2002 CHRYSLER CARAVAN heating

RADIATOR PRESSURE CAP
DESCRIPTION
The cooling system pressure cap is located on the
radiator. The cap construction includes; stainless
steel swivel top, rubber seals, and retainer, main
spring, and a spring loaded valve (Fig. 19).
OPERATION
The cooling system is equipped with a pressure cap
that releases excessive pressure; maintaining a range
of 97-124 kPa (14-18 psi).
The cooling system will operate at higher than
atmospheric pressure. The higher pressure raises the
coolant boiling point thus, allowing increased radia-
tor cooling capacity.
There is also a vent valve in the center of the cap.
This valve also opens when coolant is cooling and
contracting, allowing the coolant to return to cooling
system from coolant reserve system tank by vacuum
through a connecting hose.If valve is stuck shut,
or the coolant recovery hose is pinched, the
radiator hoses will be collapsed on cool down.
Clean the vent valve (Fig. 19) and inspect cool-
ant recovery hose routing, to ensure proper
sealing when boiling point is reached.
The gasket in the cap seals the filler neck, so that
vacuum can be maintained, allowing coolant to be
drawn back into the radiator from the reserve tank.
If the gasket is dirty or damaged, a vacuum
may not be achieved, resulting is loss of coolant
and eventual overheating due to low coolant
level in radiator and engine.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - COOLING SYSTEM
PRESSURE CAP
Dip the pressure cap in water. Clean any deposits
off the vent valve or its seat and apply cap to end of
the Pressure Cap Test Adaptor that is included with
the Cooling System Tester 7700. Working the
plunger, bring the pressure to 104 kPa (15 psi) on the
gauge. If the pressure cap fails to hold pressure of at
least 97 kPa (14 psi), replace the pressure cap.
CAUTION: The Cooling System Tester Tool is very
sensitive to small air leaks that will not cause cool-
ing system problems. A pressure cap that does not
have a history of coolant loss should not be
replaced just because it leaks slowly when tested
with this tool. Add water to the tool. Turn tool
upside down and recheck pressure cap to confirm
that cap is bad.
If the pressure cap tests properly while positioned
on Cooling System Tester (Fig. 20), but will not hold
pressure or vacuum when positioned on the filler
neck. Inspect the filler neck and cap top gasket for
irregularities that may prevent the cap from sealing
properly.
Fig. 19 Cooling System Pressure Cap Filler Neck
1 - OVERFLOW NIPPLE
2 - MAIN SPRING
3 - GASKET RETAINER
4 - STAINLESS-STEEL SWIVEL TOP
5 - RUBBER SEALS
6 - VENT VALVE
7 - PRESSURE BOTTLE
8 - FILLER NECK
Fig. 20 Testing Cooling System Pressure Cap
1 - PRESSURE CAP
2 - PRESSURE TESTER
RGENGINE7a-25
ProCarManuals.com

(a) BCM has two battery feeds at pin 1 and pin
5 of the 6±way connector.
(b) Pin 5 of the (BX2) 32 way connector of the
BCM for ignition feed.
(c) Check voltage (PX2) connector, pin 34 for 12v.
(d) If voltage OK, go to step Step 3
(e) If NO voltage repair as necessary. Refer to
the appropriate wiring information. The wiring
information includes wiring diagrams, 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.
(3) Check driver's seat belt buckle switch input
(form ORC) for a closed circuit when not buckled. If
input not seen, look for open in wiring or switch. The
switch is grounded when belt is not buckled.
(4) Verify PCI data bus communication between
ORC and BCM.
NO FASTEN SEAT BELT LAMP WHEN IGNITION
SWITCH IS TURNED ON.
(1) Check for burned out lamp.
(2) Using a voltmeter check for voltage at the clus-
ter conncctor:
(a) Pin 2 of the mechanical instrument cluster
for battery feed.
(b) Pin 11 of the mechanical instrument cluster
for ignition voltage.
(3) Repair as necessary.
