8.4 N´m
(75 in. lbs.).
(5) Position the cover for the generator output ter-
minal stud housing onto the back of the generator
and snap it into place.
(6) Secure wire assembly in place with pushpin
retainers in there original positions.
(7) Install and tighten the screw that secures the
battery negative cable eyelet terminal to the radiator
closure panel, near the battery. Tighten the screw to
40 in. lbs.
(8) Install and tighten the screw that secures the
battery negative cable eyelet terminal to the left
front side of the frame assembly. Tighten the screw
to 80 in. lbs.
(9) Install and tighten the nut that secures the
battery positive cable eyelet terminal and the gener-
ator output cable eyelet terminal to the PDC B(+)
terminal stud. Tighten the nut to 80 in. lbs.
(10) Reconnect the battery negative cable terminal
clamp to the battery negative terminal post. Tighten
the terminal clamp pinch-bolt hex nut to 35 in. lbs.
(11)
Apply a thin coating of petroleum jelly or chas-
sis grease to the exposed surfaces of the battery cable
terminal clamps and the battery terminal posts.
8F - 22 BATTERY SYSTEMBR/BE
BATTERY CABLE (Continued)

Starting System Diagnosis
CONDITION POSSIBLE CAUSE CORRECTION
STARTER ENGAGES,
SPINS OUT BEFORE
ENGINE STARTS.1. Starter ring gear faulty. 1. Refer to Starter Motor Removal and Installation.
Remove starter motor to inspect starter ring gear.
Replace starter ring gear if required.
2. Starter motor faulty. 2. If all other starting system components and circuits test
OK, replace starter motor assembly.
STARTER DOES NOT
DISENGAGE.1. Starter motor
improperly installed.1. Refer to Starter Motor Removal and Installation.
Tighten starter mounting hardware to correct torque
specifications.
2. Starter relay faulty. 2. Refer to Starter Relay Diagnosis and Testing. Replace
starter relay if required.
3. Ignition switch faulty. 3. Refer to Ignition Switch and Key Lock Cylinder.
Replace ignition switch if required.
4. Starter motor faulty. 4. If all other starting system components and circuits test
OK, replace starter motor.
INSPECTION
For complete starter wiring circuit diagrams, refer
to 8, Wiring Diagrams. Before removing any unit
from starting system for repair or diagnosis, perform
the following inspections:
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO 8, PASSIVE RESTRAINT SYS-
TEMS, BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, OR INSTRUMENT
PANEL COMPONENT DIAGNOSIS OR SERVICE.
FAILURE TO TAKE THE PROPER PRECAUTIONS
COULD RESULT IN ACCIDENTAL AIRBAG DEPLOY-
MENT AND POSSIBLE PERSONAL INJURY.
²Battery- Visually inspect battery for indica-
tions of physical damage and loose or corroded cable
connections. Determine state-of-charge and cranking
capacity of battery. Charge or replace battery if
required. Refer toBatteryin 8, Battery.Note: If
equipped with diesel engine, a dual battery sys-
tem may be used, and both batteries must be
inspected.
²Ignition Switch- Visually inspect ignition
switch for indications of physical damage and loose
or corroded wire harness connections. Refer toIgni-
tion Switch and Key Lock Cylinder.
²Clutch Pedal Position Switch- If equipped
with manual transmission, visually inspect clutch
pedal position switch for indications of physical dam-
age and loose or corroded wire harness connections.
Refer toClutch Pedal Position Switchin 6,
Clutch.
²Park/Neutral Position Switch- If equipped
with automatic transmission, visually inspect park/
neutral position switch for indications of physical
damage and loose or corroded wire harness connec-tions. Refer toPark/Neutral Position Switchin
21, Transmission.
²Starter Relay- Visually inspect starter relay
for indications of physical damage and loose or cor-
roded wire harness connections.
²Starter Motor- Visually inspect starter motor
for indications of physical damage and loose or cor-
roded wire harness connections.
²Starter Solenoid- Visually inspect starter sole-
noid for indications of physical damage and loose or
corroded wire harness connections.
²Wiring- Visually inspect wire harnesses for
damage. Repair or replace any faulty wiring, as
required. Refer to 8, Wiring Diagrams.
