
For information on master cylinder application,
bore and type, view the following table:
BRAKE SYSTEMMASTER CYLINDER
BORE/TYPE
Disc/Drum - ABS23.8 mm Conventional
Compensating Port
Disc/Drum - Non-ABS23.8 mm Conventional
Compensating Port
Disc/Disc - ABS25.4 mm (1-1/16 in.)
Conventional
Compensating Port
Disc/Disc ABS With
Traction Control25.4 mm (1-1/16 in.) Dual
Center Port
CAUTION: When replacing a master cylinder, be
sure to use the correct master cylinder for the type
of brake system the vehicle is equipped with.
The body of the master cylinder is an anodized alu-
minum casting. It has a machined bore to accept the
master cylinder pistons and threaded ports with
seats for the hydraulic brake line connections.
The brake fluid reservoir is mounted on the top of
the master cylinder. It is made of a see-through
polypropylene type plastic for easy fluid level view-
ing. A brake fluid level switch is attached to the
brake fluid reservoir.
The master cylinder is not a repairable component
and must be replaced if diagnosed to be functioning
improperly. The brake fluid reservoir and brake fluid
level switch can be replaced separately.
CAUTION: Do not hone the bore of the cylinder as
this will remove the anodized surface from the bore.
OPERATION
When the brake pedal is depressed, the master cyl-
inder primary and secondary pistons apply brake
pressure through the chassis tubes to the brakes at
each tire and wheel assembly.
The master cylinder primary outlet port supplies
hydraulic pressure to the right front and left rear
brakes. The secondary outlet port supplies hydraulic
pressure to the left front and right rear brakes.
STANDARD PROCEDURE - MASTER CYLINDER
BLEEDING
CAUTION: When clamping master cylinder in vise,
only clamp master cylinder by its mounting flange,
do not clamp on primary piston, seal or body of
master cylinder.(1) Clamp the master cylinder in a vise using only
the mounting flange.
NOTE: Two different size bleeding tubes need to be
used depending on which type of master cylinder
the vehicle is equipped with. Vehicles equipped
with traction control have different size brake tubes
and nuts at the master cylinder than the non-trac-
tion control equipped vehicles. Be sure the correct
size bleeding tubes are used when bleeding the
master cylinder.
(2) Thread Bleeding Tubes, Special Tool 8358, for a
non-traction control master cylinder or Special Tool
8129 for a traction control master cylinder into mas-
ter cylinder primary and secondary ports. Position
outlet ends of bleeding tubes in reservoir with the
outlets below surface of brake fluid when reservoir is
filled to its proper level.
(3) Fill brake fluid reservoir with Mopartbrake
fluid or equivalent conforming to DOT 3 (DOT 4 and
DOT 4+ are acceptable) specifications.
(4) Using a wooden dowel, depress push rod slowly,
and then allow pistons to return to released position.
Repeat several times until all air bubbles are
expelled from master cylinder.
(5) Remove bleeding tubes from master cylinder
outlet ports, and then plug outlet ports and install
fill cap on reservoir.
(6) Remove master cylinder from vise.
(7) Install the filler cap on master cylinder fluid
reservoir.
(8) Install master cylinder. (Refer to 5 - BRAKES -
BASE/HYDRAULIC/MECHANICAL/MASTER CYL-
INDER - INSTALLATION)
REMOVAL - MASTER CYLINDER
CAUTION: Vacuum in the power brake booster must
be pumped down (removed) before removing mas-
ter cylinder from power brake booster. This is nec-
essary to prevent the power brake booster from
sucking in any contamination as the master cylin-
der is removed. This can be done simply by pump-
ing the brake pedal, with the vehicle's engine not
running, until a firm feeling brake pedal is achieved.
(1) With engine not running, pump brake pedal
until a firm pedal is achieved (4-5 strokes).
(2) Disconnect negative battery terminal.
(3) Disconnect positive battery terminal.
(4) Remove battery shield.
(5) Remove nut and clamp securing battery to tray,
remove battery.
