2002 JEEP LIBERTY Ignition control

Starting System Diagnosis
CONDITION POSSIBLE CAUSE CORRECTION
STARTER ENGAGES,
FAILS TO TURN
ENGINE.1. Battery discharged or
faulty.1. Refer to Battery. Charge or replace battery if required.
2. Starting circuit wiring
faulty.2. Refer to 8, Wiring Diagrams. Test and repair starter
feed and/or control circuits if required.
3. Starter motor faulty. 3. If all other starting system components and circuits test
OK, replace starter motor assembly.
4. Engine seized. 4. Refer to Engine Diagnosis in the Diagnosis and Testing
section of 9, Engine.
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.
8F - 34 STARTING SYSTEMKJ
STARTING SYSTEM (Continued)

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.
(4) Verify that all lamps and accessories are
turned off.
(5) To prevent a gasoline engine from starting,
remove Automatic ShutDown (ASD) relay. To prevent
a diesel engine from starting, remove Fuel Pump
Relay. These relays are located in Power Distribution
Center (PDC). Refer to label on PDC cover for relay
location.
WARNING: IF EQUIPPED WITH DIESEL ENGINE,
ATTEMPT TO START ENGINE A FEW TIMES
BEFORE PROCEEDING WITH FOLLOWING STEP.(6) Rotate and hold ignition switch in Start posi-
tion. Note cranking voltage and current (amperage)
draw readings shown on volt-ampere tester.
(a) If voltage reads below 9.6 volts, refer to
Starter Motorin Diagnosis and Testing. If starter
motor is OK, refer toEngine Diagnosisin 9,
Engine for further testing of engine. If starter
motor is not OK, replace faulty starter motor.
(b) If voltage reads above 9.6 volts and current
(amperage) draw reads below specifications, refer
toFeed Circuit Testin this section.
(c) If voltage reads 12.5 volts or greater and
starter motor does not turn, refer toControl Cir-
cuit Testingin this section.
(d) If voltage reads 12.5 volts or greater and
starter motor turns very slowly, refer toFeed Cir-
cuit Testin this section.
NOTE: A cold engine will increase starter current
(amperage) draw reading, and reduce battery volt-
age reading.
FEED CIRCUIT TEST
The starter feed circuit test (voltage drop method)
will determine if there is excessive resistance in
high-amperage feed circuit. For complete starter wir-
ing circuit diagrams, refer 8, Wiring Diagrams.
When performing these tests, it is important to
remember that voltage drop is giving an indication of
resistance between two points at which voltmeter
probes are attached.
Example:When testing resistance of positive bat-
tery cable, touch voltmeter leads to positive battery
cable clamp and cable connector at starter solenoid.
If you probe positive battery terminal post and cable
connector at starter solenoid, you are reading com-
bined voltage drop in positive battery cable clamp-to-
terminal post connection and positive battery cable.
The following operation will require a voltmeter
accurate to 1/10 (0.10) volt. Before performing tests,
be certain that following procedures are accom-
plished:
²Battery is fully-charged and load-tested. Refer to
Batteryin 8, Battery.
²Fully engage parking brake.
²If 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.
²Verify that all lamps and accessories are turned
off.
²To prevent a gasoline engine from starting,
remove Automatic ShutDown (ASD) relay. To prevent
a diesel engine from starting, remove Fuel Pump
Relay. These relays are located in Power Distribution
Fig. 1 Volts-Amps Tester Connections - Typical
1 - POSITIVE CLAMP
2 - NEGATIVE CLAMP
3 - INDUCTION AMMETER CLAMP
KJSTARTING SYSTEM 8F - 35
STARTING SYSTEM (Continued)

equipped models use dual batteries. If equipped
with dual battery system, this procedure must
be performed on driver side battery only.
(6) If equipped with dual battery system (certain
diesel equipped models), connect positive lead of volt-
meter to positive battery cable clamp on battery
located on left side of vehicle. Connect negative lead
of voltmeter to positive battery terminal post on bat-
tery located on right side of vehicle. Rotate and hold
ignition switch in Start position. Observe voltmeter.
If reading is above 0.2 volt, clean and tighten battery
cables at both batteries. Repeat test. If reading is
still above 0.2 volt, replace faulty positive battery
cable.If resistance tests detect no feed circuit problems,
refer toStarter Motorin the Diagnosis and Testing.
CONTROL CIRCUIT TESTING
The starter control circuit components should be
tested in the order in which they are listed, as fol-
lows:
²Starter Relay- Refer toStarter RelayDiag-
nosis and Testing.
