1993 DODGE TRUCK diag code

FUEL
TUBE

REMOVAL

QUICK
CONNECT

FITTING

PUSH
PUSH PUSH

INSTALLATION

X
PUSH

/

•PUSH

PLASTIC

RETAINER
J9314-100

Fig. 19 Removing/Installing Quick-Connect Fitting (8) If pressure falls below 24 psi, it must deter­
mined if a fuel injector, the fuel module mounted fuel
pressure regulator or a fuel tube/line is leaking. (9) Again, start engine and bring to normal oper­
ating temperature.
(10) Shut engine off.
(11) Checking for fuel injector leakage: Clamp
off the rubber hose portion of tool 6539 between the
disconnected fuel tube (line) and test port inlet. If
pressure now holds at or above 24 psi, a fuel injector or the fuel rail is leaking.
Checking for fuel pressure regulator or fuel
tube leakage: Clamp off the rubber hose portion of
tool 6539 between the fuel rail and test port inlet. If
pressure now holds at or above 24 psi, a leak can be
found at a fuel tube/line. If no leaks are found at fuel

tubes,
replace the fuel filter/fuel pressure regulator.

MECHANICAL MALFUNCTIONS
Mechanical malfunctions are more difficult to diag­
nose with this system. The powertrain control mod­
ule (PCM) has been programmed to compensate for
some mechanical malfunctions such as incorrect cam
timing, vacuum leaks, etc. If engine performance
problems are encountered and a diagnostic trouble code (DTC) is not displayed, the problem may be me­
chanical rather than electronic.

FUEL FILTER-3.9L/5.2L GAS ENGINE
For diesel engines, refer to Fuel/Water Separator
Filter in the Diesel Fuel Injection—Service Proce­
dures section of this group.
REMOVAL

WARNING:
THE
FUEL
SYSTEM
IS
UNDER
A
CON­
STANT
PRESSURE
(EVEN
WITH
THE
ENGINE
OFF).
BEFORE
SERVICING
THE
FUEL FILTER,
THE
FUEL
SYSTEM
PRESSURE
MUST
BE
RELEASED.

The fuel filter is located under the vehicle and near
the fuel tank. It is mounted to the frame rail (Fig.
20). (1) Perform Fuel System Pressure Release proce­

dure.
(2) Disconnect negative battery cable from battery.
(3) Raise and support vehicle.
(4) Remove and discard both fuel hose-to-fuel filter
hose clamps. (5) Wrap a shop towel around hoses to absorb fuel.
Remove hoses at filter. (6) Remove filter from frame.
FUEL
HOSES
HOSE
CLAMPS
.
FILTER
MOUNTING
BOLT
FUEL

FILTER

J9214-68

Fig.
20
Fuel
Filter—3.9U5.2L
Engine

INSTALLATION

CAUTION:
The
tubes/hoses used
on
fuel
injected

vehicles
are of a
special construction. This
is due

to
the
higher
fuel
pressures
and the
possibility
of
contaminated
fuel
in
this system.
If it is
necessary
to replace these tubes/hoses, only tubes/hoses marked EFM/EFI
may be
used.

CAUTION:
The
hose clamps used
on
fuel
injected

vehicles
are of a
special rolled edge construction
to
prevent
the
edge
of the
clamp from cutting into
the
hose.
Only these rolled edge
type
clamps
may be

used
in
this system.
All
other types
of
clamps
may

cut into
the
hoses
and
cause high pressure
fuel
leaks.

(1) Install fuel filter to frame rail. Tighten mount­
ing bolt to 8 N»m (75 in. lbs.) torque. (2) Install new original equipment clamps to fuel

hoses.

