2003 DODGE RAM Sensors

Condition Possible Causes Correction
Gear Teeth Broke 1. Overloading. 1. Replace gears. Examine other
gears and bearings for possible
damage.
2. Erratic clutch operation. 2. Replace gears and examine the
remaining parts for damage. Avoid
erratic clutch operation.
3. Ice-spotted pavement. 3. Replace gears and examine
remaining parts for damage.
4. Improper adjustments. 4. Replace gears and examine
remaining parts for damage. Ensure
ring gear backlash is correct.
Axle Noise 1. Insufficient lubricant. 1. Fill differential with the correct
fluid type and quantity.
2. Improper ring gear and pinion
adjustment.2. Check ring gear and pinion
contact pattern.
3. Unmatched ring gear and pinion. 3. Replace gears with a matched
ring gear and pinion.
4. Worn teeth on ring gear and/or
pinion.4. Replace ring gear and pinion.
5. Loose pinion bearings. 5. Adjust pinion bearing pre-load.
6. Loose differential bearings. 6. Adjust differential bearing
pre-load.
7. Mis-aligned or sprung ring gear. 7. Measure ring gear run-out.
Replace components as necessary.
8. Loose differential bearing cap
bolts.8. Inspect differential components
and replace as necessary. Ensure
that the bearing caps are torqued
tot he proper specification.
9. Housing not machined properly. 9. Replace housing.
REMOVAL
(1) Remove wheels and tires.
(2) Remove brake calipers and rotors.
(3) Disconnect ABS wheel speed sensors.
(4) Disconnect axle vent hose.
(5) Remove front propeller shaft.
(6) Disconnect stabilizer bar links at the axle
brackets.
(7) Disconnect shock absorbers from axle brackets.
(8) Disconnect track bar from the axle bracket.
(9) Disconnect tie rod and drag link from the steer-
ing knuckles.
(10) Position suitable lifting device under the axle
assembly.
(11) Secure axle to lifting device.
(12) Mark suspension alignment cams for installa-
tion reference.
(13) Disconnect upper and lower suspension arms
from the axle bracket.(14) Lower the axle. The coil springs will drop
with the axle.
(15) Remove the coil springs from the axle bracket.
INSTALLATION
CAUTION: Suspension components with rubber
bushings should be tightened with the weight of the
vehicle on the suspension, at normal height. If
springs are not at their normal ride position, vehicle
ride comfort could be affected and premature bush-
ing wear may occur. Rubber bushings must never
be lubricated.
(1) Support the axle on a suitable lifting device.
(2) Secure axle to lifting device.
(3) Position the axle under the vehicle.
(4) Install springs, retainer clip and bolts.
(5) Raise axle and align it with the spring pads.
3 - 48 FRONT AXLE - 9 1/4 AADR
FRONT AXLE - 9 1/4 AA (Continued)

(6) Position upper and lower suspension arms in
the axle brackets. Install bolts, nuts and align the
suspension alignment cams to the reference marks.
Do not tighten at this time.
(7) Connect track bar to the axle bracket and
install the bolt. Do not tighten at this time.
(8) Install shock absorber and tighten bolts to 121
N´m (89 ft. lbs.).
(9) Install stabilizer bar link to the axle bracket.
Tighten the nut to 68 N´m (50 ft. lbs.).
(10) Install drag link and tie rod to the steering
knuckles and tighten the nuts to 108 N´m (80 ft.
lbs.).
(11) Install ABS wheel speed sensors.
(12) Install rotors and brake calipers.
(13) Connect the axle vent hose.
(14) Install front propeller shaft.
(15) Check and add differential lubricant, if neces-
sary.
(16) Install wheel and tire assemblies.
(17) Remove lower the vehicle.
(18) Tighten upper suspension arm nuts at axle to
149 N´m (110 ft. lbs.). Tighten upper suspension arm
nuts at frame to 149 N´m (110 ft. lbs.).
(19) Tighten lower suspension arm nuts at axle to
190 N´m (140 ft. lbs.). Tighten the lower suspension
arm nuts at frame to 190 N´m (140 ft. lbs.).
(20) Tighten track bar bolt at the axle bracket to
176 N´m (130 ft. lbs.).
(21) Check front wheel alignment.
ADJUSTMENTS
Ring and pinion gears are supplied as matched
sets only. Compensation for pinion depth variance is
achieved with a select shim. The shim is located
between the rear pinion bearing and the pinion gear
head.
