Trouble code DODGE RAM 1500 1998 2.G Workshop Manual

OPERATION
OPERATION - COOLING SYSTEM
The cooling system regulates engine operating tem-
perature. It allows the engine to reach normal oper-
ating temperature as quickly as possible. It also
maintains normal operating temperature and pre-
vents overheating.
The cooling system also provides a means of heat-
ing the passenger compartment and cooling the auto-
matic transmission fluid (if equipped). The cooling
system is pressurized and uses a centrifugal water
pump to circulate coolant throughout the system.
All engines utilize an ambient overflow bottle for
coolant recovery/reserve.
An optional factory installed maximum duty cool-
ing package is available on most models. This pack-
age will provide additional cooling capacity for
vehicles used under extreme conditions such as
trailer towing in high ambient temperatures.
OPERATION - HOSE CLAMPS
The spring type hose clamp applies constant ten-
sion on a hose connection. To remove a spring type
hose clamp, only use constant tension clamp pliers
designed to compress the hose clamp.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTINGÐON-BOARD
DIAGNOSTICS (OBD)
COOLING SYSTEM RELATED DIAGNOSTICS
The Engine Control Module (ECM) has been pro-
grammed to monitor certain cooling system compo-
nents:
²If the engine has remained cool for too long a
period, such as with a stuck open thermostat, a Diag-
nostic Trouble Code (DTC) can be set.
²If an open or shorted condition has developed in
the electronically controlled viscous fan clutch circuit,
a Diagnostic Trouble Code (DTC) can be set.
²If fan speed is not detected a DTC will be set.
²Coolant temperature sensor circuit problems can
set a DTC.
If the problem is sensed in a monitored circuit
often enough to indicated an actual problem, a DTC
is stored. The DTC will be stored in the ECM mem-
ory for eventual display to the service technician.
(Refer to 25 - EMISSIONS CONTROL - DESCRIP-
TION).
ACCESSING DIAGNOSTIC TROUBLE CODES
To read DTC's and to obtain cooling system data,
(Refer to 25 - EMISSIONS CONTROL - DESCRIP-
TION).
ERASING TROUBLE CODES
After the problem has been repaired, use the
DRBIIItscan tool to erase a DTC. Refer to the
appropriate Powertrain Diagnostic Procedures ser-
vice information for operation of the DRBIIItscan
tool.
DIAGNOSIS AND TESTING - COOLING SYSTEM
- TESTING FOR LEAKS
ULTRAVIOLET LIGHT METHOD
A leak detection additive is available through the
parts department that can be added to cooling sys-
tem. The additive is highly visible under ultraviolet
light (black light). Pour one ounce of additive into
cooling system. Place heater control unit in HEAT
position. Start and operate the engine until the radi-
ator upper hose is warm to the touch. Aim the com-
mercially available black light tool at the components
to be checked. If leaks are present, the black light
will cause the additive to glow a bright green color.
The black light can be used in conjunction with a
pressure tester to determine if any external leaks
exist (Fig. 5).
Fig. 4 Spring Clamp Size Location
1 - SPRING CLAMP SIZE LOCATION
DRCOOLING 7 - 5
COOLING (Continued)

COOLING SYSTEM DIAGNOSIS CHART
CONDITION POSSIBLE CAUSES CORRECTION
TEMPERATURE GAUGE READS
LOW1. Has a Diagnostic Trouble Code
(DTC) been set indicating a stuck
open thermostat?1. (Refer to 25 - EMISSIONS
CONTROL - DESCRIPTION) for
On-Board Diagnostics and DTC
information. Replace thermostat if
necessary.
2. Is the temperature sending unit
connected?2. Check the temperature sensor
connector. (Refer to 8 -
ELECTRICAL/INSTRUMENT
CLUSTER - SCHEMATIC -
ELECTRICAL) Repair connector if
necessary.
3. Is the temperature gauge
operating OK?3. Check gauge operation. (Refer to
8 - ELECTRICAL/INSTRUMENT
CLUSTER/ENGINE
TEMPERATURE GAUGE -
DESCRIPTION). Repair as
necessary.
4. Coolant level low in cold ambient
temperatures accompanied with
poor heater performance.4. Check coolant level in the coolant
reserve/overflow tank or degas
bottle and the radiator. Inspect
system for leaks. Repair leaks as
necessary. Refer to the Coolant
section of the manual text for
WARNINGS and CAUTIONS
associated with removing the
radiator cap.