²Starter Solenoid- Refer toStarter Motor
Diagnosis and Testing.
²Ignition Switch- Refer toIgnition Switch
and Key Lock Cylinder
²Clutch Pedal Position Switch- If equipped
with manual transmission, refer toClutch Pedal
Position Switchin 6, Clutch.
²Park/Neutral Position Switch- If equipped
with automatic transmission, refer toPark/Neutral
Position Switchin 21, Transmission.
²Wire harnesses and connections- Refer to 8,
Wiring Diagrams.
INSPECTION - STARTING SYSTEM
The following starting system components should
be carefully inspected whenever any starting system
problem is encountered.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR AIRBAG SYSTEM
CAPACITOR TO DISCHARGE BEFORE PERFORM-
ING FURTHER DIAGNOSIS OR SERVICE. THIS IS
THE ONLY SURE WAY TO DISABLE AIRBAG SYS-
TEM. FAILURE TO TAKE PROPER PRECAUTIONS
COULD RESULT IN ACCIDENTAL AIRBAG DEPLOY-
MENT AND POSSIBLE PERSONAL INJURY.
Battery
²Visually inspect battery for indications of physi-
cal damage and loose or corroded cable connections.
Determine state-of-charge and cranking capacity of
battery. Charge or replace battery, if required. Refer
toBatteryfor battery cleaning and inspection proce-
dures.
Ignition Switch
²Visually inspect ignition switch for indications of
physical damage and loose or corroded wire harness
connections. Clean corroded connections as required.
Refer toWiring Diagrams. Refer toIgnition
Switch and Key Lock Cylinderfor ignition switch
service procedures.
Fig. 5 Test Ground Circuit Resistance - Typical
1 - VOLTMETER
2 - BATTERY
3 - ENGINE GROUND
Fig. 6 Test Starter Ground - Typical
1 - STARTER MOTOR
2 - BATTERY
3 - VOLTMETER
KJSTARTING SYSTEM 8F - 37
STARTING SYSTEM (Continued)

HEATED SYSTEMS
TABLE OF CONTENTS
page page
HEATED MIRRORS......................... 1
WINDOW DEFOGGER....................... 3HEATED SEAT SYSTEM.................... 10
HEATED MIRRORS
TABLE OF CONTENTS
page page
HEATED MIRRORS
DESCRIPTION..........................1
OPERATION............................1DIAGNOSIS AND TESTING - HEATED
MIRRORS............................1
HEATED MIRRORS
DESCRIPTION
Vehicles equipped with the optional heated mirror
package have an electric heating grid located behind
the mirror glass of each outside rear view mirror.
The heated mirrors are controlled by the rear win-
dow defogger switch. Electrical current is directed to
the heating grid inside the mirror only when the rear
window defogger switch is in the On position.
If the outside mirror heating grids and the rear
window heating grid are all inoperative, (Refer to 8 -
ELECTRICAL/HEATED GLASS - DIAGNOSIS AND
TESTING). If the outside mirror heating grids are
inoperative, but the rear window heating grid is
operating as designed, (Refer to 8 - ELECTRICAL/
HEATED MIRRORS - DIAGNOSIS AND TESTING).
The heating grid behind each outside mirror glass
cannot be repaired and, if faulty or damaged, the
entire power mirror unit must be replaced(Refer to 8
- ELECTRICAL/POWER MIRRORS/SIDEVIEW MIR-
ROR - REMOVAL) and (Refer to 8 - ELECTRICAL/
POWER MIRRORS/SIDEVIEW MIRROR -
INSTALLATION).
OPERATION
The heated mirror is controlled by the rear window
defogger switch. The only time that the heated mir-
ror is on is when the rear window defogger is on. The
mirror should become warm to the touch.
DIAGNOSIS AND TESTING - HEATED MIRRORS
For circuit descriptions and diagrams (Refer to
Appropriate Wiring Information).
(1) Check the fuse in the junction block. 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 junction
block. 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. Remove the front door trim panel on the side
of the vehicle with the inoperative mirror heating
grid. Unplug the wire harness connector at the mir-
ror. Check for continuity between the ground circuit
cavity in the body half of the power mirror wire har-
ness connector and a good ground. If OK, go to Step
4. If not OK, repair the open circuit to ground as
required.
(4) Connect the battery negative cable. Turn the
ignition switch to the On position. Turn on the rear
window defogger system. Check for battery voltage at
the rear window defogger relay output circuit cavity
in the body half of the power mirror wire harness
connector. If OK, go to Step 5. If not OK, repair the
open circuit to the rear window defogger relay as
required.