PINION DEPTH MEASUREMENT AND ADJUSTMENT
Measurements are taken with pinion bearing cups
and pinion bearings installed in the housing. Take
measurements with Pinion Gauge Set and Dial Indi-
cator C-3339 (Fig. 1).
(1) Assemble Pinion Height Block 6739, Pinion
Block 8878 and rear pinion bearing onto Screw 6741
(Fig. 1).
(2) Insert assembled height gauge components,
rear bearing and screw into the housing through pin-
ion bearing cups (Fig. 2).
(3) Install front pinion bearing and install the
Cone-nut 6740 hand tight. Then check tool rotating
torque with an inch pound torque wrench. The rotat-
ing torque should be 1.7-2.26 N´m (15-20 in. lbs.)
(4) Place Arbor Disc 8289 on Arbor D-115-3 in posi-
tion in the housing side bearing cradles (Fig. 3).(5) Install differential bearing caps on arbor discs
and snug the bearing cap bolts. Then cross tighten
cap bolts to 85 N´m (63 ft. lbs.).
Fig. 1 PINION GEAR DEPTH GAUGE TOOLS
1 - DIAL INDICATOR
2 - ARBOR
3 - PINION HEIGHT BLOCK
4 - CONE
5 - SCREW
6 - PINION BLOCK
7 - SCOOTER BLOCK
8 - ARBOR DISC
Fig. 2 PINION HEIGHT BLOCK
1. PINION HEIGHT BLOCK
2. PINION BLOCK
DRFRONT AXLE - 9 1/4 AA 3 - 49
FRONT AXLE - 9 1/4 AA (Continued)

BRAKES - ABS
TABLE OF CONTENTS
page page
BRAKES - ABS
DESCRIPTION.........................39
OPERATION...........................39
STANDARD PROCEDURE - ABS BRAKE
BLEEDING...........................40
SPECIFICATIONS
TORQUE CHART......................40
FRONT WHEEL SPEED SENSOR
DESCRIPTION.........................41
OPERATION...........................41
REMOVAL.............................41
INSTALLATION.........................42
REAR WHEEL SPEED SENSOR
DIAGNOSIS AND TESTING - REAR WHEEL
ANTILOCK...........................42
REMOVAL.............................42
INSTALLATION.........................43
TONE WHEEL
DIAGNOSIS AND TESTING - REAR WHEEL
SPEED SENSOR......................43HYDRAULIC/MECHANICAL
DESCRIPTION - ELECTRONIC VARIABLE
BRAKE PROPORTIONING...............43
OPERATION - ELECTRONIC VARIABLE
BRAKE PROPORTIONING...............43
HCU (HYDRAULIC CONTROL UNIT)
DESCRIPTION.........................43
OPERATION...........................43
REMOVAL.............................44
INSTALLATION.........................44
R WA L VA LV E
DESCRIPTION.........................44
OPERATION...........................44
REMOVAL.............................45
INSTALLATION.........................45
BRAKES - ABS
DESCRIPTION
The antilock brake system (ABS) is an electroni-
cally operated, three channel brake control system.
The vehicle has Electronic Variable Brake Propor-
tioning (EVBP) designed into the system which elim-
inates the combination/proportioning valve.
The system is designed to prevent wheel lockup
and maintain steering control during braking. Pre-
venting lockup is accomplished by modulating fluid
pressure to the wheel brake units.
The hydraulic system is a three channel design.
The front wheel brakes are controlled individually
and the rear wheel brakes in tandem. The ABS elec-
trical system is separate from other electrical circuits
in the vehicle. A specially programmed controller
antilock brake unit operates the system components.
ABS system major components include:
²Controller Antilock Brakes (CAB)
²Hydraulic Control Unit (HCU)
²Wheel Speed Sensors (WSS)
²ABS Warning Light
OPERATION
Battery voltage is supplied to the CAB. The CAB
performs a system initialization procedure at start
up. A check of the ABS motor is performed at 15
miles per hour. Initialization consists of a static and
dynamic self check of system electrical components.
The static and dynamic checks occurs at ignition
start up. During the dynamic check, the CAB briefly
cycles solenoids to verify operation. An audible noise
may be heard during this self check. This noise
should be considered normal. The ABS motor and
pump are then checked at a speed of 15 mile per
hour.
If an ABS component exhibits a fault during ini-
tialization, the CAB illuminates the amber warning
light and registers a fault code in the microprocessor
memory.
The CAB monitors wheel speed sensor inputs con-
tinuously while the vehicle is in motion. However,
the CAB will not activate any ABS components as
long as sensor inputs indicate normal braking.