14
- 30
FUEL
SYSTEM

INPUTS

OUTPUTS
POWERTRAIN
CONTROL
MODULE
DRB
II

SCAN
TOOL

SPEED

CONTROL

BRAKE

SWITCH
A/C
LOW

PRESSURE
CUTOFF
SWITCH VEHICLE

SPEED
SENSOR PARK/NEUTRAL
SWITCH TORQUE CONVERTER
CLUTCH SOLENOID
MALFUNCTION

INDICATOR
LAMP
m
HEATED
i

*OXYGEN SENSOR ENGINE
COOLANT
yy
BATTERY
TEMPERATURE

SENSOR
MAP SENSOR

i—r
CHARGE
AIR
TEMPERATURE
SENSOR
AIR CHARGE
TEMPERATURE
SENSOR
DISTRIBUTOR

WITH
CAMSHAFT
r
POSITION
SENSOR
(|
TACHOMETER

A/C
CLUTCH RELAY
AUTO
SHUTDOWN
RELAY OVERDRIVE
SOLENOID
IDLE AIR
CONTROL MOTOR
SPEED

CONTROL
SHIFT

INDICATOR

LAMP

EMISSION

CONTROL SOLENOIDS
IGNITION
COIL
OVERDRIVE
OVERRIDE SWITCH
ASD

SENSE
FUEL
INJECTORS
PARK
THROTTLE

SOLENOID
GENERATOR CRANKSHAFT
POSITION FUEL
PUMP
RELAY
J9314-117

Fig.
1 Multi-Port
Fuel
Injection
Components—Except
Diesel

gine Control System. It is also comprised of the PCM Outputs (engine control devices that the are operated
by the PCM).

SYSTEM DIAGNOSIS
The powertrain control module (PCM) tests many
of its own input and output circuits. If a diagnostic
trouble code (DTC) is found in a major system, this information is stored in the PCM memory. Refer to
On-Board Diagnostics in the Multi-Port Fuel Injec­
tion—General Diagnosis—Except Diesel section of
this group for DTC information.

POWERTRAIN
CONTROL MODULE (PCM)
The Powertrain Control Module (PCM) (Fig. 2) op­
erates the fuel system. The PCM was formerly re­
ferred to as the SBEC or engine controller. The PCM is a pre-programmed, dual microprocessor digital computer. It regulates ignition timing, air-fuel ratio, emission control devices, charging system, speed con­trol, air conditioning compressor clutch engagement
A/C
CLUTCH RELAY STARTER RELAY
TORQUE CONVERTER CLUTCH RELAY
AUTO
SHUTDOWN RELAY
FUEL PUMP RELAY
DATA UNK
CONNECTOR
POWERTRAIN

CONTROL MODULE
J9314-164

Fig.
2 Powertrain Control
Module
(PCM) Location and idle speed. The PCM can adapt its programming
to meet changing operating conditions.
The PCM receives input signals from various
switches and sensors. Based on these inputs, the
PCM regulates various engine and vehicle operations

