service DODGE RAM 2003 Service Manual PDF

ELECTRONIC MODULE IGNITION-OFF DRAW (IOD) TABLE
ModuleTime Out?
(If Yes, Interval And Wake-Up Input)IODIOD After Time
Out
ElectroMechanical
Instrument Cluster
(EMIC)No 0.44 milliampere N/A
Combination Flasher No 0.08 milliampere N/A
(2) Determine that the underhood lamp is operat-
ing properly, then disconnect the lamp wire harness
connector or remove the lamp bulb.
(3) Disconnect the battery negative cable.
(4) Set an electronic digital multi-meter to its
highest amperage scale. Connect the multi-meter
between the disconnected battery negative cable ter-
minal clamp and the battery negative terminal post.
Make sure that the doors remain closed so that the
illuminated entry system is not activated. The multi-
meter amperage reading may remain high for up to
three minutes, or may not give any reading at all
while set in the highest amperage scale, depending
upon the electrical equipment in the vehicle. The
multi-meter leads must be securely clamped to the
battery negative cable terminal clamp and the bat-
tery negative terminal post. If continuity between the
battery negative terminal post and the negative cable
terminal clamp is lost during any part of the IOD
test, the electronic timer function will be activated
and all of the tests will have to be repeated.
(5) After about three minutes, the high-amperage
IOD reading on the multi-meter should become very
low or nonexistent, depending upon the electrical
equipment in the vehicle. If the amperage reading
remains high, remove and replace each fuse or circuit
breaker in the Integrated Power Module (IPM), one
at a time until the amperage reading becomes very
low, or nonexistent. Refer to the appropriate wiring
information in this service manual for complete Inte-
grated Power Module fuse, circuit breaker, and cir-
cuit identification. This will isolate each circuit and
identify the circuit that is the source of the high-am-
perage IOD. If the amperage reading remains high
after removing and replacing each fuse and circuit
breaker, disconnect the wire harness from the gener-
ator. If the amperage reading now becomes very low
or nonexistent, refer to Charging System for the
proper charging system diagnosis and testing proce-
dures. After the high-amperage IOD has been cor-
rected, switch the multi-meter to progressively lower
amperage scales and, if necessary, repeat the fuse
and circuit breaker remove-and-replace process to
identify and correct all sources of excessive IOD. It is
now safe to select the lowest milliampere scale of the
multi-meter to check the low-amperage IOD.CAUTION: Do not open any doors, or turn on any
electrical accessories with the lowest milliampere
scale selected, or the multi-meter may be damaged.
(6) Observe the multi-meter reading. The low-am-
perage IOD should not exceed thirty-five milliam-
peres (0.035 ampere). If the current draw exceeds
thirty-five milliamperes, isolate each circuit using the
fuse and circuit breaker remove-and-replace process
in Step 5. The multi-meter reading will drop to
within the acceptable limit when the source of the
excessive current draw is disconnected. Repair this
circuit as required; whether a wiring short, incorrect
switch adjustment, or a component failure is at fault.
STANDARD PROCEDURE - USING MICRO 420
BATTERY TESTER
Always use the Micro 420 Instruction Manual that
was supplied with the tester as a reference. If the
Instruction Manual is not available the following pro-
cedure can be used:
Fig. 9 MICRO 420 BATTERY TESTER
8F - 12 BATTERY SYSTEMDR
BATTERY (Continued)

WARNING: ALWAYS WEAR APPROPRIATE EYE
PROTECTION AND USE EXTREME CAUTION WHEN
WORKING WITH BATTERIES.
BATTERY TESTING
(1) If testing the battery OUT-OF-VEHICLE, clean
the battery terminals with a wire brush before test-
ing. If the battery is equipped with side post termi-
nals, install and tighten the supplied lead terminal
stud adapters. Do not use steel bolts. Failure to prop-
erly install the stud adapters, or using stud adapters
that are dirty or worn-out may result in false test
readings.
(2) If testing the battery IN-THE-VEHICLE, make
certain all of the vehicle accessory loads are OFF,
including the ignition.The preferred test position
is at the battery terminal. If the battery is not
accessible, you may test using both the positive and
negative jumper posts. Select TESTING AT JUMPER
POST when connecting to that location.
(3) Connect the tester (Fig. 9) to the battery or
jumper posts, the red clamp to positive (+) and the
black clamp to negative (±).
