sensor CHRYSLER VOYAGER 2001 Service Manual

(5) The coil ground terminal (85) is connected to
the electromagnet in the relay. It is grounded
through the transmission range sensor only when the
gearshift selector lever is in the Park or Neutral
positions. Check for continuity to ground at the cav-
ity for relay terminal 85. If not OK with an auto-
matic transmission, check for an open or short circuit
to the transmission range sensor and repair.
SAFETY SWITCHES
For diagnostics of the Transmission Range Sensor,
refer to the Transaxle section for more information.
If equipped with Clutch Interlock/Upstop Switch,
refer to Diagnosis and Testing in the Clutch section.
IGNITION SWITCH
After testing starter solenoid and relay, test igni-
tion switch and wiring. Refer to the Ignition Section
or Wiring Diagrams for more information. Check all
wiring for opens or shorts, and all connectors for
being loose or corroded.
BATTERY
For battery diagnosis and testing, refer to the Bat-
tery section for procedures.
ALL RELATED WIRING AND CONNECTORS
Refer to Wiring Diagrams for more information.
FEED CIRCUIT RESISTANCE TEST
Before proceeding with this operation, review Diag-
nostic Preparation and Starter Feed Circuit Tests.
The following operation will require a voltmeter,
accurate to 1/10 of a volt.
CAUTION: Ignition and Fuel systems must be dis-
abled to prevent engine start while performing the
following tests.
(1) To disable the Ignition and Fuel systems, dis-
connect the Automatic Shutdown Relay (ASD). The
ASD relay is located in the Power Distribution Cen-
ter (PDC). Refer to the PDC cover for proper relay
location.
(2) Remove the air cleaner assembly for access to
battery terminals. Refer to the Fuel section for ser-
vice procedures.
(3) With all wiring harnesses and components
properly connected, perform the following:
(a) Connect the negative lead of the voltmeter to
the battery negative post, and positive lead to the
battery negative cable clamp. Rotate and hold the
ignition switch in the START position. Observe the
voltmeter. If voltage is detected, correct poor con-
tact between cable clamp and post.(b) Connect positive lead of the voltmeter to the
battery positive post, and negative lead to the bat-
tery positive cable clamp. Rotate and hold the igni-
tion switch key in the START position. Observe the
voltmeter. If voltage is detected, correct poor con-
tact between the cable clamp and post.
(c) Connect negative lead of voltmeter to battery
negative terminal, and positive lead to engine
block near the battery cable attaching point.
Rotate and hold the ignition switch in the START
position. If voltage reads above 0.2 volt, correct
poor contact at ground cable attaching point. If
voltage reading is still above 0.2 volt after correct-
ing poor contacts, replace ground cable.
(4) Connect positive voltmeter lead to the starter
motor housing and the negative lead to the battery
negative terminal. Hold the ignition switch key in
the START position. If voltage reads above 0.2 volt,
correct poor starter to engine ground.
(a) Connect the positive voltmeter lead to the
battery positive terminal, and negative lead to bat-
tery cable terminal on starter solenoid. Rotate and
hold the ignition switch in the START position. If
voltage reads above 0.2 volt, correct poor contact at
battery cable to solenoid connection. If reading is
still above 0.2 volt after correcting poor contacts,
replace battery positive cable.
(b) If resistance tests do not detect feed circuit
failures, replace the starter motor.FEED CIRCUIT TEST
NOTE: The following results are based upon the
vehicle being at room temperature.
The following procedure will require a suitable
volt-ampere tester (Fig. 2).
CAUTION: Before performing any starter tests, the
ignition and fuel systems must be disabled.
Fig. 2 Volt Ampere Tester
RSSTARTING8F-31
STARTING (Continued)

OPERATION
The Rear Window Defogger (Fig. 1) system consists
of two vertical bus bars linked by a series of grid
lines on the inside surface of the rear window. The
electrical circuit consists of the rear defogger switch
in the HVAC control assembly and a relay with timer
switch to turn OFF the system after ten minutes.
