Trans temp DODGE RAM 1500 1998 2.G Owner's Manual

(11) Remove the two radiator upper mounting
bolts (Fig. 37).
(12) Lift the radiator straight up and out of the
engine compartment. Take care not to damage cool-
ing fins or tubes on the radiator and oil coolers when
removing.
NOTE: The radiator is equipped with one alignment
dowel on the bottom of the outlet tank and one
retaining bracket on the front side of the inlet tank.
Both features have rubber insulators attached to
them that must be present. The alignment dowel fits
into a hole at the bottom of the front end sheet
metal vertical support post and the support bracket
rests on top of the lower radiator closure tube.
CLEANING
Clean radiator fins are necessary for good heat
transfer. The radiator and oil cooler fins should be
cleaned when an accumulation of debris has
occurred. With the engine cold, apply cold water and
compressed air to the back (engine side) of the radi-
ator to flush the radiator and/or oil coolers of debris.
INSPECTION
Inspect the radiator side tanks for cracks, and bro-
ken or missing fittings. Inspect the joint where the
tanks seam up to the radiator core for signs of leak-
age and/or deteriorating seals.
Inspect radiator core for corroded, bent or missing
cooling fins. Inspect the core for bent or damaged
cooling tubes.
INSTALLATION
(1) Position the fan shroud over the fan blades
rearward towards engine.
(2) Install the rubber insulators to the lower radi-
ator mounting features (alignment dowel and support
bracket at the lower part of the radiator).
(3) Lower the radiator into position while guiding
the alignment dowel into the vertical post bracket.
Position and seat the lower radiator support bracket
onto the lower radiator closure tube.
(4) Install the upper radiator mounting bolts.
Tighten bolts to 10 N´m (90 in. lbs.).
(5) Connect the lower radiator hose and install the
clamp in the proper position.
(6) Connect the power steering hoses to the power
steering oil cooler and install the clamps.
(7) Connect the transmission oil cooler lines to the
transmission oil cooler and install the secondary
latches.
(8) Position the fan shroud into the mounting clips
on the radiator tanks and secure with bolts. Tighten
the bolts to 8.5 N´m (75 in. lbs.).
(9) Secure the power steering hoses into the clip
on the lower fan shroud.
(10) Install the windshield washer reservoir tank
and connect the hose and electrical connector.
(11) Install coolant reserve/overflow container
hose(s) to radiator filler neck and secure properly
with clamps.
(12) Install coolant reserve/overflow container or
degas container to fan shroud and tighten the bolts
to 8.5 N´m (75 in. lbs.).
(13) Connect upper radiator hose and install
clamp.
(14) Install battery negative cable.
(15) Fill cooling system with coolant (Refer to 7 -
COOLING - STANDARD PROCEDURE).
(16) Operate the engine until it reaches normal
operating temperature. Check cooling system fluid
levels.
Fig. 37 Radiator
1 - SCREW
2 - SCREW
3 - LOWER MOUNT
4 - RADIATOR
5 - DRAINCOCK
6 -LOWER MOUNT
DRENGINE 7 - 55
RADIATOR-3.7L/4.7L/5.7L (Continued)

RADIATOR - 5.9L DIESEL
DESCRIPTION
The radiator is a aluminum cross-flow design with
horizontal tubes through the radiator core and verti-
cal plastic side tanks (Fig. 38).
This radiator does not contain an internal trans-
mission oil cooler.
OPERATION
The radiator supplies sufficient heat transfer using
the cooling fins interlaced between the horizontal
tubes in the radiator core to cool the engine.
DIAGNOSIS AND TESTING - RADIATOR
COOLANT FLOW
Use the following procedure to determine if coolant
is flowing through the cooling system.
(1) Idle engine until operating temperature is
reached. If the upper radiator hose is warm to the
touch, the thermostat is opening and coolant is flow-
ing to the radiator.
WARNING: HOT, PRESSURIZED COOLANT CAN
CAUSE INJURY BY SCALDING. USING A RAG TO
COVER THE RADIATOR PRESSURE CAP, OPEN
RADIATOR CAP SLOWLY TO THE FIRST STOP. THIS
WILL ALLOW ANY BUILT-UP PRESSURE TO VENT
TO THE RESERVE/OVERFLOW TANK. AFTER PRES-
SURE BUILD-UP HAS BEEN RELEASED, REMOVE
CAP FROM FILLER NECK.