KJHEATED SYSTEMS 8G - 1

WINDOW DEFOGGER
TABLE OF CONTENTS
page page
WINDOW DEFOGGER
DESCRIPTION - REAR WINDOW DEFOGGER . . 3
OPERATION - REAR WINDOW DEFOGGER....3
DIAGNOSIS AND TESTING - REAR WINDOW
DEFOGGER SYSTEM...................4
STANDARD PROCEDURE - REAR GLASS
HEATING GRID REPAIR.................4
REAR WINDOW DEFOGGER GRID
DESCRIPTION..........................5
OPERATION............................5
DIAGNOSIS AND TESTING - REAR WINDOW
DEFOGGER GRID......................5
REAR WINDOW DEFOGGER RELAY
DESCRIPTION..........................6
OPERATION............................6DIAGNOSIS AND TESTING - REAR WINDOW
DEFOGGER RELAY.....................6
REMOVAL.............................7
INSTALLATION..........................7
REAR WINDOW DEFOGGER SWITCH
DESCRIPTION..........................8
OPERATION............................8
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - REAR
WINDOW DEFOGGER SWITCH...........8
DIAGNOSIS AND TESTING - REAR HVAC
CONTROL ASSEMBLY WINDOW
DEFOGGER FUNCTION.................9
REMOVAL.............................9
INSTALLATION..........................9
WINDOW DEFOGGER
DESCRIPTION - REAR WINDOW DEFOGGER
The rear window defogger system will only operate
when the ignition switch is in the run position. When
the defogger switch is in the run position, an electric
heater grid on the rear window glass is energized.
Vehicles with the heated mirror options also have
heater grids located behind the outside rear view
mirror glass. Each of these grids produce heat to help
clear the rear window glass and outside rear view
mirrors of ice, snow, or fog.
OPERATION - REAR WINDOW DEFOGGER
The rear window defogger system is controlled by a
switch installed with the HVAC control assembly. An
amber indicator lamp in the switch button will light
to indicate when the rear window defogger system is
turned on. The HVAC control head circuitry, which
contains the defogger system timer logic, monitors
the state of the defogger switch through a hard-wired
input. The instrument cluster circuitry controls therear window defogger system through a hard-wired
control output to the rear window defogger relay. The
rear window defogger timer and logic circuitry cannot
be adjusted or repaired and, if faulty or damaged, the
HVAC control head assembly must be replaced.
The rear window defogger system will be automat-
ically turned off after a programmed time interval of
about ten minutes. After the initial time interval has
expired, if the rear window defogger switch is turned
on again during the same ignition cycle, the defogger
system will automatically turn off after about five
minutes.
The rear window defogger system will automati-
cally shut off if the ignition switch is turned to the
Off position, or it can be turned off manually by
depressing the instrument panel switch. Following
are general descriptions of the major components in
the rear window defogger system. Refer to the own-
er's manual in the vehicle glove box for more infor-
mation on the features, use and operation of the
defogger system.
KJWINDOW DEFOGGER 8G - 3

DIAGNOSIS AND TESTING - REAR WINDOW
DEFOGGER SYSTEM
For circuit descriptions and diagrams, (Refer to
Appropriate Wiring Information). The operation of
the electrically heated rear window defogger system
can be confirmed in one of the following manners:
²Turn the ignition switch to the run position.
²Set the defogger switch in the run position. The
rear window defogger operation can be checked by
feeling the rear window or outside rear view mirror
glass. A distinct difference in temperature between
the grid lines and the adjacent clear glass or the mir-
ror glass can be detected within three to four min-
utes of operation.
²Using a 12-volt DC voltmeter, contact the rear
glass heating grid terminal B (right side) with the
negative lead, and terminal A (left side) with the pos-
itive lead (Fig. 1). The voltmeter should read battery
voltage.
The above checks will confirm system operation.
Illumination of the defogger switch indicator lamp
means that there is electrical current available at the
output of the defogger relay, but does not confirmthat the electrical current is reaching the rear glass
heating grid lines.
If the defogger system does not operate, the prob-
lem should be isolated in the following manner:
(1) Confirm that the ignition switch is in the run
position.
(2) Ensure that the rear glass heating grid feed
and ground wires are connected to the glass. Confirm
that the ground wire has continuity to ground.
(3) Check the fuses in the Power Distribution Cen-
ter (PDC) and in the junction block. The fuses must
be tight in their receptacles and all electrical connec-
tions must be secure.