•

FUEL SYSTEM
14-31 through different system components. These compo­
nents are referred to as Powertrain Control Module
(PCM) Outputs. The sensors and switches that pro­
vide inputs to the PCM are considered Powertrain Control Module (PCM) Inputs.
The PCM adjusts ignition timing based upon in­
puts it receives from sensors that react to: engine rpm, manifold absolute pressure, engine coolant tem­
perature, throttle position, transmission gear selec­
tion (automatic transmission), vehicle speed and the
brake switch.
The PCM adjusts idle speed based on inputs it re­
ceives from sensors that react to: throttle position,
vehicle speed, transmission gear selection, engine coolant temperature and from inputs it receives from
the air conditioning clutch switch and brake switch.
Based on inputs that it receives, the PCM adjusts
ignition coil dwell. The PCM also adjusts the gener­
ator charge rate through control of the generator
field and provides speed control operation.
Powertrain Control Module (PCM) Inputs:
• Generator output • A/C request (if equipped with factory A/C)
• A/C select (if equipped with factory A/C)
• Auto shut down (ASD) sense
• Charge air temperature sensor
• Battery voltage
• Brake switch
• Engine coolant temperature sensor
• Crankshaft position sensor • Ignition circuit sense (ignition switch in run posi­
tion)
• Manifold absolute pressure (MAP) sensor
• Overdrive/override switch
• Oxygen sensor(s)
• Park/neutral switch (auto, trans, only)
• SCI receive (DRB II connection) • Speed control resume switch
• Speed control set switch • Speed control on/off switch
• Camshaft position sensor signal
• Throttle position sensor
• Vehicle speed sensor
• Sensor return
• Power ground
• Signal ground Powertrain Control Module (PCM) Outputs:
• A/C clutch relay
• Idle air control (IAC) motor
• Auto shut down (ASD) relay
• Generator field
• Malfunction indicator lamp
• Service reminder indicator lamp
• EGR valve control solenoid • Fuel injectors
• Fuel pump relay
• Ignition coil • EVAP canister purge solenoid
• SCI transmit (DRB II connection)
• Shift indicator lamp (manual transmission only)
• Speed control vacuum solenoid
• Speed control vent solenoid
• Tachometer (on instrument panel, if equipped) The powertrain control module (PCM) contains a
voltage convertor. This converts battery voltage to a
regulated 8.0 volts. It is used to power the crankshaft
position sensor and camshaft position sensor. The
PCM also provides a five (5) volt supply for the man­ ifold absolute pressure (MAP) sensor and throttle po­
sition sensor (TPS).

AIR
CONDITIONING
(A/C)
CONTROLS-PCM
INPUT
The A/C control system information applies to fac­
tory installed air conditioning units. A/C SELECT SIGNAL: When the A/C switch is
in the ON position and the A/C low pressure switch
is closed, an input signal is sent to the powertrain
control module (PCM). The signal informs the PCM
that the A/C has been selected. The PCM adjusts idle speed to a pre-programmed rpm through the idle air
control (IAC) motor to compensate for increased en­
gine load. A/C REQUEST SIGNAL: Once A/C has been se­
lected, the powertrain control module (PCM) receives
the A/C request signal from the evaporator switch.
The input indicates that the evaporator temperature is in the proper range for A/C application. The PCM
uses this input to cycle the A/C compressor clutch (through the A/C relay). It will also determine the
correct engine idle speed through the idle air control (IAC) motor position. If the A/C low pressure switch opens (indicating a
low refrigerant level), the PCM will not receive an
A/C select signal. The PCM will then remove the ground from the A/C relay. This will deactivate the
A/C compressor clutch. If the evaporator switch opens, (indicating that
evaporator is not in proper temperature range), the
PCM will not receive the A/C request signal. The
PCM will then remove the ground from the A/C re­ lay, deactivating the A/C compressor clutch.

AUTOMATIC SHUT DOWN
(ASD)
SENSE-PCM INPUT
A 12 volt signal at this input indicates to the PCM
that the ASD has been activated. The ASD relay is located in the engine compartment (Fig. 2). It is used
to connect the oxygen sensor(s) heater element, igni­
tion coil, generator field winding and fuel injectors to 12 volt + power supply. This input is used only to sense that the ASD relay
is energized. If the powertrain control module (PCM)
does not see 12 volts at this input when the ASD
should be activated, it will set a diagnostic trouble
code (DTC).

•

FUEL SYSTEM
14 - 37 used only on vehicles equipped with the 5.9L heavy
duty cycle (HDC) engine. Refer to Group 25, Emis­
sion Control System for information.

EVAP CANISTER PURGE SOLENOID-PCM

OUTPUT
Refer to Group 25, Emission Control System. See
EVAP Canister Purge Solenoid.

FUEL INJECTORS-PCM
OUTPUT
The fuel injectors are attached to the fuel rail (Fig.

