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 -
REMOVAL). 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)
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 -
REMOVAL). 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%.
(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.
Fig. 7 Instrument Panel Switch Bank Connector
RSHEATED SEAT SYSTEM8G-13
PASSENGER HEATED SEAT SWITCH (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..........................5
HORN SWITCH
DESCRIPTION..........................5
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 (Refer to 8 -
ELECTRICAL/HORN/HORN RELAY - DIAGNOSIS
AND TESTING).
If the relay is OK, test horn. Refer to Horn System
Test.
CAUTION: Continuous sounding of horn may
cause horn failure.
Should the horn sound continuously:
²Unplug the horn relay from IPM.
²Refer to (Refer to 8 - ELECTRICAL/HORN/
HORN RELAY - DIAGNOSIS AND TESTING).
Refer to the appropriate wiring information.
RSHORN8H-1
CONDITION POSSIBLE CAUSE CORRECTION
(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.
(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 infor-
mation 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 con-
nectors, 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.
RSHORN8H-3
HORN SYSTEM (Continued)
also affect compass operation. If the vehicle roof
should become magnetized, the demagnetizing and
calibration procedures found in this section may be
required to restore proper compass operation.
DESCRIPTION - TEMPERATURE
All the available overhead consoles on this model
include Temperature information. The temperature
displays the outside ambient temperature in whole
degrees. The temperature display can be toggled
from Fahrenheit to Celsius by selecting the desired
U.S./Metric option from the customer programmable
features. The displayed temperature is not an instant
reading of conditions, but an average temperature. It
may take the temperature display several minutes to
respond to a major temperature change, such as driv-
ing out of a heated garage into winter temperatures.
When the ignition switch is turned to the Off posi-
tion, the last displayed temperature reading stays in
the electronic control modules (CT, CMTC, EVIC)
memory. When the ignition switch is turned to the
On position again, the electronic module will display
the memory temperature for one minute; then update
the display to the current average temperature read-
ing within five minutes.
The temperature function is supported by an ambi-
ent temperature sensor. The sensor is mounted out-
side the passenger compartment near the front and
center of the vehicle, and is hard wired to the Front
Control Module (FCM). The FCM sends temperature
status messages to the module over the J1850 PCI
data bus circuit.
Following are general descriptions of the major
components used in the overhead console. Refer to
Wiring Diagrams for complete circuit schematics.
OPERATION
Refer to the vehicle Owner's Manual for specific
operation of each overhead console and its systems.
DIAGNOSIS AND TESTING - OVERHEAD
CONSOLE
If the problem with the overhead console is an
inaccurate or scrambled display, refer toSelf-Diag-
nostic Testbelow. If the problem with the overhead
console is incorrect Vacuum Fluorescent Display
(VFD) dimming levels, use a DRB IIItscan tool and
the proper Diagnostic Procedures manual to test for
the correct dimming message inputs being received
from the Body Control Module (BCM) or Front Con-
trol Module (FCM) over the J1850 Programmable
Communications Interface (PCI) data bus circuit. If
the problem is a no-display condition, use the follow-
ing procedures. For complete circuit diagrams, refer
toOverhead Consolein the Wiring Diagrams sec-
tion of the service manual.(1) Check the fused B(+) fuse in the integrated
power module. If OK, go to Step 2. If not OK, repair
the shorted circuit or component as required and
replace the faulty fuse.
(2) Check for battery voltage at the fused B(+) fuse
in the integrated power module. If OK, go to Step 3.
If not OK, repair the open fused B(+) circuit to the
fused B(+) fuse in the integrated power module as
required.
(3) Check the fused ignition switch output (run/
start) fuse in the integrated power module. If OK, go
to Step 4. If not OK, repair the shorted circuit or
component as required and replace the faulty fuse.
(4) Turn the ignition switch to the On position.
Check for battery voltage at the fused ignition switch
output (run/start) fuse in the integrated power mod-
ule. If OK, go to Step 5. If not OK, repair the open
fused ignition switch output (run/start) circuit to the
ignition switch as required.