When the above steps have been completed and the
rear glass or outside rear view mirror heating grid is
still inoperative, one or more of the following is
faulty:
²Defogger switch
²Defogger relay
²HVAC control head circuitry
²Rear window grid lines (all grid lines would
have to be broken or one of the feed wires discon-
nected for the entire system to be inoperative)
²Outside rear view mirror heating grid.
If setting the defogger switch to the On position
produces a severe voltmeter deflection, check for a
short circuit between the defogger relay output and
the rear glass or outside rear view mirror heating
grids.
STANDARD PROCEDURE - REAR GLASS
HEATING GRID REPAIR
Repair of the rear glass heating grid lines, bus
bars, terminals or pigtail wires can be accomplished
using a Mopar Rear Window Defogger Repair Kit
(Part Number 4267922) or equivalent.
WARNING: MATERIALS CONTAINED IN THE REPAIR
KIT MAY CAUSE SKIN OR EYE IRRITATION. THE
KIT CONTAINS EPOXY RESIN AND AMINE TYPE
HARDENER, WHICH ARE HARMFUL IF SWAL-
LOWED. AVOID CONTACT WITH THE SKIN AND
EYES. FOR SKIN CONTACT, WASH THE AFFECTED
AREAS WITH SOAP AND WATER. FOR CONTACT
WITH THE EYES, FLUSH WITH PLENTY OF WATER.
DO NOT TAKE INTERNALLY. IF TAKEN INTER-
NALLY, INDUCE VOMITING AND CALL A PHYSICIAN
IMMEDIATELY. USE WITH ADEQUATE VENTILA-
TION. DO NOT USE NEAR FIRE OR FLAME. CON-
TAINS FLAMMABLE SOLVENTS. KEEP OUT OF THE
REACH OF CHILDREN.
(1) Mask the repair area so that the conductive
epoxy can be applied neatly. Extend the epoxy appli-
cation onto the grid line or the bus bar on each side
of the break (Fig. 2).
Fig. 1 REAR WINDOW DEFOGGER
1 - DEFOGGER BACKGLASS
2 - HEATED GLASS CONNECTOR9A9
3 - HINDGE MOUNTING SCREWS (2)
4 - HINDGE (LEFT SIDE)
5 - HINDGE MOUNTING SCREWS (2)
6 - HINDGE (RIGHT SIDE)
7 - HEATED GLASS CONNECTOR9B9
8 - BACKGLASS DEFOGGER GRID
8G - 4 WINDOW DEFOGGERKJ
WINDOW DEFOGGER (Continued)

no continuity between terminals 87 and 30. If OK, go
to Step 2. If not OK, replace the faulty relay.
(2) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 60.7 to 80.3 ohms. If OK, go to
Step 3. If not OK, replace the faulty relay.
(3) Connect a battery to terminals 85 and 86.
There should now be continuity between terminals
30 and 87, and no continuity between terminals 87A
and 30. If OK, see the Relay Circuit Test in this
group. If not OK, replace the faulty relay.
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
RELAY CIRCUIT TEST
(1) The relay common feed terminal cavity (30) is
connected to battery voltage and should be hot at all
times. If OK, go to Step 2. If not OK, repair the open
circuit to the PDC fuse as required.
(2) The relay normally closed terminal (87A) is
connected to terminal 30 in the de-energized position,
but is not used for this application. Go to Step 3.
(3) The relay normally open terminal (87) is con-
nected to the common feed terminal (30) in the ener-
gized position. This terminal supplies battery voltage
to the rear glass and outside rear view mirror heat-
ing grids and the defogger switch indicator lamp.
There should be continuity between the cavity for
relay terminal 87 and the rear window defogger relay
output circuit cavities of the rear glass heating grid
connector, both outside rear view mirror heating grid
connectors, and the defogger switch connector at all
times. If OK, go to Step 4. If not OK, repair the open
circuit(s) as required.(4) The coil ground terminal (85) is connected to
the electromagnet in the relay. This terminal is pro-
vided with ground by the instrument cluster rear
window defogger timer and logic circuitry to energize
the defogger relay. There should be continuity to
ground at the cavity for relay terminal 85 when the
defogger switch is turned On. However, with the
defogger relay removed, the defogger switch indicator
lamp will not light to show that the defogger system
is turned On. Be certain that you depress the defog-
ger switch at least twice to confirm that the system
is turned on during this test. If OK, go to Step 5. If
not OK, repair the open circuit to the HVAC control
head as required.