(2) Drain a small amount of coolant from the radi-
ator until the ends of the radiator tubes are visible
through the filler neck. Idle the engine at normal
operating temperature. If coolant is flowing past the
exposed tubes, the coolant is circulating.
REMOVAL
(1) Disconnect both battery negative cables.
WARNING: DO NOT REMOVE THE CYLINDER
BLOCK DRAIN PLUGS OR LOOSEN THE RADIATOR
DRAINCOCK WITH THE SYSTEM HOT AND UNDER
PRESSURE. SERIOUS BURNS FROM COOLANT
CAN OCCUR.
(2) Drain the cooling system (Refer to 7 - COOL-
ING - STANDARD PROCEDURE).
WARNING: CONSTANT TENSION HOSE CLAMPS
ARE USED ON MOST COOLING SYSTEM HOSES.
WHEN REMOVING OR INSTALLING, USE ONLY
TOOLS DESIGNED FOR SERVICING THIS TYPE OF
CLAMP, SUCH AS SPECIAL CLAMP TOOL (NUMBER6094). ALWAYS WEAR SAFETY GLASSES WHEN
SERVICING CONSTANT TENSION CLAMPS.
CAUTION: A number or letter is stamped into the
tongue of constant tension clamps. If replacement
is necessary, use only an original equipment clamp
with a matching number or letter.
(3) Remove air box and turbocharger inlet tube.
(4) Remove coolant tank hose, washer bottle hose
and the positive battery cable from the fastening
clips located on top of the radiator.
(5) Remove hose clamps and hoses from radiator.
(6) Remove the power steering cooler mounting
bolts and position the power steering cooler out of
the way.
(7) Disconnect the transmission cooler lines at the
transmission cooler. The transmission cooler will
remain on the radiator and can be removed as an
assembly.
(8) Disconnect the electronic viscous fan drive elec-
trical connector.
(9) Using a fastener removal tool, remove the two
push pins and the lower shroud assembly and elec-
tronic viscous fan drive wiring from the upper shroud
assembly. Position wiring out of the way. Do not
impact or damage the electronic viscous fan drive or
pull it's wiring.
(10) Using a fastener tool, remove the wiring har-
ness bracket from the upper fan shroud.
(11) Remove the two radiator upper mounting
bolts (Fig. 38).
(12) Lift radiator straight up and out of engine
compartment. The bottom of the radiator is equipped
with two alignment dowels that fit into holes in the
lower radiator support panel. Rubber biscuits (insu-
lators) are installed to these dowels. Take care not to
damage cooling fins or tubes on the radiator and air
conditioning condenser or the electronic viscous fan
connector when removing.
CLEANING
Clean radiator fins are necessary for good heat
transfer. The radiator and oil cooler fins should be
cleaned when an accumulation of debris has
occurred. With the engine cold, apply cold water and
compressed air to the back (engine side) of the radi-
ator to flush the radiator and/or oil coolers of debris.
INSPECTION
Inspect the radiator side tanks for cracks, and bro-
ken or missing fittings. Inspect the joint where the
tanks seam up to the radiator core for signs of leak-
age and/or deteriorating seals.
Inspect radiator core for corroded, bent or missing
cooling fins. Inspect the core for bent or damaged
cooling tubes.
7 - 56 ENGINEDR

OPERATION
The transmission oil is routed through the main
cooler first, then the auxiliary cooler where addi-
tional heat is removed from the transmission oil
before returning to the transmission. The auxiliary
cooler has an internal thermostat that controls fluid
flow through the cooler. When the transmission fluid
is cold (less then operating temperature), the fluid is
routed through the cooler bypass. When the trans-
mission fluid reaches operating temperatures and
above, the thermostat closes off the bypass allowing
fluid flow through the cooler. The thermostat is ser-
vicable.
REMOVAL
REMOVAL - AIR TO OIL COOLER
(1) Remove Charge Air Cooler (Refer to 11 -
EXHAUST SYSTEM/TURBOCHARGER SYSTEM/
CHARGE AIR COOLER AND PLUMBING -
REMOVAL).
