DLC DODGE RAM 1999 Service Owner's Guide

1) To install, reverse removal procedure. If installing small
vent tube and large fill tube on fuel tank, ensure fuel tank fittings
are clean.
2) Install disconnect fitting on fuel tank fitting until
disconnect fitting snaps onto fuel tank fitting. Pull on small vent
tube or and large fill tube to ensure disconnect fitting is locked on
fuel tank fitting. To verify proper installation of disconnect
fitting, ensure the distance between release sleeve and top of fuel
tank fitting is .50" (12.7 mm) on small vent tube or .25" (6.4 mm) o\
n
large fill tube. See Fig. 37.
3) Install fuel lines on fuel filter/fuel pressure regulator
on fuel pump module using proper procedure. See FUEL LINE DISCONNECT
FITTINGS under FUEL SYSTEM.
CAUTION: DO NOT overtighten fuel tank strap retaining nuts during
installation.
4) Tighten fuel tank strap retaining nuts to specification.
See TORQUE SPECIFICATIONS. To install remaining components, reverse
removal procedure. Start engine and check for fuel leaks.
Removal (Durango)
1) Fuel tank may be drained by removing vent hose from rear
of fuel tank, or by pumping fuel from fuel tank using the fuel pump if
fuel pump is operating. If removing vent hose from fuel tank to drain
the fuel, go to step 4). If using fuel pump to drain the fuel tank, go
to next step.
2) Disconnect fuel line from fuel rail. See FUEL LINE AT FUEL
RAIL under FUEL SYSTEM. Connect Fuel Hose (6541, 6539, 6631 or 6923)
for proper engine application at fuel line fitting on fuel rail. Place
remaining end of fuel hose in an approved gasoline container.
3) Connect scan tool to Data Link Connector (DLC). DLC is a
16-pin connector attached to bottom of driver's side of the instrument
panel, just to the right of the brake pedal. Using scan tool
manufacturer's instructions, activate the fuel pump and pump fuel from
fuel tank. Once fuel tank is empty, remove scan tool. Reinstall fuel
line on fuel rail using proper procedure. Go to step 5).
4) Release fuel pressure from fuel system. See FUEL SYSTEM
PRESSURE RELEASE. Ensure negative battery cable is disconnected.
Remove fuel tank cap to release any residual fuel tank pressure.
5) Raise and support vehicle. Remove necessary skid plates
for access to fuel tank. Disconnect vent and filler hose from rear of
fuel tank. If fuel tank was not previously drained, place drain hose
in vent hose fitting at rear of fuel tank. Drain fuel from fuel tank
into an approved gasoline container.
6) Support fuel tank with transmission jack. Remove fuel tank
strap retaining nuts. Position fuel tank straps toward outside of
vehicle. Slightly lower fuel tank. Ensure rear of fuel tank is higher
than front of fuel tank to prevent any spilling any remaining fuel in
fuel tank.
7) Disconnect fuel line from fuel filter/fuel pressure
regulator on fuel pump module using proper procedure for fuel line
disconnect fitting. See FUEL LINE DISCONNECT FITTINGS. Fuel pump
module is located on top of fuel tank. See Fig. 28. Disconnect
electrical connector at fuel pump module. Disconnect vapor line from
rollover valves on top of fuel tank and EVAP line from fuel pump
module. Lower fuel tank from vehicle.
CAUTION: DO NOT overtighten fuel tank strap retaining nuts during
installation.
Installation
1) To install, reverse removal procedure. Install fuel lines

on fuel filter/fuel pressure regulator on fuel pump module using
proper procedure. See FUEL LINE DISCONNECT FITTINGS.
2) Tighten fuel tank strap retaining nuts to specification.
See TORQUE SPECIFICATIONS. Start engine and check for fuel leaks.
Removal (Ram Pickup)
1) Fuel tank may be drained by lowering fuel tank, or by
pumping fuel from fuel tank using the fuel pump if fuel pump is
operating. If lowering fuel tank to drain the fuel, go to step 4). If
using fuel pump to drain the fuel tank, go to next step.