5 - 34 BRAKES - BASERS
MASTER CYLINDER (Continued)

BRAKE ROTOR LIMITS
Braking RotorRotor
ThicknessMinimum
Rotor
ThicknessRotor
Thickness
VariationRotor
Runout*
Front Rotor -
Disc/Drum Brakes
(TRW)27.87±28.13
mm
1.097-1.107
in.25.3 mm
0.996 in.0.009 mm
0.0004 in.0.035 mm
0.0014 in.
Front Rotor -
Disc/Disc Brakes
(Teves)27.90±28.10
mm
1.098-1.106
in.25.3 mm
0.996 in.0.008 mm
0.0003 in.0.035 mm
0.0014 in.
Rear Rotor12.25±12.75
mm
0.482 -0.502
in.11.25 mm
0.443 in.0.013 mm
0.0005 in.0.14 mm
0.0055 in.
*
TIR Total Indicator Reading (Measured On Vehicle)
REMOVAL - FRONT BRAKE ROTOR
(1) Raise vehicle on jackstands or centered on a
frame contact type hoist. See Hoisting in Lubrication
and Maintenance.
(2) Remove the front wheel and tire assembly.
(3) Remove the two mounting bolts securing the
disc brake caliper adapter with brake caliper to the
steering knuckle (Fig. 72).(4) Remove the disc brake caliper and adapter as
an assembly from the steering knuckle (Fig. 72).
Hang the assembly out of the way using wire or a
bungee cord. Use care not to overextend the brake
hose when doing this.
(5) Remove any retainer clips from the wheel
mounting studs.
(6) Remove brake rotor from hub by pulling it
straight off wheel mounting studs (Fig. 72).
INSTALLATION - FRONT BRAKE ROTOR
(1) Install the brake rotor back on the hub and
bearing (Fig. 72).
(2) Install brake caliper and adapter back over
brake rotor aligning adapter with mounting holes on
steering knuckle (Fig. 72).
(3) Install the two adapter mounting bolts securing
the adapter to the steering knuckle. Tighten the
mounting bolts to 169 N´m (125 ft. lbs.) torque.
(4) Install wheel and tire assembly on vehicle.
Tighten the wheel mounting lug nuts in proper
sequence until all nuts are torqued to half specifica-
tion, then repeat the tightening sequence to the full
specified torque of 135 N´m (100 ft. lbs.).
(5) Lower vehicle to the ground.
SUPPORT PLATE - DRUM
BRAKE
REMOVAL
(1) Using a brake pedal depressor, move and
secure brake pedal to a position past its first 1 inch
of travel. This will prevent brake fluid from draining
Fig. 72 Front Brake Mounting
1 - BRAKE ROTOR
2 - HUB AND BEARING
3 - STEERING KNUCKLE
4 - ADAPTER MOUNTING BOLTS
5 - BRAKE CALIPER
6 - ADAPTER
7 - CLIP
5 - 48 BRAKES - BASERS
ROTORS (Continued)

out of master cylinder when brake tube is remove
from wheel cylinder.
(2) Raise vehicle. (Refer to LUBRICATION &
MAINTENANCE/HOISTING - STANDARD PROCE-
DURE).
(3) Remove wheel and tire assembly.
(4) Disconnect brake tube from rear of wheel cylin-
der. Cap open ends
(5) Remove brake drum.
(6) Remove brake shoes from brake support plate.
(Refer to 5 - BRAKES/HYDRAULIC/MECHANICAL/
BRAKE PADS/SHOES - REMOVAL).
(7) Remove the 2 bolts attaching the wheel cylin-
der to the brake support plate.
(8) Remove the wheel cylinder from the brake sup-
port plate.
(9) Disconnect the park brake cable from the park
brake actuation lever.
(10) Using a suitable tool such as a 14 mm box
wrench (Fig. 73) or an aircraft type hose clamp, com-
press the flared legs on park brake cable retainer.
Then pull the park brake cable out of brake support
plate.
(11) Remove the rear hub and bearing. (Refer to 2
- SUSPENSION/REAR/HUB / BEARING -
REMOVAL)
(12) Remove the rear brake support plate from the
rear axle.
INSTALLATION
(1) Install the 4 hub and bearing to axle mounting
bolts into the mounting holes in the flange of the
rear axle.(2) Install the rear brake support plate on the 4
mounting bolts installed in the flange of the rear axle
(Fig. 74).
