fuse CHRYSLER CARAVAN 2005 User Guide

ULES/POWERTRAIN CONTROL MODULE -
DESCRIPTION) section for more DTC information.
The Charging system ªBatteryº light indicates
problems with the charging system (voltage too high/
low, generator failure, etc.). If an extreme condition is
indicated, the lamp will be illuminated. The signal to
activate the lamp is sent via the PCI bus circuits.
The lamp is located on the instrument panel. Refer
to the Instrument Cluster section for additional infor-
mation.
The PCM uses the ambient air temperature sensor
to control the charge system voltage. This tempera-
ture, along with data from monitored line voltage, is
used by the PCM to vary the battery charging rate.
The system voltage is higher at cold temperatures
and is gradually reduced as the calculated battery
temperature increases.
The ambient temperature sensor is used to control
the battery voltage based upon ambient temperature
(approximation of battery temperature). The PCM
maintains the optimal output of the generator by
monitoring battery voltage and controlling it to a
range of 13.5 - 14.7 volts based on battery tempera-
ture.
DIAGNOSIS AND TESTING
ON-BOARD DIAGNOSTIC SYSTEM
The Powertrain Control Module (PCM) monitors
critical input and output circuits of the charging sys-
tem, making sure they are operational. A Diagnostic
Trouble Code (DTC) is assigned to each input and
output circuit monitored by the OBD system. Some
circuits are checked continuously and some are
checked only under certain conditions.
If the OBD system senses that a monitored circuit
is bad, it will put a DTC into electronic memory. The
DTC will stay in electronic memory as long as the
circuit continues to be bad. The PCM is programmed
to clear the memory after 40 good trip if the problem
does not occur again.
DIAGNOSTIC TROUBLE CODES
A DTC description can be read using the DRBIIIt
scan tool. Refer to the appropriate Powertrain Diag-
nostic Procedures manual for information.
A DTC does not identify which component in a cir-
cuit is bad. Thus, a DTC should be treated as a
symptom, not as the cause for the problem. In some
cases, because of the design of the diagnostic test
procedure, a DTC can be the reason for another DTC
to be set. Therefore, it is important that the test pro-
cedures be followed in sequence, to understand what
caused a DTC to be set.ERASING DIAGNOSTIC TROUBLE CODES
The DRBIIItScan Tool must be used to erase a
DTC.
The following procedures may be used to diagnose
the charging system if:
²the check gauges lamp or battery lamp is illumi-
nated with the engine running
²the voltmeter (if equipped) does not register
properly
²an undercharged or overcharged battery condi-
tion occurs.
Remember that an undercharged battery is often
caused by:
²accessories being left on with the engine not
running
²a faulty or improperly adjusted switch that
allows a lamp to stay on. Refer to Ignition-Off Draw
Test (Refer to 8 - ELECTRICAL/BATTERY SYSTEM/
BATTERY - STANDARD PROCEDURE)
²loose generator belt.
INSPECTION
The Powertrain Control Module (PCM) monitors
critical input and output circuits of the charging sys-
tem, making sure they are operational. A Diagnostic
Trouble Code (DTC) is assigned to each input and
output circuit monitored by the On-Board Diagnostic
(OBD) system. Some charging system circuits are
checked continuously, and some are checked only
under certain conditions.
Refer to Diagnostic Trouble Codes in; Powertrain
Diagnostic manual for more DTC information. This
will include a complete list of DTC's including DTC's
for the charging system.
To perform a complete test of the charging system,
refer to the appropriate Powertrain Diagnostic Proce-
dures service manual and the DRBIIItscan tool.
Perform the following inspections before attaching
the scan tool.
(1) Inspect the battery condition. Refer to the Bat-
tery section (Refer to 8 - ELECTRICAL/BATTERY
SYSTEM - DIAGNOSIS AND TESTING) for proce-
dures.
(2) Inspect condition of battery cable terminals,
battery posts, connections at engine block, starter
solenoid and relay. They should be clean and tight.
Repair as required.
(3) Inspect all fuses in both the fuseblock and
Power Distribution Center (PDC) or IPM (if
equipped) for tightness in receptacles. They should be
properly installed and tight. Repair or replace as
required.
(4) Inspect generator mounting bolts for tightness.
Replace or tighten bolts if required. Refer to the Gen-
erator Removal/Installation section of this group for
8F - 22 CHARGINGRS
CHARGING (Continued)