15).
3.9L engines use six injectors. 5.2L and 5.9L en­
gines use eight injectors. The nozzle ends of the injectors are positioned into
openings in the intake manifold just above the in­
take valve ports of the cylinder head. The engine
wiring harness connector for each fuel injector is equipped with an attached numerical tag (INJ 1, INJ 2 etc.). This is used to identify each fuel injector with
its respective cylinder number. The injectors are energized individually in a se­
quential order by the powertrain control module (PCM). The PCM will adjust injector pulse width by
switching the ground path to each individual injector
on and off. Injector pulse width is the period of time
that the injector is energized. The PCM will adjust injector pulse width based on various inputs it re­
ceives. During start up, battery voltage is supplied to the
injectors through the ASD relay. When the engine is
operating, voltage is supplied by the charging sys­
tem. The PCM determines injector pulse width based on various inputs.
FUEL

INJECTOR
J9214-30

Fig.
15
Fuel
injectors—Typical
MALFUNCTION INDICATOR LAMP-PCM OUTPUT

The malfunction indicator lamp (formerly referred
to as the check engine lamp) illuminates at the bot­
tom of the instrument panel each time the ignition key is turned on. It will stay on for three seconds as a bulb test. If the powertrain control module (PCM) receives an
incorrect signal, or no signal from certain sensors or
emission related systems, the lamp is turned on. This
is a warning that the PCM has recorded a system or
sensor malfunction. In some cases, when a problem is
declared, the PCM will go into a limp-in mode. This
is an attempt to keep the system operating. It signals an immediate need for service. The lamp can also be used to display a diagnostic
trouble code (DTC). Cycle the ignition switch
On-Off-
On-Off-On within three seconds and any codes stored
in the PCM memory will be displayed. This is done
in a series of flashes representing digits. Refer to On-
Board Diagnostics in the General Diagnosis section
of this group for more information.

IGNITION COIL-PCM OUTPUT
System voltage is supplied to the ignition coil pos­
itive terminal. The powertrain control module (PCM)
operates the ignition coil. Base (initial) ignition
timing is not adjustable. The PCM adjusts ignition
timing to meet changing engine operating conditions. The ignition coil is located near the front of the
right cylinder head (Fig. 16 or 17). Refer to Group 8D, Ignition System for additional
information.

Fig.
16 Ignition Coii-3.9U5.2U5.9L
LDC-Gas
Engine

SCI
TRANSMIT—PCM OUTPUT
SCI Transmit is the serial data communication
transmit circuit for the DRB II scan tool. The power- train control module (PCM) transmits data to the DRB II through the SCI Transmit circuit.

MULTI-PORT
FUEL
INJECTION
(MPI)—GENERAL DIAGNOSIS—EXCEPT DIESEL

INDEX

page

Camshaft Position Sensor Testing
............
52
Charge
Air
Temperature Sensor Test
52

Coolant Temperature Sensor Test
52

Crankshaft Position Sensor Test
54

Diagnostic Trouble Code (DTC)
60

DRB
II
Scan
Tool
........................
60

Fuel
Injector
Test
57

Fuel Pump Pressure Test
57
Idle
Air
Control
(IAC) Motor Test
55

Manifold Absolute Pressure (MAP) Sensor Test
. 53
page

On-Board
Diagnostics (OBD)
59

Oxygen
(02)
Sensor Heating Element Test
54
Powertrain
Control
Module (PCM) 60-Way Connector
. 47

Relays—Operation/Testing
56

Starter
Motor Relay Test
57

System
Schematics
. 47

Throttle
Position Sensor (TPS) Test
54

Visual Inspection
43

VISUAL
INSPECTION
A visual inspection
for
loose, disconnected,
or
incor­
rectly routed wires
and
hoses should
be
made. This should
be
done before attempting
to
diagnose
or
ser­
vice
the
fuel injection system.
A
visual check will
help spot these faults
and
save unnecessary test
and
diagnostic time.
A
thorough visual inspection will
in­

clude
the
following checks: (1) Verify that
the
60-way connector
is
fully
in­

serted into
the
connector
of the
powertrain control
module
(PCM) (Fig. 1).
Verify that
the
connector
mounting screw
is
tightened
to 4 N#m (35 in. lbs.)
torque.
PCM
MOUNTING
BOLTS