5. Improper operation of internal
heater doors or heater controls.5. Inspect heater and repair as
necessary. (Refer to 24 - HEATING
& AIR CONDITIONING -
DIAGNOSIS AND TESTING) for
procedures.
TEMPERATURE GAUGE READS
HIGH OR THE COOLANT
WARNING LAMP ILLUMINATES.
COOLANT MAY OR MAY NOT BE
LOST OR LEAKING FROM THE
COOLING SYSTEM1. Trailer is being towed, a steep
hill is being climbed, vehicle is
operated in slow moving traffic, or
engine is being idled with very high
ambient (outside) temperatures and
the air conditioning is on. Higher
altitudes could aggravate these
conditions.1. This may be a temporary
condition and repair is not
necessary. Turn off the air
conditioning and attempt to drive the
vehicle without any of the previous
conditions. Observe the temperature
gauge. The gauge should return to
the normal range. If the gauge does
not return to the normal range,
determine the cause for overheating
and repair. Refer to Possible
Causes (2-18).
2. Is the temperature gauge reading
correctly?2. Check gauge. (Refer to 8 -
ELECTRICAL/INSTRUMENT
CLUSTER - SCHEMATIC -
ELECTRICAL). Repair as
necessary.
DRCOOLING 7 - 11
COOLING (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
INADEQUATE HEATER
PERFORMANCE. THERMOSTAT
FAILED IN OPEN POSITION1. Has a Diagnostic trouble Code
(DTC) been set?1. (Refer to 25 - EMISSIONS
CONTROL - DESCRIPTION) for
correct procedures and replace
thermostat if necessary
2. Coolant level low 2. (Refer to 7 - COOLING -
DIAGNOSIS AND TESTING).
3. Obstructions in heater hose/
fittings3. Remove heater hoses at both
ends and check for obstructions
4. Heater hose kinked 4. Locate kinked area and repair as
necessary
5. Water pump is not pumping
water to/through the heater core.
When the engine is fully warmed
up, both heater hoses should be
hot to the touch. If only one of the
hoses is hot, the water pump may
not be operating correctly or the
heater core may be plugged.
Accessory drive belt may be
slipping causing poor water pump
operation.5. (Refer to 7 - COOLING/ENGINE/
WATER PUMP - REMOVAL). If a
slipping belt is detected, (Refer to 7
- COOLING/ACCESSORY
DRIVE/DRIVE BELTS - DIAGNOSIS
AND TESTING). If heater core
obstruction is detected, (Refer to 24
- HEATING & AIR
CONDITIONING/PLUMBING/
HEATER CORE - REMOVAL).
STEAM IS COMING FROM THE
FRONT OF VEHICLE NEAR THE
GRILL AREA WHEN WEATHER IS
WET, ENGINE IS WARMED UP
AND RUNNING, AND VEHICLE IS
STATIONARY. TEMPERATURE
GAUGE IS IN NORMAL RANGE1. During wet weather, moisture
(snow, ice or rain condensation) on
the radiator will evaporate when the
thermostat opens. This opening
allows heated water into the
radiator. When the moisture
contacts the hot radiator, steam
may be emitted. This usually occurs
in cold weather with no fan or air
flow to blow it away.1. Occasional steam emitting from
this area is normal. No repair is
necessary.
COOLANT COLOR 1. Coolant color is not necessarily
an indication of adequate corrosion
or temperature protection. Do not
rely on coolant color for determining
condition of coolant.1. (Refer to LUBRICATION &
MAINTENANCE/FLUID TYPES -
DESCRIPTION) Adjust coolant
mixture as necessary.
COOLANT LEVEL CHANGES IN
COOLANT RESERVE/OVERFLOW
TANK. TEMPERATURE GAUGE IS
IN NORMAL RANGE1. Level changes are to be
expected as coolant volume
fluctuates with engine temperature.
If the level in the tank was between
the FULL and ADD marks at normal
operating temperature, the level
should return to within that range
after operation at elevated
temperatures.1. A normal condition. No repair is
necessary.
7 - 16 COOLINGDR
COOLING (Continued)

DIAGNOSIS AND TESTINGÐTHERMOSTAT
ON-BOARD DIAGNOSTICS
Allgasoline powered modelsare equipped with
On-Board Diagnostics for certain cooling system com-
ponents. Refer to On-Board Diagnostics (OBD) in the
Diagnosis section of this group for additional infor-
mation. If the powertrain control module (PCM)
detects low engine coolant temperature, it will record
a Diagnostic Trouble Code (DTC) in the PCM mem-
ory. Do not change a thermostat for lack of heat as
indicated by the instrument panel gauge or by poor
heater performance unless a DTC is present. Refer to
the Diagnosis section of this group for other probable
causes.
