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.
Each switch provides separate resistor, hard wire
inputs to its respective 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
Refer to the appropriate wiring information for
complete circuit schematic or connector pin-out infor-
mation.
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) Connect the battery negative cable. Place the
heated seat switch in the LO position. 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 the switch, as
indicated in the Heated Seat Switch Test Table. 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 -
REMOVAL). Check for continuity between the
ground circuit cavity (#10) of the instrument panel
center bezel switch 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) Connect 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 center bezel
switch electrical connector (#4). If OK, turn the igni-
tion 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 instrument panel center bezel switch
assembly.
RSHEATED SEAT SYSTEM8G-9
HEATED SEAT SWITCH (Continued)
(3) Install the center bezel onto the instrument
panel, (Refer to 23 - BODY/INSTRUMENT PANEL/
INSTRUMENT PANEL CENTER BEZEL - INSTAL-
LATION).
(4) Connect 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 attached to 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 8 - ELECTRICAL/HEATED
SEATS/HEATED SEAT ELEMENT - REMOVAL).
OPERATION
The heated seat elements resist the flow of electri-
cal current. When battery current is passed through
the elements, the resistance of the elements to the
current flow is released in the form of heat. The tem-
perature sensor is a Negative Temperature Coeffi-
cient (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 signal to one side of each sensor, and monitors
the voltage drop through the sensor on a return cir-
cuit. 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. Refer to the appro-
priate wiring information for complete circuit sche-
matic or connector pin-out information.
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 elements for
continuity, be certain to move the heating element
being checked. Moving 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 in a certain position.
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 and disconnect the green 4-way electri-
cal connector, connected to the heated seat module.
(5) Check for continuity between the two outboard
circuit cavities of the wire harness connector (Pins
Fig. 5 SWITCH RETAINING SCREWS
1 - HEATED SEAT SWITCH ASSEMBLY
2 - RETAINING SCREWS
RSHEATED SEAT SYSTEM8G-11
HEATED SEAT SWITCH (Continued)
1&4). There should be continuity. If OK, (Refer to 8 -
ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/MEMORY HEATED SEAT/MIRROR MOD-
ULE - DIAGNOSIS AND TESTING) for complete
system testing procedures. If not OK, install a
replacement heated seat cushion element, (Refer to 8
- ELECTRICAL/HEATED SEATS/HEATED SEAT
ELEMENT - INSTALLATION).
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 and disconnect the gray 2-way electrical
connector, connected to 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 8 - ELECTRI-
CAL/ELECTRONIC CONTROL MODULES/MEM-
ORY HEATED SEAT/MIRROR MODULE -
DIAGNOSIS AND TESTING) for complete system
testing procedures. If not OK, install a replacement
heated seat back element, (Refer to 8 - ELECTRI-
CAL/HEATED SEATS/HEATED SEAT ELEMENT -
INSTALLATION).
REMOVAL
NOTE: Do not remove the factory installed heating
elements from the seat or seat back cushions. The
original element is permanently attached and can-
not be removed without permanent damage. The
replacement heating element is designed to be
applied directly on top of the factory installed heat-
ing element.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the appropriate seat cushion or seat
back trim cover.
(3) Disconnect the inoperative heated seat cushion
or seat back element electrical connectors (Fig. 6).
(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
top of the factory installed heating element (Fig. 7).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.
Fig. 6 HEATING ELEMENT INSTALLED - TYPICAL
1 - SEAT BACK WIRE HARNESS
2 - HEATED SEAT WIRE HARNESS CONNECTOR
3 - HEATED SEAT CUSHION ELEMENT
Fig. 7 HEATING ELEMENT INSTALLATION
1 - ORIGINAL (INOPERATIVE) HEATING ELEMENT
2 - REPLACEMENT HEATING ELEMENT
8G - 12 HEATED SEAT SYSTEMRS
HEATED SEAT ELEMENTS (Continued)
(2) Connect the new heating element electrical
connectors (Fig. 8).Passenger seat shown, driver
seat similar.
(3) Connect the battery negative cable.
(4) Verify heated seat system operation.
(5) Install the appropriate seat cushion or seat
back trim cover.
NOTE: Make certain the seat wire harness is cor-
rectly 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 Negative Temperature
Coefficient (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 mon-
itors the voltage drop through the sensor on a return
circuit. The heated seat module uses this tempera-
ture sensor input to monitor the temperature of the
seat, and regulates the current flow to the seat heat-
ing elements accordingly.