PCM CONNECTOR CONNECTOR MOUNTING BOLT
J9314-165

Fig.
1
Powertrain Control
Module
(PCM) (2) Inspect
the
battery cable connections.
Be
sure
that they
are
clean
and
tight.
(3) Inspect fuel pump relay
and air
conditioning
compressor clutch relay
(if
equipped). Inspect
the

ASD relay connections. Inspect starter motor relay connections. Inspect relays
for
signs
of
physical dam­
age
and
corrosion.
The
relays
are
located
in the en­

gine compartment
(Fig. 2).
TORQUE CONVERTER
CLUTCH RELAY
A/C
CLUTCH RELAY STARTER RELAY
AUTO SHUTDOWN RELAY FUEL PUMP RELAY POWERTRAIN
DATA UNK CONTROL
CONNECTOR MODULE
J9314-164

Fig.
2
Relay Location (4) Inspect ignition coil connections. Verify that
coil secondary cable
is
firmly connected
to
coil (Fig.
3

or 4).
|X COIL

frCONNECTOR J9214-7

Fig.
3
Ignition Coil—3.9U5.2L/5.9L
LDC-Gas
Engine

14 - 58
FUEL
SYSTEM
• INJECTOR DIAGNOSIS-VEHICLE RUNS ROUGH AND/OR HAS A
MISS

DO PRELIMINARY INSPECTION OF DISTRIBUTOR CAP,
IGNITION

CABLES
SPARK
PLUGS,
AND

CHECK
FOR VACUUM
LEAKS.
START VEHICLE, PULL THE

ELECTRICAL
CONNECTORS OFF
THE INJECTORS ONE AT A TIME
TO DETERMINE
WHICH
CYLINDER
IS
NOT FIRING.

REPLACE
THE INJECTOR -NO •

CHECK
POWER FEED AND
GROUND CIRCUITS BETWEEN POWERTRAIN CONTROL MODULE
AND THE INJECTOR CONNECTOR.
REFER
TO WIRING SCHEMATIC
FOR COLOR CODES AND PIN
TERMINAL NUMBERS. - NO-
YES

TEST THE VEHICLE
WITH
THE DRB II

SCAN
TOOL
NO

REPAIR
OR REPLACE THE WIRING
HARNESS
AS NECESSARY.

REPLACE
INJECTOR IF VISUALLY

PLUGGED
AT INJECTOR FUEL INLET.

REPLACE
FUEL RAIL IF VISUALLY

PLUGGED
OR RESTRICTED AT INJECTOR DELIVERY COUPLING. -NO

REPLACE
INJECTOR •NO-TEST THE INJECTOR RESISTANCE
USING AN OHMMETER
ACROSS

THE INJECTOR TERMINALS
WITH

THE INJECTOR CONNECTOR
REMOVED.

PLACE
A 12
VOLT
TEST LAMP

ACROSS
THE INJECTOR

ELECTRICAL
CONNECTOR

TERMINALS.
OBSERVE THE TEST LAMP WHILE CRANKING THE

ENGINE.

CIRCUIT IS OK. CHECK FOR FUEL DELIVERY AT SUSPECT INJECTOR

BY
REMOVING THE INJECTOR FROM THE RAIL AND OBSERVING
FOR FUEL AND/OR RESTRICTIONS IN THE RAIL OR INJECTOR FUEL INLET.

WITH
INJECTOR REMOVED FROM
THE FUEL RAIL, CONNECT A 12V
SOURCE
TO ONE TERMINAL ON
THE INJECTOR CONNECTOR AND

A
GROUND WIRE TO THE OTHER
TERMINAL. THE INJECTOR SHOULD "CLICK" EACH TIME THE GROUND WIRE IS CONNECTED
AND DISCONNECTED TO THE TERMINAL.