The main feed circuit is protected by fuse 13 (40
amp) in the Power Distribution Center (PDC) which
is integrated as a unit call Integrated Power Module
(IPM). The rear defogger switch and relay also acti-
vates the heated power side view mirrors and heated
windshield wiper de-icer. The heated windshield
wiper de-icer is powered by the RUN/ACC relay in
the IPM and feed thru fuse #11 (20 amp) in the PDC.
The heated mirror circuit is protected by a non-servi-
cable Positive Temperature Coefficient (PTC) located
inside the PDC. The heated windshield wiper de-icer
circuit is protected by fuse 11 (20 amp) in the PDC.
The Heated Windshield Wiper Deicer is also acti-
vated when the DEFROST mode is selected on the
HVAC. In the DEFROST mode the rear defogger
relay/timer is bypassed, the heated windshield wiper
de-icer will stay ON until the another mode is
selected. For circuit information and component loca-
tion refer to appropriate section for Wiring Diagrams.
CAUTION:
Since grid lines can be damaged or scraped off
with sharp instruments, care should be taken in
cleaning the glass or removing foreign materials,
decals or stickers. Normal glass cleaning solvents
or hot water used with rags or toweling is recom-
mended.
DEFOGGER RELAY
DESCRIPTION
There is no heated glass relay it is integrated into
the (E.B.L) relay that is located in the IPM in the
engine compartment.
REAR WINDOW DEFOGGER
GRID
STANDARD PROCEDURE - GRID LINE
REPAIR-REAR
For Grid repair procedure for the rear window
defogger (Refer to 8 - ELECTRICAL/HEATED
GLASS/WINDSHIELD GRID - STANDARD PROCE-
DURE).
REAR WINDOW DEFOGGER
SWITCH
DESCRIPTION
The rear window defogger switch is integrated into
the HVAC control panel assembly (Fig. 3)
OPERATION
A LED indicator will illuminate when the switch is
activated. The switch energizes the HVAC control
assembly when it requests the Front Control Module
(FCM) to activate the rear window defogger relay.
The relay controls the current to flow to the grids of
the rear window defogger, heated power side view
mirrors and the heated windshield wiper de-icer. The
defogger relay will be on for approximately 10 min-
utes or until the control switch or ignition is turned
off.
Fig. 3 HVAC CONTROL PANEL
1 - Trim Bezel
2 - ACT Sensor
3 - A/C Request Switch
4 - Rear Window Defogger/Heated Mirrors Switch Combo
5 - Front Window Defroster Mode Selector
8G - 2 HEATED GLASSRS
HEATED GLASS (Continued)

HEATED MIRRORS
TABLE OF CONTENTS
page page
HEATED MIRRORS
DESCRIPTION............................5
OPERATION.............................5
DIAGNOSIS AND TESTING..................5
HEATED MIRROR TEST...................5
MIRROR SWITCH
DESCRIPTION............................5OPERATION.............................5
HEATED MIRROR GRID
STANDARD PROCEDURE...................6
HEATED MIRROR.......................6
RELAY
DESCRIPTION............................6
HEATED MIRRORS
DESCRIPTION
Heated mirrors are available on models with
Power Mirrors and Rear Window Defogger only.
OPERATION
The heated mirror is controlled by the rear window
defogger switch. The heated mirror is ON when the
rear window defogger is ON (Fig. 1)
DIAGNOSIS AND TESING - HEATED MIRROR
TEST
Heated mirrors are available on models with
Power Mirrors and Rear Window Defogger only. The
heated mirror is controlled by the rear window defog-
ger switch. The heated mirror is ON when the rear
window defogger is ON.
(1) The mirror glass should be warm to the touch.
(2) If not, check the 20 amp fuse (11) in the Power
Distribution Center (PDC) part of the Integrated
Power Module (IPM) in the engine compartment.