The DTC can also be accessed through the
DRBIIItscan tool. Refer to the appropriate Power-
train Diagnostic Procedures information for diagnos-
tic information and operation of the DRBIIItscan
tool.
REMOVAL
WARNING: DO NOT LOOSEN THE RADIATOR
DRAINCOCK WITH THE COOLING SYSTEM HOT
AND PRESSURIZED. SERIOUS BURNS FROM THE
COOLANT CAN OCCUR.Do not waste reusable coolant. If the solution is
clean, drain the coolant into a clean container for
reuse.
If the thermostat is being replaced, be sure that
the replacement is the specified thermostat for the
vehicle model and engine type.
Factory installed thermostat housings on 5.9L
engine is installed on a gasket with an anti-stick
coating. This will aid in gasket removal and clean-up.
(1) Disconnect the negative battery cable.
(2) Drain the cooling system until the coolant level
is below the thermostat (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(3) Air Conditioned vehicles: Remove the support
bracket (generator mounting bracket-to-intake mani-
fold) located near the rear of the generator (Fig. 17).
NOTE: On air conditioning equipped vehicles, the
generator must be partially removed.
(4) Remove the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL) (Fig. 18).
(5) Remove the generator mounting bolts. Do not
remove any of the wiring at the generator. If
equipped with 4WD, unplug the 4WD indicator lamp
wiring harness (located near rear of generator).
(6) Remove the generator. Position the generator
to gain access for the thermostat gasket removal.
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. ALWAYS WEAR SAFETY GLASSES WHEN
SERVICING CONSTANT TENSION CLAMPS.
Fig. 16 Thermostat - 5.7L/5.9L Gas Powered
Engines
1 - THERMOSTAT HOUSING
2 - GASKET
3 - INTAKE MANIFOLD
4 - THERMOSTAT
5 - MACHINED GROOVE
Fig. 17 Generator Support Bracket ± 5.9L Engine
1 - IDLER PULLEY BUSHING
2 - A/C AND/OR GENERATOR MOUNTING BRACKET
3 - IDLER PULLEY
4 - SCREW AND WASHER
7 - 42 ENGINEDR
ENGINE COOLANT THERMOSTAT- 5.7L (Continued)

(7) Air Conditioned vehicles; Install the generator.
Tighten the bolts to 41 N´m (30 ft. lbs.).
(8) Install the support bracket (generator mount-
ing bracket-to-intake manifold). (Fig. 17). Tighten the
bolts to 54 N´m (40 ft. lbs.).
(9) Install the accessory drive belt (Fig. 18)(Refer
to 7 - COOLING/ACCESSORY DRIVE/DRIVE
BELTS - INSTALLATION).
(10) Fill the cooling system (Refer to 7 - COOLING
- STANDARD PROCEDURE).
(11) Connect battery negative cable.
(12) Start and warm the engine. Check for leaks.
ENGINE COOLANT
THERMOSTAT - 3.7L/4.7L
DESCRIPTION
CAUTION: Do not operate the engine without a ther-
mostat, except for servicing or testing.
A pellet-type thermostat controls the operating
temperature of the engine by controlling the amount
of coolant flow to the radiator. On all engines the
thermostat is closed below 195ÉF (90ÉC). Above this
temperature, coolant is allowed to flow to the radia-
tor. This provides quick engine warm up and overall
temperature control. On the 3.7L4.7L engine the
thermostat is designed to block the flow of the cool-
ant bypass journal by 50% instead of completely
blocking the flow. This design controls coolant tem-
perature more accurately (Fig. 23).The same thermostat is used for winter and sum-
mer seasons. An engine should not be operated with-
out a thermostat, except for servicing or testing.
Operating without a thermostat causes other prob-
lems. These are: longer engine warmup time, unreli-
able warmup performance, increased exhaust
emissions and crankcase condensation. This conden-
sation can result in sludge formation.
OPERATION
The wax pellet is located in a sealed container at
the spring end of the thermostat. When heated, the
pellet expands, overcoming closing spring tension
and water pump pressure to force the valve to open.