(2) Place a drain pan under the oil cooler.
(3) Raise the vehicle.
(4) Disconnect the oil cooler quick-connect fittings
from the transmission lines.
(5) Remove the charge air cooler-to-oil cooler bolt
(Fig. 5).
(6) Remove two mounting nuts.
(7) Remove the oil cooler and line assembly
towards the front of vehicle. Cooler must be rotated
and tilted into position while removing.
REMOVAL - WATER TO OIL COOLER
CAUTION: If a leak should occur in the water-to-oil
cooler mounted to the side of the engine block,
engine coolant may become mixed with transmis-
sion fluid. Transmission fluid may also enter engine
cooling system. Both cooling system and transmis-
sion should be drained and inspected in case of oil
cooler leakage.
(1) Disconnect both battery negative cables.
(2) Remove starter (Refer to 8 - ELECTRICAL/
STARTING/STARTER MOTOR - REMOVAL).
(3) Drain cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(4) Disconnect coolant lines from cooler.
(5) Disconnect transmission oil lines from cooler.
Plug cooler lines to prevent oil leakage.
(6) Remove cooler bracket to transmission adapter
bolt.
(7) Remove two cooler bracket to block bolts.
(8) Remove cooler assembly from vehicle. (Fig. 6)
Fig. 5 Auxiliary Transmission Oil CoolerÐDiesel
Engine
1 - MOUNTING BOLTS
2 - THERMOSTATIC BYPASS VALVE
3 - RADIATOR
4 - QUICK-CONNECT FITTINGS
5 - TRANSMISSION OIL COOLER
Fig. 6 Transmission Water-To- Oil Cooler - Diesel
1 - TRANSMISSION WATER-TO-OIL COOLER
DRTRANSMISSION 7 - 69
TRANS COOLER - 5.9L DIESEL (Continued)

(3) Remove instrument panel center bezel (Refer to
23 - BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL CENTER BEZEL - REMOVAL).
(4) Remove instrument panel lower right center
bezel (Refer to 23 - BODY/INSTRUMENT PANEL/IP
LOWER RIGHT CENTER BEZEL - REMOVAL).
(5) Disconnect electrical harness connector from
amplifier (Fig. 1).
(6) Remove mounting bolts.
INSTALLATION
(1) Connect electrical harness connector and
install amplifier.
(2) Install mounting bolts. Tighten to 10 N´m (90
in. lbs.).
(3) Install instrument panel lower right center
bezel (Refer to 23 - BODY/INSTRUMENT PANEL/IP
LOWER RIGHT CENTER BEZEL - INSTALLA-
TION).
(4) Install instrument panel center bezel (Refer to
23 - BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL CENTER BEZEL - INSTALLATION).
(5) Install glove box (Refer to 23 - BODY/INSTRU-
MENT PANEL/GLOVE BOX - INSTALLATION).
(6) Connect battery negative cable.
ANTENNA BODY & CABLE
DESCRIPTION
The antenna body and cable is secured below the
fender panel by the antenna cap nut through a
mounting hole in the right front fender. The primary
coaxial antenna cable is then routed beneath the
fender sheet metal and through a entry hole in theright cowl side panel into the interior of the vehicle.
Inside the vehicle, the primary coaxial cable is con-
nected to a secondary instrument panel antenna
coaxial cable with an in-line connector that is located
behind the right kick panel. The secondary coaxial
cable is then routed behind the instrument panel to
the back of the radio.
OPERATION
The antenna body and cable connects the antenna
mast to the radio. The radio antenna is an electro-
magnetic circuit component used to capture radio fre-
quency signals that are broadcast by local
commercial radio stations in both the Amplitude
Modulating (AM) and Frequency Modulating (FM)
frequency ranges. These electromagnetic radio fre-
quency signals induce small electrical modulations
into the antenna as they move past the mast. The
antenna body transfers the weak electromagnetic
radio waves induced into the rigid antenna mast into
the center conductor of the flexible primary antenna
coaxial cable. The braided outer shield of the
antenna coaxial cable is grounded through both the
antenna body and the radio chassis, effectively
shielding the radio waves as they are conducted to
the radio. The radio then tunes and amplifies the
weak radio signals into stronger electrical signals in
order to operate the audio system speakers.