(5) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Remove the overhead console. Check for continuity
between the ground circuit cavity of the roof wire
harness connector for the electronics module and a
good ground. There should be continuity. If OK, go to
Step 6. If not OK, repair the open ground circuit to
ground as required.
(6) Connect the battery negative cable. Check for
battery voltage at the fused B(+) circuit cavity of the
roof wire harness connector for the electronics mod-
ule. If OK, go to Step 7. If not OK, repair the open
fused B(+) circuit to the fused B(+) fuse in the inte-
grated power module as required.
(7)
Turn the ignition switch to the On position.
Check for battery voltage at the fused ignition switch
output (run/start) circuit cavity of the roof wire har-
ness connector for the electronics module. If OK, refer
toSelf-Diagnostic Test
later this group for further
diagnosis of the electronics module and the J1850
PCI data bus circuit. If not OK, repair the open fused
ignition switch output (run/start) circuit to the fuse
in the integrated power module as required.
SELF-DIAGNOSTIC TEST
A self-diagnostic test is used to determine that the
electronics module is operating properly, and that all
the J1850 PCI data bus messages are being received
for initial operation. Initiate the self-diagnostic test
as follows:
(1) With the ignition switch in the Off position, on
Electronic Vehicle Information Center (EVIC) and
Compass Mini-Trip Computer (CMTC) equipped vehi-
cles simultaneously depress and hold theSTEP and
the RESET buttons. On Compass Temperature
Module (CT) equipped vehicles depress theC/T and
the US/M push buttons.
8M - 2 MESSAGE SYSTEMSRS
OVERHEAD CONSOLE (Continued)
used to read and troubleshoot these Diagnostic Trou-
ble Codes (DTC). Refer to the Body Diagnostic Man-
ual for a complete list of diagnostic routines.
For additional information refer to Power Liftgate
Operation. For a complete system wiring schematic
refer to Wiring Diagrams. For system operationinstructions refer to the vehicles owner manual.
Refer to the Body section of the service manual
for additional information on liftgate components
such as the prop rods, hinges, door alignment and
striker alignment.
WARNING: BE CERTAIN TO READ ALL WARNINGS
AND CAUTIONS (NOTED BELOW) IN POWER LIFT-
GATE SYSTEM OPERATION BEFORE ATTEMPTING
ANY SERVICE OF THE POWER LIFTGATE SYSTEM
OR COMPONENTS.
OPERATION
With the push of a power liftgate open/close com-
mand switch (key fob or overhead console mounted) a
signal is sent out on the J1850 PCI Data Bus circuit.
This signal is detected at the body control module
(BCM). The BCM then sends a signal out on the
J1850 PCI Data Bus circuit to the power liftgate
module. The power liftgate module then signals the
power liftgate motor to start an open or close cycle,
depending on what position the liftgate is in open or
closed.
During a liftgate open or close cycle, if the power
liftgate module detects sufficient resistance to liftgate
travel, such as an obstruction in the liftgates path,
the power liftgate control module will immediately
stop the liftgate movement and reverse travel to the
full open or closed position. The ability for the power
liftgate module to detect resistance to liftgate travel
is accomplished by hall effect sensors, drive motor
speed and pinch sensors (tape switches).
The power liftgate control module has the ability to
learn. Anytime the liftgate is opened or closed using
the power liftgate system the module learns from its
cycle. If a replacement power liftgate component is
installed or a liftgate adjustment is made, the mod-
ule will relearn the effort and/or time required to
open or close the door. This learn cycle can be per-
formed with a Diagnostic Scan Tool, such as the
DRB IIItor with a complete cycle of the liftgate,
using any one of the command switches. Refer to
Standard Procedures in this section for detailed
instructions.