FASTEN SEAT BELT LAMP OR TONE CONTINUES
FOR MORE THAN 10 SECONDS AFTER SEAT
BELTS ARE FASTENED AND DRIVER'S DOOR IS
CLOSED.
Refer to the proper Body Diagnostic Procedures
manual.
NO TONE WHEN PARK OR HEADLAMPS ARE ON
AND DRIVER'S DOOR IS OPEN.
Make sure ignition is in lock position with the key
removed.
(1) Check the BCM DTC's and BCM sensors to
verify the door is open. Repair as necessary.
(2) Actuate Chime (BCM actuates).
(3) Inspect BCM connectors and wires for proper
connection.
(4) Measure with a voltmeter the voltage (12v) on
BCM connector (PX2) pin 34 with harness connected.
DIAGNOSIS AND TESTING - DOME LAMP ON
CHIME
The dome lamp on chime will warn the driver that
the dome lamps have been left on.When the ignition is OFF and the key is out of the
ignition:
²Driver's door OPEN (door ajar switch is closed to
ground) and
²Dome lamps are ON (dome lamp switch is closed
to ground),
The chime will sound continuously until the driv-
ers door is closed, dome lamps turned OFF or until
the battery protection time out of 15 minutes has
expired. Chime rate: 168 to 192 chimes per minute.
DIAGNOSIS AND TESTING - ENGINE
TEMPERATURE CRITICAL CHIME
The engine temperature critical chime will warn
the driver that the vehicle's engine is overheating.
While monitoring the coolant temperature, the Pow-
ertrain Control Module (PCM) will send on the PCI
data bus as engine temperature every 1.376 seconds
to the cluster. The MIC calculates engine tempera-
ture and determines if a warning should occur. This
feature is functional only with the Ignition Switch in
the Run/Start position.
When the engine temperature reaches 122ÉC
(252ÉF) the MIC requests a chime from the BCM and
the engine temperature lamp comes ON. The MIC
turns OFF the lamp when the engine temperature
reaches 117ÉC (242ÉF). The MIC will chime continu-
ously (request from the BCM). The chime will turn
OFF after four minutes or when the temperature
reaches 117ÉC (242ÉF), which ever occurs first.
DIAGNOSIS AND TESTING - EXTERIOR LAMPS
ON CHIME
The exterior lamp on chime will warn the driver
that the exterior lights have been left on.
With the ignition switch OFF/key out of ignition:
²Driver's door is open (door ajar switch is closed
to ground)
²Parking lamps or headlamps ON (parking lamp
switch is closed to ground)
The chime will sound until lights are turned OFF,
driver's door closed or until the battery protection
time out of 3 minutes has expired.
Chime rate: 168 to 192 chimes per minute.
To test the exterior lamps left on function:
²Turn ignition off
²Remove ignition key
²Turn exterior lamps on with driver's door open.
Chime should sound until lamps are turned off or
driver's door is closed.
DIAGNOSIS AND TESTING - KEY-IN IGNITION
CHIME
The key-in ignition chime will act as a warning to
the driver that the ignition key has been left in the
8B - 2 CHIME/BUZZERRS
CHIME/BUZZER (Continued)
ProCarManuals.com

²Ignition sense
²Intake Air Temperature Sensor
²Knock Sensor
²Leak Detection Pump Feedback
²Manifold Absolute Pressure (MAP) Sensor
²Park/Neutral (from transmission control module)
²PCI Bus
²Power Steering Pressure Switch
²Proportional Purge Sense
²SCI Receive
²Speed Control
²Throttle Position Sensor
²Torque Management Input (From TCM)
²Transaxle Control Module (TCM)
²Transaxle Gear Engagement (From TCM)
²Vehicle Speed (from transmission control mod-
ule)
NOTE: PCM Outputs:
²Air Conditioning Clutch Relay
²Automatic Shut Down (ASD) and Fuel Pump
Relays
²Data Link Connector (PCI and SCI Transmit)
²Double Start Override
²EGR Solenoid
²Fuel Injectors
²Generator Field
²High Speed Fan Relay
²Idle Air Control Motor
²Ignition Coils
²Leak Detection Pump
²Low Speed Fan Relay
²MTV Actuator
²Proportional Purge Solenoid
²SRV Valve
²Speed Control Relay
²Speed Control Vent Relay
²Speed Control Vacuum Relay
²8 Volt Output
²5 Volt Output
Based on inputs it receives, the powertrain control
module (PCM) adjusts fuel injector pulse width, idle
speed, ignition timing, and canister purge operation.