DIAGNOSIS AND TESTING - ANTENNA BODY
AND CABLE
The following four tests are used to diagnose the
antenna with an ohmmeter:
²Test 1- Mast to ground test
²Test 2- Tip-of-mast to tip-of-conductor test
²Test 3- Body ground to battery ground test
²Test 4- Body ground to antenna coaxial cable
shield test.
WARNING: DISABLE THE AIRBAG SYSTEM
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, SEAT BELT TENSIONER, SIDE
AIRBAG, 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 ohmmeter test lead connections for each test
are shown in the illustration (Fig. 2).
Fig. 1 AMPLIFIER MOUNTING
1 - INSTRUMENT PANEL
2 - AMPLIFIER
3 - MOUNTING BOLTS
4 - ELECTRICAL CONNECTOR
8A - 4 AUDIO/VIDEODR
AMPLIFIER (Continued)

Engine Control Module (ECM) over the PCI data bus
to illuminate the check gauges indicator for a coolant
temperature high condition.
²Fasten Seat Belt Warning- The instrument
cluster chime tone generator will generate repetitive
chimes at a slow rate each time the ignition switch is
turned to the On or Start positions to announce that
the hard wired inputs from the seat belt switch and
the ignition switch indicate that the driver side front
seat belt is not fastened. The chimes will continue to
sound for a duration of about six seconds, until the
driver side front seat belt is fastened, or until the
ignition switch is turned to the Off position, which-
ever occurs first.
²Head/Park Lamps-On Warning- The instru-
ment cluster chime tone generator will generate
repetitive chimes at a slow rate to announce that the
hard wired inputs from the driver door ajar switch,
the ignition switch, and the exterior lighting circuitry
of the headlamp switch indicate that the exterior
lamps are turned On with the driver door opened
and the ignition switch in the Off position. The
chimes will continue to sound until the exterior
lamps are turned Off, the driver door is closed, or the
ignition switch is turned to the On position, or the
battery protection time-out expires, whichever occurs
first.
²Key-In-Ignition Warning- The instrument
cluster chime tone generator will generate repetitive
chimes at a slow rate to announce that the hard
wired inputs from the driver door ajar switch, the
ignition switch, and the key-in ignition circuitry of
the ignition switch indicate that the key is in the
ignition lock cylinder with the driver door opened
and the ignition switch in the Off position. The
chimes will continue to sound until the key is
removed from the ignition lock cylinder, the driver
door is closed, or the ignition switch is turned to the
On position, whichever occurs first.
²Low Fuel Warning- The instrument cluster
chime tone generator will generate one chime tone
when the low fuel indicator is illuminated by the
instrument cluster. The instrument cluster uses a
percent tank full message input received from the
PCM over the PCI data bus indicating that there is
less than about one-eighth tank of fuel remaining to
illuminate the low fuel indicator. This chime feature
will only occur once in an ignition cycle.
²Low Oil Pressure Warning (Diesel Engine
Only)- The instrument cluster chime tone generator
will generate repetitive chimes at a fast rate when
the check gauges indicator is illuminated for a low oil
pressure condition. The instrument cluster uses
engine speed and oil pressure message inputs
received from the diesel Engine Control Module
(ECM) over the PCI data bus indicating that theengine is running and that the oil pressure is low to
illuminate the check gauges indicator. The chimes
will continue to sound for five seconds, until the
engine oil pressure message indicates that the oil
pressure is not low, or until the engine speed mes-
sage indicates that the engine is not running, which-
ever occurs first. This chime tone will only occur once
in an ignition cycle.
²Low Wash Warning- The instrument cluster
chime tone generator will generate one chime tone
when the low washer fluid indicator is illuminated by
the instrument cluster. The instrument cluster uses a
message input received from the Front Control Mod-
ule (FCM) over the PCI data bus indicating that
washer fluid level is low within the washer reservoir.
This chime feature will only occur once in an ignition
cycle.
²Overspeed Warning- The instrument cluster
chime tone generator will generate one chime tone to
announce that a vehicle speed message input
received from the PCM over the PCI data bus indi-
cates that the vehicle speed is above a pre-programed
limit.