(5) The coil battery terminal (86) is connected to
the electromagnet in the relay. It is connected to
fused ignition switch output voltage and should be
hot when the ignition switch is in the run position.
Check for battery voltage at the cavity for relay ter-
minal 86 with the ignition switch in the run position.
If OK, see the diagnosis for Instrument Cluster in
this group. If not OK, repair the open circuit to the
fuse in the junction block as required.
REMOVAL
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 AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Unplug the rear window defogger relay from
the junction block.
INSTALLATION
(1) Install the rear window defogger relay by align-
ing the relay terminals with the cavities in the junc-
tion block and pushing the relay firmly into place.
(2) Connect the battery negative cable.
(3) Test the relay operation.
Fig. 4 DEFOGGER RELAY- TERMINAL LEGEND
KJWINDOW DEFOGGER 8G - 7
REAR WINDOW DEFOGGER RELAY (Continued)

HEATED SEAT SYSTEM
TABLE OF CONTENTS
page page
HEATED SEAT SYSTEM
DESCRIPTION.........................10
OPERATION...........................10
DIAGNOSIS AND TESTING - HEATED SEAT
SYSTEM............................11
DRIVER SEAT HEATER SWITCH
DESCRIPTION.........................11
OPERATION...........................12
DIAGNOSIS AND TESTING - HEATED SEAT
SWITCH............................12
REMOVAL.............................13
INSTALLATION.........................13
HEATED SEAT ELEMENT
DESCRIPTION.........................13OPERATION...........................13
DIAGNOSIS AND TESTING - HEATED SEAT
ELEMENT...........................13
HEATED SEAT SENSOR
DIAGNOSIS AND TESTING - HEATED SEAT
SENSOR............................14
PASSENGER SEAT HEATER SWITCH
DESCRIPTION.........................14
OPERATION...........................14
DIAGNOSIS AND TESTING - HEATED SEAT
SWITCH............................14
REMOVAL.............................15
INSTALLATION.........................15
HEATED SEAT SYSTEM
DESCRIPTION
Individually controlled electrically heated front
seats are available on models that are also equipped
with the optional leather trim package. Vehicles with
this option can be visually identified by the two sep-
arate heated seat switches mounted on the outboard
seat cushion side shields. The heated seat system
allows the front seat driver and passenger to select
from two different levels of supplemental electrical
seat heating, or no seat heating to suit their individ-
ual comfort requirements. The heated seat system for
this vehicle includes the following major components:
²Heated Seat Switches- Two heated seat
switches are used per vehicle, including two Light-
Emitting Diode (LED) indicator lamps and an incan-
descent back lighting bulb for each switch. One
switch for the driver and one for the passenger front
seats. The switches are mounted on the outboard
seat cushion side shields.
²Heated Seat Module- also referred to as the
Seat Heat Interface Module (SHIM), this module con-
tains the solid state electronic control and diagnostic
logic circuitry for the heated seat system. One heated
seat module is used per vehicle and is mounted
under the left front seat cushion. Refer to the Elec-
tronic Control Modules section of the service manual
for heated seat module information.
²Heated Seat Elements- Four heated seat ele-
ments are used per vehicle, one for each front seat
back and one for each front seat cushion. The ele-
ments are integral to the individual front seat andseat back cushions and cannot be removed from the
cushions, once installed at the factory.
²Heated Seat Sensors- Two heated seat sen-
sors are used per vehicle, one for each front seat. The
sensors are integral to the individual front seat heat-
ing elements.
Following are general descriptions of the major
components in the heated seat system. See the own-
er's manual in the vehicle glove box for more infor-
mation on the features, use and operation of the
heated seat system. Refer toWiring Diagramsfor
the location of complete heated seat system wiring
diagrams.
OPERATION
The heated seat module receives fused battery cur-
rent through fuse #29 in the Junction Block (JB)
when the ignition switch is in the ªONº position. The
heated seat switches receive battery current through
fuse #25 in the Junction Block also, when the igni-
tion switch is in the ªONº position. The heated seat
module shares a common ground circuit with each of
the heated seat elements. The heated seat elements
will only operate when the surface temperature of
the seat cushion is below the designed temperature
set points of the system.
The heated seat system will also be turned off
automatically whenever the ignition switch is turned
to any position except On. If the ignition switch is
turned to the Off position while a heated seat is
turned ON, the heated seat will remain Off after the
ignition switch is turned back ªONº until a heated
seat switch is depressed again.
8G - 10 HEATED SEAT SYSTEMKJ