DIAGNOSIS AND TESTING
HEATED SEAT SENSOR
Refer to the appropriate wiring information for
complete circuit schematic or connector pin-out infor-
mation.
(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.
Fig. 8 HEATED SEAT WIRE HARNESS ROUTING
1 - SEAT BACK HEATED SEAT WIRE HARNESS
2 - PASSENGER SEAT BACK
3 - SEAT BACK ELEMENT CONNECTOR
4 - SEAT CUSHION ELEMENT CONNECTOR
RSHEATED SEAT SYSTEM8G-13
HEATED SEAT ELEMENTS (Continued)
HORN
TABLE OF CONTENTS
page page
HORN SYSTEM
DESCRIPTION..........................1
OPERATION............................1
DIAGNOSIS AND TESTING
HORN SYSTEM........................1
HORN
DIAGNOSIS AND TESTING
HORN...............................3REMOVAL.............................4
INSTALLATION..........................4
HORN SWITCH
DESCRIPTION..........................4
HORN SYSTEM
DESCRIPTION
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAG, REFER TO ELECTRICAL, RESTRAINTS FOR
SAFETY PRECAUTIONS. DISCONNECT THE NEGA-
TIVE CABLE FROM THE BATTERY BEFORE SER-
VICING COMPONENTS INVOLVING THE AIRBAG
SYSTEM. ACCIDENTAL DEPLOYMENT OF AIRBAG
AND PERSONAL INJURY CAN RESULT.
The horn circuit consists of a horn switch, clock-
spring, horn relay, horns and Integrated Power Mod-
ule (IPM). The horn switch is a membrane switch
located in the airbag trim cover. The horns are
located forward of the left front wheel behind the
bumper fascia.
OPERATION
The horn relay plugs into the Integrated Power
Module (IPM) which is located in the engine com-
partment. For circuit information and component
locations, refer to the appropriate wiring information.
The wiring information includes wiring diagrams,
proper wire and connector repair procedures, details
of wire harness routing and retention, connector pin-
out information and location views for the various
wire harness connectors, splices and grounds.
The horns will not function if the switch is
ªCLOSEDº for more than 30 seconds. Once the
switch is ªOPENº, a 20±30 second delay will occur
before the horns are functional again.
DIAGNOSIS AND TESTING
HORN SYSTEM
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO ELECTRICAL, RESTRAINTS
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. FAILURE
TO TAKE THE PROPER PRECAUTIONS COULD
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
Refer to Horn System Test below. If the horn does
not sound, check horn fuse located in the Integrated
Power Module (IPM). If the fuse is blown, replace
with the correct fuse. If the horns fail to sound and
the new fuse blows when depressing the horn switch,
a short circuit in the horn or the horn wiring
between the fuse terminal and the horn is responsi-
ble, or a defective horn switch allowed the horn to
burn out is responsible.
If the fuse is OK, test horn relay.
If the relay is OK, test horn.
CAUTION: Continuous sounding of horn may
cause horn failure.
Should the horn sound continuously, unplug the
horn relay from IPM.
Refer to the appropriate wiring information.
RSHORN8H-1
HORN SYSTEM TEST
CONDITION POSSIBLE CAUSE CORRECTION
HORN SOUNDS CONTINUOUSLY.
NOTE: IMMEDIATELY UNPLUG HORN
RELAY IN THE IPM.(1) HORN RELAY
INOPERATIVE.(1) REPLACE RELAY.
(2) HORN CONTROL
CIRCUIT TO RELAY
SHORTED TO GROUND.(2) CHECK TERMINAL 85 IN IPM FOR
CONTINUITY TO GROUND. IF
CONTINUITY TO GROUND INDICATES:
(A) STEERING WHEEL HORN SWITCH/
LEAD SHORTED TO GROUND.
(B) WIRING HARNESS SHORTED TO
GROUND. FIND THE SHORT AND
REPAIR AS NECESSARY.
(3) PINCHED HORN SWITCH
WIRE UNDER DRIVER
AIRBAG MODULE.(3) REPLACE DRIVER AIRBAG TRIM
COVER.
(4) HORN SWITCH
INOPERATIVE.(4) REPLACE DRIVER AIRBAG TRIM
COVER.
(5) CLOCKSPRING
INOPERATIVE.(5) REPLACE CLOCKSPRING.
(6) FRONT CONTROL
MODULE INOPERATIVE.(6) REFER TO ELECTRONIC CONTROL
MODULES/FRONT CONTROL MODULE.