²Park Brake Reminder- The instrument clus-
ter chime tone generator will generate ten repetitive
chimes at a slow rate to announce that the hard
wired input from the park brake switch and a vehicle
speed message input received from the PCM over the
PCI data bus indicates that the park brake is applied
and the vehicle is moving. This chime feature will
repeat each time the input conditions are met.
²Sentry Key Immobilizer System ªCustomer
Learnº Mode Announcement- This chime feature
is only active on vehicles equipped with the optional
Sentry Key Immobilizer System (SKIS) and sold in
markets where the optional ªCustomer Learnº pro-
gramming feature is available. The instrument clus-
ter chime tone generator will generate one chime to
announce that a status message input received from
the Sentry Key Immobilizer Module (SKIM) over the
PCI data bus indicates that the SKIS is in the ªCus-
tomer Learnº mode, which is used for programming
additional sentry key transponders.
²Transmission Temperature High Warning
(Automatic Transmission only)- The instrument
cluster chime tone generator will generate repetitive
chimes at a slow rate when the transmission temper-
ature indicator is illuminated for a high or critical
transmission fluid temperature condition. The instru-
ment cluster uses transmission temperature message
inputs received from the Transmission Control Mod-
ule (TCM) over the PCI data bus to illuminate the
indicator for a transmission temperature high condi-
tion.
²Turn Signal On Warning- The instrument
cluster chime tone generator will generate repetitive
8B - 2 CHIME/BUZZERDR
CHIME WARNING SYSTEM (Continued)

chimes at a slow rate to announce that the hard
wired input for the right or left turn signal indicator
as well as vehicle distance and speed message inputs
received from the PCM over the PCI data bus indi-
cate that a turn signal has been active continuously
for 1.6 kilometers (1 mile) with the vehicle speed
greater than 22 kilometers-per-hour (15 miles-per
hour). Vehicles built for markets other than the
United States and Canada have a revised distance
threshold of 4 kilometers for this feature. The chime
will continue until the turn signal input becomes
inactive, the status changes, or until the vehicle
speed message indicates that the speed is less than
22 kilometers-per-hour (15 miles-per-hour), which-
ever occurs first. The hazard warning flashers will
not activate this chime feature.
²Warning Lamp Announcement- The instru-
ment cluster chime tone generator will generate a
single chime when the check gauges indicator is illu-
minated when any critical engine and transmission
systems are out of their operating parameters. The
instrument cluster uses system inputs received over
the PCI data bus to illuminate the check gauges indi-
cator.
The instrument cluster provides chime service for
all available features in the chime warning system.
The instrument cluster relies upon its internal pro-
gramming, hard wired inputs from numerous
switches, and electronic message inputs received
from other electronic modules over the PCI data bus
network. Upon receiving the proper inputs, the
instrument cluster activates the integral chime tone
generator to provide the audible chime to the vehicle
operator. The chime tone generator in the instrument
cluster is capable of producing single chime tones, or
repeated chime tones at two different rates: about
fifty chime tones per minute, or about 180 chime
tones per minute. The internal programming of the
instrument cluster determines the priority of each
chime request input that is received, as well as the
rate and duration of each chime that is to be gener-
ated.
The hard wired chime warning system inputs to
the instrument cluster, as well as other hard wiredcircuits for this system may be diagnosed and tested
using conventional diagnostic tools and procedures.
However, conventional diagnostic methods may not
prove conclusive in the diagnosis of the instrument
cluster or the PCI data bus network. The most reli-
able, efficient and accurate means to diagnose the
instrument cluster and the PCI data bus network
inputs for the chime warning system requires the use
of a DRBIIItscan tool. Refer to the appropriate diag-
nostic information.
DIAGNOSIS AND TESTING - CHIME WARNING
SYSTEM
The chime warning system features driven by hard
wired inputs to the instrument cluster may be diag-
nosed and tested using conventional diagnostic tools
and procedures. However, conventional diagnostic
methods may not prove conclusive in the diagnosis of
the chime warning system features driven by mes-
sage inputs to the instrument cluster over the Pro-
grammable Communications Interface (PCI) data bus
network. The most reliable, efficient and accurate
means to diagnose the instrument cluster and the
PCI data bus network inputs for the chime warning
system requires the use of a DRBIIItscan tool. Refer
to the appropriate diagnostic and 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.