TESTING
COLD CRANKING TEST
For complete starter wiring circuit diagrams, refer
to 8, Wiring Diagrams. The battery must be fully-
charged and load-tested before proceeding. Refer to
Batteryin 8, Battery.
(1) Connect volt-ampere tester to battery terminals
(Fig. 1). See instructions provided by manufacturer of
volt-ampere tester being used.Note: Certain diesel
equipped models use dual batteries. If equipped
with dual battery system, tester should be con-
nected to battery on left side of vehicle only.
Also, tester current reading must be taken from
positive battery cable lead that connects to
starter motor.
(2) Fully engage parking brake.
(3) If equipped with manual transmission, place
gearshift selector lever in Neutral position and block
clutch pedal in fully depressed position. If equipped
with automatic transmission, place gearshift selector
lever in Park position.
BR/BESTARTING 8F - 33
STARTING (Continued)

OPERATION - HEATED MIRROR SYSTEM
The solid state electronic control logic and timer
circuitry for the heated mirror system receives bat-
tery current from a fuse in the Junction Block (JB)
only when the ignition switch is in the On or Start
positions. After the heated mirror system is turned
On, the electronic control logic and timer circuitry
will automatically turn the system off after a pro-
grammed time interval of about fifteen minutes.
After the initial time interval has expired, if the
heated mirror switch is depressed and released a sec-
ond time during the same ignition cycle, the elec-
tronic control logic and timer circuitry will
automatically turn the heated mirror system off after
a programmed time interval of about five minutes.
The heated mirror system will be shut off automati-
cally if the ignition switch is turned to the Off or
Accessory positions. After the heated mirror system
is turned On, it can also be turned off manually by
depressing and releasing the heated mirror switch a
second time.
When the heated mirror system is turned On, the
heated mirror system control logic and timer cir-
cuitry energizes the heated mirror system indicator
lamp and the heated mirror relay. When energized,
the heated mirror relay supplies fused ignition
switch output (run/start) current from a fuse in the
JB to the outside mirror heating grids located behind
the mirror glass of each of the outside rear view mir-
rors. When energized, each of the outside mirror
heating grids produces enough heat to warm the
glass of the outside rear view mirrors.
DIAGNOSIS AND TESTING - HEATED MIRROR
SYSTEM
If only one of the outside mirror heating grids is
inoperative, perform continuity checks on the circuits
and heater grid for that mirror only. If both outside
mirror heating grids are inoperative, proceed with
the heated mirror system diagnosis as follows. (Refer
to Appropriate Wiring Information).
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.The operation of the heated mirror system can be
confirmed in one of the following manners:
²Turn the ignition switch to the On position.
While monitoring the instrument panel voltmeter,
momentarily depress and release the heated mirror
switch. When the heated mirror system is turned On,
a distinct voltmeter needle deflection should be
noted.
²Turn the ignition switch to the On position.
Momentarily depress and release the heated mirror
switch to turn the heated mirror system On. The
heated mirror operation can be checked by feeling
the outside rear view mirror glass. A distinct differ-
ence in temperature between the unheated and
heated mirror glass can be detected within three to
four minutes of system operation.
The above checks will confirm system operation.
Illumination of the heated mirror system indicator
lamp means that there is electrical current available
at the heated mirror relay, but does not confirm that
the electrical current is reaching the outside mirror
heating grids.
If the heated mirror system does not operate, the
problem should be isolated in the following manner:
(1) Confirm that the ignition switch is in the On
position.
(2) Check the fuses in the Power Distribution Cen-
ter (PDC) and in the Junction Block (JB). The fuses
must be tight in their receptacles and all electrical
connections must be secure.
When the above steps have been completed and
both outside mirror heating grids are still inopera-
tive, one or more of the following is faulty:
²Heated mirror switch, electronic control logic
and timer circuitry, and heated mirror relay.
²Heated mirror wire harness circuits or connec-
tors.
²Outside mirror heating grid (both mirror grids
would have to be faulty).
If turning On the heated mirror system produces a
severe voltmeter deflection or fuse failures, check for
a shorted circuit between the output of the heated
mirror relay and the outside mirror heating grids.