NOTE: Multiple batteries connected in parallel must
have the ground cable disconnected to perform a
battery test. Failure to disconnect may result in
false battery test readings.
(4) Using the ARROW key selectinoroutof vehi-
cle testing and press ENTER to make a selection.
(5) If not selected, choose the Cold Cranking Amp
(CCA) battery rating. Or select the appropriate bat-
tery rating for your area (see menu). The tester will
then run its self programmed test of the battery and
display the results. Refer to the test result table
noted below.
CAUTION: If REPLACE BATTERY is the result of the
test, this may mean a poor connection between the
vehicle's cables and battery exists. After discon-
necting the vehicle's battery cables from the bat-
tery, retest the battery using the OUT-OF-VEHICLE
test before replacing.
(6) While viewing the battery test result, press the
CODE button and the tester will prompt you for the
last 4 digits of the VIN. Use the UP/DOWN arrow
buttons to scroll to the correct character; then press
ENTER to select and move to the next digit. Then
press the ENTER button to view the SERVICE
CODE. Pressing the CODE button a second time will
return you to the test results.
BATTERY TEST RESULTS
GOOD BATTERY Return to service
GOOD - RECHARGE Fully charge battery and
return to service
CHARGE & RETEST Fully charge battery and
retest battery
REPLACE BATTERY Replace the battery and
retest complete system
BAD-CELL REPLACE Replace the battery and
retest complete system
NOTE: The SERVICE CODE is required on every
warranty claim submitted for battery replacement.
REMOVAL
(1) Turn the ignition switch to the Off position. Be
certain that all electrical accessories are turned off.
(2) Loosen the battery negative cable terminal
clamp pinch-bolt hex nut.
(3) Disconnect the battery negative cable terminal
clamp from the battery negative terminal post. If
necessary, use a battery terminal puller to remove
the terminal clamp from the battery post (Fig. 10).
(4) Loosen the battery positive cable terminal
clamp pinch-bolt hex nut.
(5) Disconnect the battery positive cable terminal
clamp from the battery positive terminal post. If nec-
essary, use a battery terminal puller to remove the
terminal clamp from the battery post (Fig. 10).
(6) Remove the battery hold down retaining bolt.
WARNING: WEAR A SUITABLE PAIR OF RUBBER
GLOVES (NOT THE HOUSEHOLD TYPE) WHEN
REMOVING A BATTERY BY HAND. SAFETY
GLASSES SHOULD ALSO BE WORN. IF THE BAT-
TERY IS CRACKED OR LEAKING, THE ELECTRO-
LYTE CAN BURN THE SKIN AND EYES.
Fig. 10 Removing Battery Cable Terminal Clamp
1 - BATTERY
2 - BATTERY TERMINAL PULLER
DRBATTERY SYSTEM 8F - 13
BATTERY (Continued)

(7) Remove the battery from the battery tray.
INSTALLATION
(1) Clean and inspect the battery.
(2) Position the battery onto the battery tray.
Ensure that the battery positive and negative termi-
nal posts are correctly positioned. The battery cable
terminal clamps must reach the correct battery ter-
minal post without stretching the cables.
(3) Position the battery hold down and install the
retaining bolt.
CAUTION: Be certain that the battery cable terminal
clamps are connected to the correct battery termi-
nal posts. Reversed battery polarity may damage
electrical components of the vehicle.
(4) Clean the battery cable terminal clamps and
the battery terminal posts.
(5) Reconnect the battery positive cable terminal
clamp to the battery positive terminal post. Tighten
the terminal clamp pinch-bolt hex nut to 4 N´m (35
in. lbs.).
(6) Reconnect the battery negative cable terminal
clamp to the battery negative terminal post. Tighten
the terminal clamp pinch-bolt hex nut to 4 N´m (35
in. lbs.).
(7) Apply a thin coating of petroleum jelly or chas-
sis grease to the exposed surfaces of the battery cable
terminal clamps and the battery terminal posts.
(8) Obtain a DRB IIItscan tool and check the
PCM for any stored battery disconnect trouble code,
if required.
BATTERY HOLDDOWN
DESCRIPTION
The battery hold down hardware includes a bolt
and a molded plastic hold down bracket which
meshes with the battery tray when properly
installed. The battery tray and hold down hardware
combine to form a very stable and secure battery
hold down assembly.