2) Disconnect fuel line from fuel rail. See FUEL LINE AT FUEL
RAIL. Connect Fuel Hose (6541, 6539, 6631 or 6923) for proper engine
application at fuel line fitting on fuel rail. Place remaining end of
fuel hose in an approved gasoline container.
3) Connect scan tool to Data Link Connector (DLC). DLC is a
16-pin connector attached to bottom of driver's side of the instrument
panel, just straight above the accelerator pedal. Using scan tool
manufacturer's instructions, activate the fuel pump and pump fuel from
fuel tank. Once fuel tank is empty, remove scan tool. Reinstall fuel
line on fuel rail using proper procedure. Go to step 5).
4) Release fuel pressure from fuel system. See FUEL SYSTEM
PRESSURE RELEASE. Ensure negative battery cable is disconnected.
Remove fuel tank cap to release any residual fuel tank pressure.
5) Raise and support vehicle. Open fuel tank filler door.
Remove fuel tank filler tube assembly-to-body screws. Support fuel
tank with transmission jack. Remove fuel tank strap retaining nuts.
6) Slightly lower fuel tank. If fuel tank was not previously
drained, slightly rotate fuel tank so vent hose and filler hose on
fuel tank are above the fuel level in the fuel tank to prevent fuel
leakage when hoses are disconnected. Vent hose and filler hose attach
to fitting on the fuel tank. See Fig. 29.
7) Disconnect vent hose from vent hose fitting on fuel tank.
If fuel tank was previously drained, go to next step. If fuel tank was
not previously drained, place drain hose in vent hose fitting on fuel
tank. Drain fuel from fuel tank into an approved gasoline container.
Go to next step.
8) Disconnect filler hose from filler hose fitting on fuel
tank. Disconnect electrical connector at fuel pump module. Fuel pump
module is located on top of fuel tank. See Fig. 29.
9) Disconnect fuel line from fuel filter/fuel pressure
regulator on fuel pump module using proper procedure for fuel line
disconnect fitting. See FUEL LINE DISCONNECT FITTINGS under FUEL
SYSTEM.
10) Disconnect necessary vapor hoses from rollover valves on
top of fuel tank or fuel pump module. See Fig. 29. Lower fuel tank
from vehicle.
CAUTION: DO NOT overtighten fuel tank strap retaining nuts during
installation.
Installation
1) To install, reverse removal procedure. Install fuel lines
on fuel filter/fuel pressure regulator on fuel pump module using
proper procedure. See FUEL LINE DISCONNECT FITTINGS.
2) Tighten fuel tank strap retaining nuts to specification.
See TORQUE SPECIFICATIONS. Start engine and check for fuel leaks.
Removal (Ram Van & Ram Wagon)
1) Fuel tank may be drained by siphoning fuel out through
small vent hose on fuel and vent hose fitting assembly on fuel tank,
or by pumping fuel from fuel tank using the fuel pump if fuel pump is
operating. If siphoning fuel out through small vent hose on fuel and
vent hose fitting assembly on fuel tank, go to step 4). If using fuel

pump to drain the fuel tank, go to next step.
2) Disconnect fuel line from fuel rail. See FUEL LINE AT FUEL
RAIL. Connect Fuel Hose (6541, 6539, 6631 or 6923) for proper engine
application at fuel line fitting on fuel rail. Place remaining end of
fuel hose in an approved gasoline container.
3) Connect scan tool to Data Link Connector (DLC). DLC is a
16-pin connector attached to bottom of driver's side of the instrument
panel, just straight above the accelerator pedal. Using scan tool
manufacturer's instructions, activate the fuel pump and pump fuel from
fuel tank. Once fuel tank is empty, remove scan tool. Reinstall fuel
line on fuel rail using proper procedure. Go to step 5).