DRCHIME/BUZZER 8B - 3
CHIME WARNING SYSTEM (Continued)

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 Temperature
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
²Fuel pressure sensor
²Fan speed (engine cooling fan)
²Ground circuits
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
²Fan Clutch PWM
²Five volt sensor supply
²Fuel Control Actuator
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)
²Wait-to-start warning lamp (databus)
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.To avoid possible voltage spike damage to the
ECM, ignition key must be off, and both negative
battery cables must be disconnected before unplug-
ging ECM connectors.
(2) Disconnect both negative battery cables at both
batteries.
(3) Remove the 50±way and 60±way connector
bolts at the ECM. Note: The connector bolt is a
female allen head. As bolt is being removed, very
carefully remove connectors from the ECM.
(4) Remove five ECM mounting bolts and remove
ECM from the vehicle (Fig. 2).
INSTALLATION
Do not apply paint to ECM or a poor ground will
result.
(1) Position the ECM to the ECM support bracket
and install the five mounting bolts. Tighten the bolts
to 24 N´m (18 ft. lbs.).
(2) Check pin connectors in ECM, 50±way and
60±way connectors for corrosion or damage. Repair
as necessary.
(3) Clean pins in the 50±way and 60±way electri-
cal connectors with a electrical contact cleaner.
(4) Install the 50±way and 60±way connectors to
ECM. Tighten connector bolts to 3 N´m (27 in. lbs.).
(5) Reconnect both negative battery cables.
(6) Use DRBIIItscan tool to erase any stored com-
panion DTC's from 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
ENGINE CONTROL MODULE (Continued)

HEATED SEAT MODULE
DESCRIPTION
The heated seat module is also known as the Seat
Heat Interface Module. The heated seat module (Fig.
3) 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-ments and sensors, and controls the ground for the
heated seat switch indicator lamps.
When a heated seat switch (Driver or Passenger) is
depressed a signal is received by the heated seat
module, the module energizes the proper indicator
LED (Low or High) in the switch by grounding the
indicator lamp circuit to indicate that the heated seat
system is operating. At the same time, the heated
seat module energizes the selected heated seat sensor
circuit and the sensor provides the module with an
input indicating the surface temperature of the
selected seat cushion.
The Low heat set point is about 36É C (96.8É F),
and the High heat set point is about 42É C (107.6É F).
If the seat cushion surface temperature input is
below the temperature set point for the selected tem-
perature setting, the heated seat module energizes
an N-channel Field Effect Transistor (N-FET) within
the module which energizes the heated seat elements
in the selected seat cushion and back. When the sen-
sor input to the module indicates the correct temper-
ature set point has been achieved, the module
de-energizes the N-FET which de-energizes the
heated seat elements. The heated seat module will
continue to cycle the N-FET as needed to maintain
the selected temperature set point.
If the heated seat module detects a heated seat
sensor value input that is out of range or a shorted
or open heated seat element circuit, it will notify the
vehicle operator or the repair technician of this con-
dition by flashing the High and/or Low indicator
lamps in the affected heated seat switch. Refer to
Diagnosis and Testing Heated Seat Systemin
Heated Systems for flashing LED diagnosis and test-
ing procedures. Refer toDiagnosis and Testing
Heated Seat Modulein this section for heated seat
module diagnosis and testing procedures.
DIAGNOSIS AND TESTING - HEATED SEAT
MODULE
If a heated seat fails to heat and one or both of the
indicator lamps on a heated seat switch flash, refer
toDiagnosis and Testing Heated Seat Systemin
Heated Seats for the location of flashing LED heated
seat system diagnosis and testing procedures. If a
heated seat heats but one or both indicator lamps on
the heated seat switch fail to operate, test the heated
seat switch. Refer toDiagnosis and Testing
Heated Seat Switchin Heated Seats for heated
seat switch diagnosis and testing procedures. If the
heated seat switch checks OK, proceed as follows.
(1) Check the heated seat element (Refer to 8 -
ELECTRICAL/HEATED SEATS/HEATED SEAT
ELEMENT - DIAGNOSIS AND TESTING).