(3) Install the rear hub and bearing (and connect
wheel speed sensor where applicable) stopping short
of installing the brake drum. (Refer to 2 - SUSPEN-
SION/REAR/HUB / BEARING - INSTALLATION)
(4) Install the rear park brake cable into its
mounting hole in the rear brake support plate.
(5) Install the park brake cable on the park brake
actuation lever.
(6) Apply sealant such as Mopar Gasket-In-A-Tube
or equivalent around the wheel cylinder opening in
the brake support plate.
(7) Install wheel cylinder onto brake support.
Install and tighten the wheel cylinder to brake sup-
port plate attaching bolts to 8 N´m (75 in. lbs.)
torque.
(8) Install brake tube into wheel cylinder. Tighten
tube nut to a torque of 17 N´m (145 in. lbs.) torque.
(9) Install the rear brake shoes on the brake sup-
port plate. (Refer to 5 - BRAKES/HYDRAULIC/ME-
CHANICAL/BRAKE PADS/SHOES -
INSTALLATION).
(10) Install brake drum.
(11) Install wheel and tire.
(12) Tighten wheel stud nuts to 135 N´m (100 ft.
lbs.).
(13) Adjust drum brake shoes. (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/BRAKE
PADS/SHOES - ADJUSTMENTS)
(14) Remove brake pedal depressor tool.
(15) Bleed the brake system as necessary. (Refer to
5 - BRAKES - BASE - STANDARD PROCEDURE).
(16) Lower the vehicle.
Fig. 73 Removing Park Brake Cable From Brake
Support Plate
1 - PARK BRAKE CABLE
2 - CABLE RETAINER
3 - 14 mm BOX WRENCH
4 - BRAKE SUPPORT PLATE
Fig. 74 Brake Support Plate Mounted On Bearing
Attaching Bolts
1 - REAR BRAKE SUPPORT PLATE
2 - HUB/BEARING MOUNTING BOLTS
RSBRAKES - BASE5-49
SUPPORT PLATE - DRUM BRAKE (Continued)

WHEEL CYLINDERS
REMOVAL
(1) Using a brake pedal depressor, move and
secure brake pedal to a position past its first 1 inch
of travel. This will prevent brake fluid from draining
out of master cylinder when brake tube is remove
from wheel cylinder.
(2) Raise vehicle. (Refer to LUBRICATION &
MAINTENANCE/HOISTING - STANDARD PROCE-
DURE).
(3) Remove wheel and tire assembly.
(4) Disconnect brake tube from rear of wheel cylin-
der. Cap open ends
(5) Remove brake drum.
(6) Remove brake shoes from brake support plate
(Discard if contaminated).(Refer to 5 - BRAKES/HY-
DRAULIC/MECHANICAL/BRAKE PADS/SHOES -
REMOVAL)
(7) Remove the 2 bolts attaching the wheel cylin-
der to the brake support plate.
(8) Remove the wheel cylinder from the brake sup-
port plate.
INSPECTION
With brake drums removed, inspect the wheel cyl-
inder boots for evidence of a brake fluid leak. Visu-
ally check the boots for cuts, tears, or heat cracks. If
any of these conditions exist, the wheel cylinders
should be completely cleaned, inspected and new
parts installed.
If a wheel cylinder is leaking and the brake lining
material is saturated with brake fluid, the brake
shoes must be replaced.
INSTALLATION
(1) Apply sealant such as Mopar Gasket-In-A-Tube
or equivalent around the wheel cylinder opening in
the brake support plate.
(2) Install wheel cylinder onto brake support.
Install and tighten the wheel cylinder to brake sup-
port plate attaching bolts to 8 N´m (75 in. lbs.)
torque.
(3) Install brake tube into wheel cylinder. Tighten
tube nut to a torque of 17 N´m (145 in. lbs.) torque.
(4) Install the rear brake shoes on the brake sup-
port plate. (Refer to 5 - BRAKES/HYDRAULIC/ME-
CHANICAL/BRAKE PADS/SHOES -
INSTALLATION).
(5) Install brake drum.