DIAGNOSIS AND TESTINGÐTHERMOSTAT
ON-BOARD DIAGNOSTICS
Allgasoline powered modelsare equipped with
On-Board Diagnostics for certain cooling system com-
ponents. Refer to On-Board Diagnostics (OBD) in the
Diagnosis section of this group for additional infor-
mation. If the powertrain control module (PCM)
detects low engine coolant temperature, it will record
a Diagnostic Trouble Code (DTC) in the PCM mem-
ory. Do not change a thermostat for lack of heat as
Fig. 21 Thermostat PositionÐ5.9L EnginesFig. 22 Belt Routing ± 5.9L Engines
1 - IDLER PULLEY
2 - GENERATOR PULLEY
3 - A/C COMPRESSOR PULLEY
4 - IF W/OUT A/C
5 - POWER STEERING PUMP PULLEY
6 - WATER PUMP PULLEY
7 - CRANKSHAFT PULLEY
8 - AUTOMATIC TENSIONER
7 - 44 ENGINEDR
ENGINE COOLANT THERMOSTAT- 5.7L (Continued)

(7) Start the engine and check for coolant leaks.
Run engine to check for proper thermostat operation.
ENGINE COOLANT
THERMOSTAT - 8.0L
DESCRIPTION
CAUTION: Do not operate an engine without a ther-
mostat, except for servicing or testing.
The thermostat on all gas powered engines is
located beneath the thermostat housing at the front
of the intake manifold (Fig. 27).
The thermostat is a moveable sleeve type.
Coolant leakage into the pellet container will cause
the thermostat to fail in the open position. Thermo-
stats very rarely stick. Do not attempt to free a ther-
mostat with a prying device.
The same thermostat is used for winter and sum-
mer seasons. An engine should not be operated with-
out a thermostat, except for servicing or testing.
Operating without a thermostat causes longer engine
warmup time, unreliable warmup performance,
increased exhaust emissions and crankcase condensa-
tion that can result in sludge formation.
OPERATION
The wax pellet is located in a sealed container at
the spring end of the thermostat. When heated, the
pellet expands, overcoming closing spring tension
and water pump pressure to force the valve to open.
DIAGNOSIS AND TESTING - THERMOSTAT
ON-BOARD DIAGNOSTICS
Allgasoline powered modelsare equipped with
On-Board Diagnostics for certain cooling system com-
ponents. Refer to On-Board Diagnostics (OBD) in the
Diagnosis section of this group for additional infor-
mation. If the powertrain control module (PCM)
detects low engine coolant temperature, it will record
a Diagnostic Trouble Code (DTC) in the PCM mem-
ory. Do not change a thermostat for lack of heat as
indicated by the instrument panel gauge or by poor
heater performance unless a DTC is present. Refer to
the Diagnosis section of this group for other probable
causes. For other DTC numbers, (Refer to 25 - EMIS-
SIONS CONTROL - DESCRIPTION).
Fig. 26 Thermostat Removal/Installation
1 - THERMOSTAT HOUSING
2 - CYLINDER HEAD
3 - THERMOSTAT
Fig. 27 Thermostat - 8.0L V-10 Engine
1 - COOLANT TEMP. SENSOR (FOR PCM)
2 - HEATER SUPPLY FITTING
3 - BOLTS (6)
4 - HOUSING WITH INTEGRAL SEAL
5 - THERMOSTAT
6 - RUBBER LIP SEAL
7 - TEMP. GAUGE SENDING UNIT
7 - 48 ENGINEDR
ENGINE COOLANT THERMOSTAT - 5.9L DIESEL (Continued)

The PCI data bus can be monitored using the
DRBIIItscan tool. It is possible, however, for the bus
to pass all DRBIIIttests and still be faulty if the
voltage parameters are all within the specified range
and false messages are being sent.
CONTROLLER ANTILOCK
BRAKE
DESCRIPTION
The Controler Antilock Brake (CAB) is mounted to
the Hydraulic Control Unit (HCU) and operates the
ABS system (Fig. 1).
OPERATION
The CAB voltage source is through the ignition
switch in the RUN position. The CAB contains a self
check program that illuminates the ABS warning
light when a system fault is detected. Faults are
stored in a diagnostic program memory and are
accessible with the DRB III scan tool. ABS faults
remain in memory until cleared, or until after the
vehicle is started approximately 50 times. Stored
faults arenoterased if the battery is disconnected.
NOTE: If the CAB is being replaced with a new CAB
is must be reprogrammed with the use of a DRB III.
REMOVAL
(1) Remove the negative battery cable from the
battery.
(2) Pull up on the CAB harness connector release
and remove connector.
(3) Remove the CAB mounting bolts.
(4) Remove the pump connector from the CAB.
(5) Remove the CAB from the HCU.