During normal braking, the master cylinder, power
booster and wheel brake units all function as they
would in a vehicle without ABS. The HCU compo-
nents are not activated.
DRBRAKES - ABS 5 - 39

The purpose of the antilock system is to prevent
wheel lockup. Preventing lockup helps maintain vehi-
cle braking action and steering control.
The antilock CAB activates the system whenever
sensor signals indicate periods of wheel slip.
The antilock system prevents lockup during a
wheel slip condition by modulating fluid apply pres-
sure to the wheel brake units.
Brake fluid apply pressure is modulated according
to wheel speed, degree of slip and rate of decelera-
tion. Sensors at each front wheel convert wheel speed
into electrical signals. These signals are transmitted
to the CAB for processing and determination of
wheel slip and deceleration rate.
The ABS system has three fluid pressure control
channels. The front brakes are controlled separately
and the rear brakes in tandem. A speed sensor input
signal indicating a wheel slip condition activates the
CAB antilock program.
There are Two solenoid valves (Isolation and Dump
valve) which are used in each antilock control chan-
nel. The valves are all located within the HCU valve
body and work in pairs to either increase, hold, or
decrease apply pressure as needed in the individual
control channels.
During an ABS stop the ISO valve is energized
which acts to prevent further pressure build-up tothe calipers. Then the Dump valve dumps off pres-
sure until the wheel unlocks. This will continue until
the wheels quit slipping altogether.
STANDARD PROCEDURE - ABS BRAKE
BLEEDING
ABS system bleeding requires conventional bleed-
ing methods plus use of the DRB scan tool. The pro-
cedure involves performing a base brake bleeding,
followed by use of the scan tool to cycle and bleed the
HCU pump and solenoids. A second base brake bleed-
ing procedure is then required to remove any air
remaining in the system.
(1) Perform base brake bleeding,(Refer to 5 -
BRAKES - STANDARD PROCEDURE) OR (Refer to
5 - BRAKES - STANDARD PROCEDURE).
(2) Connect scan tool to the Data Link Connector.
(3) Select ANTILOCK BRAKES, followed by MIS-
CELLANEOUS, then ABS BRAKES. Follow the
instructions displayed. When scan tool displays TEST
COMPLETE, disconnect scan tool and proceed.
(4) Perform base brake bleeding a second time,(Re-
fer to 5 - BRAKES - STANDARD PROCEDURE) OR
(Refer to 5 - BRAKES - STANDARD PROCEDURE).
(5) Top off master cylinder fluid level and verify
proper brake operation before moving vehicle.
SPECIFICATIONS
TORQUE CHART
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
ABS Assembly
Mounting Bolts15 11 Ð
ABS Assembly
CAB Screws3.5 Ð 31
ABS Assembly
Brake Line Fittings19 Ð 170
Wheel Speed Sensors
Front Sensor Bolt21 Ð 190
Wheel Speed Sensors
Bracket To Knuckle6.7 Ð 60
Wheel Speed Sensors
Rear Sensor Stud22.5 Ð 200
Controller
Mounting Screws6Ð53
RWAL Module
Mounting Bolts15 11 Ð
5 - 40 BRAKES - ABSDR
BRAKES - ABS (Continued)

DESCRIPTION N´m Ft. Lbs. In. Lbs.
RWAL Valve
Brake Line Fittings19 Ð 170
Rear Wheel Speed Sensor
Mounting Bolt24 Ð 200
FRONT WHEEL SPEED
SENSOR
DESCRIPTION
The ABS brake system uses 3 wheel speed sensors.
A sensor is mounted to each front hub/bearings. The
third sensor is mounted on top of the rear axle dif-
ferential housing.
OPERATION
The Wheel Speed Sensor consists of a magnet sur-
rounded by windings from a single strand of wire.
The sensor sends a small AC signal to the CAB. This
signal is generated by magnetic induction. The mag-
netic induction is created when a toothed sensor ring
(exciter ring or tone wheel) passes the stationary
magnetic WSS.
When the ring gear is rotated, the exciter ring
passes the tip of the WSS. As the exciter ring tooth
approaches the tip of the WSS, the magnetic lines of
force expand, causing the magnetic field to cut across
the sensor's windings. This, in turn causes current to
flow through the WSS circuit (Fig. 1) in one direc-
tion. When the exciter ring tooth moves away from
the sensor tip, the magnetic lines of force collapse
cutting the winding in the opposite direction. This
causes the current to flow in the opposite direction.