(6) Install wheel and tire. Install and tighten
wheel lug nuts to 135 N´m (100 ft. lbs.).
(7) Adjust drum brake shoes. (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/BRAKE
PADS/SHOES - ADJUSTMENTS)
(8) Remove brake pedal depressor tool.(9) Bleed the brake system as necessary. (Refer to
5 - BRAKES - BASE - STANDARD PROCEDURE).
(10) Lower vehicle.
PARKING BRAKE
DESCRIPTION
The parking brake system is operated by a foot
operated parking brake lever. The parking brake
lever is mounted on the body of the vehicle to the left
of the brake pedal (Fig. 75). It is a automatic-adjust-
ing type lever.
The vehicle has four flexible steel parking brake
cables. They are:
²Front
²Intermediate
²Left rear
²Right rear
The front parking brake cable extends from the
parking brake lever. A steel equalizer bracket con-
nects the front parking brake cable to the left rear
and intermediate cable. The intermediate cable is
connected to the right rear cable using a parking
brake cable connector.
On vehicles equipped with rear drum brakes, the
rear service brakes also act as the vehicle's parking
brakes.
Vehicles equipped with rear disc brakes use a
small duo-servo brake assembly mounted to the each
rear disc brake caliper adapter as the parking brake.
The inside of the brake rotor (hat section of drum-in-
Fig. 75 Parking Brake Lever (Pedal)
1 - PARK BRAKE PEDAL ASSEMBLY
2 - PARK BRAKE PEDAL
3 - CARPET
4 - FRONT PARK BRAKE CABLE
5 - SEAL
6 - FLOOR PAN
5 - 50 BRAKES - BASERS

(5) Disconnect the right rear parking brake cable
from the connector on the intermediate cable (Fig.
110).
(6) To remove the right parking brake cable hous-
ing from the body bracket, slide a 14 mm box end
wrench over the end of cable retainer to compress the
retaining fingers (Fig. 111). The alternate method
using an aircraft type hose clamp will not work on
the right side of the vehicle.(7) Remove the brake shoes from the brake sup-
port plate. (Refer to 5 - BRAKES/HYDRAULIC/ME-
CHANICAL/BRAKE PADS/SHOES - REMOVAL).
(8) Disconnect parking brake cable from parking
brake actuator lever.
(9) Remove the parking brake cable housing
retainer from the brake support plate using a 14mm
wrench to compress the retaining fingers (Fig. 112).
Remove the cable.
REMOVAL - PARKING BRAKE CABLE (LEFT
REAR)
(1) Raise vehicle on jackstands or centered on a
hoist. (Refer to LUBRICATION & MAINTENANCE/
HOISTING - STANDARD PROCEDURE).
(2) Remove rear tire and wheel assembly.
(3) Remove rear brake drum from the rear wheel
of the vehicle requiring service to the rear park
brake cable.
(4) Create slack in rear park brake cables by lock-
ing out the automatic adjuster as described here.
Grasp an exposed section of front park brake cable
near the equalizer and pull down on it. Then install
a pair of locking pliers on the cable just rearward of
the second body outrigger bracket (Fig. 113).
(5) Disconnect the left rear parking brake cable
from the parking brake cable equalizer (Fig. 114).
Fig. 110 Right Rear Cable Connection To
Intermediate Cable
1 - RIGHT REAR PARKING BRAKE CABLE
2 - LOCKING NUT
3 - INTERMEDIATE PARKING BRAKE CABLE
Fig. 111 Right Park Brake Cable Removal From
Body Bracket
1 - RIGHT REAR BODY BRACKET
2 - PARK BRAKE CABLE
3 - 14MM WRENCH
4 - LEAF SPRING AND BRACKET
Fig. 112 Removing Park Brake Cable From Brake
Support Plate
1 - PARK BRAKE CABLE RETAINER
2 - PARK BRAKE CABLE
3 - 14MM BOX WRENCH
4 - BRAKE SUPPORT PLATE
RSBRAKES - BASE5-63
CABLES (Continued)

tem enters the ABS mode. During ABS braking,
hydraulic pressure in the four wheel circuits is mod-
ulated to prevent any wheel from locking. Each
wheel circuit is designed with a set of electric sole-
noids to allow modulation, although for vehicle sta-
bility, both rear wheel solenoids receive the same
electrical signal. Wheel lockup may be perceived at
the very end of an ABS stop and is considered nor-
mal.