4) Release fuel pressure from fuel system. See FUEL SYSTEM
PRESSURE RELEASE. Ensure negative battery cable is disconnected.
Remove fuel tank cap to release any residual fuel tank pressure.
5) Raise and support vehicle. Disconnect the small vent hose
from fill and vent hose fitting assembly at driver's side frame rail.
Fill and vent hose fitting assembly is permanently attached on fuel
tank. See Fig. 30.
6) If fuel tank was previously drained, go to next step. If
fuel tank was not previously drained, siphon fuel from fuel tank into
an approved gasoline container by installing siphon hose in small vent
hose fitting on fill and vent hose fitting assembly. Go to next step.
7) Disconnect large fill hose from fill and vent hose fitting
assembly at driver's side frame rail. Fill and vent hose fitting
assembly is permanently attached on fuel tank. See Fig. 30.
8) Support fuel tank with transmission jack. Remove fuel tank
strap retaining nuts from L-shaped bolts securing fuel tank straps on
frame rail. Remove fuel tank straps.
CAUTION: Fill and vent hose fitting assembly must be released from
plastic shield before lowering fuel tank. Use care when
lowering fuel tank as not to damage fill and vent hose
fitting assembly or the fuel tank.
9) Fill and vent hose fitting assembly is permanently
attached on fuel tank and is protected from the frame by a plastic
shield. See Fig. 30. Push retaining tabs inward to release fill and
vent hose fitting assembly from the plastic shield before lowering the
fuel tank. See Fig. 38.
Fig. 38: Releasing Retaining Tabs From Plastic Shield (Ram Van &
Ram Wagon)
Courtesy of Chrysler Corp.
10) Slightly lower fuel tank while guiding fill and vent hose

* Charging System
* Cruise Control System
* Intake Manifold Air Heater
* Tachometer
* Torque Convertor Clutch Engagement (A/T Only)
* Transmission Overdrive Solenoid (A/T Only) Components are
grouped into 2 categories. The first category covers INPUT
DEVICES, which control or produce voltage signals monitored
by the PCM. The second category covers OUTPUT SIGNALS, which
are components controlled by the PCM. See PCM INPUT SIGNALS
and ECM/PCM OUTPUT SIGNALS.
ECM INPUT SIGNALS
Accelerator Pedal Position Sensor (APPS)
APPS sensor is mounted on top left of engine. See Fig. 2.
Sensor provides DC voltage input signal to Engine Control Module (ECM)\
to indicate throttle position. On previous engines, there were
linkages between accelerator pedal, throttle position sensor and
injection pump. On this engine, no linkage exists between accelerator
pedal and injection pump. ECM uses input signals from APPS sensor to
determine proper fuel delivery. ECM also outputs this signal to PCM.
Battery Voltage
Battery voltage input signal provides operating voltage to
Engine Control Module (ECM). This input signal keeps ECM memory alive
and informs ECM what generator output voltage is when engine is
running. ECM memory is used to store Diagnostic Trouble Codes (DTCs),
store APPS sensor voltages from previous key cycles and provide a
speed control adaptive memory.
Camshaft Position Sensor (CMP)
Camshaft Position (CMP) sensor is a hall effect sensor (0-5
volts switched), located below injection pump in rear face of timing
gear cover. Sensor is not used for fuel control. Sensor is used only
for diagnostic purposes.
CCD Bus Circuits
These circuits are connected between Engine Control Module
(ECM) and Powertrain Control Module (PCM) to allow communication
between modules.
Crankshaft Position Sensor (CKP)
Crankshaft Position (CKP) sensor delivers input signal (35
tooth wheel with gap) to Engine Control Module (ECM) to indicate
engine speed and crankshaft position. ECM uses CKP signal along with
other input signals for controlling injector firing sequence and
timing. Sensor is located below fuel transfer pump, on side of engine
block. See Fig. 2.