RELAY CIRCUIT TEST
(1) The relay common feed terminal cavity (30) is
connected to battery voltage and should be hot at all
times. If OK, go to Step 2. If not OK, repair the open
circuit to the PDC fuse as required.
(2) The relay normally closed terminal (87A) is
connected to terminal 30 in the de-energized position,
but is not used for this application. Go to Step 3.
(3) The relay normally open terminal (87) is con-
nected to the common feed terminal (30) in the ener-
gized position. This terminal supplies battery voltage
to the starter solenoid field coils. There should be
continuity between the cavity for relay terminal 87
and the starter solenoid terminal at all times. If OK,
go to Step 4. If not OK, repair the open circuit to the
starter solenoid as required.
(4) The coil battery terminal (85) is connected to
the electromagnet in the relay. It is energized when
the ignition switch is held in the Start position and
the clutch pedal is depressed (manual trans). Check
for battery voltage at the cavity for relay terminal 86
with the ignition switch in the Start position and the
clutch pedal is depressed (manual trans), and no
voltage when the ignition switch is released to the
On position. If OK, go to Step 5. If not OK, check for
an open or short circuit to the ignition switch and
repair, if required. If the circuit to the ignition switch
is OK, see the Ignition Switch Test procedure in this
group.
(5) The coil ground terminal (86) is connected to
the electromagnet in the relay. It is grounded by the
PCM if the conditions are right to start the car. For
automatic trans. cars the PCM must see Park Neu-
tral switch low and near zero engine speed (rpm).
For manual trans. cars the PCM only needs to see
near zero engine speed (rpm) and low clutch inter-
lock input and see near zero engine speed (rpm). To
diagnose the Park Neutral switch of the trans range
sensor refer to the transaxle section. Check for conti-
nuity to ground while the ignition switch is in the
start position and if equipped the clutch pedal
depressed. If not OK and the vehicle has an auto-
matic trans. verify Park Neutral switch operation. If
that checks OK check for continuity between PCM
and the terminal 86. Repair open circuit as required.
Also check the clutch interlock switch operation if
equipped with a manual transmission. If OK, the
PCM may be defective.
SAFETY SWITCHES
For diagnostics of the Transmission Range Sensor,
refer to the Transaxle section for more information.
If equipped with Clutch Interlock/Upstop Switch,
refer to Diagnosis and Testing in the Clutch section.
IGNITION SWITCH
After testing starter solenoid and relay, test igni-
tion switch and wiring. Refer to the Ignition Section
or Wiring Diagrams for more information. Check all
wiring for opens or shorts, and all connectors for
being loose or corroded.
BATTERY
For battery diagnosis and testing, refer to the Bat-
tery section for procedures.
ALL RELATED WIRING AND CONNECTORS
Refer to Wiring Diagrams for more information.
DIAGNOSIS AND TESTING - FEED CIRCUIT
RESISTANCE TEST
Before proceeding with this operation, review Diag-
nostic Preparation and Starter Feed Circuit Tests.
The following operation will require a voltmeter,
accurate to 1/10 of a volt.
CAUTION: Ignition and Fuel systems must be dis-
abled to prevent engine start while performing the
following tests.
(1) To disable the Ignition and Fuel systems, dis-
connect the Automatic Shutdown Relay (ASD). The
ASD relay is located in the Power Distribution Cen-
ter (PDC). Refer to the PDC cover for proper relay
location.
(2) Gain access to battery terminals.
(3) With all wiring harnesses and components
properly connected, perform the following:
(a) Connect the negative lead of the voltmeter to
the battery negative post, and positive lead to the
battery negative cable clamp. Rotate and hold the
ignition switch in the START position. Observe the
voltmeter. If voltage is detected, correct poor con-
tact between cable clamp and post.
(b) Connect positive lead of the voltmeter to the
battery positive post, and negative lead to the bat-
tery positive cable clamp. Rotate and hold the igni-
tion switch key in the START position. Observe the
voltmeter. If voltage is detected, correct poor con-
tact between the cable clamp and post.
(c) Connect negative lead of voltmeter to battery
negative terminal, and positive lead to engine
block near the battery cable attaching point.
Rotate and hold the ignition switch in the START
position. If voltage reads above 0.2 volt, correct
poor contact at ground cable attaching point. If
voltage reading is still above 0.2 volt after correct-
ing poor contacts, replace ground cable.
(4) Connect positive voltmeter lead to the starter
motor housing and the negative lead to the battery
negative terminal. Hold the ignition switch key in
RSSTARTING8F-35
STARTING (Continued)