INSTALLATION
NOTE: If the CAB is being replaced with a new CAB
is must be reprogrammed with the use of a DRB III.
(1) Install CAB to the HCU.
(2) Install the pump connector to the CAB.
(3) Install mounting bolts. Tighten to 2 N´m (16 in.
lbs.).
(4) Install the wiring harness connector to the
CAB and push down on the release to secure the con-
nector.
(5) Install negative battery cable to the battery.
DATA LINK CONNECTOR
DESCRIPTION - DATA LINK CONNECTOR
The Data Link Connector (DLC) is located at the
lower edge of the instrument panel near the steering
column.
OPERATION - DATA LINK CONNECTOR
The 16±way data link connector (diagnostic scan
tool connector) links the Diagnostic Readout Box
(DRB) scan tool or the Mopar Diagnostic System
(MDS) with the Powertrain Control Module (PCM).
ENGINE CONTROL MODULE
DESCRIPTION - ECM
The engine control module (ECM) for the 5.9L Die-
sel engine is bolted to the left side of the engine
below the intake manifold.
OPERATION - ECM
The main function of the Engine Control Module
(ECM) is to electrically control the fuel system. The
Powertrain Control Module (PCM)does notcontrol
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.
Fig. 1 HYDRAULIC CONTROL UNIT
1 - HYDRAULIC CONTROL UNIT
2 - MOUNTING BOLTS
DRELECTRONIC CONTROL MODULES 8E - 3
COMMUNICATION (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)

REMOVAL
USE THE DRB SCAN TOOL TO REPROGRAM
THE NEW POWERTRAIN CONTROL MODULE
(PCM) WITH THE VEHICLES ORIGINAL IDEN-
TIFICATION NUMBER (VIN) AND THE VEHI-
CLES ORIGINAL MILEAGE. IF THIS STEP IS
NOT DONE, A DIAGNOSTIC TROUBLE CODE
(DTC) MAY BE SET.
The PCM is located in the engine compartment
attached to the dash panel (Fig. 5).
To avoid possible voltage spike damage to the
PCM, ignition key must be off, and negative battery
cable must be disconnected before unplugging PCM
connectors.
(1) Disconnect negative battery cable at battery.
(2) Remove cover over electrical connectors. Cover
snaps onto PCM.
(3) Carefully unplug the three 32±way connectors
(four 38±way connectors if equipped with NGC) from
PCM (Fig. 6).
(4) Remove three PCM mounting bolts (Fig. 6) and
remove PCM from vehicle.
INSTALLATION
USE THE DRB SCAN TOOL TO REPROGRAM
THE NEW POWERTRAIN CONTROL MODULE
(PCM) WITH THE VEHICLES ORIGINAL IDEN-
TIFICATION NUMBER (VIN) AND THE VEHI-
CLES ORIGINAL MILEAGE. IF THIS STEP ISNOT DONE, A DIAGNOSTIC TROUBLE CODE
(DTC) MAY BE SET.
(1) Install PCM and 3 mounting bolts to vehicle.
(2) Tighten bolts. Refer to torque specifications.
(3) Check pin connectors in the PCM and the three
32±way connectors (four 38±way connectors if
equipped with NGC) for corrosion or damage. Also,
the pin heights in connectors should all be same.
Repair as necessary before installing connectors.
(4) Install three 32±way connectors (four 38±way
connectors if equipped with NGC).
(5) Install cover over electrical connectors. Cover
snaps onto PCM.
(6) Install negative battery cable.
(7)The 5.7L V-8 engine is equipped with a
fully electronic accelerator pedal position sen-
sor. If equipped with a 5.7L, also perform the
following 3 steps:
(a) Connect negative battery cable to battery.
(b) Turn ignition switch ON, but do not crank
engine.
(c) Leave ignition switch ON for a minimum of
10 seconds. This will allow PCM to learn electrical
parameters.
(d) The DRB IIItScan Tool may also be used to
learn electrical parameters. Go to the Miscella-
neous menu, and then select ETC Learn.
Fig. 5 PCM LOCATION
1 - COWL GRILL
2 - PCM
3 - COWL (RIGHT-REAR)
Fig. 6 PCM REMOVAL / INSTALLATION
1 - THREE 32-WAY CONNECTORS WITH JTEC (FOUR 38-WAY
CONNECTORS WITH NGC)
2 - PCM MOUNTING BRACKET
3 - PCM
4 - PCM MOUNTING SCREWS (3)
8E - 12 ELECTRONIC CONTROL MODULESDR
POWERTRAIN CONTROL MODULE (Continued)

(8) If the previous step is not performed, a Diag-
nostic Trouble Code (DTC) will be set.
