wiring CHRYSLER CARAVAN 2003 Workshop Manual
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Page 369 of 2177
CONDITION POSSIBLE CAUSE CORRECTION
2. STARTING CIRCUIT
WIRING FAULTY.2. REFER TO THE FEED CIRCUIT RESISTANCE TEST AND
THE FEED CIRCUIT TEST IN THIS SECTION. REPAIR AS
NECESSARY.
3. STARTER ASSEMBLY
FAULTY.3. IF ALL OTHER STARTING SYSTEM COMPONENTS AND
CIRCUITS CHECK OK, REPLACE STARTER ASSEMBLY.
4. ENGINE SEIZED. 4. REFER TO THE ENGINE SECTION, FOR DIAGNOSTIC AND
SERVICE PROCEDURES.
5. LOOSE
CONNECTION AT
BATTERY, PDC,
STARTER, OR ENGINE
GROUND.5. INSPECT FOR LOOSE CONNECTIONS.
6. FAULTY TEETH ON
RING GEAR.6. ROTATE FLYWHEEL 360É, AND INSPECT TEETH AND RING
GEAR REPLACED IF DAMAGED.
STARTER
ENGAGES,
SPINS OUT
BEFORE
ENGINE
STARTS.1. BROKEN TEETH ON
STARTER RING GEAR.1. REMOVE STARTER. INSPECT RING GEAR AND REPLACE
IF NECESSARY.
2. STARTER ASSEMBLY
FAULTY.2. IF ALL OTHER STARTING SYSTEM COMPONENTS AND
CIRCUITS CHECK OK, REPLACE STARTER ASSEMBLY.
STARTER DOES
NOT
DISENGAGE.1. STARTER
IMPROPERLY
INSTALLED.1. INSTALL STARTER. TIGHTEN STARTER MOUNTING
HARDWARE TO CORRECT TORQUE SPECIFICATIONS.
2. STARTER RELAY
FAULTY.2. REFER TO RELAY TEST, IN THIS SECTION. REPLACE
RELAY, IF NECESSARY.
3. IGNITION SWITCH
FAULTY.3. REFER TO IGNITION SWITCH TEST, IN THE STEERING
SECTION. REPLACE SWITCH, IF NECESSARY.
4. STARTER ASSEMBLY
FAULTY.4. IF ALL OTHER STARTING SYSTEM COMPONENTS AND
CIRCUITS CHECK OK, REPLACE STARTER ASSEMBLY.
5. FAULTY TEETH ON
RING GEAR.5. ROTATE FLYWHEEL 360É, AND INSPECT TEETH AND RING
GEAR REPLACED IF DAMAGED.
DIAGNOSIS AND TESTING - CONTROL
CIRCUIT TEST
The starter control circuit has:
²Starter motor with integral solenoid
²Starter relay
²Transmission range sensor, or Park/Neutral
Position switch with automatic transmissions
²Ignition switch
²Battery
²All related wiring and connections
²Powertrain Control Module (PCM)
CAUTION: Before performing any starter tests, the
ignition and fuel systems must be disabled.²To disable ignition and fuel systems, disconnect
the Automatic Shutdown Relay (ASD). The ASD relay
is located in the Power Distribution Center (PDC).
Refer to the PDC cover for the proper relay location.
STARTER SOLENOID
WARNING: CHECK TO ENSURE THAT THE TRANS-
MISSION IS IN THE PARK POSITION WITH THE
PARKING BRAKE APPLIED.
(1) Verify battery condition. Battery must be in
good condition with a full charge before performing
any starter tests. Refer to Battery Tests.
(2) Perform Starter Solenoid test BEFORE per-
forming the starter relay test.
8F - 30 STARTINGRS
STARTING (Continued)
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Page 370 of 2177
(3) Perform a visual inspection of the starter/
starter solenoid for corrosion, loose connections or
faulty wiring.
(4) Locate and remove the starter relay from the
Power Distribution Center (PDC). Refer to the PDC
label for relay identification and location.
(5) Connect a remote starter switch or a jumper
wire between the remote battery positive post and
terminal 87 of the starter relay connector.