Fig. 3 Heated Seat Module
1 - MOUNTING TABS (NOT USED ON DR)
2 - HEATED SEAT MODULE
3 - ELECTRICAL CONNECTOR RECEPTACLE
8E - 6 ELECTRONIC CONTROL MODULESDR

During Closed Loop modes, the PCM will monitor
the oxygen (O2S) sensors input. This input indicates
to the PCM whether or not the calculated injector
pulse width results in the ideal air-fuel ratio. This
ratio is 14.7 parts air-to-1 part fuel. By monitoring
the exhaust oxygen content through the O2S sensor,
the PCM can fine tune the injector pulse width. This
is done to achieve optimum fuel economy combined
with low emission engine performance.
The fuel injection system has the following modes
of operation:
²Ignition switch ON
²Engine start-up (crank)
²Engine warm-up
²Idle
²Cruise
²Acceleration
²Deceleration
²Wide open throttle (WOT)
²Ignition switch OFF
The ignition switch On, engine start-up (crank),
engine warm-up, acceleration, deceleration and wide
open throttle modes are Open Loop modes. The idle
and cruise modes, (with the engine at operating tem-
perature) are Closed Loop modes.
IGNITION SWITCH (KEY-ON) MODE
This is an Open Loop mode. When the fuel system
is activated by the ignition switch, the following
actions occur:
²The PCM pre-positions the idle air control (IAC)
motor.
²The PCM determines atmospheric air pressure
from the MAP sensor input to determine basic fuel
strategy.
²The PCM monitors the engine coolant tempera-
ture sensor input. The PCM modifies fuel strategy
based on this input.
²Intake manifold air temperature sensor input is
monitored.
²Throttle position sensor (TPS) is monitored.
²The auto shutdown (ASD) relay is energized by
the PCM for approximately three seconds.
²The fuel pump is energized through the fuel
pump relay by the PCM. The fuel pump will operate
for approximately three seconds unless the engine is
operating or the starter motor is engaged.
²The O2S sensor heater element is energized via
the ASD or O2S heater relay. The O2S sensor input
is not used by the PCM to calibrate air-fuel ratio dur-
ing this mode of operation.
ENGINE START-UP MODE
This is an Open Loop mode. The following actions
occur when the starter motor is engaged.
The PCM receives inputs from:²Battery voltage
²Engine coolant temperature sensor
²Crankshaft position sensor
²Intake manifold air temperature sensor
²Manifold absolute pressure (MAP) sensor
²Throttle position sensor (TPS)
²Camshaft position sensor signal
The PCM monitors the crankshaft position sensor.
If the PCM does not receive a crankshaft position
sensor signal within 3 seconds of cranking the
engine, it will shut down the fuel injection system.
The fuel pump is activated by the PCM through
the fuel pump relay.
Voltage is applied to the fuel injectors with the
ASD relay via the PCM. The PCM will then control
the injection sequence and injector pulse width by
turning the ground circuit to each individual injector
on and off.
The PCM determines the proper ignition timing
according to input received from the crankshaft posi-
tion sensor.
ENGINE WARM-UP MODE
This is an Open Loop mode. During engine warm-
up, the PCM receives inputs from:
²Battery voltage
²Crankshaft position sensor
²Engine coolant temperature sensor
²Intake manifold air temperature sensor
²Manifold absolute pressure (MAP) sensor
²Throttle position sensor (TPS)
²Camshaft position sensor signal
²Park/neutral switch (gear indicator signalÐauto.
trans. only)
²Air conditioning select signal (if equipped)
²Air conditioning request signal (if equipped)
Based on these inputs the following occurs:
²Voltage is applied to the fuel injectors with the
ASD relay via the PCM. The PCM will then control
the injection sequence and injector pulse width by
turning the ground circuit to each individual injector
on and off.
²The PCM adjusts engine idle speed through the
idle air control (IAC) motor and adjusts ignition tim-
ing.
²The PCM operates the A/C compressor clutch
through the A/C compressor clutch relay. This is done
if A/C has been selected by the vehicle operator and
specified pressures are met at the high and low±pres-
sure A/C switches. Refer to Heating and Air Condi-
tioning for additional information.