MIRROR SWITCH
DESCRIPTION
The heated mirror switch, the heated mirror sys-
tem indicator lamp, the heated mirror system solid
state electronic control logic and timer circuitry and
the heated mirror relay are all integral to the a/c
heater control, which is located between the instru-
ment cluster and the radio near the center of the
instrument cluster bezel on the instrument panel.
The heated mirror switch and the heated mirror sys-
8G - 2 HEATED MIRRORSBR/BE
HEATED MIRRORS (Continued)

tem indicator lamp are visible in the lower left corner
of the a/c heater control face plate (Fig. 2).
The heated mirror switch, the heated mirror sys-
tem indicator lamp, the heated mirror system solid
state electronic control logic and timer circuitry and
the heated mirror relay cannot be repaired. If any of
these components is damaged or faulty, the entire a/c
heater control must be replaced. (Refer to 24 - HEAT-
ING & AIR CONDITIONING/CONTROLS/A/C
HEATER CONTROL - REMOVAL)
OPERATION
The momentary-type heated mirror switch provides
a hard-wired battery current signal to the heated
mirror system electronic control logic circuitry each
time it is depressed. In response to the heated mirror
switch input, the electronic control logic and timer
circuitry energizes or de-energizes the amber heated
mirror system indicator lamp next to the heated mir-
ror switch to indicate that the heated mirror system
is turned On or Off. The electronic control logic and
timer circuitry also energizes or de-energizes the
heated mirror relay, which controls the feed of elec-
trical current to the outside mirror heating grids.
The heated mirror system electronic control logic
and timer circuitry is programmed to turn the heated
mirror system Off automatically after about fifteen
minutes of operation. If the heated mirror system is
turned On a second time following an initial time-out
event during the same ignition switch cycle, the
heated mirror system electronic control logic and
timer circuit is programmed to turn the system Offautomatically after about five minutes. When the
electronic control logic and timer circuit detects that
a programmed time interval has elapsed, it will auto-
matically de-energize the heated mirror system indi-
cator lamp and the heated mirror relay. The heated
mirror system will also be turned Off if the heated
mirror switch is depressed while the system is
turned On, or if the ignition switch is turned to the
Off or Accessory positions.
DIAGNOSIS AND TESTING - HEATED MIRROR
SWITCH
The heated mirror switch, the solid state electronic
heated mirror system control logic and timer cir-
cuitry, the heated mirror system indicator lamp and
the heated mirror relay are all integral to the a/c
heater control. For circuit descriptions and diagrams
(Refer to Appropriate Wiring Information).
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Check the fused ignition switch output (run/
start) fuse in the Junction Block (JB). If OK, go to
Step 2. If not OK, repair the shorted circuit or com-
ponent as required and replace the faulty fuse.
(2) Turn the ignition switch to the On position.
Check for battery voltage at the fused ignition switch
output (run/start) fuse in the JB. If OK, go to Step 3.
If not OK, repair the open circuit to the ignition
switch as required.
(3) Disconnect and isolate the battery negative
cable. Disconnect the 3-way instrument panel wire
harness connector for the heated mirror switch from
the heated mirror switch connector receptacle on the
back of the a/c heater control. Check for continuity
between the ground circuit cavity of the wire harness
connector and a good ground. There should be conti-
nuity. If OK, go to Step 4. If not OK, repair the open
ground circuit to ground as required.
(4) Reconnect the battery negative cable. Turn the
ignition switch to the On position. Check for battery
voltage at the fused ignition switch output (run/start)
circuit cavity of the 3-way instrument panel wire
Fig. 2 HEATED MIRROR SWITCH
1 - A/C HEATER CONTROL
2 - HEATED MIRROR SWITCH
3 - HEATED MIRROR SYSTEM INDICATOR LAMP
BR/BEHEATED MIRRORS 8G - 3
MIRROR SWITCH (Continued)

If the heated seat system failure is identified by
flashing heated seat switch indicator lamps, go to the
appropriate diagnosis and testing procedure in this
section and confirm the condition, using the step by
step procedure. If the monitored failure is confirmed,
replace the component. If the monitored failure is not
confirmed, replace the heated seat module with a
known good unit and retest the system.