The PCM regulates the cooling fans, air conditioning
and speed control systems. The PCM changes gener-
ator charge rate by adjusting the generator field.
The PCM adjusts injector pulse width (air-fuel
ratio) based on the following inputs.
²Battery Voltage
²Intake Air Temperature Sensor
²Engine Coolant Temperature
²Engine Speed (crankshaft position sensor)²Exhaust Gas Oxygen Content (heated oxygen
sensors)
²Manifold Absolute Pressure
²Throttle Position
The PCM adjusts engine idle speed through the
idle air control motor based on the following inputs.
²Brake Switch
²Engine Coolant Temperature
²Engine Speed (crankshaft position sensor)
²Park/Neutral (transmission gear selection)
²Transaxle Gear Engagement
²Throttle Position
²Vehicle Speed (from Transmission Control Mod-
ule)
The PCM adjusts ignition timing based on the fol-
lowing inputs.
²Intake Air Temperature
²Engine Coolant Temperature
²Engine Speed (crankshaft position sensor)
²Knock Sensor
²Manifold Absolute Pressure
²Park/Neutral (transmission gear selection)
²Transaxle Gear Engagement
²Throttle Position
The automatic shut down (ASD) and fuel pump
relays are mounted externally, but turned on and off
by the powertrain control module through the same
circuit.
The camshaft and crankshaft signals are sent to
the powertrain control module. If the PCM does not
receive both signals within approximately one second
of engine cranking, it deactivates the ASD and fuel
pump relays. When these relays are deactivated,
power is shut off to the fuel injectors, ignition coils,
fuel pump and the heating element in each oxygen
sensor.
The PCM contains a voltage converter that
changes battery voltage to a regulated 8.0 volts. The
8.0 volts power the camshaft position sensor, crank-
shaft position sensor and vehicle speed sensor. The
PCM also provides a 5.0 volts supply for the engine
coolant temperature sensor, intake air temperature
sensor, manifold absolute pressure sensor and throt-
tle position sensor.
The PCM engine control strategy prevents reduced
idle speeds until after the engine operates for 320 km
(200 miles). If the PCM is replaced after 320 km (200
miles) of usage, update the mileage in new PCM. Use
the DRB scan tool to change the mileage in the PCM.
Refer to the appropriate Powertrain Diagnostic Man-
ual and the DRB scan tool.
8E - 12 ELECTRONIC CONTROL MODULESRS
POWERTRAIN CONTROL MODULE (Continued)
ProCarManuals.com

HEATED SEAT SYSTEM
TABLE OF CONTENTS
page page
HEATED SEAT SYSTEM
DESCRIPTION..........................7
OPERATION............................8
DIAGNOSIS AND TESTING - HEATED SEAT
SYSTEM.............................8
DRIVER HEATED SEAT SWITCH
DESCRIPTION..........................9
OPERATION............................9
DIAGNOSIS AND TESTING - DRIVER HEATED
SEAT SWITCH.........................9
REMOVAL.............................10
INSTALLATION.........................10
HEATED SEAT ELEMENT
DESCRIPTION.........................11
OPERATION...........................11
DIAGNOSIS AND TESTING - HEATED SEAT
ELEMENTS..........................11REMOVAL.............................12
INSTALLATION.........................12
HEATED SEAT SENSOR
DESCRIPTION.........................12
OPERATION...........................12
DIAGNOSIS AND TESTING - HEATED SEAT
SENSOR............................12
PASSENGER HEATED SEAT SWITCH
DESCRIPTION.........................13
OPERATION...........................13
DIAGNOSIS AND TESTING - PASSENGER
HEATED SEAT SWITCH.................13
REMOVAL.............................14
INSTALLATION.........................15
HEATED SEAT SYSTEM
DESCRIPTION
Vehicles with the heated seat option can be visu-
ally identified by the two separate heated seat
switches located in the instrument panel center
stack, just above the radio (Fig. 1). The heated seat
system allows the front seat driver and passenger to
select from two different levels of supplemental elec-
trical seat heating (HI/LO), or no seat heating to suit
their individual comfort requirements. The heated
seat system for this vehicle includes the following
major components, which are described in further
detail later in this section:
²Heated Seat Elements- Four heated seat ele-
ments are used per vehicle, two for each front seat.