OPERATION
The battery holddown secures the battery in the
battery tray. This holddown is designed to prevent
battery movement during the most extreme vehicle
operation conditions. Periodic removal and lubrica-
tion of the battery holddown hardware is recom-
mended to prevent hardware seizure at a later date.
CAUTION: Never operate a vehicle without a battery
holddown device properly installed. Damage to the
vehicle, components and battery could result.
REMOVAL
(1) Loosen and remove the battery hold down
retaining bolt.
(2) Remove the battery hold down bracket from
the battery case.
INSTALLATION
(1) Clean and inspect the battery hold down hard-
ware (Refer to 8 - ELECTRICAL/BATTERY SYSTEM
- CLEANING).
(2) Position the battery hold down bracket in the
battery tray. Be certain that the hold down bracket is
properly positioned in the battery tray before tight-
ening the hold down hardware.
(3) Install and tighten the battery hold down
retaining bolt.
BATTERY CABLES
DESCRIPTION
The battery cables are large gauge, stranded cop-
per wires sheathed within a heavy plastic or syn-
thetic rubber insulating jacket. The wire used in the
battery cables combines excellent flexibility and reli-
ability with high electrical current carrying capacity.
Refer to Wiring for the location of the proper battery
cable wire gauge information.
The battery cables cannot be repaired and, if dam-
aged or faulty they must be replaced. Both the bat-
tery positive and negative cables are available for
service replacement only as a unit with the battery
positive cable wire harness or the battery negative
cable wire harness, which may include portions of
the wiring circuits for the generator and other com-
ponents on some models.
Most models feature a stamped brass clamping
type female battery terminal crimped onto one end of
the battery cable wire and then solder-dipped. A
pinch-bolt and hex nut are installed at the open end
of the female battery terminal clamp. The battery
positive cable also includes a red molded rubber pro-
tective cover for the female battery terminal clamp.
Large eyelet type terminals are crimped onto the
opposite end of the battery cable wire and then sol-
der-dipped. The battery positive cable wires have a
red insulating jacket to provide visual identification
and feature a larger female battery terminal clamp
to allow connection to the larger battery positive ter-
minal post. The battery negative cable wires have a
black insulating jacket and a smaller female battery
terminal clamp.
OPERATION
The battery cables connect the battery terminal
posts to the vehicle electrical system. These cables
8F - 14 BATTERY SYSTEMDR
BATTERY (Continued)

²a faulty or improperly adjusted switch that
allows a lamp to stay on. Refer to Ignition-Off Draw
Test in 8, Battery for more information.
INSPECTION
The PCM (Powertrain Control Module), or ECM
(Diesel) monitors critical input and output circuits of
the charging system, making sure they are opera-
tional. 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
Control Module; Electronic Control Modules 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 DRBtscan tool. Per-
form the following inspections before attaching the
scan tool.
(1) Inspect the battery condition. Refer to 8, Bat-
tery for procedures.(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) 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
torque specifications.
(5) Inspect generator drive belt condition and ten-
sion. Tighten or replace belt as required. Refer to
Belt Tension Specifications in 7, Cooling System.
(6) Inspect automatic belt tensioner (if equipped).
Refer to 7, Cooling System for information.
(7) Inspect generator electrical connections at gen-
erator field, battery output, and ground terminal (if
equipped). Also check generator ground wire connec-
tion at engine (if equipped). They should all be clean
and tight. Repair as required.
SPECIFICATIONS
GENERATOR RATINGS
TYPE PART NUMBER RATED SAE AMPS ENGINES
DENSO 56029700AA 136 3.7L / 4.7L
DENSO 56029701AA 136 5.9L Gas
BOSCH 56041120AC 136 3.7L / 4.7L
BOSCH 56028238AB 136 5.9L Gas
DENSO 56028560AA 136 8.0L
DENSO 56028696AA 136 5.7L Gas/5.9L Diesel
BOSCH 56028699AA 136 5.7L Gas/5.9L Diesel
SPECIFICATIONS - TORQUE - GENERATOR /
CHARGING SYSTEM
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Generator Mounting Bolts - 5.7L 41 30 -
Generator Support Bracket
Bolt/Nuts - 5.7L41 30 -
Generator Mounting Bolts - 8.0L 41 30 -
Generator Upper Mounting Bolt -
5.9L Diesel Engine41 30 -
Generator Upper Mounting Bolt -
5.9L Gas Engine41 30 -
8F - 20 CHARGINGDR
CHARGING (Continued)

GENERATOR
DESCRIPTION
The generator is belt-driven by the engine using a
serpentine type drive belt. It is serviced only as a
complete assembly. If the generator fails for any rea-
son, the entire assembly must be replaced.