(a) If engine cranks, starter/starter solenoid is
good. Go to the Starter Relay Test.
(b) If engine does not crank or solenoid chatters,
check wiring and connectors from starter relay to
starter solenoid and from the battery positive ter-
minal to starter post for loose or corroded connec-
tions. Particularly at starter terminals.
(c) Repeat test. If engine still fails to crank prop-
erly, trouble is within starter or starter mounted
solenoid, and replace starter. Inspect the ring gear
teeth.
STARTER RELAY
WARNING: CHECK TO ENSURE THAT THE TRANS-
MISSION IS IN THE PARK/NEUTRAL POSITION
WITH THE PARKING BRAKE APPLIED.
RELAY TEST
The starter relay is located in the Power Distribu-
tion Center (PDC) in the engine compartment. Refer
to the PDC label for relay identification and location.
Remove the starter relay from the PDC as
described in this group to perform the following tests:
(1) A relay in the de-energized position should
have continuity between terminals 87A and 30, and
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 75 5 ohms. If OK, go to Step
3. If not OK, replace the faulty relay.
(3) Connect a battery B+ lead to terminals 85 and
a ground lead to terminal 86 to energize the relay.
The relay should click. Also test for continuity
between terminals 30 and 87, and no continuity
between terminals 87A and 30. If OK, refer to Relay
Circuit Test procedure. If not OK, replace the faulty
relay.
CAV FUNCTION
30 B (+)
85 IGNITION SWITCH OUTPUT
86 PCM-CONTROLLED GROUND
87 STARTER RELAY OUTPUT
87A NO CONNECT
Starter Relay Pinout
Starter Relay Pinout
Starter Relay Pinout
RSSTARTING8F-31
STARTING (Continued)
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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 starter solenoid field coils. There should be
continuity between the cavity for relay terminal 87
and the starter solenoid terminal at all times. If OK,
go to Step 4. If not OK, repair the open circuit to the
starter solenoid as required.
(4) The coil battery terminal (85) is connected to
the electromagnet in the relay. It is energized when
the ignition switch is held in the Start position and
the clutch pedal is depressed (manual trans). Check
for battery voltage at the cavity for relay terminal 86
with the ignition switch in the Start position and the
clutch pedal is depressed (manual trans), and no
voltage when the ignition switch is released to the
On position. If OK, go to Step 5. If not OK, check for
an open or short circuit to the ignition switch and
repair, if required. If the circuit to the ignition switch
is OK, see the Ignition Switch Test procedure in this
group.
(5) The coil ground terminal (86) is connected to
the electromagnet in the relay. It is grounded by the
PCM if the conditions are right to start the car. For
automatic trans. cars the PCM must see Park Neu-
tral switch low and near zero engine speed (rpm).
For manual trans. cars the PCM only needs to see
near zero engine speed (rpm) and low clutch inter-
lock input and see near zero engine speed (rpm). To
diagnose the Park Neutral switch of the trans range
sensor refer to the transaxle section. Check for conti-
nuity to ground while the ignition switch is in the
start position and if equipped the clutch pedal
depressed. If not OK and the vehicle has an auto-
matic trans. verify Park Neutral switch operation. If
that checks OK check for continuity between PCM
and the terminal 86. Repair open circuit as required.
Also check the clutch interlock switch operation if
equipped with a manual transmission. If OK, the
PCM may be defective.
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.
DIAGNOSIS AND TESTING - 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) Gain access to battery terminals.
(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
8F - 32 STARTINGRS
STARTING (Continued)
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Page 377 of 2177
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 connected directly to the front control mod-
ule (FCM) to form an integrated unit called an Inte-
grated Power Module (IPM). The rear defogger
switch and relay also activates the heated power side
view mirrors. The rear defogger switch also activates
the heated windshield wiper de-icer which 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-servicable 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
timout is bypassed, the heated windshield wiper de-
icer will stay ON until another mode is selected. For
circuit information and component location refer to
appropriate section for Wiring Diagrams.
CAUTION:
Since grid lines can be damaged or scraped off by
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 recommended.
DEFOGGER RELAY
DESCRIPTION
There is no heated windshield wiper de-icer relay.