(3) Test voltage at rear window defogger switch.
²If no voltage repair wire.
²Remove mirror glass and test the wires for con-
tinuity. If no continuity repair wires.
²If wires are OK, replace mirror glass.
²To test defogger switch refer to the appropriate
section in Electrical.
MIRROR SWITCH
DESCRIPTION
The heated mirror switch is integrated into the
rear window defogger switch located in the HVAC
control panel (Fig. 1)
OPERATION
A LED indicator will illuminate when the switch is
activated. The switch energizes the HVAC control
assembly when it requests the Front Control Module
(FCM) to activate the rear window defogger relay.
The relay controls the current to flow to the grids of
the rear window defogger, heated power side view
mirrors and the heated windshield wiper de-icer. The
defogger relay will be on for approximately 10 min-
utes or until the control switch or ignition is turned
off.
Fig. 1 HVAC CONTROL PANEL
1 - Trim Bezel
2 - ACT Sensor
3 - A/C Request Switch
4 - Rear Window Defogger/Heated Mirrors Switch Combo
5 - Front Window Defroster Mode Selector
RSHEATED MIRRORS8G-5

HEATED SEAT SYSTEM
TABLE OF CONTENTS
page page
HEATED SEAT SYSTEM
DESCRIPTION............................7
OPERATION.............................8
DRIVER HEATED SEAT SWITCH
DESCRIPTION............................8
OPERATION.............................9
DIAGNOSIS AND TESTING..................9
HEATED SEAT SWITCH...................9
REMOVAL..............................10
INSTALLATION...........................10
HEATED SEAT ELEMENT
DESCRIPTION...........................10
OPERATION.............................11DIAGNOSIS AND TESTING.................11
HEATED SEAT ELEMENT.................11
HEATED SEAT SENSOR
DESCRIPTION...........................11
DIAGNOSIS AND TESTING.................11
HEATED SEAT SENSOR..................11
PASSENGER HEATED SEAT SWITCH
DESCRIPTION...........................11
OPERATION.............................11
DIAGNOSIS AND TESTING.................12
HEATED SEAT SWITCH..................12
REMOVAL..............................13
INSTALLATION...........................13
HEATED SEAT SYSTEM
DESCRIPTION
Individually controlled driver and passenger side
electrically heated front seats are available factory-
installed optional equipment on this model, when it
is also equipped with the power seat option. The
heated seat system allows both the driver and the
front seat passenger the option to select one of twoseat heating ranges, Low or High, or to turn the indi-
vidual seat heaters Off using the heated seat
switches located in the instrument panel center bezel
near the bottom of the HVAC outlets (Fig. 1). The
heated seat switch circuit operates on ignition
switched battery current supplied through a fuse in
the intelligent power module, only when the ignition
switch is in the On position.
This section covers the following components of the
heated seat system:
²Heated seat elements
²Heated seat sensors
²Heated seat switches
The Heated seat module (or memory heated seat
module) can be found in the Electronic Control Mod-
ules section of the service manual.
The heated seat system also relies upon resources
shared with other electronic modules in the vehicle
over the Programmable Communications Interface
(PCI) J1850 data bus network. The J1850 (PCI) data
bus network allows the sharing of sensor informa-
tion. This helps to reduce wire harness complexity,
internal controller hardware, and component sensor
current loads. At the same time, this system provides
increased reliability, enhanced diagnostics, and
allows the addition of many new feature capabilities.
For diagnosis of these electronic modules or of the
J1850 (PCI) data bus network, the use of a DRB IIIt
scan tool, or equivalent and the proper Diagnostic
Procedures manual are recommended.
The electronic modules that may affect heated seat
system operation are as follows:
²Body Control Module (BCM)- Refer toBody
Control Modulein Electronic Control Modules for
more information.
Fig. 1 HEATED SEAT SWITCHES
RSHEATED SEAT SYSTEM8G-7

²Remote Keyless Entry Module (RKE)- Refer
toRemote Keyless Entry Modulein Power Locks
for more information.