OPERATION
As the energized rotor begins to rotate within the
generator, the spinning magnetic field induces a cur-
rent into the windings of the stator coil. Once the
generator begins producing sufficient current, it also
provides the current needed to energize the rotor.
The stator winding connections deliver the induced
alternating current to 3 positive and 3 negative
diodes for rectification. From the diodes, rectified
direct current is delivered to the vehicle electrical
system through the generator battery terminal.
Although the generators appear the same exter-
nally, different generators with different output rat-
ings are used on this vehicle. Be certain that the
replacement generator has the same output rating
and part number as the original unit. Refer to Gen-
erator Ratings in the Specifications section at the
back of this group for amperage ratings and part
numbers.
Noise emitting from the generator may be caused
by: worn, loose or defective bearings; a loose or defec-
tive drive pulley; incorrect, worn, damaged or misad-
justed fan drive belt; loose mounting bolts; a
misaligned drive pulley or a defective stator or diode.
REMOVAL
3.7L / 4.7L
WARNING: DISCONNECT NEGATIVE CABLE FROM
BATTERY BEFORE REMOVING BATTERY OUTPUT
WIRE (B+ WIRE) FROM GENERATOR. FAILURE TO
DO SO CAN RESULT IN INJURY OR DAMAGE TO
ELECTRICAL SYSTEM.
(1) Disconnect negative battery cable at battery.
(2) Remove generator drive belt. Refer to 7, Cool-
ing System for procedure.
(3) Unsnap plastic insulator cap from B+ output
terminal (Fig. 2).
(4) Remove B+ terminal mounting nut at rear of
generator (Fig. 2). Disconnect terminal from genera-
tor.
(5) Disconnect field wire connector at rear of gen-
erator (Fig. 2) by pushing on connector tab.
(6) Remove 1 rear vertical generator mounting bolt
(Fig. 3).(7) Remove 2 front horizontal generator mounting
bolts (Fig. 3).
(8) Remove generator from vehicle.
Fig. 2 GENERATOR CONNECTORS - 3.7L / 4.7L
1 - GENERATOR
2-B+NUT
3 - PLASTIC INSULATOR CAP
4 - FIELD WIRE CONNECTOR
Fig. 3 REMOVE / INSTALL GENERATOR - 3.7L / 4.7L
1 - LOWER BOLTS
2 - REAR BOLT
3 - GENERATOR
8F - 22 CHARGINGDR

VOLTAGE REGULATOR
DESCRIPTION
The Electronic Voltage Regulator (EVR) is not a
separate component. It is actually a voltage regulat-
ing circuit located within the PCM (Powertrain Con-
trol Module) (within the ECM for diesel engines). The
EVR is not serviced separately. If replacement is nec-
essary, the PCM must be replaced.
OPERATION
The amount of direct current produced by the gen-
erator is controlled by EVR circuitry contained
within the PCM. This circuitry is connected in series
with the generators second rotor field terminal and
its ground.
Voltage is regulated by cycling the ground path to
control the strength of the rotor magnetic field. TheEVR circuitry monitors system line voltage (B+) and
battery temperature (refer to Battery Temperature
Sensor for more information). It then determines a
target charging voltage. If sensed battery voltage is
0.5 volts or lower than the target voltage, the PCM
grounds the field winding until sensed battery volt-
age is 0.5 volts above target voltage. A circuit in the
PCM cycles the ground side of the generator field up
to 100 times per second (100Hz), but has the capabil-
ity to ground the field control wire 100% of the time
(full field) to achieve the target voltage. If the charg-
ing rate cannot be monitored (limp-in), a duty cycle
of 25% is used by the PCM in order to have some
generator output. Also refer to Charging System
Operation for additional information.
DRCHARGING 8F - 27

Starting System Diagnosis
CONDITION POSSIBLE CAUSE CORRECTION
STARTER ENGAGES,
SPINS OUT BEFORE
ENGINE STARTS.1. Starter ring gear faulty. 1. Refer to Starter Motor Removal and Installation.
Remove starter motor to inspect starter ring gear.
Replace starter ring gear if required.
2. Starter motor faulty. 2. If all other starting system components and circuits test
OK, replace starter motor assembly.