HEATED SYSTEMS
TABLE OF CONTENTS
page page
HEATED GLASS........................... 1
HEATED MIRRORS......................... 6HEATED SEAT SYSTEM..................... 7
HEATED GLASS
TABLE OF CONTENTS
page page
HEATED GLASS
DESCRIPTION..........................1
OPERATION............................2
DIAGNOSIS AND TESTING
ELECTRIC BACKLIGHT (EBL) SYSTEM.....2
REAR WINDOW DEFOGGER RELAY
DESCRIPTION..........................3
OPERATION............................3REMOVAL.............................4
INSTALLATION..........................4
REAR WINDOW DEFOGGER SWITCH
DESCRIPTION..........................4
OPERATION............................4
REAR WINDOW DEFOGGER GRID
STANDARD PROCEDURE
GRID REPAIR PROCEDURE..............5
HEATED GLASS
DESCRIPTION
CAUTION: Grid lines can be damaged or scraped
off with sharp instruments. Care should be taken in
cleaning glass or removing foreign materials,
decals or stickers. Normal glass cleaning solvents
or hot water used with rags or toweling is recom-
mended.
The rear window defogger system, also known as
electrical backlight (EBL), consists of two vertical bus
bars linked by a series of grid lines fired onto the
inside surface of the rear window (Fig. 1).
The EBL system is turned ON or OFF by a control
switch located on the A/C-heater control at the center
of the instrument panel and by a rear window defog-
ger relay timing circuit integral to the integrated
power module (IPM) (Refer to 8 - ELECTRICAL/
HEATED GLASS/REAR WINDOW DEFOGGER
SWITCH - DESCRIPTION).
Circuit protection is provided by a 40 amp fuse
located in the IPM.
Fig. 1 Rear Window Defogger - Typical
1 - REAR DEFOGGER GRID
2 - REAR WINDOW
RSHEATED SYSTEMS8G-1

OPERATION
When the rear window defogger button is
depressed to the On position, current is directed to
the rear defogger grid lines and the heated power
mirrors (if equipped). The heated grid lines heat the
glass to help clear the rear window and side mirror
surfaces of fog or frost.
The electric backlight (EBL) system is controlled
by a momentary switch located in the A/C-heater
control on the instrument panel. A yellow indicator in
the switch will illuminate to indicate when the sys-
tem is turned on. The integrated power module (IPM)
contains the EBL system control circuitry.
NOTE: The rear window defogger turns off automat-
ically after approximately 10 minutes of initial oper-
ation. Each following activation cycle of the
defogger system will last approximately five min-
utes.
The EBL system will be automatically turned off
after a programmed time interval of about ten min-
utes. After the initial time interval has expired, if the
defogger switch is turned on again during the same
ignition cycle, the defogger system will automatically
turn off after about five minutes.
The EBL system will automatically shut off if the
ignition switch is turned to the Off position, or it can
be turned off manually by depressing the defogger
switch a second time.
DIAGNOSIS AND TESTING
ELECTRIC BACKLIGHT (EBL) SYSTEM
NOTE: Illumination of the defogger switch indicator
lamp means that there is electrical current available
at the output of the rear window defogger logic cir-
cuitry, but does not confirm that the electrical cur-
rent is reaching the rear glass heating grid lines.
NOTE: For circuit descriptions and diagrams of the
rear window defogger system, refer to 8W - WIRING
DIAGRAM INFORMATION.
Operation of the electrical backlight (EBL) system
can be confirmed by the following:(1) Turn the ignition switch to the On position. Set
the defogger switch in the On position. The rear win-
dow defogger operation can be checked by feeling the
rear window glass. A distinct difference in tempera-
ture between the grid lines and the adjacent clear
glass can be detected within three to four minutes of
operation.
(2) If a temperature difference is not detected, use
a 12-volt DC voltmeter and contact the rear glass
heating grid terminal B with the negative lead, and
terminal A with the positive lead (Fig. 2). The volt-
meter should read battery voltage. If the voltmeter
does not read battery voltage, check the following:
²Confirm that the ignition switch is in the On
position.
²Make sure that the rear glass heating grid feed
wire and ground wire are connected to the terminals.
Confirm that the ground wire has continuity to
ground.
²Check that fuse 13 (40 amp) in the integrated
power module (IPM) is OK. The fuse must be tight in
it's receptacle and all electrical connections must be
secure.
(3) When the above steps have been completed and
the rear glass heating grid is still inoperative, one or
more of the following is faulty. It may be necessary to
connect a DRBIIItscan tool to perform further diag-
nostics. Refer to Body Diagnostic Procedures.
²Rear window defogger switch in the A/C-heater
control.
²J1850 bus communication between the A/C-
heater control and the front control module (FCM).
²Rear window defogger (EBL) relay in the IPM.
²Rear window defogger (EBL) relay control circu-
ity in the IPM.
²Check for a loose wire connector or a wire
pushed out of a connector.
²Rear window grid lines (all grid lines would
have to be broken, or the power feed or ground wire
not connected, for the entire heating grid to be inop-
erative).
(4) If the system operation has been verified but
defogger switch LED indicator does not illuminate,
replace the A/C-heater control.
8G - 2 HEATED GLASSRS
HEATED GLASS (Continued)

