²Heated Seat Switch- Two heated seat
switches are used per vehicle, one for the driver and
one for the passenger side front seats. The switches
are mounted to in the instrument panel center stack.
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-acc) circuit so that the system willonly operate when the ignition switch is in the On or
Accessory positions. The heated seat system will be
turned Off automatically whenever the ignition
switch is turned to any position except On or Acces-
sory. Also, the heated seat system 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 system. The
heated seat system has a self-diagnostic capability.
When certain failures are detected within the heated
seat system, the system will provide a visual indica-
tion of the failure by flashing the Light Emitting
Diode (LED) indicator lamps located in the heated
seat switches. See the owner's manual in the vehicle
glove box for more information on the features, use
and operation of the heated seat system.
DIAGNOSIS AND TESTING - HEATED SEAT
SYSTEM
Refer toWiring Diagramsfor complete 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.
HEATED SEAT SYSTEM DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
NO HEATED SEAT SWITCH
ILLUMINATION WITH
IGNITION ON (SYSTEM ON)1. Faulty fuse 1. Check heated seat fuse in Integrated Power
Module. Replace fuse, repair short if required.
2. Faulty components 2. Refer to individual Heated Seat System
components for the proper diagnosis and testing
procedures.
3. Ground faulty 3. Check for ground at heated seat switch and
module. Repair, if required.
4. Wiring faulty 4. Check fused ignition switch output (run-acc)
circuits at switch and module. Repair, if required.
8G - 8 HEATED SEAT SYSTEMRS
HEATED SEAT SYSTEM (Continued)
ProCarManuals.com
HORN
TABLE OF CONTENTS
page page
HORN SYSTEM
DESCRIPTION..........................1
OPERATION............................1
DIAGNOSIS AND TESTING - HORN SYSTEM . . . 1
HORN
DIAGNOSIS AND TESTING - HORN..........3
REMOVAL.............................4INSTALLATION..........................4
HORN RELAY
DIAGNOSIS AND TESTING - HORN RELAY....5
REMOVAL.............................5
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. 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.
RSHORN8H-1
ProCarManuals.com
CONDITION POSSIBLE CAUSE CORRECTION
(5) FAULTY HORN SWITCH. (5) REPLACE DRIVER AIRBAG
MODULE TRIM COVER.
(6) FAULTY CLOCKSPRING. (6) REPLACE CLOCKSPRING.
(7) FAULTY FRONT
CONTROL MODULE.(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) FAULTY CLOCKSPRING. (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) FAULTY CLOCKSPRING. (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.
(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.
RSHORN8H-3
HORN SYSTEM (Continued)
ProCarManuals.com
(3) Install the retaining screws.
(4) Reconnect the battery negative cable.
FOG LAMP
DIAGNOSIS AND TESTING - FOG LAMP
When a vehicle experiences problems with the fog
lamp system, verify the condition of the battery con-
nections, fuses, charging system, fog lamp bulbs, wire
connectors, relay, high beam switch, and headlamp
switch. Refer to the appropriate wiring information.
Each vehicle is equipped with various lamp assem-
blies. A good ground is necessary for proper lighting
operation. Grounding is provided by the lamp socket
when it comes in contact with the metal body, or
through a separate ground wire.
When changing lamp bulbs check the socket for
corrosion. If corrosion is present, clean it with a wire
brush.
When it is necessary to remove components to ser-
vice another, it should not be necessary to apply
excessive force or bend a component to remove it.
Before damaging a trim component, verify hidden
fasteners or captured edges are not holding the com-
ponent in place.
FOG LAMP DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
FOG LAMPS ARE DIM
WITH ENGINE IDLING
OR IGNITION TURNED
OFF.1. Loose or corroded battery
cables.1. Clean and secure battery cable clamps and
posts.
2. Loose or worn generator drive
belt.2. Adjust or replace generator drive belt.
3. Charging system output too low. 3. Test and repair charging system. Refer to
Electrical, Charging,
4. Battery has insufficient charge. 4. Test battery state-of-charge. Refer to
Electrical, Battery System.
5. Battery is sulfated or shorted. 5. Load test battery. Refer to Electrical, Battery
System.
6. Poor lighting circuit Z349/Z248
ground.6. Test for voltage drop across Z349/248
ground locations. Refer to Electrical, Wiring
Information.
FOG LAMP BULBS
BURN OUT
FREQUENTLY1. Charging system output too
high.1. Test and repair charging system. Refer to
Electrical, Charging.
2. Loose or corroded terminals or
splices in circuit.2. Inspect and repair all connectors and splices.
Refer to Electrical, Wiring Information.
Fig. 6 CHMSL BULB
1 - CHMSL UNIT
2 - CHMSL BULB
RSLAMPS/LIGHTING - EXTERIOR8L-7
CENTER HIGH MOUNTED STOP LAMP UNIT (Continued)
ProCarManuals.com
CONDITION POSSIBLE CAUSES CORRECTION
FOG LAMPS ARE DIM
WITH ENGINE
RUNNING ABOVE IDLE1. Charging system output too low. 1. Test and repair charging system. Refer to
Electrical, Charging.
2. Poor lighting circuit Z349/Z248
ground.2. Test for voltage drop across Z349/Z248
ground locations. Refer to Electrical, Wiring
Information.
3. High resistance in fog lamp
circuit.3. Test amperage draw of fog lamp circuit.