²Electronic Vehicle Information Center
(EVIC)- Refer toElectronic Vehicle Information
Centerin Overhead Console for more information.
²Heated Seat Module (HSM)- Refer toHeated
Seat Modulein Electronic Control Modules for more
information.
²Memory Heated Seat Module (MHSM)-If
the vehicle is equipped with the Memory System,
refer toMemory Seat Mirror Module (MSMM)in
Electronic Control Modules for more information.
Refer toWiring Diagramsfor complete circuit
diagrams. Following are general descriptions of the
major components in the heated seat system.
OPERATION
The heated seat system will only operate when the
ignition switch is in the On position, and the surface
temperature at the front seat heating element sen-
sors is below the designed temperature set points of
the system. The heated seat system will not operate
in ambient temperatures greater than about 41É C
(105É F). The front seat heating elements and sensors
are hard wired to the Heated Seat Module (HSM) or
the Memory Heated Seat Module (MHSM).
The heated seat switches are hard wired to the
Body Control Module (BCM). The BCM monitors the
heated seat switch inputs, then sends heated seat
switch status messages to the HSM or MHSM over
the Programmable Communications Interface J1850
(PCI) data bus. The HSM or MHSM contains the con-
trol logic for the heated seat system. The HSM or
MHSM responds to the heated seat switch status
messages, ignition switch status messages, and the
front seat heating element sensor inputs by control-
ling the output to the front seat heating elements
through integral solid-state relays.
When a seat heater is turned on, the sensor
located on the seat cushion electric heater element
provides the HSM or MHSM with an input indicating
the surface temperature of the seat cushion. If the
surface temperature input is below the temperature
set point for the selected Low or High heated seat
switch position, the HSM or MHSM energizes the
integral solid-state relay, which supplies battery cur-
rent to the heating elements in the seat cushion and
back. When the sensor input indicates the correct
temperature set point has been achieved, the HSM or
MHSM de-energizes the solid-state relay. The HSM
or MHSM will continue to cycle the solid-state relay
as needed to maintain the temperature set point.
The HSM or MHSM and the seat heater elements
operate on non-switched battery current supplied
through the power seat fuse in the intelligent powermodule. However, the HSM or MHSM will automati-
cally turn off the heating elements if it detects an
open in the sensor circuit, a short in the heating ele-
ment circuit causing an excessive current draw, or
when the ignition switch is turned to the Off posi-
tion.
See the owner's manual in the vehicle glove box for
more information on the features, use and operation
of the heated seat system.
DRIVER HEATED SEAT
SWITCH
DESCRIPTION
The heated seat switches are mounted in the
instrument panel center bezel (Fig. 2). The two three-
position rocker-type switches, one switch for each
front seat, are incorporated into one large switch
assembly that also includes the hazzard, rear window
wiper and washer switches. The heated seat switches
provide a resistor multiplexed signal to the Body
Control Module (BCM) through separate hard wired
circuits. Each switch has an Off, Low, and High posi-
tion so that both the driver and the front seat pas-
senger can select a preferred seat heating mode.
Each switch has two Light-Emitting Diodes (LED)
which light to indicate that the heater for the seat is
turned on.
The heated seat switches and their LEDs cannot
be repaired. If either switch or LED is faulty or dam-
aged, the entire switch assembly must be replaced.
Fig. 2 HEATED SEAT SWITCHES
8G - 8 HEATED SEAT SYSTEMRS
HEATED SEAT SYSTEM (Continued)

OPERATION
There are three positions that can be selected with
each of the heated seat switches: Off, Low, or High.
When the left side of the switch rocker is fully
depressed, the Low position is selected and the high
position LED indicator illuminates. When the right
side of the switch rocker is fully depressed, the High
position is selected and the low position LED indica-
tor illuminates. When the switch rocker is moved to
its neutral position (middle), Off is selected and both
LED indicators are extinguished.