Data Link Connector (DLC)
Data Link Connector (DLC) provides an input signal to Engine
Control Module (ECM) when using scan tool to retrieve Diagnostic
Trouble Codes (DTCs) from ECM. Input signal may also be used when
performing various tests on the ECM and electronic control system.
Data link connector is a 16-pin connector located at lower edge of
driver's side of instrument panel, just above accelerator pedal.
Engine Coolant Temperature (ECT) Sensor
Engine coolant temperature sensor delivers input signal to
Engine Control Module (ECM) to indicate engine coolant temperature.
ECM uses input signal for controlling fuel control and timing. Engine
coolant temperature sensor is located on front of head, near

located in power distribution center at driver's side front corner of
engine compartment, near the battery. Automatic Shutdown (ASD) relay
may also be referred to as Auto Shutdown (ASD) relay.
Battery Temperature Sensor
Battery temperature sensor delivers input signal to
Powertrain Control Module (PCM) to indicate the battery temperature.
PCM uses battery temperature input to modify rate of output from the
charging system. Battery temperature sensor is snapped into battery
tray below driver's side battery.
Battery Voltage
Battery voltage input signal provides operating voltage to
Powertrain Control Module (PCM). This input signal keeps PCM memory
alive and informs PCM what generator output voltage is when engine is
running. PCM memory is used to store Diagnostic Trouble Codes (DTCs),
store APPS sensor voltages from previous key cycles and provide a
speed control adaptive memory.
Brake Switch
Brake switch delivers input signal to Powertrain Control
Module (PCM) to indicate when brakes are applied. PCM uses input
signal for controlling cruise control system and transmission torque
converter clutch operation on A/T models. Brake switch is located near
top of brake pedal and may also be referred to as brakelight switch.
CKP Sensor
Crankshaft Position (CKP) sensor delivers input signal (35
tooth wheel with gap) to Engine Control Module (ECM) to indicate
engine speed and crankshaft position. ECM uses CKP signal along with
other input signals for controlling injector firing sequence and
timing. Sensor is located below fuel transfer pump, on side of engine
block. See Fig. 2.
Cruise Control System Switches
Cruise control system functions, controlled by momentary
contact switches, are monitored through multiplexed input signal to
Powertrain Control Module (PCM). Resistance monitored at this input
signal, in conjunction with the length of time the PCM measures the
resistance, determines which switch feature has been selected.
Data Link Connector (DLC)
Data Link Connector (DLC) provides an input signal to
Powertrain Control Module (PCM) when using scan tool to retrieve
Diagnostic Trouble Codes (DTCs) from PCM. Input signal may also be
used when performing various tests on the PCM and electronic control
system. DLC is a 16-pin connector located at lower edge of driver's
side of instrument panel, just above accelerator pedal.
Fuel Level Sensor
The Powertrain Control Module (PCM) sends a 5-volt signal to
the fuel level sensor. The fuel level sensor will return a signal to
PCM. This signal is used for fuel gauge operation and to prevent
setting a false misfire or fuel system trouble codes. If fuel level is
less than 15 percent, PCM will not set code.
Ignition Sense
Ignition switch position input to Powertrain Control Module
(PCM). PCM uses input to determine proper output functions, including
cruise control, generator output, sensor supply and transmission
functions.
Transmission Speed Sensor (A/T Models)

brakelines are attached to and is mounted in the engine compartment.
ECM OUTPUT SIGNALS
APPS & CKP Output To PCM
See ACCELERATOR PEDAL POSITION SENSOR (APPS) OUTPUT FROM ECM
under PCM INPUT SIGNALS.
CCD Bus
These circuits are connected between Engine Control Module
(ECM) and Powertrain Control Module (PCM) to allow communication
between modules.
DLC Output
Data Link Connector (DLC) is connected to Engine Control
Module (ECM). Using a scan tool, data can be retrieved (output) from\
ECM.