The grid is powered directly from fuse #11 in the
PDC and is controlled directly from the HVAC con-
trol assembly.
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. The defogger relay will be on for approxi-
mately 10 minutes or until the control switch or igni-
tion 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)
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WINDSHIELD GRID
DIAGNOSIS AND TESTING - SYSTEM TEST
Electrically heated rear window defogger or the
heated windshield wiper deicer operation can be
checked on the vehicle in the following manner:
(1) Turn the ignition switch to the ON position.
(2) Using a ammeter on the battery, turn the rear
defogger control switch to the ON position, a distinct
increase in amperage draw should be noted.
(3) The rear window defogger or the heated wind-
shield wiper deicer operation can be checked by feel-
ing the glass. A distinct difference in temperature
between the grid lines and adjacent clear glass can
be detected in 3 to 4 minutes of operation.
(4) Using a DC voltmeter (Fig. 4) contact terminal
B with the negative lead, and terminal A with the
positive lead. The voltmeter should read 10-14 volts.
(5) Indicator light illumination means that there is
power available at the switch only and does not nec-
essarily verify system operation.
(6) If turning the defogger switch ON, no distinct
current draw on the ammeter the problem should be
isolated in the following manner:
²Confirm that ignition switch is ON.
²Ensure that the heated rear window or the
heated windshield wiper deicer feed pigtail is con-
nected to the wiring harness and that the ground
pigtail is in fact grounded.
²Ensure that the proper fuse in the PDC is OK.
(7) When the above steps have been completed and
the system is still inoperative it may be necessary to
connect a DRBIII scan tool and refer to the Diagnos-
tic Service Manual, you may also check for the fol-
lowing being defective:
²HVAC control assembly
²Rear window defogger relay in the PDC portion
of the IPM.
²Rear window defogger relay control circuity in
the FCM portion of the IPM.
²Check for loose connector or a wire pushed out
of connector.
²Rear window or the windshield grid lines (all
grid lines would have to be broken, or one of the feed
pigtails not connected to the bus bar, for no ammeter
deflection).
(8) If turning the switch ON produces severe volt-
meter deflection, the circuit should be closely checked
for a shorting condition.
(9) If the system operation has been verified but
indicator LED does not light, replace the HVAC con-
trol assembly.
(10) For detailed wiring information, refer to the
appropriate section for Wiring Diagrams.
STANDARD PROCEDURE - GRID LINE AND
TERMINAL REPAIR
WARNING: REPAIR KIT MAY CAUSE SKIN OR EYE
IRRITATION. CONTAINS EPOXY RESIN AND AMINE
TYPE HARDENER, HARMFUL IF SWALLOWED.
AVOID CONTACT WITH SKIN AND EYES. FOR SKIN,
WASH AFFECTED AREAS WITH SOAP AND WATER.
DO NOT TAKE INTERNALLY. IF TAKEN INTER-
NALLY, INDUCE VOMITING; CALL A PHYSICIAN
IMMEDIATELY. IF IN CONTACT WITH EYES, FLUSH
WITH PLENTY OF WATER. USE WITH ADEQUATE
VENTILATION. DO NOT USE NEAR FIRE OR FLAME.
CONTENTS CONTAINS 3% FLAMMABLE SOL-
VENTS. KEEP OUT OF REACH OF CHILDREN.
The repair for the front windshield or the rear win-
dow grids are the same.
The repair of grid lines and replacement of the ter-
minal is possible using the MopartRepair Package
or equivalent.
(1) Clean area surrounding grid line or terminal
by gently rubbing area with steel wool.
(2) Wipe area with clean cloth soaked in alcohol or
similar solvent. It is necessary that all contaminants
be removed from repair area.
(3) Remove package separator clamp and mix plas-
tic conductive epoxy thoroughly.
(4) For grid line, mark off area to be repaired with
masking tape (Fig. 5).
(5) Apply conductive epoxy through slit in masking
tape. Overlap both ends of the break.
Fig. 4 Grid Line Test
1 - VOLTMETER
2 - TERMINAL B
3 - FEED WIRE
4 - MID-POINT C (TYPICAL)
5 - HEATED REAR WINDOW GRIDS
6 - GROUND WIRE
7 - TERMINAL A
RSHEATED GLASS8G-3
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Page 383 of 2177
Refer to the description of the heated seat switch
later in this section for additional information.