HEATED SEAT SYSTEM TESTING
Refer toWiring Diagramsfor the location of com-
plete heated seat system wiring diagrams. Before
testing the individual components in the heated seat
system, perform the following preliminary checks:
WARNING: DISABLE THE AIRBAG SYSTEM
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. DISCON-
NECT AND ISOLATE THE BATTERY NEGATIVE
CABLE, THEN WAIT TWO MINUTES FOR THE AIR-
BAG SYSTEM CAPACITOR TO DISCHARGE
BEFORE PERFORMING FURTHER DIAGNOSIS OR
SERVICE. THIS IS THE ONLY SURE WAY TO DIS-
ABLE THE AIRBAG SYSTEM. FAILURE TO TAKE
THE PROPER PRECAUTIONS COULD RESULT IN
ACCIDENTAL AIRBAG DEPLOYMENT AND POSSI-
BLE PERSONAL INJURY.
²If the heated seat switch back lighting and the
cluster illumination lamps do not illuminate with the
headlamps or park lamps turned On, refer to the
Instrument Clustersection of the service manual
for the location of cluster illumination lamps diagno-
sis and testing procedures. If the heated seat switch
back lighting does not illuminate, but the cluster illu-
mination lamps do illuminate with the headlamps or
park lamps turned On, refer toDiagnosis and Test-
ing the Heated Seat Switchin this section for the
location of the heated seat switch diagnosis and test-
ing procedures.
²If a single indicator lamp for one heated seat
switch does not operate and the heated seat elements
do heat, refer toDiagnosis and Testing the
Heated Seat Switchin this section for heated seat
switch diagnosis and testing procedures.
²If both indicator lamps for a heated seat switch
operate, but the heated seat elements do not heat,
refer toDiagnosis and Testing the Heated Seat
Modulein Electronic Control Modules for heated
seat module diagnosis and testing procedures.
²If none of the indicator lamps for both heated
seat switches will operate and the heated seat ele-
ments for both seats do not heat, refer toDiagnosis
and Testing the Heated Seat Relayin the Power
Distribution section of the service manual for heated
seat relay diagnosis and testing procedures.²If the an indicator lamp on either heated seat
switch remains illuminated after the heated seat has
been turned Off, refer toDiagnosis and Testing
the Heated Seat Modulein Electronic Control
Modules for heated seat module diagnosis and test-
ing procedures. Also refer to the Body Diagnostic
Manual for additional diagnosis and testing proce-
dures.DRIVER SEAT HEATER
SWITCH
DESCRIPTION
The heated seat switches are both mounted in a
heated seat switch bezel (Fig. 2), which replaces the
standard equipment cubby bin located in the lower
right corner of the instrument cluster bezel next to
the radio receiver. The two switches are snapped into
the mounting holes of the heated seat switch bezel,
and the heated seat switch bezel is secured with
three screws to the instrument panel. The mounts for
the heated seat switch bezel are concealed behind the
instrument cluster bezel. The two heated seat
switches are identical in appearance and construc-
tion, except for the location of a keyway in the single
connector receptacle on the back of each switch. The
instrument panel wire harness connectors for the
heated seat switches are keyed to match the connec-
Fig. 2 Heated Seat Switches
1 - Driver Switch
2 - Passenger Switch
3 - Indicator Lamps
4 - Heated Seat Switch Bezel
BR/BEHEATED SEAT SYSTEM 8G - 7
HEATED SEAT SYSTEM (Continued)

tor receptacles on the switches so that the two
heated seat switches can only be connected to the
proper heated seat electrical.
The momentary, bidirectional rocker-type heated
seat switch provides a resistor-multiplexed signal to
the heated seat module on the mux circuit. Each
switch has a center neutral position and momentary
Low and High positions so that both the driver and
the front seat passenger can select a preferred level
of seat heating. Each heated seat switch has two
Light-Emitting Diode (LED) indicator lamps, which
indicate the selected mode (Low or High) of the seat
heater. These indicator lamps also provide diagnostic
feedback for the heated seat system. Each switch
also has an incandescent bulb, which provides dim-
mer controlled back lighting of the switch when the
headlamps or park lamps are on.