5-Volt Sensor Supply Output
Engine Control Module (ECM) supplies a 5-volt reference
signal to the following sensors:
* Crankshaft Position (CKP) Sensor
* Camshaft Position (CMP) Sensor
* Intake Air Temperature (IAT) Sensor
* Engine Oil Pressure Sensor
* Manifold Absolute Pressure (MAP) Sensor
Engine Control Module (ECM) also supplies voltage to the
following sensors:
* Accelerator Pedal Position Sensor (APPS)
* Intake Air Temperature (IAT) Sensor
* Engine Oil Pressure Sensor
* Engine Coolant Temperature (ECT) Sensor
* Manifold Absolute Pressure (MAP) Sensor
* Water-In-Fuel (WIF) Sensor
Fuel Injection Pump Relay
The Engine Control Module (ECM) energizes the fuel injection
pump and integral Fuel Pump Control Module (FPCM) through the relay.
When ignition is turned on, ECM supplies 12 volts to fuel injection
pump relay, located in Power Distribution Center.
Fuel Pump Control Module (FPCM)
Fuel Pump Control Module (FPCM) controls fuel pump using
inputs from Engine Control Module (ECM). FPCM is integral to top of
fuel pump. ECM and FPCM are interconnected together for fuel injection
control.
Fuel Transfer Pump
Engine Control Module (ECM) supplies power to fuel transfer
pump. Transfer fuel pump supplies fuel under low pressure (14 psi)
while engine is running to fuel injection pump. Fuel transfer pump
supplies an excess of fuel to cool fuel injection pump. Excess fuel is
returned to fuel tank by fuel injection pump.
Intake Manifold Air Heater Relays
Intake manifold air heater relays provide voltage to intake
manifold air heater for warming of intake. See Fig. 5. Warming of
intake air aids in engine starting and improved driveability during
cold ambient temperatures. Intake manifold air heater relays are
mounted on inner wheelwell, below driver's side battery. See Fig. 6.

WAIT-TO-START Warning Light
WAIT-TO-START warning light is located on instrument panel,
just below the speedometer. WAIT-TO-START warning light will come on
for a short period and then go off as a bulb and wiring circuit test
each time ignition switch is turned to the ON position. If Engine
Control Module (ECM) determines intake manifold air temperature is
less than 59
F (15C) by input signal received from intake manifold
air temperature sensor, ECM delivers output signal to operate WAIT-TO-
START warning light and intake manifold air heater for a preheat
cycle.
WAIT-TO-START warning light will remain on until intake
manifold air heater preheat cycle is complete. WAIT-TO-START warning
light will flash on and off if intake manifold air temperature sensor
signal to ECM is not within a specified value and Diagnostic Trouble
Code (FTC) will be stored in ECM memory.
WATER-IN-FUEL Warning Light
WATER-IN-FUEL warning light is located on instrument panel,
just below tachometer. WATER-IN-FUEL warning light will come on for a
short period and then go off as a bulb and wiring circuit test each
time ignition switch is turned to the ON position. If Engine Control
Module (ECM) determines water exists in fuel/water separator by input
signal from Water-In-Fuel (WIF) sensor, ECM will deliver output signal\
to turn on the WATER-IN-FUEL warning light.
ECM/PCM OUTPUT SIGNALS
A/C Clutch Relay
The Engine Control Module (ECM) controls A/C compressor
operation by controlling ground circuit for A/C clutch relay. ECM de-
energizes A/C clutch relay if engine coolant temperature is more than
257
F (125C). The A/C clutch relay is located in power distribution
center at driver's side front corner of engine compartment, near the
battery.
Automatic Shutdown (ASD) Relay
The Engine Control Module (ECM) controls ASD operation by
controlling ground circuit for ASD relay. ASD provides voltage to
operate generator field control for charging system. ASD relay is
located in power distribution center at driver's side front corner of
engine compartment, near the battery. Automatic Shutdown (ASD) relay
may also be referred to as Auto Shutdown (ASD) relay.
CCD Bus
These circuits are connected between Engine Control Module
(ECM) and Powertrain Control Module (PCM) to allow communication
between modules.