Every time a tooth of the exciter ring passes the tip
of the WSS, an AC signal is generated. Each AC sig-
nal (positive to negative signal or sinewave) is inter-
preted by the CAB. It then compares the frequency of
the sinewave to a time value to calculate vehicle
speed. The CAB continues to monitor the frequency
to determine a deceleration rate that would indicate
a possible wheel-locking tendency.
The signal strength of any magnetic induction sen-
sor is directly affected by:
²Magnetic field strength; the stronger the mag-
netic field, the stronger the signal
²Number of windings in the sensor; more wind-
ings provide a stronger signal
²Exciter ring speed; the faster the exciter ring/
tone wheel rotates, the stronger the signal will be
²Distance between the exciter ring teeth and
WSS; the closer the WSS is to the exciter ring/tone
wheel, the stronger the signal will be
The rear WSS is not adjustable. A clearance speci-
fication has been established for manufacturing toler-ances. If the clearance is not within these
specifications, then either the WSS or other compo-
nents may be damaged. The clearance between the
WSS and the exciter ring is 0.005 ± 0.050 in.
The assembly plant performs a ªRolls Testº on
every vehicle that leaves the assembly plant. One of
the test performed is a test of the WSS. To properly
test the sensor, the assembly plant connects test
equipment to the Data Link Connector (DLC). This
connector is located to the right of the steering col-
umn and attached to the lower portion of the instru-
ment panel (Fig. 2). The rolls test terminal is spliced
to the WSS circuit. The vehicle is then driven on a
set of rollers and the WSS output is monitored for
proper operation.
REMOVAL
(1) Remove the front rotor (Refer to 5 - BRAKES/
HYDRAULIC/MECHANICAL/ROTORS - REMOV-
AL).
(2) Remove the wheel speed sensor mounting bolt
from the hub. (Fig. 3)
Fig. 1 Operation of the Wheel Speed Sensor
1 - MAGNETIC CORE
2 - CAB
3 - AIR GAP
4 - EXCITER RING
5 - COIL
DRBRAKES - ABS 5 - 41
BRAKES - ABS (Continued)

Many of the electronic control modules in a vehicle
require information from the same sensing device. In
the past, if information from one sensing device was
required by several controllers, a wire from each con-
troller needed to be connected in parallel to that sen-
sor. In addition, each controller utilizing analog
sensors required an Analog/Digital (A/D) converter in
order to9read9these sensor inputs. Multiplexing
reduces wire harness complexity, sensor current
loads and controller hardware because each sensing
device is connected to only one controller, which
reads and distributes the sensor information to the
other controllers over the data bus. Also, because
each controller on the data bus can access the con-
troller sensor inputs to every other controller on the
data bus, more function and feature capabilities are
possible.
In addition to reducing wire harness complexity,
component sensor current loads and controller hard-
ware, multiplexing offers a diagnostic advantage. A
multiplex system allows the information flowing
between controllers to be monitored using a diagnos-
tic scan tool. The DaimlerChrysler system allows an
electronic control module to broadcast message data
out onto the bus where all other electronic control
modules can9hear9the messages that are being sent.
When a module hears a message on the data bus
that it requires, it relays that message to its micro-
processor. Each module ignores the messages on the
data bus that are being sent to other electronic con-
trol modules.
OPERATION
Data exchange between modules is achieved by
serial transmission of encoded data over a single wire
broadcast network. The wire colors used for the PCI
data bus circuits are yellow with a violet tracer, or
violet with a yellow tracer, depending upon the appli-
cation. The PCI data bus messages are carried over
the bus in the form of Variable Pulse Width Modu-
lated (VPWM) signals. The PCI data bus speed is an
average 10.4 Kilo-bits per second (Kbps). By compar-
ison, the prior two-wire Chrysler Collision Detection
(CCD) data bus system is designed to run at 7.8125
Kbps.
The voltage network used to transmit messages
requires biasing and termination. Each module on
the PCI data bus system provides its own biasing
and termination. Each module (also referred to as a
node) terminates the bus through a terminating
resistor and a terminating capacitor. There are two
types of nodes on the bus. The dominant node termi-
nates the bus througha1KWresistor and a 3300 pF
capacitor. The Powertrain Control Module (PCM) is
the only dominant node for the PCI data bus system.A standard node terminates the bus through an 11
KW resistor and a 330 pF capacitor.