Hard wired circuitry connects the heated seat sys-
tem components to each other through the electrical
system of the vehicle. These hard wired circuits are
integral to several wire harnesses, which are routed
throughout the vehicle and retained by many differ-
ent methods. These circuits may be connected to each
other, to the vehicle electrical system and to the
heated seat system components through the use of a
combination of soldered splices and splice block con-
nectors. Refer to Wiring for complete system wiring
schematics. The wiring information also includes the
proper wire and connector repair procedures, further
details on wire harness routing and retention, as well
as pin-out and location views for the various wire
harness connectors, splices and grounds.
OPERATION
The heated seat system components operate on
battery current received through a fuse in the Inte-
grated Power Module (IPM) on a fused ignition
switch output (run) circuit so that the system will
only operate when the ignition switch is in the On
position. The heated seat system will be turned Off
automatically whenever the ignition switch is turned
to any position except On. Also, the heated seat sys-
tem will not operate when the surface temperature of
the seat cushion cover at either heated seat sensor is
above the designed temperature set points of the sys-
tem. See the owner's manual in the vehicle glove box
for more information on the features, use and opera-
tion of the heated seat system.
DIAGNOSIS AND TESTING - HEATED SEAT
SYSTEM
The most reliable, efficient, and accurate means to
diagnose the heated seat system requires the use of a
DRBIIItscan tool and the proper Diagnostic Proce-
dures manual. The DRBIIItscan tool can provide
confirmation that the PCI data bus is functional, that
all of the electronic modules are sending and receiv-
ing the proper messages on the PCI data bus, and
that the heated seat modules are receiving the
proper hard wired inputs from and relaying the
proper hard wired outputs to the Body Control Mod-
ule in order to perform its functions. Refer toWiring
Diagramsfor complete wiring schematics. The wir-
ing information also includes the proper wire and
connector repair procedures, further details on wire
harness routing and retention, as well as pin-out and
location views for the various wire harness connec-
tors, splices and grounds.
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 hazard, rear window
wiper and washer switches. The heated seat switches
each provide a resistor multiplexed signal to its
respective Heated Seat Module (HSM) through sepa-
rate hard wired circuits. Each switch has an Off,
Low, and High position so that both the driver and
the front seat passenger 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
depressed, the Low position is selected and the low
position LED indicator illuminates. When the right
side of the switch rocker is fully depressed, the High
position is selected and the high position LED indi-
Fig. 2 HEATED SEAT SWITCH LOCATION
1 - HEATED SEAT SWITCHES
8G - 8 HEATED SEAT SYSTEMRS
HEATED SEAT SYSTEM (Continued)
ProCarManuals.com
Page 384 of 2177
cator illuminates. When the switch rocker is moved
to its neutral position (middle), Off is selected and
both LED indicators are extinguished.
Each switch provides separate resistor multiplexed
hard wire inputs to its respective Heated Seat Mod-
ule (HSM) to indicate the selected switch position.
The heated seat module 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 AND TESTING - DRIVER HEATED
SEAT SWITCH
For complete circuit diagrams, refer toWiring
Diagrams.
WARNING: REFER TO THE RESTRAINTS SECTION
OF THIS MANUAL BEFORE ATTEMPTING ANY
STEERING 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.
CHECKING SWITCH SIGNAL AND WIRING AT THE
MODULE
(1) Disconnect and isolate the battery negative
cable.
(2) Access and disconnect the gray 4-way connector
from the heated seat module. Visually inspect wiring
terminals for damage that would prevent positive
connection. If not OK, repair or replace the necessary
components.
(3) Place the heated seat switch in the LO posi-
tion. Using an Ohmmeter, check the resistance
between cavities 2 and 3 of the gray connector noted
above. Resistance should be about 3.5 kilohms (3500
ohms). If not OK, check resistance directly at switch,
as noted below. If OK, proceed to the next step. If not
OK, replace the faulty switch.
(4) Place the heated seat switch in the HI position.