Both switches provide separate resistor multi-
plexed hard wire inputs to the BCM to indicate the
selected switch position. The BCM monitors the
switch inputs and sends heated seat switch status
messages to the Heated Seat Module (HSM) or the
Memory Heated Seat Module (MHSM) over the Pro-
grammable Communications Interface (PCI) data
bus. The HSM or MHSM responds to the heated seat
switch status messages by controlling the output to
the seat heater elements of the selected seat. The
Low heat position set point is about 36É C (97É F),
and the High heat position set point is about 41É C
(105É F).
DIAGNOSIS & TESTING - HEATED SEAT
SWITCH
For complete circuit diagrams, refer toWiring
Diagrams.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO THE RESTRAINTS SECTION OF
THIS MANUAL BEFORE ATTEMPTING ANY STEER-
ING WHEEL, STEERING COLUMN, SEAT OR
INSTRUMENT PANEL COMPONENT DIAGNOSIS OR
SERVICE. 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)
fuse in the intelligent power module. 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) fuse in the intelligent power module. If
OK, go to Step 3. If not OK, repair the open fused
ignition switch output (run) circuit to the ignition
switch as required.
(3) Disconnect and isolate the battery negative
cable. Remove the center bezel from the instrument
panel and disconnect the instrument panel wire har-
ness connectors from the heated seat switch connec-
tor receptacle. Check for continuity between the
ground circuit cavity of the instrument panel wireharness connector for the inoperative heated seat
switch(es) 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) cir-
cuit cavity of the instrument panel wire harness con-
nector for the inoperative heated seat switch(es). If
OK, turn the ignition switch to the Off position, dis-
connect and isolate the battery negative cable, and go
to Step 5. If not OK, repair the open fused ignition
switch output (run) circuit to the intelligent power
module fuse as required.
(5) Test the heated seat switch(es) as shown in the
Heated Seat Switch Test chart (Fig. 3). If OK, go to
Step 6. If not OK, replace the faulty heated seat
switch(es).
DRIVER HEATED SEAT SWITCH TEST
SWITCH
POSITIONRESISTANCE
BETWEENRESISTANCE
(OHMS)
Off Pin4&5OPEN
Low Pin4&53570
High Pin4&51430
All resistance values are61%.
(6) Disconnect the instrument panel wire harness
connector from the Body Control Module (BCM) con-
nector receptacle. Check for continuity between the
seat heater switch sensor ground circuit cavity of the
instrument panel wire harness connector for the
Fig. 3 SWITCH CONNECTOR
RSHEATED SEAT SYSTEM8G-9
DRIVER HEATED SEAT SWITCH (Continued)

inoperative heated seat switch(es) and a good ground.
There should be no continuity. If OK, go to Step 7. If
not OK, repair the shorted seat heater switch sensor
ground circuit as required.
(7) Check for continuity between the seat heater
switch sensor ground circuit cavities of the instru-
ment panel wire harness connector for the in opera-
tive heated seat switch and the instrument panel
wire harness connector for the BCM. There should be
continuity. If OK, go to Step 8. If not OK, repair the
open seat heater switch sensor ground circuit as
required.
(8) Check for continuity between the seat heater
switch mux circuit cavity of the instrument panel
wire harness connector for the inoperative heated
seat switch and a good ground. There should be no
continuity. If OK, go to Step 9. If not OK, repair the
shorted seat heater switch mux circuit as required.
(9) Check for continuity between the seat heater
switch mux circuit cavity of the instrument panel
wire harness connector for the inoperative heated
seat switch and the instrument panel wire harness
connector for the BCM. There should be continuity. If
OK, use a DRB IIItscan tool and the proper Diag-
nostic Procedures manual to test the BCM. If not
OK, repair the open seat heater switch mux circuit
as required.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO THE RESTRAINTS SECTION OF
THIS MANUAL BEFORE ATTEMPTING ANY STEER-
ING WHEEL, STEERING COLUMN, SEAT OR
INSTRUMENT PANEL COMPONENT DIAGNOSIS OR
SERVICE. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the instrument panel center bezel.