During an ABS stop, the brakes hydraulic system
is still diagonally split. However, the brake system
pressure is further split into three control channels.
During antilock operation of the vehicle's brake sys-
tem, the front wheels are controlled independently
and are on two separate control channels, and the
rear wheels of the vehicle are controlled together.
The system can build and release pressure at each
wheel, depending on signals generated by the wheel
speed sensors (WSS) at each wheel and received at
the controller antilock brake (CAB).
NOISE AND BRAKE PEDAL FEEL
During ABS braking, some brake pedal movement
may be felt. In addition, ABS braking will create
ticking, popping, or groaning noises heard by the
driver. This is normal and is due to pressurized fluid
being transferred between the master cylinder and
the brakes. If ABS operation occurs during hard
braking, some pulsation may be felt in the vehicle
body due to fore and aft movement of the suspension
as brake pressures are modulated.
At the end of an ABS stop, ABS is turned off when
the vehicle is slowed to a speed of 3±4 mph. There
may be a slight brake pedal drop anytime that the
ABS is deactivated, such as at the end of the stop
when the vehicle speed is less than 3 mph or during
an ABS stop where ABS is no longer required. These
conditions exist when a vehicle is being stopped on a
road surface with patches of ice, loose gravel, or sand
on it. Also, stopping a vehicle on a bumpy road sur-
face activates ABS because of the wheel hop caused
by the bumps.
TIRE NOISE AND MARKS
Although the ABS system prevents complete wheel
lockup, some wheel slip is desired in order to achieve
optimum braking performance. Wheel slip is defined
as follows: 0 percent slip means the wheel is rolling
freely and 100 percent slip means the wheel is fully
locked. During brake pressure modulation, wheel slip
is allowed to reach up to 25±30 percent. This means
that the wheel rolling velocity is 25±30 percent less
than that of a free rolling wheel at a given vehicle
speed. This slip may result in some tire chirping,
depending on the road surface. This sound should not
be interpreted as total wheel lockup.Complete wheel lockup normally leaves black tire
marks on dry pavement. The ABS will not leave dark
black tire marks since the wheel never reaches a
fully locked condition. However, tire marks may be
noticeable as light patched marks.
START-UP CYCLE
When the ignition is turned on, a popping sound
and a slight brake pedal movement may be noticed.
The ABS warning lamp will also be on for up to 5
seconds after the ignition is turned on. When the
vehicle is first driven off, a humming may be heard
or felt by the driver at approximately 20±40 kph
(12±25 mph). All of these conditions are a normal
function of ABS as the system is performing a diag-
nosis check.
PREMATURE ABS CYCLING
Symptoms of premature ABS cycling include: click-
ing sounds from the solenoid valves; pump/motor
running; and pulsations in the brake pedal. Prema-
ture ABS cycling can occur at any braking rate of the
vehicle and on any type of road surface. Neither the
red BRAKE warning lamp, nor the amber ABS warn-
ing lamp, illuminate and no fault codes are stored in
the CAB.
Premature ABS cycling is a condition that needs to
be correctly assessed when diagnosing problems with
the antilock brake system. It may be necessary to use
a DRB scan tool to detect and verify premature ABS
cycling.
Check the following common causes when diagnos-
ing premature ABS cycling: damaged tone wheels;
incorrect tone wheels; damaged steering knuckle
wheel speed sensor mounting bosses; loose wheel
speed sensor mounting bolts; excessive tone wheel
runout; or an excessively large tone wheel-to-wheel
speed sensor air gap. Give special attention to these
components when diagnosing a vehicle exhibiting
premature ABS cycling.
After diagnosing the defective component, repair or
replace it as required. When the component repair or
replacement is completed, test drive the vehicle to
verify that premature ABS cycling has been cor-
rected.