STARTER DOES NOT
DISENGAGE.1. Starter motor
improperly installed.1. Refer to Starter Motor Removal and Installation.
Tighten starter mounting hardware to correct torque
specifications.
2. Starter relay faulty. 2. Refer to Starter Relay Diagnosis and Testing. Replace
starter relay if required.
3. Ignition switch faulty. 3. Refer to Ignition Switch and Key Lock Cylinder.
Replace ignition switch if required.
4. Starter motor faulty. 4. If all other starting system components and circuits test
OK, replace starter motor.
INSPECTION
For complete starter wiring circuit diagrams, refer
to 8, Wiring Diagrams. Before removing any unit
from starting system for repair or diagnosis, perform
the following inspections:
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO 8, PASSIVE RESTRAINT SYS-
TEMS, 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 DEPLOY-
MENT AND POSSIBLE PERSONAL INJURY.
²Battery- Visually inspect battery for indica-
tions of physical damage and loose or corroded cable
connections. Determine state-of-charge and cranking
capacity of battery. Charge or replace battery if
required. Refer toBatteryin 8, Battery.Note: If
equipped with diesel engine, a dual battery sys-
tem may be used, and both batteries must be
inspected.
²Ignition Switch- Visually inspect ignition
switch for indications of physical damage and loose
or corroded wire harness connections. Refer toIgni-
tion Switch and Key Lock Cylinder.
²Clutch Pedal Position Switch- If equipped
with manual transmission, visually inspect clutch
pedal position switch for indications of physical dam-
age and loose or corroded wire harness connections.
Refer toClutch Pedal Position Switchin 6,
Clutch.
²Park/Neutral Position Switch- If equipped
with automatic transmission, visually inspect park/
neutral position switch for indications of physical
damage and loose or corroded wire harness connec-tions. Refer toPark/Neutral Position Switchin
21, Transmission.
²Starter Relay- Visually inspect starter relay
for indications of physical damage and loose or cor-
roded wire harness connections.
²Starter Motor- Visually inspect starter motor
for indications of physical damage and loose or cor-
roded wire harness connections.
²Starter Solenoid- Visually inspect starter sole-
noid for indications of physical damage and loose or
corroded wire harness connections.
²Wiring- Visually inspect wire harnesses for
damage. Repair or replace any faulty wiring, as
required. Refer to 8, Wiring Diagrams.
TESTING
COLD CRANKING TEST
For complete starter wiring circuit diagrams, refer
to 8, Wiring Diagrams. The battery must be fully-
charged and load-tested before proceeding. Refer to
Batteryin 8, Battery.
(1) Connect volt-ampere tester to battery terminals
(Fig. 1). See instructions provided by manufacturer of
volt-ampere tester being used.Note: Certain diesel
equipped models use dual batteries. If equipped
with dual battery system, tester should be con-
nected to battery on left side of vehicle only.
Also, tester current reading must be taken from
positive battery cable lead that connects to
starter motor.
(2) Fully engage parking brake.
(3) If equipped with manual transmission, place
gearshift selector lever in Neutral position and block
clutch pedal in fully depressed position. If equipped
8F - 30 STARTINGDR
STARTING (Continued)

heated mirror switch is depressed and released a sec-
ond time during the same ignition cycle, the elec-
tronic control logic and timer circuitry will
automatically turn the heated mirror system off after
a programmed time interval of about five minutes.
The heated mirror system will be shut off automati-
cally if the ignition switch is turned to the Off or
Accessory positions. After the heated mirror system
is turned On, it can also be turned off manually by
depressing and releasing the heated mirror switch a
second time.
When the heated mirror system is turned On, the
heated mirror system control logic and timer cir-
cuitry energizes the heated mirror system indicator
lamp and the heated mirror relay. When energized,
the heated mirror relay supplies fused ignition
switch output (run/start) current from a fuse in the
JB to the outside mirror heating grids located behind
the mirror glass of each of the outside rear view mir-
rors. When energized, each of the outside mirror
heating grids produces enough heat to warm the
glass of the outside rear view mirrors.
DIAGNOSIS AND TESTING - HEATED MIRROR
SYSTEM
If only one of the outside mirror heating grids is
inoperative, perform continuity checks on the circuits
and heater grid for that mirror only. If both outside
mirror heating grids are inoperative, proceed with
the heated mirror system diagnosis as follows. (Refer
to Appropriate Wiring Information).