²When engine has reached operating tempera-
ture, the PCM will begin monitoring O2S sensor
input. The system will then leave the warm-up mode
and go into closed loop operation.
8E - 8 ELECTRONIC CONTROL MODULESDR
POWERTRAIN CONTROL MODULE (Continued)

IDLE MODE
When the engine is at operating temperature, this
is a Closed Loop mode. At idle speed, the PCM
receives inputs from:
²Air conditioning select signal (if equipped)
²Air conditioning request signal (if equipped)
²Battery voltage
²Crankshaft position sensor
²Engine coolant temperature sensor
²Intake manifold air temperature sensor
²Manifold absolute pressure (MAP) sensor
²Throttle position sensor (TPS)
²Camshaft position sensor signal
²Battery voltage
²Park/neutral switch (gear indicator signalÐauto.
trans. only)
²Oxygen sensors
Based on these inputs, the following occurs:
²Voltage is applied to the fuel injectors with the
ASD relay via the PCM. The PCM will then control
injection sequence and injector pulse width by turn-
ing the ground circuit to each individual injector on
and off.
²The PCM monitors the O2S sensor input and
adjusts air-fuel ratio by varying injector pulse width.
It also adjusts engine idle speed through the idle air
control (IAC) motor.
²The PCM adjusts ignition timing by increasing
and decreasing spark advance.
²The PCM operates the A/C compressor clutch
through the A/C compressor clutch relay. This is done
if A/C has been selected by the vehicle operator and
specified pressures are met at the high and low±pres-
sure A/C switches. Refer to Heating and Air Condi-
tioning for additional information.
CRUISE MODE
When the engine is at operating temperature, this
is a Closed Loop mode. At cruising speed, the PCM
receives inputs from:
²Air conditioning select signal (if equipped)
²Air conditioning request signal (if equipped)
²Battery voltage
²Engine coolant temperature sensor
²Crankshaft position sensor
²Intake manifold air temperature sensor
²Manifold absolute pressure (MAP) sensor
²Throttle position sensor (TPS)
²Camshaft position sensor signal
²Park/neutral switch (gear indicator signalÐauto.
trans. only)²Oxygen (O2S) sensors
Based on these inputs, the following occurs:
²Voltage is applied to the fuel injectors with the
ASD relay via the PCM. The PCM will then adjust
the injector pulse width by turning the ground circuit
to each individual injector on and off.
²The PCM monitors the O2S sensor input and
adjusts air-fuel ratio. It also adjusts engine idle
speed through the idle air control (IAC) motor.
²The PCM adjusts ignition timing by turning the
ground path to the coil(s) on and off.
²The PCM operates the A/C compressor clutch
through the clutch relay. This happens if A/C has
been selected by the vehicle operator and requested
by the A/C thermostat.
ACCELERATION MODE
This is an Open Loop mode. The PCM recognizes
an abrupt increase in throttle position or MAP pres-
sure as a demand for increased engine output and
vehicle acceleration. The PCM increases injector
pulse width in response to increased throttle opening.
DECELERATION MODE
When the engine is at operating temperature, this
is an Open Loop mode. During hard deceleration, the
PCM receives the following inputs.
²Air conditioning select signal (if equipped)
²Air conditioning request signal (if equipped)
²Battery voltage
²Engine coolant temperature sensor
²Crankshaft position sensor
²Intake manifold air temperature sensor
²Manifold absolute pressure (MAP) sensor
²Throttle position sensor (TPS)
²Camshaft position sensor signal
²Park/neutral switch (gear indicator signalÐauto.
trans. only)
²Vehicle speed
If the vehicle is under hard deceleration with the
proper rpm and closed throttle conditions, the PCM
will ignore the oxygen sensor input signal. The PCM
will enter a fuel cut-off strategy in which it will not
supply a ground to the injectors. If a hard decelera-
tion does not exist, the PCM will determine the
proper injector pulse width and continue injection.
Based on the above inputs, the PCM will adjust
engine idle speed through the idle air control (IAC)
motor.
The PCM adjusts ignition timing by turning the
ground path to the coil on and off.
DRELECTRONIC CONTROL MODULES 8E - 9
POWERTRAIN CONTROL MODULE (Continued)