OPERATION - ELECTRONIC BRAKE
DISTRIBUTION
Upon entry into EBD the inlet valve for the rear
brake circuit is switched on so that the fluid supply
from the master cylinder is shut off. In order to
decrease the rear brake pressure, the outlet valve for
the rear brake circuit is pulsed. This allows fluid to
enter the low pressure accumulator (LPA) in the
hydraulic control unit (HCU) resulting in a drop in
fluid pressure to the rear brakes. In order to increase
5 - 68 BRAKES - ABSRS
BRAKES - ABS (Continued)

²Remote Keyless Entry Module (RKE)- Refer
toRemote Keyless Entry Modulein Power Locks
for more information.
²Electronic Vehicle Information Center
(EVIC)- Refer toElectronic Vehicle Information
Centerin Overhead Console for more information.
²Heated Seat Module (HSM)- Refer toHeated
Seat Modulein Electronic Control Modules for more
information.
²Memory Heated Seat Module (MHSM)-If
the vehicle is equipped with the Memory System,
refer toMemory Seat Mirror Module (MSMM)in
Electronic Control Modules for more information.
Refer toWiring Diagramsfor complete circuit
diagrams. Following are general descriptions of the
major components in the heated seat system.
OPERATION
The heated seat system will only operate when the
ignition switch is in the On position, and the surface
temperature at the front seat heating element sen-
sors is below the designed temperature set points of
the system. The heated seat system will not operate
in ambient temperatures greater than about 41É C
(105É F). The front seat heating elements and sensors
are hard wired to the Heated Seat Module (HSM) or
the Memory Heated Seat Module (MHSM).
The heated seat switches are hard wired to the
Body Control Module (BCM). The BCM monitors the
heated seat switch inputs, then sends heated seat
switch status messages to the HSM or MHSM over
the Programmable Communications Interface J1850
(PCI) data bus. The HSM or MHSM contains the con-
trol logic for the heated seat system. The HSM or
MHSM responds to the heated seat switch status
messages, ignition switch status messages, and the
front seat heating element sensor inputs by control-
ling the output to the front seat heating elements
through integral solid-state relays.
When a seat heater is turned on, the sensor
located on the seat cushion electric heater element
provides the HSM or MHSM with an input indicating
the surface temperature of the seat cushion. If the
surface temperature input is below the temperature
set point for the selected Low or High heated seat
switch position, the HSM or MHSM energizes the
integral solid-state relay, which supplies battery cur-
rent to the heating elements in the seat cushion and
back. When the sensor input indicates the correct
temperature set point has been achieved, the HSM or
MHSM de-energizes the solid-state relay. The HSM
or MHSM will continue to cycle the solid-state relay
as needed to maintain the temperature set point.
The HSM or MHSM and the seat heater elements
operate on non-switched battery current supplied
through the power seat fuse in the intelligent powermodule. However, the HSM or MHSM will automati-
cally turn off the heating elements if it detects an
open in the sensor circuit, a short in the heating ele-
ment circuit causing an excessive current draw, or
when the ignition switch is turned to the Off posi-
tion.
See the owner's manual in the vehicle glove box for
more information on the features, use and operation
of the heated seat system.
DRIVER HEATED SEAT
SWITCH
DESCRIPTION
The heated seat switches are mounted in the
instrument panel center bezel (Fig. 2). The two three-
position rocker-type switches, one switch for each
front seat, are incorporated into one large switch
assembly that also includes the hazzard, rear window
wiper and washer switches. The heated seat switches
provide a resistor multiplexed signal to the Body
Control Module (BCM) through separate hard wired
circuits. Each switch has an Off, Low, and High posi-
tion so that both the driver and the front seat pas-
senger can select a preferred seat heating mode.
Each switch has two Light-Emitting Diodes (LED)
which light to indicate that the heater for the seat is
turned on.
The heated seat switches and their LEDs cannot
be repaired. If either switch or LED is faulty or dam-
aged, the entire switch assembly must be replaced.
Fig. 2 HEATED SEAT SWITCHES
8G - 8 HEATED SEAT SYSTEMRS
HEATED SEAT SYSTEM (Continued)

OPERATION
The heated seat elements resist the flow of electri-
cal current. When battery current is passed through
the elements, the energy lost by the resistance of the
elements to the current flow is released in the form
of heat. The temperature sensor is a NTC thermistor.