(5) If broken defogger grid lines are suspected, use
a 12-volt DC voltmeter and contact terminal B with
the negative lead and each rear glass heating grid
line at it's mid-point with the positive lead. The volt-
meter should read approximately 6 volts at each grid
line mid-point C. If the voltmeter does not read
approximately 6 volts, repair the open grid line(s)
(Refer to 8 - ELECTRICAL/HEATED GLASS/REAR
WINDOW DEFOGGER GRID - STANDARD PROCE-
DURE).
REAR WINDOW DEFOGGER
RELAY
DESCRIPTION
The rear window defogger (EBL) relay (Fig. 3) is a
International Standards Organization (ISO)-type
relay. Relays conforming to the ISO specifications
have common physical dimensions, current capaci-
ties, terminal patterns, and terminal functions. The
rear window defogger relay is a electromechanical
device that switches battery current through a fuse
in the integrated power module (IPM) to the rear
window defogger grid and switches battery current
through a positive thermal coefficient (PTC) in the
IPM to the outside mirror heating grids. The relay isenergized when the relay coil is provided a ground
path by the rear window defogger relay control in the
front control module (FCM).
The rear window defogger (EBL) relay is located in
the IPM in the engine compartment. See the fuse
and relay layout map on the inner surface of the
cover of the IPM for rear window defogger relay iden-
tification and location.
The rear window defogger (EBL) relay cannot be
adjusted or repaired and, if damaged or faulty, it
must be replaced.
OPERATION
The ISO-standard rear window defogger (EBL)
relay consists of an electromagnetic coil, a resistor or
diode, and three (two fixed and one movable) electri-
cal contacts. The movable (common feed) relay con-
tact is held against one of the fixed contacts
(normally closed) by spring pressure. When the elec-
tromagnetic coil is energized, it draws the movable
contact away from the normally closed fixed contact,
and holds it against the other (normally open) fixed
contact.
When the electromagnetic coil is de-energized,
spring pressure returns the movable contact to the
normally closed position. The resistor is connected in
parallel with the electromagnetic coil in the relay,
and helps to dissipate voltage spikes that are pro-
duced when the coil is de-energized.
Refer to the appropriate wiring information for
diagnosis and testing of the EBL relay and for com-
plete EBL system wiring diagrams.
Fig. 2 Grid Line Test
1 - VOLTMETER
2 - VOLTAGE FEED (A)
3 - FEED WIRE
4 - MID-POINT (C)
5 - HEATED WINDOW GRID
6 - GROUND WIRE
7 - GROUND (B)Fig. 3 Rear Window Defogger (EBL) Relay
RSHEATED GLASS8G-3
HEATED GLASS (Continued)