The modules bias the bus when transmitting a
message. The PCI bus uses low and high voltage lev-
els to generate signals. Low voltage is around zero
volts and the high voltage is about seven and one-
half volts. The low and high voltage levels are gener-
ated by means of variable-pulse width modulation to
form signals of varying length. The Variable Pulse
Width Modulation (VPWM) used in PCI bus messag-
ing is a method in which both the state of the bus
and the width of the pulse are used to encode bit
information. A9zero9bit is defined as a short low
pulse or a long high pulse. A9one9bit is defined as a
long low pulse or a short high pulse. A low (passive)
state on the bus does not necessarily mean a zero bit.
It also depends upon pulse width. If the width is
short, it stands for a zero bit. If the width is long, it
stands for a one bit. Similarly, a high (active) state
does not necessarily mean a one bit. This too depends
upon pulse width. If the width is short, it stands for
a one bit. If the width is long, it stands for a zero bit.
In the case where there are successive zero or one
data bits, both the state of the bus and the width of
the pulse are changed alternately. This encoding
scheme is used for two reasons. First, this ensures
that only one symbol per transition and one transi-
tion per symbol exists. On each transition, every
transmitting module must decode the symbol on the
bus and begin timing of the next symbol. Since tim-
ing of the next symbol begins with the last transition
detected on the bus, all of the modules are re-syn-
chronized with each symbol. This ensures that there
are no accumulated timing errors during PCI data
bus communication.
The second reason for this encoding scheme is to
guarantee that the zero bit is the dominant bit on
the bus. When two modules are transmitting simul-
taneously on the bus, there must be some form of
arbitration to determine which module will gain con-
trol. A data collision occurs when two modules are
transmitting different messages at the same time.
When a module is transmitting on the bus, it is read-
ing the bus at the same time to ensure message
integrity. When a collision is detected, the module
that transmitted the one bit stops sending messages
over the bus until the bus becomes idle.
Each module is capable of transmitting and receiv-
ing data simultaneously. The typical PCI bus mes-
sage has the following four components:
²Message Header- One to three bytes in length.
The header contains information identifying the mes-
sage type and length, message priority, target mod-
ule(s) and sending module.
²Data Byte(s)- This is the actual message that
is being sent.
8E - 2 ELECTRONIC CONTROL MODULESDR
COMMUNICATION (Continued)

ENGINE CONTROL MODULE
DESCRIPTION - ECM
The Engine Control Module (ECM) is bolted to the
left side of the engine below the intake manifold (Fig.
2).
OPERATION - ECM
The main function of the Engine Control Module
(ECM) is to electrically control the fuel system. The
Powertrain Control Module (PCM)does not control
the fuel system.
The ECM can adapt its programming to meet
changing operating conditions.If the ECM has
been replaced, flashed or re-calibrated, the
ECM must learn the Accelerator Pedal Position
Sensor (APPS) idle voltage. Failure to learn
this voltage may result in unnecessary diagnos-
tic trouble codes. Refer to ECM Removal/Instal-
lation for learning procedures.
The ECM receives input signals from various
switches and sensors. Based on these inputs, the
ECM regulates various engine and vehicle operations
through different system components. These compo-
nents are referred to asECM Outputs.The sensors
and switches that provide inputs to the ECM are
consideredECM Inputs.NOTE: ECM Inputs:
²Accelerator Pedal Position Sensor (APPS) Volts
²APPS1 Signal Ð For off engine APPS
²APPS2 Signal Ð For off engine APPS
²APPS Idle Validation Switches #1 and #2
²Battery voltage
²Camshaft Position Sensor (CMP)
²CCD bus (+) circuits
²CCD bus (-) circuits
²Crankshaft Position Sensor (CKP)
²Data link connection for DRB scan tool
²Engine Coolant Temperature (ECT) sensor
²Ground circuits
²Fuel Pressure Sensor
²Battery Temperature
²Fan speed
²Inlet Air Temperature Sensor/Pressure Sensor
²Intake Air Temperature Sensor/MAP Sensor
²Oil Pressure SWITCH
²Power ground
²Sensor return
²Signal ground
²Water-In-Fuel (WIF) sensor
NOTE: ECM Outputs:
After inputs are received by the ECM, certain sen-
sors, switches and components are controlled or reg-
ulated by the ECM. These are consideredECM
Outputs.These outputs are for:
²CCD bus (+) circuits
²CCD bus (-) circuits
²CKP and APPS outputs to the PCM
²Data link connection for DRB scan tool
²Five volt sensor supply
²Fuel transfer (lift) pump
²Intake manifold air heater relays #1 and #2 con-
trol circuits
²Malfunction indicator lamp (Check engine lamp)
(databus)
²Oil Pressure Swith/warning lamp (databus)
²Fuel Control Actuator
²Wait-to-start warning lamp (databus)
²Fan Clutch PWM
²Water-In-Fuel (WIF) warning lamp (databus)
REMOVAL
The Engine Control Module (ECM) is bolted to a
support bracket near the fuel filter. The support
bracket mounts to the block with four capscrews and
vibration isolators. A ground wire is fastened to the
bracket. The other end of the wire is fastened to the
engine block.