Refer toInstrument Panel Center Bezelin the
Body section for the procedure.
(3) Remove the three screws (Fig. 4) that secure
the heated seat switch to the back of the instrument
panel center bezel.
(4) Remove the heated seat switch from the back
of the instrument panel center bezel.
INSTALLATION
(1) Position the heated seat switch onto the back
of the instrument panel center bezel.
(2) Install and tighten the three screws that secure
the heated seat switch to the back of the instrumentpanel center bezel. Tighten the screws to 1.5 N´m (13
in. lbs.) (Fig. 4).
(3) Install the center bezel onto the instrument
panel. Refer toInstrument Panel Center Bezelin
the Body section for the procedure.
(4) Reconnect the battery negative cable.
HEATED SEAT ELEMENT
DESCRIPTION
The heated seat system includes two seat heating
elements in each front seat, one for the seat cushion
and the other for the seat back. The two elements for
each seat that are connected in series with the
Heated Seat Module (HSM). The temperature sensor
is a Negative Temperature Coefficient (NTC) ther-
mistor. One temperature sensor is used for each seat,
and it is located on the seat cushion heating element
for all models.
The seat heating elements are sewn into the seat
cushion cover trim and seat back cover trim units.
The heated seat elements and the temperature sen-
sor cannot be adjusted or repaired and, if faulty or
damaged, the seat cushion or seat back assembly
must be replaced. Refer toSeat CushionorSeat
Backin the Removal and Installation section of
Body for the seat cushion and seat back service pro-
cedures.
Fig. 4 SWITCH RETAINING SCREWS
1 - HEATED SEAT SWITCH ASSEMBLY
2 - RETAINING SCREWS
8G - 10 HEATED SEAT SYSTEMRS
DRIVER HEATED SEAT SWITCH (Continued)

OPERATION
The heated seat elements resist the flow of electri-
cal current. When battery current is passed through
the elements, the energy lost by the resistance of the
elements to the current flow is released in the form
of heat. The temperature sensor is a NTC thermistor.
When the temperature of the seat cushion cover
rises, the resistance of the sensor decreases. The
HSM or MHSM supplies a five-volt current to one
side of each sensor, and monitors the voltage drop
through the sensor on a return circuit. The MSM or
MHSM uses this temperature sensor input to moni-
tor the temperature of the seat, and regulates the
current flow to the seat heating elements accordingly.
DIAGNOSIS & TESTING - HEATED SEAT
ELEMENT
The wire harness connectors for the seat cushion
and seat back heating elements are located under the
seat, near the rear edge of the seat cushion frame.
For circuit descriptions and diagrams, refer to Group
8W, Wiring Diagrams.
SEAT CUSHION
(1) Disconnect and isolate the battery negative
cable. Unplug the 4-way heated seat cushion wire
harness connector.
(2) Check for continuity between the two heated
seat driver circuit cavities of the seat cushion cover
half of the heated seat cushion wire harness connec-
tor. There should be continuity. If OK, go to Step 3. If
not OK, replace the faulty seat cushion cover.
(3) Check for continuity between one of the heated
seat driver circuit cavities of the seat cushion cover
half of the heated seat cushion wire harness connec-
tor and the seat cushion frame. There should be no
continuity. If OK, go to the Seat Back test. If not OK,
replace the faulty seat cushion cover.
SEAT BACK
(1) Disconnect and isolate the battery negative
cable. Unplug the 2-way heated seat back wire har-
ness connector.
(2) Check for continuity between the heated seat
driver circuit cavity and the ground circuit cavity of
the seat back cover half of the heated seat back wire
harness connector. There should be continuity. If OK,
go to Step 3. If not OK, replace the faulty seat back
cover.