Cruise Control System
Engine Control Module (ECM) regulates cruise control system
operation by controlling vacuum at cruise control servo. Vacuum is
controlled by use of vacuum and vent solenoids in cruise control
servo.
Data Link Connector
Engine Control Module (ECM) provides output information at
Data Link Connector (DLC) when using scan tool to perform various
tests on the ECM and electronic control system. Data link connector is
a 16-pin connector located at lower edge of driver's side of
instrument panel, just above the accelerator pedal.
5-Volt Sensor Supply Output
Powertrain Control Module (PCM) supplies a 5-volt reference

Module (FPCM). Because of electronic control, pump timing is not
adjustable. See ON-VEHICLE ADJUSTMENTS - TRUCKS - DIESEL article.
FUEL FILTER/WATER SEPARATOR
Fuel filter/water separator is located on left side of engine
and contains fuel heater, Water-In-Fuel (WIF) sensor and drain valve.
See Fig. 2 . The WIF sensor delivers an input signal to Engine Control
Module (ECM) when water exists in fuel filter/water separator. ECM
will then turn on WATER-IN-FUEL warning light. WATER-IN-FUEL warning
light is located on instrument panel, just below tachometer. The
WATER-IN-FUEL warning light informs the operator to drain water from
fuel filter/water separator to prevent damage to fuel system
components. Water may be drained from fuel filter/water separator by
using drain valve on fuel filter/water separator.
FUEL HEATER
Fuel heater is used to prevent diesel fuel from waxing during
cold temperatures. Fuel heater is located in fuel filter/water
separator. See Fig. 2. Fuel flows from fuel tank to fuel transfer pump
and then to fuel filter/water separator. Fuel heater contains a fuel
heater temperature sensor that senses the fuel temperature. When
temperature is less than 37-53
F (3-12C), fuel heater temperature
sensor allows current to flow to the fuel heater to warm the fuel.
When temperature is more than 67-83
F (19-28C), fuel heater
temperature sensor turns off the current flow to the fuel heater.
Voltage to operate fuel heater is provided from ignition switch,
through fuel heater relay and to fuel heater. Fuel heater and fuel
heater relay are not controlled by Engine Control Module (ECM).
EMISSION SYSTEMS
INTAKE MANIFOLD AIR HEATER SYSTEM
Intake manifold air heater is used to warm intake air during
cold starting conditions. Heater system consists of 2 relays and 2
grid heaters installed on top of intake manifold. See Fig. 5.
Engine Control Module (ECM) energizes intake manifold air
heater relays to provide voltage to intake manifold air heater before
and after starting depending on input signals from intake manifold air
temperature sensor, engine speed sensor and vehicle speed. Intake
manifold air heater relays are not energized when intake manifold air
temperature is greater than 59
F (15C) or during engine cranking.
Intake manifold air heater relays are mounted on left inner wheelwell,
below left side battery. See Fig. 6.
Intake manifold air temperature sensor monitors intake
manifold air temperature and delivers an input signal to ECM for
controlling intake manifold air heater. Intake manifold air
temperature sensor is located in intake manifold. See Figs. 2 and 4.
SELF-DIAGNOSTIC SYSTEM
DATA LINK CONNECTOR
The Data Link Connector (DLC) is a 16-pin connector located
at lower edge of driver's side of instrument panel, just above the
accelerator pedal. The Engine Control Module (ECM) contains a self-
diagnostic system which stores a Diagnostic Trouble Code (FTC) if an
incorrect signal or no signal is received from certain sensors or
components. FTC may be retrieved from ECM for system diagnosis by

using DLC and a scan tool. The DLC also provides a means to
communicate with various vehicle control modules, check system
operating conditions and to operate various system components.
MALFUNCTION INDICATOR LIGHT (MIL)
The MIL is located on the instrument panel, just below
tachometer and may also be referred to as the CHECK ENGINE light. MIL
comes on for a short period and then goes off as a bulb and wiring
circuit test each time ignition switch is turned to the ON position.