The two LED indicator lamps and the incandescent
bulb in each heated seat switch cannot be repaired. If
the indicator lamps or back lighting bulb are faulty
or damaged, the individual heated seat switch must
be replaced.
OPERATION
The heated seat switches receive battery current
through a fused ignition switch output (run) circuit
when the ignition switch is in the On position.
Depressing the heated seat switch rocker to its
momentary High or Low position provides a hard-
wired resistor multiplexed voltage request signal to
the heated seat module to power the heated seat ele-
ment of the selected seat and maintain the requested
temperature setting. If the heated seat switch is
depressed to a different position (Low or High) than
the currently selected state, the heated seat module
will change states to support the new selection. If a
heated seat switch is depressed a second time to the
same position as the currently selected state, the
heated seat module interprets the second input as a
request to turn the seat heater off. The heated seat
module will then turn the heated seat elements for
that seat off.
The indicator lamps in the heated seat switches
receive battery current through a fused ignition
switch output (run) circuit when the ignition switch
is in the On position. The ground side of each indi-
cator lamp is controlled by a separate (high or low/
driver or passenger) indicator lamp driver circuit by
the heated seat module. The heated seat module con-
trol of the switch indicator lamps also allows the
module to provide diagnostic feedback to the vehicle
operator to indicate monitored heated seat system
faults by flashing the indicator lamps on and off. One
side of the incandescent back lighting bulb in each
heated seat switch is connected to ground at all
times. The other side of the incandescent bulb is con-nected to the fused panel lamps dimmer switch sig-
nal circuit. These bulbs are energized when the park
lamps or headlamps are turned on, and their illumi-
nation intensity is controlled by the panel lamps dim-
mer switch.
DIAGNOSIS AND TESTING - HEATED SEAT
SWITCH
Refer toWiring Diagramsfor the location of com-
plete heated seat system wiring diagrams.
WARNING: DISABLE THE AIRBAG SYSTEM
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. DISCON-
NECT AND ISOLATE THE BATTERY NEGATIVE
(GROUND) CABLE, THEN WAIT TWO MINUTES FOR
THE AIRBAG SYSTEM CAPACITOR TO DISCHARGE
BEFORE PERFORMING FURTHER DIAGNOSIS OR
SERVICE. THIS IS THE ONLY SURE WAY TO DIS-
ABLE THE AIRBAG SYSTEM. FAILURE TO TAKE
THE PROPER PRECAUTIONS COULD RESULT IN
ACCIDENTAL AIRBAG DEPLOYMENT AND POSSI-
BLE PERSONAL INJURY.
(1) If the problem being diagnosed involves inoper-
ative heated seat switch back lighting and the cluster
illumination lamps operate, go to Step 2. If the prob-
lem being diagnosed involves inoperative heated seat
switch back lighting and the cluster illumination
lamps are also inoperative, refer toInstrument
Clusterin the index of this service manual for the
proper cluster illumination lamps diagnosis and test-
ing procedures. If the problem being diagnosed
involves inoperative heated seat switch indicator
lamps and the heated seat elements do not heat,
refer to Step 4. If the problem being diagnosed
involves inoperative heated seat switch indicator
lamps and the heated seat elements do heat, go to
Step 8. If the problem being diagnosed involves a
heated seat switch indicator lamp that remains illu-
minated after the heated seat has been turned Off,
refer toHeated Seat Modulein Electronic Control
Modules for the location of the proper heated seat
module diagnosis and testing procedures. Also refer
to the Body Diagnostic Manual for additional diagno-
sis and testing procedures.
(2) Disconnect and isolate the battery negative
cable. Remove the heated seat switch and bezel unit
from the instrument panel. Disconnect the instru-
ment panel wire harness connector from the connec-
tor receptacle on the back of the heated seat switch
to be tested. Check for continuity between the ground
circuit cavity of the instrument panel wire harness
connector for the heated seat switch and a good
ground. There should be continuity. If OK, go to Step
8G - 8 HEATED SEAT SYSTEMBR/BE
DRIVER SEAT HEATER SWITCH (Continued)