(3) Check for continuity between the heated seat
driver circuit cavity of the seat back cover half of the
heated seat back wire harness connector and the seat
back frame. There should be no continuity. If OK,
test the heated seat sensor as described in this
group. If not OK, replace the faulty seat back cover.
HEATED SEAT SENSOR
DESCRIPTION
The heated seat temperature sensor is a Negative
Temperature Coefficient (NTC) thermistor. One tem-
perature sensor is used for each seat, and is inte-
grated into the seat cushion heating element.
DIAGNOSIS & TESTING - HEATED SEAT
SENSOR
For complete circuit diagrams, refer toWiring
Diagrams.
(1) Disconnect and isolate the battery negative
cable. Disconnect the 4-way heated seat cushion ele-
ment wire harness connector from the power seat
wire harness. The power seat wire harness connec-
tors for the seat cushion and seat back heating ele-
ments are secured to a bracket located under the
rear edge of the seat cushion frame.
(2) Using an ohmmeter, check the resistance
between the seat sensor circuit and the seat temper-
ature sensor input circuit cavities of the 4-way
heated seat cushion element wire harness connector.
The sensor resistance should be between 2 kilohms
at 15É C (60É F) and 200 kilohms at 30É C (85É F). If
not OK, replace the faulty seat cushion cover trim
and sensor unit.
PASSENGER HEATED SEAT
SWITCH
DESCRIPTION
The heated seat switches are mounted in the
instrument panel center bezel (Fig. 5). The two three-
position rocker-type switches, one switch for each
front seat, are incorporated into one large switch
assembly that also includes the hazzard, rear window
wiper and washer switches. The heated seat switches
provide a resistor multiplexed signal to the Body
Control Module (BCM) through separate hard wired
circuits. Each switch has an Off, Low, and High posi-
tion so that both the driver and the front seat pas-
senger can select a preferred seat heating mode.
Each switch has two Light-Emitting Diodes (LED)
which light to indicate that the heater for the seat is
turned on.
The heated seat switches and their LEDs cannot
be repaired. If either switch or LED is faulty or dam-
aged, the entire switch assembly must be replaced.
OPERATION
There are three positions that can be selected with
each of the heated seat switches: Off, Low, or High.
When the left side of the switch rocker is fully
RSHEATED SEAT SYSTEM8G-11
HEATED SEAT ELEMENT (Continued)

depressed, the Low position is selected and the high
position LED indicator illuminates. When the right
side of the switch rocker is fully depressed, the High
position is selected and the low position LED indica-
tor illuminates. When the switch rocker is moved to
its neutral position (middle), Off is selected and both
LED indicators are extinguished.
Both switches provide separate resistor multi-
plexed hard wire inputs to the BCM to indicate the
selected switch position. The BCM monitors the
switch inputs and sends heated seat switch status
messages to the Heated Seat Module (HSM) or the
Memory Heated Seat Module (MHSM) over the Pro-
grammable Communications Interface (PCI) data
bus. The HSM or MHSM responds to the heated seat
switch status messages by controlling the output to
the seat heater elements of the selected seat. The
Low heat position set point is about 36É C (97É F),
and the High heat position set point is about 41É C
(105É F).
DIAGNOSIS & TESTING - HEATED SEAT
SWITCH
For complete circuit diagrams, refer toWiring
Diagrams.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO THE RESTRAINTS SECTION OF
THIS MANUAL BEFORE ATTEMPTING ANY STEER-
ING WHEEL, STEERING COLUMN, SEAT OR
INSTRUMENT PANEL COMPONENT DIAGNOSIS OR
SERVICE. 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)
fuse in the intelligent power module. 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) fuse in the intelligent power module. If
OK, go to Step 3. If not OK, repair the open fused
ignition switch output (run) circuit to the ignition
switch as required.