J9314-114

•

FUEL SYSTEM
14 - 59
fill
DHADn
HIAf5MflCTipQ
/f|Rn

The powertrain control module (PCM) has been
programmed to monitor many different circuits of the
fuel injection system. If a problem is sensed in a monitored circuit often enough to indicate an actual
problem, a diagnostic trouble code (DTC) is stored.
The DTC will be stored in the PCM memory for eventual display to the service technician. If the
problem is repaired or ceases to exist, the PCM can­ cels the DTC after 51 engine starts.
Certain criteria must be met for a diagnostic trou­
ble code (DTC) to be entered into PCM memory. The criteria may be a specific range of engine rpm, en­
gine temperature and/or input voltage to the PCM.
It is possible that a DTC for a monitored circuit
may not be entered into memory even though a mal­
function has occurred. This may happen because one
of the DTC criteria for the circuit has not been met. Example: assume that one of the criteria for the
MAP sensor circuit is that the engine must be oper­ ating between 750 and 2000 rpm to be monitored for
a DTC. If the MAP sensor output circuit shorts to
ground when the engine rpm is above 2400 rpm, a 0
volt input will be seen by the PCM. A DTC will not
be entered into memory because the condition does not occur within the specified rpm range.
A DTC indicates that the powertrain control mod­
ule (PCM) has recognized an abnormal signal in a
circuit or the system. A DTC may indicate the result
of a failure, but never identify the failed component
directly.
There are several operating conditions that the
PCM does not monitor and set a DTC for. Refer to
the following Monitored Circuits and Non-Monitored Circuits in this section.

MONITORED
CIRCUITS
The powertrain control module (PCM) can detect
certain problems in the fuel injection system.
Open or Shorted Circuit - The PCM can deter­
mine if sensor output (which is the input to PCM) is
within proper range. It also determines if the circuit is open or shorted.
Output Device Current Flow - The PCM senses
whether the output devices are hooked up.
If there is a problem with the circuit, the PCM
senses whether the circuit is open, shorted to ground
(-), or shorted to
(
+
)
voltage.
Oxygen Sensor - The PCM can determine if the
oxygen sensor is switching between rich and lean.
This is, once the system has entered Closed Loop. Re­ fer to Open Loop/Closed Loop Modes Of Operation in
the Component Description/System Operation section
for an explanation of Closed (or Open) Loop opera­ tion.
NON-MONITORED CIRCUITS

The PCM does not monitor the following circuits,
systems or conditions that could have malfunctions
that result in driveability problems. A diagnostic trouble code (DTC) may not be displayed for these
conditions.
Fuel Pressure: Fuel pressure is controlled by the
vacuum assisted fuel pressure regulator. The PCM
cannot detect a clogged fuel pump inlet filter, clogged
in-line fuel filter, or a pinched fuel supply or return

line.
However, these could result in a rich or lean
condition causing an oxygen sensor DTC to be stored in the PCM.
Secondary Ignition Circuit: The PCM cannot de­
tect an inoperative ignition coil, fouled or worn spark

plugs,
ignition cross firing, or open circuited spark
plug cables.
Engine Timing: The PCM cannot detect an incor­
rectly indexed timing chain, camshaft sprocket or crankshaft sprocket. The PCM also cannot detect an
incorrectly indexed distributor. However, these could
result in a rich or lean condition causing an oxygen
sensor DTC to be stored in the PCM.
Cylinder Compression: The PCM cannot detect
uneven, low, or high engine cylinder compression.
Exhaust System: The PCM cannot detect
a

