1993 DODGE TRUCK codes

8W
- 2
WIRING
DIAGRAMS

•
WIRE CODE
IDENTIFICATION

Each wire shown in the diagrams contains a code
(Fig. 3) which identifies the main circuit, part of the
main circuit, gauge of wire, and color. The color is shown as a two letter code which can be identified by
referring to the Wire Color Code Chart (Fig. 4). If
the wire has a tracer and it is a standard color an asterisk will follow the main wire color. If the tracer
is non-standard the main wire color will have a slash (/) after it followed by the tracer color. 18
LB/YL*
COLOR
OF
WIRE

(Light
Blue
with
Yellow
Tracer)
.
GAUGE
OF
WIRE
(18
Gauge)

PART
OF
AAAIN CIRCUIT

(Varies
Depending
on
Equipment)

AAAIN CIRCUIT
IDENTIFICATION
918W-16

Fig.
3
Wire
Color
Code
Identification

CIRCUIT IDENTIFICATION
All circuits in the diagrams use an alpha/numeric
code to identify the, wire and its function. To identify
which circuit code applies to a system, refer to the
Circuit Identification Code Chart. This chart shows
the main circuits only and does not show the second­ ary codes that may apply to some models.
COLOR

CODE COLOR
STANDARD
TRACER

COLOR COLOR

CODE
COLOR
STANDARD

TRACER
CODE
BL BLUE WT
OR ORANGE

BK
BK
BLACK
WT PK
PINK
BK
OR WT

BR
BROWN
WT RD
RED WT
DB DARK
BLUE WT
TN
TAN WT
DG DARK
GREEN WT
VT

VIOLET
WT
GY GRAY
BK

WT

WHITE
BK

LB
LIGHT

BLUE
BK

YL YELLOW

BK

LG
LIGHT

GREEN
BK

*

WITH
TRACER

918W-136
Fig.
4
Wire
Color
Code
Chart

LOCATING
A
SYSTEM
OR
COMPONENT
To locate a system or component in the diagrams,
refer to the alphabetical index at the front of the di­ agrams. Determine the diagram sheet number. Sheet
numbers are located at the lower right or left hand
corner of each sheet. Page numbers at the top of
the page do not apply to diagram sheets. The diagram index identifies the main system and
all components that relate to that system. There are
also sections of the index that identify specific com­
ponents only (for example modules, lamps, etc.). Re-

MAIN
CIRCUIT IDENTIFICATION

CIRCUIT
DESCRIPTION
CIRCUIT
DESCRIPTION

A
Battery
Feed: Fused and Unfused
P
Power
Assist
System:
Locks,
Mirrors

B
ABS
System Q Power
Assist
System: Windows

C
Air Conditioning System

R
Airbag System

D
CCD
(+),
CCD
(-)
S
Air Suspension, Automatic Load Leveling

E
Interior
Lamp
Illumination
T Electronic Automatic Transaxle
F
Battery
Feed: Fused and Unfused
V
Windshield Wipers and Washers,

G
Sensors,
Sending Units, Switches Vehicle Speed Control System

K
Powertrain
Central
Module W Power
Assist
System: Windows

L
Exterior
Lighting, Stop Lamp Switch
X
Horn, Radio, Radio Speakers, Power Locks
M
Interior
Lamps
Z
Ground Circuits: Includes power and signal

Interior
Lamps

grounds
for PCM

938W-17

•

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.

CAV

WIRE

COLOR DESCRIPTION
CAV
WIRE

COLOR DESCRIPTION

1 DG/RD*
MAP SENSOR 37
BK/OR OVERDRIVE LAMP
2 TN/BK*
ENGINE COOLANT TEMPERATURE SENSOR 38 PK/BK INJECTOR DRIVE
#5

3 RD/WT DIRECT BATTERY 39 GY/RD IAC MOTOR
#4

4
BK/LB*

SENSOR RETURN 40 BR/WT
IAC MOTOR
#2

5 BK/WT SIGNAL GROUND 41
BK/DG* OXYGEN SENSOR SIGNAL
6 VT/WT
5-VOLT
OUTPUT
(MAP AND TPS)
42
7 OR

8-VOLT
OUTPUT (DISTRIBUTOR PICK-UP) 43

GY/LB*
TACHOMETER SIGNAL OUTPUT (VEHICLES W/TACHOMETER)
8 44 GY CAMSHAFT POSITION SENSE
9 DB
J2-IGNITION FEED 45
LG SCI RECIEVE
10 R/WT OVERDRIVE OVERRIDE
46 CCD
(-)