HORN SOUND INTERMITTENTLY AS
THE STEERING WHEEL IS TURNED.(1) HORN RELAY CONTROL
CIRCUIT X3 IS SHORTED TO
GROUND INSIDE STEERING
COLUMN OR WHEEL.(1) REMOVE DRIVER AIRBAG AND/OR
WHEEL. CHECK FOR RUBBING OR
LOOSE WIRE/CONNECTOR, REPAIR AS
NECESSARY.
(2) PINCHED HORN SWITCH
WIRE UNDER DRIVER
AIRBAG MODULE.(2) REPLACE DRIVER AIRBAG TRIM
COVER.
(3) HORN SWITCH
INOPERATIVE.(3) REPLACE DRIVER AIRBAG TRIM
COVER.
(4) CLOCKSPRING
INOPERATIVE.(4) REPLACE CLOCKSPRING.
HORN DOES NOT SOUND (1) CHECK FUSE 8 IN
INTELLIGENT POWER
MODULE.(1) REPLACE FUSE IF BLOWN REPAIR
AS NECESSARY.
(2) NO VOLTAGE AT HORN
RELAY TERMINALS 30 & 86,
AND FUSE IS OK.(2) NO VOLTAGE, REPAIR THE CIRCUIT
AS NECESSARY.
(3) OPEN CIRCUIT FROM
TERMINAL 85 OF THE HORN
RELAY TO HORN SWITCH,
X3 CIRCUIT.(3) REPAIR CIRCUIT AS NECESSARY.
(4) HORN INOPERATIVE OR
DAMAGED.(4) CHECK VOLTAGE AT HORN WHEN
HORN SWITCH IS PRESSED. IF NO
VOLTAGE, REPLACE HORN.
(5) HORN SWITCH
INOPERATIVE.(5) REPLACE DRIVER AIRBAG TRIM
COVER.
8H - 2 HORNRS
HORN SYSTEM (Continued)
CONDITION POSSIBLE CAUSE CORRECTION
(6) CLOCKSPRING
INOPERATIVE.(6) REPLACE CLOCKSPRING.
(7) FRONT CONTROL
MODULE INOPERATIVE.(7) REFER TO ELECTRONIC CONTROL
MODULES/FRONT CONTROL MODULE.
FUSE BLOWS WHEN HORN SOUNDS (1) SHORT CIRCUIT IN
HORN OR HORN WIRING.(1) REMOVE HORN RELAY, CHECK
FOR SHORTED HORN OR HORN
WIRING. DISCONNECT HORN WIRE
HARNESS TO ISOLATE SHORT AND
REPAIR AS NECESSARY.
(2) CLOCKSPRING
INOPERATIVE.(2) REPLACE CLOCKSPRING.
FUSE BLOWS WITHOUT BLOWING
HORN(1) SHORT CIRCUIT. (1) REMOVE RELAY, INSTALL NEW
FUSE, IF FUSE DOES NOT BLOW
REPLACE HORN RELAY. IF FUSE
BLOWS WITH RELAY REMOVED,
CHECK FOR SHORT TO GROUND
WITH OHMMETER ON CIRCUIT
BETWEEN TERMINALS 30 & 86 AND
THE FUSE TERMINAL. REPAIR AS
NECESSARY.
(2) CLOCKSPRING
INOPERATIVE.(2) REPLACE CLOCKSPRING.
HORN
DIAGNOSIS AND TESTING
HORN
HORN
(1) Disconnect wire connector at horn.
(2) Using a voltmeter, connect one lead to ground
terminal and the other lead to the positive wire ter-
minal (Fig. 1).
(3) Depress the horn switch, battery voltage
should be present.
(4) If no voltage, refer toHORNS WILL NOT
SOUND. If voltage is OK, go to step Step 5.
(5) Using ohmmeter, test ground wire for continu-
ity to ground.
(6) If no ground repair as necessary.
(7) If wires test OK and horn does not sound,
replace horn.
HORNS SOUND CONTINUOUSLY
CAUTION: Continuous sounding of horns may
cause relay to fail.
The horn switch (membrane) sometimes can be the
cause without the switch being depressed.(1) Remove the horn relay from the intelligent
power module.
(2)
Using a continuity tester, test continuity from the
X3 cavity of the horn relay to ground. Refer to the
appropriate wiring information. The wiring information
includes wiring diagrams, proper wire and connector
repair procedures, details of wire harness routing and
retention, connector pin-out information and location
views for the various wire harness connectors, splices
and grounds.
(a)If continuity is detected, proceed to step Step 3.