(3) Disconnect and isolate the battery negative
cable. Remove the center bezel from the instrument
panel and disconnect the instrument panel wire har-
ness connectors from the heated seat switch connec-
tor receptacle. Check for continuity between the
ground circuit cavity of the instrument panel wire
harness connector for the inoperative heated seat
switch(es) 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) cir-
cuit cavity of the instrument panel wire harness con-
nector for the inoperative heated seat switch(es). If
OK, turn the ignition switch to the Off position, dis-
connect and isolate the battery negative cable, and go
to Step 5. If not OK, repair the open fused ignition
switch output (run) circuit to the intelligent power
module fuse as required.
(5) Test the heated seat switch(es) as shown in the
Heated Seat Switch Test chart (Fig. 6). If OK, go to
Step 6. If not OK, replace the faulty heated seat
switch(es).
PASSENGER HEATED SEAT SWITCH TEST
SWITCH
POSITIONRESISTANCE
BETWEENRESISTANCE
(OHMS)
Off Pin3&4OPEN
Low Pin3&43570
High Pin3&41430
All resistance values are61%.
(6) Disconnect the instrument panel wire harness
connector from the Body Control Module (BCM) con-
nector receptacle. Check for continuity between the
seat heater switch sensor ground circuit cavity of the
instrument panel wire harness connector for the
inoperative heated seat switch(es) and a good ground.
There should be no continuity. If OK, go to Step 7. If
not OK, repair the shorted seat heater switch sensor
ground circuit as required.
Fig. 5 HEATED SEAT SWITCHES
8G - 12 HEATED SEAT SYSTEMRS
PASSENGER HEATED SEAT SWITCH (Continued)

(7) Check for continuity between the seat heater
switch sensor ground circuit cavities of the instru-
ment panel wire harness connector for the in opera-
tive heated seat switch and the instrument panel
wire harness connector for the BCM. There should be
continuity. If OK, go to Step 8. If not OK, repair the
open seat heater switch sensor ground circuit as
required.
(8) Check for continuity between the seat heater
switch mux circuit cavity of the instrument panel
wire harness connector for the inoperative heated
seat switch and a good ground. There should be no
continuity. If OK, go to Step 9. If not OK, repair the
shorted seat heater switch mux circuit as required.
(9) Check for continuity between the seat heater
switch mux circuit cavity of the instrument panel
wire harness connector for the inoperative heated
seat switch and the instrument panel wire harness
connector for the BCM. There should be continuity. If
OK, use a DRB IIItscan tool and the proper Diag-
nostic Procedures manual to test the BCM. If not
OK, repair the open seat heater switch mux circuit
as required.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO THE RESTRAINTS SECTION OF
THIS MANUAL BEFORE ATTEMPTING ANY STEER-
ING WHEEL, STEERING COLUMN, SEAT OR
INSTRUMENT PANEL COMPONENT DIAGNOSIS OR
SERVICE. FAILURE TO TAKE THE PROPER PRE-CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the instrument panel center bezel.
Refer toInstrument Panel Center Bezelin the
Body section for the procedure.
(3) Remove the three screws (Fig. 7) that secure
the heated seat switch to the back of the instrument
panel center bezel.
(4) Remove the heated seat switch from the back
of the instrument panel center bezel.
INSTALLATION
(1) Position the heated seat switch onto the back
of the instrument panel center bezel.
(2) Install and tighten the three screws that secure
the heated seat switch to the back of the instrument
panel center bezel. Tighten the screws to 1.5 N´m (13
in. lbs.) (Fig. 4).
(3) Install the center bezel onto the instrument
panel. Refer toInstrument Panel Center Bezelin
the Body section for the procedure.
(4) Reconnect the battery negative cable.
Fig. 6 SWITCH CONNECTOR
Fig. 7 SWITCH RETAINING SCREWS
1 - HEATED SEAT SWITCH ASSEMBLY
2 - RETAINING SCREWS
RSHEATED SEAT SYSTEM8G-13
PASSENGER HEATED SEAT SWITCH (Continued)