11 BK/TN POWER GROUND 47 WT/OR* SPEED SENSOR SIGNAL
12 BK/TN POWER GROUND 48 BR/RD* SPEED CONTROL
SET
SWITCH
13 LB/BR
INJECTOR DRIVER
#4
49
YL/RD* SPEED CONTROL ON/OFF SWITCH
14 YL/WT
INJECTOR DRIVER
#3
50 WT/LG* SPEED CONTROL RESUME SWITCH
15 TN INJECTOR DRIVER
#2
51 DB/YL*
AUTO SHUTDOWN
(ASD)
RELAY
-
RETURN
16
WT/DB*

INJECTOR DRIVER
#1
52 PK/BK
EVAP CANISTER PURGE SOLENOID
17 DB/TN INJECTOR DRIVER
#7
(V-8
ONLY) 53 LG/RD* SPEED CONTROL VENT SOLENOID
18 DB/GY
INJECTOR DRIVER
#8
(V-8
ONLY) 54
OR/BK* SHIFT INDICATOR LIGHT (MANUAL TRANSMISSION ONLY)
19 BK/GY*
IGNITION COIL DRIVER 54
OR/BK* CONVERTOR CLUTCH SOLENOID (AUTO TRANSMISSION)
20 DG
GENERATOR FIELD CONTROL 55
OR/WT OVERDRIVE SOLENOID (AUTO TRANSMISSION ONLY)
21 BK/RD
CHARGE TEMPERATURE SENSOR 56
GY/PK SRI LAMP
(5.9L HDC
ENGINE)
22
OR/DB*

THROTTLE POSITION SENSOR
(TPS)
57
DG/OR ASD SENSE
23 TN/WT
OXYGEN SENSOR SIGNAL
(5.9L HDC
ENGINE) 58 LG/BK
INJECTOR DRIVER
#6

24 GY/BK IGNITION (CAMSHAFT POSITION SENSOR) 59
VT/BK IAC MOTOR
#1

25 PK
,
SCI
TRANSMIT 60
YL/BK* IAC MOTOR
#3

26 CCD
(-:-)
WIRE COLOR CODES LB
LIGHT BLUE
VT VIOLET

27 BR
A/C SWITCH SENSE BK BLACK
LG LIGHT GREEN
WT

WHITE
28 VT A/C SELECT BR BROWN
OR ORANGE
YL YELLOW
29 WT/PK* BRAKE SWITCH
-
DB DARK BLUE PK
PINK *
WITH TRACER
30 BY/YL*
PARK/NEUTRAL SWITCH DG DARK GREEN
RD
RED
31 GY
GRAY TN TAN
32 BK/PK*
MALFUNCTION INDICATOR LAMP
33 TN/RD*
SPEED CONTROL VACUUM SOLENOID CONNECTOR
34 DB/OR* A/C CLUTCH RELAY TERMINAL

|(pcKX>coooop0ffoj'
oooooooooojj
35 GY/YL*
EGR SOLENOID SHOWN W'41
30
50«M#5l31
604

%\
oooooooooo ••ooooooooooj

36 J9314-171
Fig.
17 PCM
Connector—Gas
Powered
Engines

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

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.

14 - 82
FUEL 'SYSTEM
—. — ~—— — «

INTAKE HEATER CYCLE CHART

Intake
featperafwre
Preheat
Cycle
Time

Ignition
l£ey ON

Engine
Not
Running
Pestheat
Cycle

Ignition
Key ON
Snglne Running

Above
15
°C
(59
°F)
0 Seconds
No

-8°C(18°F)to
15°C (59
°F)
10
Seconds

Yes

-17°C(1
°F)
-9
°C(]6°F)
15
Seconds
Yes

«2d°C(-15°F)
to-18°C(0
°F) 17.5
Seconds
Yes

Below-26
°C (-15
*F)
20 Seconds

Yes

J9114-239
AUTO SHUT DOWN (ASD) RELAY-PCM OUTPUT
The ASD relay is located in the engine compart­
ment (Fig. 14).
TORQUE CONVERTER
CLUTCH RELAY A/C CLUTCH RELAY STARTER RELAY
AUTO SHUTDOWN RELAY FUEL PUMP RELAY DATA LINK
CONNECTOR
POWERTRAIN

CONTROL MODULE
J9314-164

Fig.
14 Relay Location—Typical The ASD relay supplies battery voltage to the gen­
erator field winding to provide regulation of the
charging system. The ground circuit for the ASD re­
lay is controlled by the PCM. The PCM operates the
relay by switching the ground circuit on and off.