FOG LAMPS FLASH
RANDOMLY1. Poor lighting circuit Z349/Z248
ground.1. Test for voltage drop across Z349/Z248
ground locations. Refer to Electrical, Wiring
Information.
2. Variable resistance in fog lamp
circuit.2. Test amperage draw of fog lamp circuit.
3. Faulty fog lamp switch (part of
headlamp switch).3. Replace headlamp switch.
4. Loose or corroded terminals or
splices in circuit.4. Inspect and repair all connectors and splices.
Refer to Electrical, Wiring Information.
5. Is relay engaging properly? 5. Verify function of fog lamp relay in IPM.
6. PCI Bus Communication. 6. Verify PCI bus message (fog lamp info)
transmitted from BCM and received by FCM.
FOG LAMPS DO NOT
ILLUMINATE1. Blown fuse for fog lamp. 1. Replace fuse. Refer to Electrical, Wiring
Information.
2. No Z349/Z248 ground at fog
lamps.2. Repair circuit ground. Refer to Electrical,
Wiring Information.
3. Faulty fog lamp switch (part of
headlamp switch).3. Replace headlamp switch.
4. Broken connector terminal or
wire splice in fog lamp circuit.4. Repair connector terminal or wire splice.
5. Faulty or burned out bulb. 5. Replace bulb.
6. Is relay engaging? 6. Verify function of fog lamp relay in IPM.
7. PCI Bus Communication. 7. Verify PCI bus message (fog lamp info)
transmitted from BCM and received by FCM.
8L - 8 LAMPS/LIGHTING - EXTERIORRS
FOG LAMP (Continued)
ProCarManuals.com
(4) Install the headlamp unit.
(5) Connect the battery negative cable.
HEADLAMP
DIAGNOSIS AND TESTING - HEADLAMP
When a vehicle experiences problems with the
headlamp system, verify the condition of the battery
connections, fuses, charging system, headlamp bulbs,
wire connectors, relay, high beam switch, dimmer
switch, and headlamp switch. Refer to the appropri-
ate wiring information.
Each vehicle is equipped with various lamp assem-
blies. A good ground is necessary for proper lighting
operation. Grounding is provided by the lamp socket
when it comes in contact with the metal body, or
through a separate ground wire.
When changing lamp bulbs check the socket for
corrosion. If corrosion is present, clean it with a wire
brush.
When it is necessary to remove components to ser-
vice another, it should not be necessary to apply
excessive force or bend a component to remove it.
Before damaging a trim component, verify hidden
fasteners or captured edges are not holding the com-
ponent in place.
HEADLAMP DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
HEADLAMPS ARE DIM
WITH ENGINE IDLING
OR IGNITION TURNED
OFF.1. Loose or corroded battery
cables.1. Clean and secure battery cable clamps and
posts.
2. Loose or worn generator drive
belt.2. Adjust or replace generator drive belt.
3. Charging system output too low. 3. Test and repair charging system, refer to
Electrical, Charging
4. Battery has insufficient charge. 4. Test battery state-of-charge, refer to
Electrical, Battery System.
5. Battery is sulfated or shorted. 5. Load test battery, refer to Electrical, Battery
System.
6. Poor lighting circuit Z343/Z344-
ground.6. Test for voltage drop across Z343/Z344-
ground locations, refer to Electrical, Wiring
Diagram Information.
HEADLAMP BULBS
BURN OUT
FREQUENTLY.1. Integrated Power Module (IPM)
not controlling voltage.1. Test and repair Integrated Power Module.
2. Loose or corroded terminals or
splices in circuit.2. Inspect and repair all connectors and splices.
Refer to Electrical, Wiring Information.
Fig. 11 FRONT POSITION LAMP
1 - TURN SIGNAL LAMP
2 - HIGH BEAM LAMP
3 - FRONT POSITION LAMP
4 - LOW BEAM LAMP
8L - 12 LAMPS/LIGHTING - EXTERIORRS
FRONT POSITION LAMP - EXPORT (Continued)
ProCarManuals.com
The power liftgate control module communicates
on the J1850 Programmable Communication Inter-
face (PCI) Bus Circuit. Therefore, the power liftgate
control module can generate and store its own Diag-
nostic Trouble Codes (DTC). The vehicles Body Con-
trol Module (BCM) receives and supplies messages tothe power liftgate control module via the PCI bus cir-
cuit. A diagnostic scan tool, such as the DRB IIItis
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 operation
instructions 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.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)
ProCarManuals.com
LIFTGATE SYSTEM DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
Liftgate opens unexpectedly 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 latch assembly Check wiring connections and for blown
fuse
Check for trouble codes, replace latch if
necessary
Failure of open/close command
switchCheck for shorted or defective switch
Liftgate will not open from
outside of vehicle manuallyFailure of key cylinder assembly Check for broken key cylinder assembly
Check link rod connections at the latch and
key cylinder assembly
Check for binds or kinks in link rod
Check for foreign matter preventing the
operation of key cylinder assembly
Replace the necessary components
Failure of latch assembly Check wire connections and for blown fuse
Check for foreign matter preventing the
operation of latch assembly
Replace latch assembly, if necessary
Binding or sticking of components Check for foreign matter preventing the
operation of door
Establish location of binding
Replace necessary components
Liftgate will not open/close
under powerFailure 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 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
Failure of motor assembly Troubleshoot using Body Diagnostic
Manual
Failure of full open switch Troubleshoot using Body Diagnostic
Manual
RSPOWER LIFTGATE SYSTEM8N-5
POWER LIFTGATE SYSTEM (Continued)
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