When the temperature of the seat cushion cover
rises, the resistance of the sensor decreases. The
HSM or MHSM supplies a five-volt current to one
side of each sensor, and monitors the voltage drop
through the sensor on a return circuit. The MSM or
MHSM uses this temperature sensor input to moni-
tor the temperature of the seat, and regulates the
current flow to the seat heating elements accordingly.
DIAGNOSIS & TESTING - HEATED SEAT
ELEMENT
The wire harness connectors for the seat cushion
and seat back heating elements are located under the
seat, near the rear edge of the seat cushion frame.
For circuit descriptions and diagrams, refer to Group
8W, Wiring Diagrams.
SEAT CUSHION
(1) Disconnect and isolate the battery negative
cable. Unplug the 4-way heated seat cushion wire
harness connector.
(2) Check for continuity between the two heated
seat driver circuit cavities of the seat cushion cover
half of the heated seat cushion wire harness connec-
tor. There should be continuity. If OK, go to Step 3. If
not OK, replace the faulty seat cushion cover.
(3) Check for continuity between one of the heated
seat driver circuit cavities of the seat cushion cover
half of the heated seat cushion wire harness connec-
tor and the seat cushion frame. There should be no
continuity. If OK, go to the Seat Back test. If not OK,
replace the faulty seat cushion cover.
SEAT BACK
(1) Disconnect and isolate the battery negative
cable. Unplug the 2-way heated seat back wire har-
ness connector.
(2) Check for continuity between the heated seat
driver circuit cavity and the ground circuit cavity of
the seat back cover half of the heated seat back wire
harness connector. There should be continuity. If OK,
go to Step 3. If not OK, replace the faulty seat back
cover.
(3) Check for continuity between the heated seat
driver circuit cavity of the seat back cover half of the
heated seat back wire harness connector and the seat
back frame. There should be no continuity. If OK,
test the heated seat sensor as described in this
group. If not OK, replace the faulty seat back cover.
HEATED SEAT SENSOR
DESCRIPTION
The heated seat temperature sensor is a Negative
Temperature Coefficient (NTC) thermistor. One tem-
perature sensor is used for each seat, and is inte-
grated into the seat cushion heating element.
DIAGNOSIS & TESTING - HEATED SEAT
SENSOR
For complete circuit diagrams, refer toWiring
Diagrams.
(1) Disconnect and isolate the battery negative
cable. Disconnect the 4-way heated seat cushion ele-
ment wire harness connector from the power seat
wire harness. The power seat wire harness connec-
tors for the seat cushion and seat back heating ele-
ments are secured to a bracket located under the
rear edge of the seat cushion frame.
(2) Using an ohmmeter, check the resistance
between the seat sensor circuit and the seat temper-
ature sensor input circuit cavities of the 4-way
heated seat cushion element wire harness connector.
The sensor resistance should be between 2 kilohms
at 15É C (60É F) and 200 kilohms at 30É C (85É F). If
not OK, replace the faulty seat cushion cover trim
and sensor unit.
PASSENGER HEATED SEAT
SWITCH
DESCRIPTION
The heated seat switches are mounted in the
instrument panel center bezel (Fig. 5). The two three-
position rocker-type switches, one switch for each
front seat, are incorporated into one large switch
assembly that also includes the hazzard, rear window
wiper and washer switches. The heated seat switches
provide a resistor multiplexed signal to the Body
Control Module (BCM) through separate hard wired
circuits. Each switch has an Off, Low, and High posi-
tion so that both the driver and the front seat pas-
senger can select a preferred seat heating mode.
Each switch has two Light-Emitting Diodes (LED)
which light to indicate that the heater for the seat is
turned on.
The heated seat switches and their LEDs cannot
be repaired. If either switch or LED is faulty or dam-
aged, the entire switch assembly must be replaced.
OPERATION
There are three positions that can be selected with
each of the heated seat switches: Off, Low, or High.
When the left side of the switch rocker is fully
RSHEATED SEAT SYSTEM8G-11
HEATED SEAT ELEMENT (Continued)