Using an ohmmeter, check the resistance between
cavities 2 and 3 of the gray connector noted above.
Resistance should be about 1.4 kilohms (1400 ohms).
If not OK, check resistance directly at switch, as
noted below. If OK, proceed. If not OK replace the
faulty switch.
(5) With the system ON in the HI position, check
for battery voltage and ground at cavities 4 and 1. If
OK, proceed with testing remaining components. If
not OK, repair open or shorted wiring.
CHECKING SWITCH ONLY
(1) Disconnect and isolate the battery negative
cable. Remove the center bezel from the instrument
panel (Refer to 23 - BODY/INSTRUMENT PANEL/
INSTRUMENT PANEL CENTER BEZEL - REMOV-
AL). Check for continuity between the ground circuit
cavity (#10) of the instrument panel switch bank
electrical connector and a good ground. There should
be continuity. If OK, go to Step 2. If not OK, repair
the open ground circuit to ground as required.
(2) 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 switch bank con-
nector (#4). If OK, turn the ignition switch to the Off
position, and go to Step 3. If not OK, repair the open
fused ignition switch output (run) circuit as required.
(3) Test the heated seat switch as shown in the
Heated Seat Switch Test chart and the connector pin-
out below (Fig. 3). If OK, go to Step 4. If not OK,
replace the faulty switch bank assembly.
DRIVER HEATED SEAT SWITCH TEST
SWITCH
POSITIONRESISTANCE
BETWEENRESISTANCE
(OHMS)
Off Pin4&5OPEN
Low Pin4&53570
High Pin4&51430
All resistance values are 1%.
Fig. 3 Instrument Panel Switch Bank Connector
RSHEATED SEAT SYSTEM8G-9
DRIVER HEATED SEAT SWITCH (Continued)
ProCarManuals.com
Page 385 of 2177
(4) Reconnect the instrument panel switch bank
and test the heated seat system for proper operation.
If the system is still inoperative proceed with check-
ing remaining components.
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 instrument
panel center bezel (Fig. 4). Tighten the screws to 1.5
N´m (13 in. lbs.).
(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 ELEMENTS
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 element assembly must be
replaced. Refer to the procedure in this section.
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
heated seat module supplies a five-volt current to one
side of each sensor, and monitors the voltage drop
through the sensor on a return circuit. The heated
seat module uses this temperature sensor input to
monitor the temperature of the seat, and regulates
the current flow to the seat heating elements accord-
ingly.
DIAGNOSIS AND TESTING - HEATED SEAT
ELEMENTS
The wire harness connectors for the seat cushion
and seat back heating elements are located under the
seat, at the heated seat module. For circuit descrip-
tions and diagrams, refer to section 8W, Wiring Dia-
grams.
Fig. 4 SWITCH RETAINING SCREWS
1 - HEATED SEAT SWITCH ASSEMBLY
2 - RETAINING SCREWS
8G - 10 HEATED SEAT SYSTEMRS
DRIVER HEATED SEAT SWITCH (Continued)
ProCarManuals.com
Page 387 of 2177
OPERATION
The temperature sensor is a NTC thermistor.
When the temperature of the seat cushion cover
rises, the resistance of the sensor decreases. The
heated seat module supplies a five-volt current to one
side of each sensor, and monitors the voltage drop
through the sensor on a return circuit. The heated
seat module uses this temperature sensor input to
monitor the temperature of the seat, and regulates
the current flow to the seat heating elements accord-
ingly.
DIAGNOSIS AND TESTING - HEATED SEAT
SENSOR
For complete circuit diagrams, refer toWiring
Diagrams.
(1) Disconnect and isolate the battery negative
cable. Disconnect the green 4-way heated seat mod-
ule wire harness connector.
(2) Using an ohmmeter, check the resistance
between cavities 2 and 3. The sensor resistance
should be between 50 kilohms at 15É C (60É F) and 2
kilohms at 30É C (85É F). If not OK, replace the
faulty seat element and sensor assembly.