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.The operation of the heated mirror system can be
confirmed in one of the following manners:
1. Turn the ignition switch to the On position.
While monitoring the instrument panel voltmeter,
momentarily depress and release the heated mirror
switch. When the heated mirror system is turned On,
a distinct voltmeter needle deflection should be
noted.
2. Turn the ignition switch to the On position.
Momentarily depress and release the heated mirror
switch to turn the heated mirror system On. The
heated mirror operation can be checked by feeling
the outside rear view mirror glass. A distinct differ-
ence in temperature between the unheated and
heated mirror glass can be detected within three to
four minutes of system operation.
The above checks will confirm system operation.
Illumination of the heated mirror system indicator
lamp means that there is electrical current available
at the heated mirror relay, but does not confirm that
the electrical current is reaching the outside mirror
heating grids.
If the heated mirror system does not operate, the
problem should be isolated in the following manner:
(1) Confirm that the ignition switch is in the On
position.
(2) Check the fuses in the Power Distribution Cen-
ter (PDC) and in the Junction Block (JB). The fuses
must be tight in their receptacles and all electrical
connections must be secure.
When the above steps have been completed and
both outside mirror heating grids are still inopera-
tive, one or more of the following is faulty:
²Heated mirror switch, electronic control logic
and timer circuitry, and heated mirror relay.
²Heated mirror wire harness circuits or connec-
tors.
²Outside mirror heating grid (both mirror grids
would have to be faulty).
If turning On the heated mirror system produces a
severe voltmeter deflection or fuse failures, check for
a shorted circuit between the output of the heated
mirror relay and the outside mirror heating grids.
8G - 2 HEATED MIRRORSDR
HEATED MIRRORS (Continued)

HEATED SEAT SYSTEM
TABLE OF CONTENTS
page page
HEATED SEAT SYSTEM
DESCRIPTION..........................3
OPERATION............................4
DIAGNOSIS AND TESTING - HEATED SEAT
SYSTEM.............................4
HEATED SEAT ELEMENT
DESCRIPTION..........................5
OPERATION............................6
DIAGNOSIS AND TESTING - HEATED SEAT
ELEMENT............................6
REMOVAL.............................6
INSTALLATION..........................6
HEATED SEAT SENSOR
DESCRIPTION..........................7OPERATION............................7
DIAGNOSIS AND TESTING - HEATED SEAT
SENSOR.............................7
REMOVAL.............................7
HEATED SEAT SWITCH
DESCRIPTION..........................7
OPERATION............................8
DIAGNOSIS AND TESTING - HEATED SEAT
SWITCH.............................8
REMOVAL.............................9
INSTALLATION..........................9
HEATED SEAT SYSTEM
DESCRIPTION
Individually controlled, electrically heated front
seats are available as a factory-installed option on
some DR models. Vehicles with this option can be
visually identified by the leather trim seats and two
separate heated seat switches mounted in the lower
center of the instrument panel. The heated seat sys-
tem allows the front seat driver and passenger to
select from two different levels of electrical seat heat-
ing, or no seat heating to suit their individual com-
fort requirements. The heated seat system for this
vehicle includes the following major components,
which are described in further detail later in this sec-
tion:
²Heated Seat Switches- Two heated seat
switches are used per vehicle. One switch is used for
each front seat. The switches are mounted in the
instrument panel, below the radio (Fig. 1). Each
switch also includes two Light-Emitting Diode (LED)
indicator lamps and an incandescent back lighting
bulb.
²Heated Seat Module- also referred to as the
Seat Heat Interface Module (SHIM), this module con-
tains the solid state electronic control and diagnostic
logic circuitry for the heated seat system. One heated
seat module is used per vehicle and is mounted
under the drivers front seat cushion (Fig. 1). Refer to
the Electronic Control Modules section of the service
manual for additional heated seat module informa-
tion.²Heated Seat Elements- Four heated seat ele-
ments are used per vehicle. One element is used for
each front seat back and one element and sensor
assembly is used for each front seat cushion (Fig. 1).
The heating elements are integral to the individual
front seat and seat back cushions and cannot be
removed once installed at the factory. Replacement
seat heating elements are available, without having
to replace the entire seat cushion or trim cover. Refer
to the detailed procedure later in this section.