One heated seat element is integral to each front
seat trim cover, one in the seat back and one in the
seat bottom (cushion). Service replacement heating
elements are available, refer to heated seat elements
later in this section for additional information.
²Heated Seat Modules- Two heated seat mod-
ules are used per vehicle. One module is mounted to
each of the seat cushion pans, located under the for-
ward edge of each front seat. Refer to heated seat
module in the electronic control modules section of
the service manual for additional information.
²Heated Seat Sensors- Two heated seat sen-
sors are used per vehicle, one for each front seat. The
heated seat sensors are integral to each of the heated
seat bottoms (cushions).
Fig. 1 HEATED SEAT SWITCH LOCATIONS
1 - HEATED SEAT SWITCHES
RSHEATED SEAT SYSTEM8G-7
ProCarManuals.com

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
provide a resistor multiplexed signal to the Heated
Seat Module (HSM) through separate hard wired cir-
cuits. 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-cator 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 Heated Seat Module
(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) 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.
Fig. 2 HEATED SEAT SWITCH LOCATION
1 - HEATED SEAT SWITCHES
RSHEATED SEAT SYSTEM8G-9
ProCarManuals.com

(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.
HEATED SEAT ELEMENT
DESCRIPTION
The heated seat system includes two seat heating ele-
ments 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) thermistor. One temper-
ature 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 electrical
current. When battery current is passed through the
elements, the energy lost by the resistance of the ele-
ments 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 accordingly.
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 descriptions and
diagrams, refer to section 8W, Wiring Diagrams.
In order to access and test the heated seat ele-
ments it will be necessary to remove the appropriate
front seat retaining bolts and lay the seat rearward,
up against one of the rear seats. It is not necessary
to disconnect the seat electrical connectors, just use
care not to damage the attached wire harnesses
while testing.NOTE: WHEN CHECKING HEATED SEAT ELE-
MENTS FOR CONTINUITY, BE CERTAIN TO MOVE
THE HEATING ELEMENT BEING CHECKED. MOV-
ING THE ELEMENT, SUCH AS SITTING IN THE SEAT
WILL ELIMINATE THE POSSIBILITY OF AN INTER-
MITTENT OPEN IN THE ELEMENT WHICH WOULD
ONLY BE EVIDENT IF THE ELEMENT WAS MOVED
IN A CERTAIN DIRECTION. FAILURE TO CHECK
THE ELEMENT IN VARIOUS POSITIONS COULD
RESULT IN AN INCOMPLETE TEST.
SEAT CUSHION ELEMENT
(1) From under the vehicle, remove the appropri-
ate seats four retaining nuts.
(2) From inside the vehicle, pull the seat up, off
the mounting studs and lay it back, up against one of
the rear seats.
(3) Locate the heated seat module, attached to the
bottom of the seat cushion pan. Remove the heated
seat module from the seat cushion pan. Do not dis-
connect the electrical connectors at this time.
(4) Locate the green 4-way electrical connector,
connected to the heated seat module. Disconnect the
green 4-way connector from the heated seat module.