The power liftgate system is designed with a num-
ber of system inhibitors. These inhibitors are neces-
sary for safety and / or feasibility of the power
liftgate system. Refer to power liftgate system inhib-
itors noted below:
POWER LIFTGATE SYSTEM INHIBITORS
²The Power Liftgate may not operate in extreme
temperatures. These extreme temperatures will be
approximately -12É F (-24.4É C) on the low side and
143É F (61.6É C) for the high side. A chime/thermister
Fig. 2 KEY FOB
1 - Left Sliding Door Switch
2 - Right Sliding Door Switch
3 - Liftgate Switch
Fig. 3 LIFTGATE FUSE LOCATION
RSPOWER LIFTGATE SYSTEM8N-3
POWER LIFTGATE SYSTEM (Continued)
CONDITION POSSIBLE CAUSES CORRECTION
Binding or sticking of components Establish location of binding and replace
necessary components
Wiring problems (system or vehicle) Troubleshoot using electrical schematics.
Refer to wiring diagrams
Power loss during Liftgate
operationWiring problems (system or vehicle) Troubleshoot using electrical schematics.
Refer to wiring diagrams
Low battery voltage Charge battery
Failure of Power Liftgate or Body
Control ModuleDisconnect then reconnect battery to reset
module, function liftgate, if no function
exists check for loose wire connections,
see Body Diagnostic Manual for detailed
procedures
Failure of motor assembly Check for no drive condition
No power latching in
primary and/or secondary
positionsFailure of latch assembly Check wire connections and for blown fuse
Check for foreign matter preventing the
operation of latch assembly
Troubleshoot using Body Diagnostic
Manual. Replace latch assembly, if
necessary
Binding or sticking of components Establish location of binding and replace
necessary components
Failure of Power Liftgate or Body
Control ModuleDisconnect then reconnect battery to reset
module, function liftgate, if no function
exists check for loose wire connections,
see Body Diagnostic Manual for detailed
procedures
Door seal force too high Inspect seals for damage, mis-assembly,
foreign matter or other possible obstruction
Failure of motor assembly Check for no drive condition
Latch will not fully release
from primary positionFailure of latch assembly Check wire connections and for blown fuse
Check for foreign matter or damaged
components preventing the operation of
latch assembly
Troubleshoot using body electrical
troubleshooting manual Replace latch
assembly, if necessary
Failure of outside handle switch Troubleshoot using Body Diagnostic
Manual Replace switch, if necessary
Failure of Power Liftgate or Body
Control ModuleDisconnect then reconnect battery to reset
module, function liftgate, if no function
exists check for loose wire connections,
see Body Diagnostic Manual for detailed
procedures
Binding or sticking of components Establish location of binding and replace
necessary components
8N - 6 POWER LIFTGATE SYSTEMRS
POWER LIFTGATE SYSTEM (Continued)
CONDITION POSSIBLE CAUSES CORRECTION
Key fob, Outside Handle or
overhead console switches
do not power operate
liftgateBlown Fuse Check fuse and replace
Battery voltage low Charge or replace battery in key fob or
vehicle
Failure of latch assembly Check for foreign matter preventing the
operation of latch assembly
Check wire connection
Pawl and/or ratchet switch inoperative
Replace latch if necessary
Wiring problems (system or vehicle) Troubleshoot using electrical schematics.
Refer to wiring diagrams
Failure of Body Control Module
(BCM)Check electrical connections
Refer to the Body electrical troubleshooting
guide for additional checks
Replace BCM if necessary
Failure of key fob Reprogram key fob
Replace key fob if necessary
Failure of Power Liftgate Module Disconnect then reconnect battery to reset
module, function liftgate, if no function
exists check for loose wire connections,
see Body Diagnostic Manual for detailed
procedures
Failure of liftgate motor assembly Check for foreign matter preventing the
operation of gear motor assembly
Check wire connections
Motor clutch does not engage, replace
assembly
Full open switch inoperative, replace
switch, if necessary
Troubleshoot using Body Diagnostic
Manual Replace motor, if necessary
Liftgate does not stay open Failure of liftgate prop rods Replace prop rods, if necessary
Check for broken attachments
High inside/outside opening
effortFailure of liftgate prop rods Replace prop rods, if necessary
Check for broken attachments
Gear motor did not disengage Troubleshoot using Body Diagnostic
Manual Replace components, if necessary
Binding or sticking of components Establish location of binding and replace
necessary components
RSPOWER LIFTGATE SYSTEM8N-7
POWER LIFTGATE SYSTEM (Continued)