(b) If NO continuity, replace the horn relay.
(3) Remove the airbag trim cover from the steering
wheel and disengage horn connector.
(4) Install horn relay into Integrated Power Mod-
ule (IPM).
(a)
If horn does not sound, replace airbag trim
cover.
(b) If horn sounds, repair grounded X3 circuit
from IPM to clockspring in the steering column.
HORNS WILL NOT SOUND
Check horn fuse#8intheIPM. If fuse is blown,
check for a shorted switch in the airbag module. and
refer to FUSE BLOWN section. If fuse is OK, refer to
FUSE OK section.
FUSE BLOWN
(1) Verify condition of battery terminals and volt-
age, (Refer to 8 - ELECTRICAL/BATTERY SYSTEM
RSHORN8H-3
HORN SYSTEM (Continued)
- DIAGNOSIS AND TESTING). If battery connec-
tions and battery charge is OK proceed to Step 2.
(2) Using a voltmeter, test for battery voltage at
both sides of horn fuse 7. If voltage is OK, on both
sides of fuse, proceed to Fuse OK. If voltage is OK,
on one side of fuse, the fuse is blown, proceed to Step
3.
(3) Using a suitable ammeter in place of the fuse,
test amperage draw of the horn circuit. If amperage
draw is greater than 20 amps without the horn
switch depressed, a grounded circuit exists between
the fuse and the horn relay. Proceed to Step 4. If
amperage draw is greater than 20 amps with the
horn switch depressed, a grounded circuit exists
between the horn relay and the horn. Proceed to step
Step 5.
(4) Remove the horn relay from the IPM. If the
amperage draw drops to 0 amps, the horn switch or
circuit is shorted. If the amperage draw does not
drop to 0 amps, repair short at the IPM.
(5) Disengage a wire connector from one of the
horns. If amperage drops and the connected horn
sounds, replace the faulty horn. If amperage does not
drop with both horns disconnected and the horn
switch depressed, proceed to Step 6.
(6) Using a continuity tester, with the horns dis-
connected test continuity of the X2 cavity of the horn
relay to ground. If continuity is detected, the circuit
is grounded between the Junction Block and the
horns. Locate and repair pinched harness.
FUSE OK
(1) Remove the horn relay from the intelligent
power module.
(2) Using a continuity tester, Depress horn switch
and test continuity from the X3 cavity of the horn
relay to ground.
(a) If continuity is detected, proceed to Step 3.
(b) If NO continuity, proceed to Step 4.
(3) Using a suitable jumper wire, jump across the
fuse F62 cavity and the X2 cavity of the horn relay in
the Junction Block.
(a) If the horn sounds, replace the horn relay.
(b) If the horn does not sound, proceed to Step 4.
(4) Remove airbag trim cover from steering wheel.
Refer to ELECTRICAL, RESTRAINTS.
(5) Test continuity across horn switch connectors
with horn switch depressed.
(a) If continuity is detected, repair open circuit
between the relay and the horn switch.
(b) If NO continuity, replace airbag trim cover.
(6) Install horn relay into intelligent power mod-
ule.
(7) Disengage wire connectors from horns.(8) Using a voltmeter, with the horn switch
depressed test voltage across horn connector termi-
nals of the wire harness (Fig. 1).
(a) If voltage is detected, replace horns.
(b) If NO voltage, proceed to step Step 9.
(9) With the horn switch depressed, test for volt-
age between the X2 circuit and ground.
(a) If voltage OK, repair system ground at right
cowl area.
(b) If NO voltage, repair open X2 circuit between
the relay and the horns.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Hoist and support the front of the vehicle on
safety stands.
(3) From behind the front fascia and forward of
the left front wheel, disconnect the wire connectors
from horn.
(4) Remove the mounting bracket attaching nut
from the bottom of radiator closure panel. Do not
remove the horn from mounting bracket.
(5) Separate the horn(s) from vehicle.
INSTALLATION
(1) Install the horns to the vehicle.
(2) Install the mounting bracket fastener.
(3) Reconnect the wire connectors to the horns.
(4) Lower the vehicle.
(5) Reconnect the battery negative cable.
HORN SWITCH
DESCRIPTION
The horn switch is molded into the airbag trim
cover. The horn switch can not be serviced separately.
For service procedures (Refer to 8 - ELECTRICAL/
RESTRAINTS/AIRBAG COVER - REMOVAL).
Fig. 1 Horn Connector
8H - 4 HORNRS
HORN (Continued)