(5) Check for continuity between the two outboard
circuit cavities of the wire harness connector (Pins
1&4). There should be continuity. If OK, refer to
Heated Seat Module Diagnosis and Testing in the
Electronic Control Modules section of the service
manual for complete system testing procedures. If
not OK, install a replacement heated seat cushion
element. Refer to the procedure in this section.
SEAT BACK ELEMENT
(1) From under the vehicle, remove the appropri-
ate seats four retaining nuts.
(2) From inside the vehicle, pull the seat up and
off the mounting studs and lay it back, up against
one of the rear seats.
(3) Locate the heated seat module, attached to the
bottom of the seat cushion pan. Remove the heated
seat module from the seat cushion pan. Do not dis-
connect the electrical connectors at this time.
(4) Locate the gray 2-way electrical connector, con-
nected to the heated seat module. Disconnect the
2-way connector from the heated seat module.
(5) Check for continuity between the two circuit
cavities of the 2-way wire harness connector. There
should be continuity. If OK, refer to Heated Seat
Module Diagnosis and Testing in the Electronic Con-
trol Modules section of the service manual for com-
plete system testing procedures. If not OK, install a
replacement heated seat back element. Refer to the
procedure in this section.
RSHEATED SEAT SYSTEM8G-11
DRIVER HEATED SEAT SWITCH (Continued)
ProCarManuals.com

REMOVAL
Do not remove the OEM heating element from the
seat or seat back cushion/trim covers. The original
element is permanently attached and cannot be
removed without permanent damage. The service
replacement heating element is designed to be
applied directly on the seat cushion.
(1) Disconnect and isolate the negative battery
cable.
(2) Remove the appropriate seat cushion or seat
back trim cover. Refer to the Body section of the ser-
vice manual for the procedures.
(3) Disconnect the inoperative heated seat cushion
or seat back element electrical connectors.
(4) Locate the wires leading from the inoperative
heating element and cut them off flush with the edge
of the original heating element.
INSTALLATION
(1) Peel off the adhesive backing on the back of the
replacement heating element and stick directly on
the foam cushion.
CAUTION: During the installation of the replace-
ment heating element, be careful not to fold or
crease the element assembly. Folds or creases will
cause premature failure.
(2) Connect the new heating element electrical
connectors (Fig. 5).
(3) Connect the negative battery cable.
(4) Verify heated seat system operation.
(5) Install the appropriate seat cushion or seat
back trim cover. Make certain the seat wire harness
is correctly routed through the seat and seat back.
The excess wire between the cushion and back ele-
ments should be securely tucked between the rear of
the cushion foam and the rear carpet flap of the trim
cover.
HEATED SEAT SENSOR
DESCRIPTION
Two heated seat sensors are used per vehicle, one
in each front seat cushion heating element. The
heated seat temperature sensor is a Negative Tem-
perature Coefficient (NTC) thermistor.
The heated seat sensors cannot be repaired or
adjusted and if found to be faulty, the complete
heated seat cushion element must be replaced.
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 2 kilohms at 15É C (60É F) and 50
kilohms at 30É C (85É F). If not OK, replace the
faulty seat element and sensor assembly.
Fig. 5 HEATING ELEMENT INSTALLED - TYPICAL
1 - SEAT BACK WIRE HARNESS
2 - HEATED SEAT WIRE HARNESS CONNECTOR
3 - HEATED SEAT CUSHION ELEMENT
8G - 12 HEATED SEAT SYSTEMRS
HEATED SEAT ELEMENT (Continued)
ProCarManuals.com

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
provide a resistor multiplexed signal to the Heated
Seat Module (HSM) through separate hard wired cir-
cuits. 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-cator 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 Heated Seat Module
(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.
Fig. 6 HEATED SEAT SWITCH LOCATION
1 - HEATED SEAT SWITCHES
RSHEATED SEAT SYSTEM8G-13
ProCarManuals.com