PASSENGER HEATED SEAT
SWITCH
DESCRIPTION
The heated seat switches are mounted in the
instrument panel center bezel (Fig. 6). The two three-
position rocker-type switches, one switch for each
front seat, are incorporated into one large switch
assembly that also includes the hazard, rear window
wiper and washer switches. The heated seat switches
each provide a resistor multiplexed signal to its
respective Heated Seat Module (HSM) through sepa-
rate hard wired circuits. Each switch has an Off,
Low, and High position so that both the driver and
the front seat passenger 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
depressed, the Low position is selected and the low
position LED indicator illuminates. When the right
side of the switch rocker is fully depressed, the High
position is selected and the high position LED indi-
Fig. 5 HEATING ELEMENT INSTALLED - TYPICAL
1 - SEAT BACK WIRE HARNESS
2 - HEATED SEAT WIRE HARNESS CONNECTOR
3 - HEATED SEAT CUSHION ELEMENT
Fig. 6 HEATED SEAT SWITCH LOCATION
1 - HEATED SEAT SWITCHES
8G - 12 HEATED SEAT SYSTEMRS
HEATED SEAT SENSOR (Continued)
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Page 388 of 2177
cator illuminates. When the switch rocker is moved
to its neutral position (middle), Off is selected and
both LED indicators are extinguished.
Each switch provides separate resistor multiplexed
hard wire inputs to its respective Heated Seat Mod-
ule (HSM) to indicate the selected switch position.
The heated seat module 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 AND TESTING - PASSENGER
HEATED SEAT SWITCH
For complete circuit diagrams, refer toWiring
Diagrams.
WARNING: REFER TO THE RESTRAINTS SECTION
OF THIS MANUAL BEFORE ATTEMPTING ANY
STEERING 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.
CHECKING SWITCH SIGNAL AND WIRING AT THE
MODULE
(1) Disconnect and isolate the battery negative
cable.
(2) Access and disconnect the gray 4-way connector
from the heated seat module. Visually inspect wiring
terminals for damage that would prevent positive
connection. If not OK, repair or replace the necessary
components.
(3) Reconnect the negative battery cable and Turn
heated seat ON in the LO position. Using an Ohm-
meter, check the resistance between cavities 2 and 3
of the gray connector noted above. Resistance should
be about 3.5 kiloohms (3500 ohms). If not OK, check
resistance directly at switch, as noted below. If OK,
proceed. If NOT OK replace the switch or faulty wir-
ing.
(4) Turn heated seat ON in the HI position. Using
an Ohmmeter, check the resistance between cavities
2 and 3 of the gray connector noted above. Resistance
should be about 1.4 kiloohms (1400 ohms). If not OK,
check resistance directly at switch, as noted below. If
OK, proceed. If NOT OK replace the switch or faulty
wiring.
(5) With the system ON in the HI position, Check
for battery voltage and ground at cavities 4 and 1. If
OK, proceed with testing remaining components. If
NOT OK, repair open or wiring short.
CHECKING SWITCH ONLY
(1) Disconnect and isolate the battery negative
cable. Remove the center bezel from the instrument
panel (Refer to 23 - BODY/INSTRUMENT PANEL/
INSTRUMENT PANEL CENTER BEZEL - REMOV-
AL). Check for continuity between the ground circuit
cavity (#10) of the instrument panel switch bank
electrical connector and a good ground. There should
be continuity. If OK, go to Step 2. If not OK, repair
the open ground circuit to ground as required.
(2) 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 switch bank con-
nector (#4). If OK, turn the ignition switch to the Off
position, and go to Step 3. If not OK, repair the open
fused ignition switch output (run) circuit as required.
(3) Test the heated seat switch as shown in the
Heated Seat Switch Test chart and the connector pin-
out below (Fig. 7). If OK, go to Step 4. If not OK,
replace the faulty switch bank assembly.
PASSENGER HEATED SEAT SWITCH TEST
SWITCH
POSITIONRESISTANCE
BETWEENRESISTANCE
(OHMS)
Off Pin3&4OPEN
Low Pin3&43570
High Pin3&41430
All resistance values are 1%.
Fig. 7 Instrument Panel Switch Bank Connector
RSHEATED SEAT SYSTEM8G-13
PASSENGER HEATED SEAT SWITCH (Continued)
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