(1) Record any Diagnostic Trouble Codes (DTC's)
found in the ECM.
Fig. 2 DIESEL ECM
1 - ENGINE CONTROL MODULE (ECM)
2 - ECM MOUNTING BOLT
3 - 50-WAY CONNECTOR
4 - SUPPORT PLATE
5 - 60-WAY CONNECTOR
8E - 4 ELECTRONIC CONTROL MODULESDR

DIAGNOSIS AND TESTING - FRONT CONTROL
MODULE
The front control module is a printed circuit board
based module with a on-board micro-processor. The
front control module interfaces with other electronic
modules in the vehicle via the Programmable Com-
munications Interface (PCI) data bus (J1850). In
order to obtain conclusive testing the Programmable
Communications Interface (PCI) data bus network
and all of the electronic modules that provide inputs
to, or receive outputs from the front control module
must be checked. All PCI (J1850) communication
faults must be resolved prior to further diagnosing
any front control module related issues.
The front control module was designed to be diag-
nosed with an appropriate diagnostic scan tool, such
as the DRB IIIt. The most reliable, efficient, and
accurate means to diagnose the front control module
requires the use of a DRB IIItscan tool and the
proper Body Diagnostic Procedures manual.
Before any testing of the front control module is
attempted, the battery should be fully charged and
all wire harness and ground connections inspected
around the affected areas on the vehicle.
REMOVAL
(1) Disconnect the positive and negative battery
cables from the battery.
(2) Partially remove the integrated power module
from the engine compartment (Refer to 8 - ELECTRI-
CAL/POWER DISTRIBUTION/INTEGRATED
POWER MODULE - REMOVAL).
(3) Remove the front control module retaining
screws.
(4) Using both hands, pull the front control module
straightfrom the integrated power module assembly
to disconnect the 49-way electrical connector and
remove the front control module from the vehicle.
INSTALLATION
(1) Install the front control module on the inte-
grated power module assembly by pushing the
49-way electrical connector straight in.
(2) Install the front control module retaining
screws. Torque the screws to 7 in. lbs.
(3) Install the integrated power module (Refer to 8
- ELECTRICAL/POWER DISTRIBUTION/INTE-
GRATED POWER MODULE - INSTALLATION).
(4) Connect the positive and negative battery
cables.
HEATED SEAT MODULE
DESCRIPTION
The heated seat module is also known as the Seat
Heat Interface Module. The heated seat module (Fig.
4) is located under the drivers front seat cushion,
where it is secured to a mounting bracket. The
heated seat module has a single connector receptacle
that allows the module to be connected to all of the
required inputs and outputs through the seat wire
harness.
The heated seat module is an electronic micropro-
cessor controlled device designed and programmed to
use inputs from the battery, the two heated seat
switches and the two heated seat sensors to operate
and control the heated seat elements in both front
seats and the two heated seat indicator lamp Light-
Emitting Diodes (LEDs) in each heated seat switch.
The heated seat module is also programmed to per-
form self-diagnosis of certain heated seat system
functions and provide feedback of that diagnosis
through the heated seat switch indicator lamps.
The heated seat module cannot be repaired. If the
heated seat module is damaged or faulty, the entire
module must be replaced.
OPERATION
The heated seat module operates on fused battery
current received from the integrated power module.
Inputs to the module include a resistor multiplexed
heated seat switch request circuit for each of the two
heated seat switches and the heated seat sensor
inputs from the seat cushions of each front seat. In
response to those inputs the heated seat module con-
trols battery current feeds to the heated seat ele-
Fig. 4 Heated Seat Module
1 - MOUNTING TABS (NOT USED ON DR)
2 - HEATED SEAT MODULE
3 - ELECTRICAL CONNECTOR RECEPTACLE
8E - 6 ELECTRONIC CONTROL MODULESDR
FRONT CONTROL MODULE (Continued)