²Heated Seat Sensors- Two heated seat sen-
sors are used per vehicle. One heated seat tempera-
ture sensor is used for each front seat cushion. The
sensors are integral to the individual front seat cush-
ion heating elements (Fig. 1) and cannot be removed
once installed at the factory. Replacement seat heat-
ing elements with the sensors are available, without
having to replace the entire seat cushion or trim
cover. Refer to the detailed procedure later in this
section.
Following are general descriptions and operations
of the major components in the heated seat system.
See the owner's manual in the vehicle glove box for
more information on the features, use and operation
of the heated seat system. Refer toWiringfor the
location of complete heated seat system wiring dia-
grams.
DRHEATED SEAT SYSTEM 8G - 3

Diagnostic logic is built into the heated seat mod-
ule to help the person trying to locate the problem by
the most efficient means possible. Anytime a problem
is suspected, locate the diagnosis and testing proce-
dure for the component in question and follow the
steps until the specific problem is located and
resolved. Once the problem is thought to be cor-
rected, verify correct system operation. If the heated
seat system is functioning correctly return the vehi-
cle to service.
If a problem could not be verified such as not find-
ing anything wrong when following the diagnostic
procedure, this is a good indication that a INTER-
MITTENT problem may be present. You must then
attempt to find the intermittent problem, such as
moving the heating element within the seat while
testing continuity or wiggling the wire harness's/elec-
trical connectors under the seat while testing conti-
nuity. Always, eliminate all other potential problems
before attempting to replace the heated seat module.
PRELIMINARY TEST
Refer toWiringfor the location of complete heated
seat system wiring diagrams. Before testing the indi-
vidual components in the heated seat system, per-
form the following preliminary checks:
WARNING: DISABLE THE AIRBAG SYSTEM
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. DISCON-
NECT AND ISOLATE THE BATTERY NEGATIVE
CABLE, THEN WAIT TWO MINUTES FOR THE AIR-
BAG SYSTEM CAPACITOR TO DISCHARGE
BEFORE PERFORMING FURTHER DIAGNOSIS OR
SERVICE. THIS IS THE ONLY SURE WAY TO DIS-
ABLE THE AIRBAG SYSTEM. FAILURE TO TAKE
THE PROPER PRECAUTIONS COULD RESULT IN
ACCIDENTAL AIRBAG DEPLOYMENT AND POSSI-
BLE PERSONAL INJURY.
²If the heated seat switch back lighting and the
cluster illumination lamps do not illuminate with the
headlamps or park lamps turned On, refer to the
Instrument Clustersection of the service manual
for the location of cluster illumination lamp diagnosis
and testing procedures. If the heated seat switch
back lighting does not illuminate, but the cluster illu-
mination lamps do illuminate with the headlamps or
park lamps turned On, refer toDiagnosis and Test-
ing the Heated Seat Switchin this section for the
location of the heated seat switch diagnosis and test-
ing procedures.
²If a single LED indicator lamp for one heated
seat switch does not operate and the heated seat ele-
ments do heat, refer toDiagnosis and Testing theHeated Seat Switchin this section for heated seat
switch diagnosis and testing procedures.
²If both LED indicator lamps for a heated seat
switch operate, but the heated seat elements do not
heat, refer toDiagnosis and Testing the Heated
Seat Modulein Electronic Control Modules for
heated seat module diagnosis and testing procedures.
²If the indicator lamp on either heated seat
switch remains illuminated after the heated seat has
been turned Off, refer toDiagnosis and Testing
the Heated Seat Modulein Electronic Control
Modules for heated seat module diagnosis and test-
ing procedures.
HEATED SEAT ELEMENT
DESCRIPTION
Vehicles equipped with the optional heated seat
system have two sets of electrically operated heating
element grids located in each front seat, one set for
the seat cushion and the other set for the seat back.
Each of the heated seat element grids consists of a
single length of resistor wire that is routed in a zig-
zag pattern and captured between a covering and the
adhesive foam rubber backing. Short pigtail wires
with connectors (Fig. 2) are soldered to each end of
each resistor wire element grid, which connect all of
Fig. 2 Heating Element Installed on Seat Cushion
Foam
1 - SEAT BACK WIRE HARNESS
2 - HEATED SEAT WIRE HARNESS CONNECTOR
3 - HEATED SEAT CUSHION ELEMENT
DRHEATED SEAT SYSTEM 8G - 5
HEATED SEAT SYSTEM (Continued)