REMOVAL
(1) Disconnect and isolate the negative battery
cable.
(2) Remove the cover from the integrated power
module (IPM) (Fig. 4).
NOTE: Refer to the fuse and relay layout map on
the inner surface of the cover of the IPM for rear
window defogger (EBL) relay identification and
location.
(3) Remove the EBL relay from the IPM.
INSTALLATION
NOTE: Refer to the fuse and relay map on the inner
surface of the cover of the integrated power module
(IPM) for rear window defogger (EBL) relay identifi-
cation and location.
(1) Position the EBL relay into the proper recepta-
cle in the IPM.
(2) Align the EBL relay terminals with the termi-
nal cavities in the IPM receptacle.
(3) Push down firmly on the EBL relay until the
terminals are fully seated in the terminal cavities.
(4) Install the cover onto the IPM.
(5) Reconnect the negative battery cable.
REAR WINDOW DEFOGGER
SWITCH
DESCRIPTION
The switch for the EBL system is integrated into
the A/C-heater control located in the center of the
instrument panel (Fig. 5).
When the rear window defogger switch is turned to
the ON position, current is directed to the rear defog-
ger grid lines and the heated power mirrors (if
equipped). The heated grid lines heat the glass to
help clear the surface of fog or frost.
OPERATION
Depressing the rear window defogger switch ener-
gizes the A/C-heater control module which then
requests the front control module (FCM) to activate
the rear window defogger (EBL) relay via the com-
munication bus. The EBL relay controls the current
to flow to the grids of the rear window defogger and
the heated power side view mirrors. The EBL relay
will be on for approximately 10 minutes or until the
control switch or ignition is turned off. An amber
indicator lamp in the defogger switch illuminates to
indicate when the EBL system is On.
The rear window defogger switch and indicator
lamp cannot be repaired and, if faulty or damaged,
the entire A/C-heater control must be replaced.
Fig. 4 Rear Window Defogger (EBL) Relay
1 - INTEGRATED POWER MODULE (IPM)
2 - REAR WINDOW DEFOGGER (EBL) RELAY
3 - FRONT CONTROL MODULE (FCM)
Fig. 5 A/C-Heater Control - Typical
1 - TRIM BEZEL
2 - INFRARED TEMPERATURE SENSOR
3 - A/C REQUEST SWITCH
4 - EBL/HEATED MIRROR SWITCH
5 - FRONT WINDOW DEFROSTER SELECTOR
8G - 4 HEATED GLASSRS
REAR WINDOW DEFOGGER RELAY (Continued)

Hard wired circuitry connects the heated seat sys-
tem components to each other through the electrical
system of the vehicle. These circuits may be con-
nected 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 connectors. Refer to the appropriate wir-
ing information for complete circuit schematic or con-
nector pin-out information.
OPERATION
The heated seat system components operate on
battery current received through a fuse in the Inte-
grated Power Module (IPM) on a fused ignition
switch output (run) circuit from the Body Control
Module (BCM). The system will only operate when
the ignition switch is in the On position. The heated
seat system will be turned Off automatically when-
ever the ignition switch is turned to any position
except On. Also, the heated seat system will not oper-
ate when the surface temperature of the seat cushion
cover at either heated seat sensor is above the
designed temperature set points of the system.
DIAGNOSIS AND TESTING
HEATED SEAT SYSTEM
The most efficient means of diagnosing the heated
seat system is by individual component. For diagno-
sis of a specific component refer to the following:
²Heated seat module, (Refer to 8 - ELECTRICAL/
ELECTRONIC CONTROL MODULES/MEMORY
HEATED SEAT/MIRROR MODULE - DIAGNOSIS
AND TESTING).
²Heated seat elements, (Refer to 8 - ELECTRI-
CAL/HEATED SEATS/HEATED SEAT ELEMENT -
DIAGNOSIS AND TESTING).
²Heated seat switch, (Refer to 8 - ELECTRICAL/
HEATED SEATS/DRIVER HEATED SEAT SWITCH
- DIAGNOSIS AND TESTING).
²Heated seat sensor, (Refer to 8 - ELECTRICAL/
HEATED SEATS/HEATED SEAT SENSOR - DIAG-
NOSIS AND TESTING).
Refer to the appropriate wiring information for
complete circuit schematic or connector pin-out infor-
mation.
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. Each heated seat switch
provides a resistor multiplexed signal to its respec-
tive Heated Seat Module (HSM) through separate
hard wired circuits. Each switch has an Off, Low,
and High position so that both the driver and the
front seat passenger can select a preferred seat heat-
ing 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.
Fig. 2 HEATED SEAT SWITCH LOCATION
1 - HEATED SEAT SWITCHES
8G - 8 HEATED SEAT SYSTEMRS
HEATED SEAT SYSTEM (Continued)

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)

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)