If Engine Control Module (ECM) receives an incorrect signal or
receives no signal from certain sensors or components, ECM will turn
on the MIL to warn the driver that a malfunction exists in the
electronic system.
MISCELLANEOUS CONTROLS
TRANSMISSION
Transmission Overdrive Solenoid (A/T Models)
Engine Control Module (ECM) operates transmission overdrive
solenoid for controlling transmission overdrive shifts. Transmission
overdrive solenoid is located on transmission valve body.
Transmission Torque Converter Clutch Solenoid (A/T Models)
Engine Control Module (ECM) operates transmission torque
converter clutch solenoid for torque converter lock-up. ECM uses
various input signals such as transmission temperature, output shaft
speed, central module timer, engine speed, APPS and brake switch
position to determine operation of transmission torque converter
clutch solenoid. Torque converter clutch solenoid is located on
transmission valve body.

VEH IC LE C O M MUNIC ATIO N

1999 D odge P ic ku p R 1500
1999 ACCESSORIES & EQUIPMENT
CHRY - Vehicle Communications
Ram Pickup
IDENTIFYING VEHICLE COMMUNICATION PROBLEMS
Connect scan tool to Data Link Connector (DLC) to retrieve
messages. If scan tool message is blank, disconnect scan tool. Ensure
ground circuit has continuity at DLC terminal No. 4. Ensure 12 volts
exists at DLC terminal No. 16. Check power to DLC terminal No. 16 from
Power Distribution Center (PDC) fuse No. 12. Try another scan tool
and/or cable. If scan tool DTC or fault message is present, see
following bus fault messages list and proceed to appropriate DTC or
fault message:
* BUS (+) & BUS (-) OPEN
* BUS (+) OPEN
* BUS (-) OPEN
* BUS (+) & BUS (-) SHORTED TOGETHER
* BUS BIAS LEVEL TOO HIGH
* BUS BIAS LEVEL TOO LOW
* NO BUS BIAS
* NO RESPONSE AIR BAG CONTROL MODULE
* NO RESPONSE CENTRAL TIMER MODULE
* NO RESPONSE INSTRUMENT CLUSTER
* NO RESPONSE POWERTRAIN CONTROL MODULE
* NO RESPONSE COMPASS/MINI-TRIP SYSTEM
* NO RESPONSE RADIO
* NO TERMINATION
* NOT RECEIVING BUS MESSAGES CORRECTLY
* BUS SHORT TO 5 VOLTS
* BUS SHORT TO BATTERY
* BUS SHORT TO GROUND
BUS (+) & BUS (-) OPEN, (BUS (+) OPEN OR BUS (-) OPEN)
NOTE: For connector terminal identification and wiring diagrams,
see BODY CONTROL COMPUTER - INTRODUCTION article. Perform
VERIFICATION TEST VER-1 after each repair.
CAUTION: Always turn ignition off prior to disconnecting any module
connector.
1) Disconnect scan tool. Ensure ignition is on. Using an
external voltmeter, measure voltage between ground and DLC terminal
No. 3 (Violet/Brown wire). If voltage is not 1.8-2.3 volts, go to step\
3). If voltage is 1.8-2.3 volts, go to next step.
2) Measure voltage between ground and DLC terminal No. 11
(White/Black wire). If voltage is not 1.8-2.3 volts, go to next step.
If voltage is 1.8-2.3 volts, replace scan tool cable or scan tool.
3) Connect jumper wire between ground and DLC connector
terminal No. 11 (White/Black wire). Turn ignition off. Remove
instrument cluster. Using external ohmmeter, measure resistance
between ground and instrument cluster connector C1 terminal No. 9
(White/Black wire). If resistance is less than 5 ohms, go to next
step. If resistance is 5 ohms or more, repair open White/Black wire.
4) Disconnect jumper wire. Connect jumper wire between ground
and DLC connector terminal No. 3 (White/Black wire). Measure