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.

OVERDRIVE
INDICATOR LAMP-PCM OUTPUT
Indicates the state of the overdrive defeat switch
on the instrument panel.

OVERDRIVE
S0LEN0ID-PCM OUTPUT
The overdrive solenoid is used on vehicles that
have an automatic transmission. The solenoid is op­ erated by the PCM. It controls shifting in and out of
overdrive through the overdrive solenoid. Refer to Group 21 for overdrive solenoid service.

SCI
TRANSMIT—PCM OUTPUT
SCI Transmit is the serial data communication
transmit circuit for the DRB II scan tool. The PCM
transmits data to the DRB II through the SCI Trans­
mit circuit.

SPEED
C0NTR0L-PCM OUTPUT
The speed control vacuum and vent solenoids are
operated by the PCM. The vacuum solenoid main­
tains vacuum at a required pressure to resume, set or accelerate the speed control system. The vent so­
lenoid allows vacuum to bleed off during decelera­
tion, when the brakes are applied, or the
transmission is shifted into park or neutral.

TACHOMETER-PCM
OUTPUT
This output generates the necessary signal needed
to operate a dealer installed tachometer (if equipped).
The input for this signal is from the engine speed sensor.

WAIT-TO-START LAMP-PCM OUTPUT
The wait-to-start lamp is turned on and off by the
PCM based on the charge air temperature sensor in­
put. The light is turned on when the ignition is first ac­
tivated. It will remain on for two seconds as a bulb
test. If the PCM reads intake manifold air tempera­
ture below 15°C (59°F), it will turn the wait-to-start light on for the intake heater preheat cycle. The
light stays on until the preheat cycle is over. The wait-to-start light will flash on and off if the
charge air temperature sensor input to the PCM is

14
- 94
FUEL
SYSTEM

•
THROTTLE POSITION
SENSOR
TEST

CAUTION;
Before checking
the
TPS,
the
throttle
linkage must
be
checked
for
correct
adjustment.
The
throttle
lever must
contact
the low idle
speed screw.
The
throttle
lever must reach breakover when
the
throttle
is
wide
open. Refer
to the
Accelerator Pedal and
Throttle
Cable section
of
Group
14,
Fuel Systems.

The throttle position sensor (TPS) can be tested
with the DRB II or a digital voltmeter (Fig. 16). The center terminal of the TPS is the output terminal.

J9114-244

Fig.
16
Throttle
Position
Sensor
(TPS) Testing
Turn the ignition key to the On position. Check
TPS output voltage at the center terminal wire of the connector. Measure the voltage at idle (throttle lever contacting low idle speed screw) and at wide open
throttle
(WOT).
At idle TPS output voltage should be approximately 1 volt. At wide open throttle, the TPS
output voltage must be 2.25 to 2.75 volts higher than
the reading at idle. The output voltage should in­
crease gradually as the throttle lever is slowly
opened from idle to WOT. If the TPS is not within
the proper range, adjust the sensor. Refer to the Die­ sel Fuel Injection—Service Procedures section of this
group.

ON-BOARD
DIAGNOSTICS
(OBD) The powertrain control module (PCM) has been
programmed to monitor many different circuits. 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 ser­
vice technician. If the problem is repaired or ceases
to exist, the PCM cancels 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, en­gine 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.
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 en­
gine compartment. For operation of the DRB II, refer
to the appropriate Powertrain Diagnostic Procedures service manual.

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. Refet* 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. 17).
J9214-20
D-1
1
GROUND

D-2
N/C
D-3
SCI
TRANS

D-4
SCI
RECEIVE
D-5 IGNITION

D-6
NOT USED
Fig.
17
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.

•

FUEL SYSTEM
14 - 95
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 the
diesel engine.
A DTC
indi­ cates that
the
powertrain control module
(PCM) has

recognized
an
abnormal signal
in a
circuit
or the
sys­
tem.
A DTC may
indicate
the
result
of a
failure,
but
never identify
the
failed component directly.

SYSTEM SCHEMATICS—5.9L DIESEL ENGINE
Refer
to the
following system schematic
for the

5.9L diesel engine.