(9) If necessary, use DRB IIItScan Tool to erase
any Diagnostic Trouble Codes (DTC's) from PCM.
Also use the DRB scan tool to reprogram new PCM
with vehicles original Vehicle Identification Number
(VIN) and original vehicle mileage.
SENTRY KEY IMMOBILIZER
MODULE
DESCRIPTION
The Sentry Key Immobilizer Module (SKIM) con-
tains a Radio Frequency (RF) transceiver and a cen-
tral processing unit, which includes the Sentry Key
Immobilizer System (SKIS) program logic. The SKIS
programming enables the SKIM to program and
retain in memory the codes of at least two, but no
more than eight electronically coded Sentry Key
transponders. The SKIS programming also enables
the SKIM to communicate over the Programmable
Communication Interface (PCI) bus network with the
Powertrain Control Module (PCM) or Electronic Con-
trol Module (ECM), depending on engine application,
and/or the DRBIIItscan tool.
OPERATION
The SKIM transmits and receives RF signals
through a tuned antenna enclosed within a molded
plastic ring that is integral to the SKIM housing.
When the SKIM is properly installed on the steering
column, the antenna ring is oriented around the igni-
tion lock cylinder housing. This antenna ring must be
located within eight millimeters (0.31 inches) of the
Sentry Key in order to ensure proper RF communica-
tion between the SKIM and the Sentry Key tran-
sponder.
For added system security, each SKIM is pro-
grammed with a unique ªSecret Keyº code and a
security code. The SKIM keeps the ªSecret Keyº code
in memory. The SKIM also sends the ªSecret Keyº
code to each of the programmed Sentry Key tran-
sponders. The security code is used by the assembly
plant to access the SKIS for initialization, or by the
dealer technician to access the system for service.
The SKIM also stores in its memory the Vehicle
Identification Number (VIN), which it learns through
a PCI bus message from the PCM (NGC) or ECM
(Cummins) during initialization.The SKIM and the PCM/ECM both use software
that includes a rolling code algorithm strategy, which
helps to reduce the possibility of unauthorized SKIS
disarming. The rolling code algorithm ensures secu-
rity by preventing an override of the SKIS through
the unauthorized substitution of the SKIM or the
PCM/ECM. However, the use of this strategy also
means that replacement of either the SKIM or the
PCM/ECM units will require a system initialization
procedure to restore system operation.
When the ignition switch is turned to the ON or
START positions, the SKIM transmits an RF signal
to excite the Sentry Key transponder. The SKIM then
listens for a return RF signal from the transponder
of the Sentry Key that is inserted in the ignition lock
cylinder. If the SKIM receives an RF signal with
valid ªSecret Keyº and transponder identification
codes, the SKIM sends a ªvalid keyº message to the
PCM/ECM over the PCI bus. If the SKIM receives an
invalid RF signal or no response, it sends ªinvalid
keyº messages to the PCM/ECM. The PCM/ECM will
enable or disable engine operation based upon the
status of the SKIM messages.
The SKIM also sends messages to the Instrument
Cluster which controls the VTSS indicator LED. The
SKIM sends messages to the Instrument Cluster to
turn the LED on for about three seconds when the
ignition switch is turned to the ON position as a bulb
test. After completion of the bulb test, the SKIM
sends bus messages to keep the LED off for a dura-
tion of about one second. Then the SKIM sends mes-
sages to turn the LED on or off based upon the
results of the SKIS self-tests. If the VTSS indicator
LED comes on and stays on after the bulb test, it
indicates that the SKIM has detected a system mal-
function and/or that the SKIS has become inopera-
tive.
If the SKIM detects an invalid key when the igni-
tion switch is turned to the ON position, it sends
messages to flash the VTSS indicator LED. The
SKIM can also send messages to flash the LED as an
indication to the customer that the SKIS has been
placed in it's ªCustomer Learnº programming mode.
See Sentry Key Immobilizer System Transponder
Programming in this section for more information on
the ªCustomer Learnº programming mode.
For diagnosis or initialization of the SKIM and the
PCM/ECM, a DRBIIItscan tool and the proper Pow-
ertrain Diagnostic Procedures manual are required.
The SKIM cannot be repaired and, if faulty or dam-
aged, the unit must be replaced.
DRELECTRONIC CONTROL MODULES 8E - 13
POWERTRAIN CONTROL MODULE (Continued)