plugged, restricted or leaking exhaust system.
Fuel Injector Malfunctions: The PCM cannot de­
termine if the fuel injector is clogged, or the wrong injector is installed. However, these could result in a
rich or lean condition causing an oxygen sensor DTC
to be stored in the PCM.
Excessive Oil Consumption: Although the PCM
monitors exhaust stream oxygen content through ox­
ygen sensor (closed loop), it cannot determine exces­ sive oil consumption.
Throttle Body Air Flow: The PCM cannot detect
a clogged or restricted air cleaner inlet or air filter
element.
Evaporative System: The PCM will not detect a
restricted, plugged or loaded EVAP canister. Vacuum Assist: Leaks or restrictions in the vac­
uum circuits of vacuum assisted engine control sys­
tem devices are not monitored by the PCM. However, a vacuum leak at the MAP sensor will be monitored
and a diagnostic trouble code (DTC) will be gener­
ated by the PCM.
Powertrain Control Module (PCM) System
Ground: The PCM cannot determine a poor system
ground. However, a DTC may be generated as a re­
sult of this condition.
Powertrain Control Module (PCM) Connector
Engagement: The PCM cannot determine spread or
damaged connector pins. However, a DTC may be generated as a result of this condition.

14 - SO
FUEL
SYSTEM

•
HIGH
AND LOW
LIMITS

The powertrain control module (PCM) compares in­
put signal voltages from each input device. It will es­
tablish high and low limits that are programmed into it for that device. If the input voltage is not
within specifications and other diagnostic trouble code (DTC) criteria are met, a DTC will be stored in
memory. Other DTC criteria might include engine
rpm limits or input voltages from other sensors or switches. The other inputs might have to be sensed
by the PCM when it senses a high or low input volt­ age from the control system device in question.
ACCESSING DIAGNOSTIC TROUBLE CODES A stored diagnostic trouble code (DTC) can be dis­
played by cycling the ignition key On-Off-On-Off-On
within three seconds and observing the malfunction indicator lamp. This lamp was formerly referred to
as the check engine lamp. The lamp is located on the
instrument panel.
They can also be displayed through the use of the
Diagnostic Readout Box II (DRB II scan tool). The
DRB II connects to the data link connector in the ve­
hicle (Fig. 37). For operation of the DRB II, refer to
the appropriate Powertrain Diagnostic Procedures service manual.
TORQUE CONVERTER
CLUTCH RELAY
A/C
CLUTCH RELAY
.
STARTER RELAY

AUTO
SHUTDOWN RELAY FUEL PUMP RELAY POWERTRAIN
DATA LINK CONTROL
CONNECTOR MODULE
J9314-164

Fig.
37
Data
Link
Connector
Location—Typical
EXAMPLES

• If the lamp flashes 4 times, pauses and flashes 1
more time, a diagnostic trouble code (DTC) number
41 is indicated.
• If the lamp flashes 4 times, pauses and flashes 6
more times, a diagnostic trouble code (DTC) number
46 is indicated. Refer to the Diagnostic Trouble Code (DTC) charts
for DTC identification. If the problem is repaired or ceases to exist, the
powertrain control module (PCM) cancels the DTC after 51 engine starts.
Diagnostic trouble codes indicate the results of a
failure, but never identify the failed component di­
rectly. The circuits of the data link connector are shown
in (Fig. 38).
J9214-20
D-1

GROUND

D-2 Im/c
D-3
SCI
TRANS

D-4
SCI
RECEIVE

D-5
IGNITION

D-6
NOT
USED

Fig.
38
Data
Link
Connector
Schematic

ERASING TROUBLE CODES The DRB II scan tool must be used to erase a di­
agnostic trouble code (DTC). Refer to the appropriate
Powertrain Diagnostic Procedures service manual for operation of the DRB II scan tool.

DRB
II
SCAN
TOOL
For operation of the DRB II scan tool, refer to the
appropriate Powertrain Diagnostic Procedures ser­
vice manual.

DIAGNOSTIC TROUBLE CODE
(DTC) On the following pages, a list of diagnostic trouble
codes is provided for all gas powered engines. A DTC indicates that the powertrain control module (PCM)
has recognized an abnormal signal in a circuit or the system. A DTC may indicate the result of a failure,
but never identify the failed component directly.