1993 DODGE TRUCK sensor

14
- 72
FUEL
SYSTEM

•

MANIFOLD ABSOLUTE
Fig.
24 MAP
Sensor—
Typical
Fig.
25 MAP
Sensor L-Shaped Rubber
Fitting

INSTALLATION
(1) Install rubber L-shaped fitting to MAP sensor.
(2) Position sensor to throttle body while guiding
rubber fitting over throttle body vacuum nipple.
(3) Install MAP sensor mounting bolts (screws).
Tighten screws to 3 N»m (25 in. lbs.) torque.
(4) Install throttle body. Refer to Throttle Body in­
stallation in this section. (5) Install air cleaner.

OXYGEN
(02)
SENSOR
On 3.9L/5.2L/5.9L LDC engines, the single 02 sen­
sor is located on the right exhaust down pipe (Fig.

26).
On 5.9L HDC engines, the dual 02 sensors are
located on each (left and right) exhaust down pipe (Fig. 27).
Fig.
27
Dual Oxygen Sensors—5.9L
HDC
Engine

REMOVAL
WARNING:
THE
EXHAUST MANIFOLD BECOMES
VERY
HOT
DURING ENGINE OPERATION. ALLOW ENGINE
TO
COOL BEFORE REMOVING OXYGEN

SENSOR.

(1) Raise and support the vehicle.
(2) Disconnect the wire connector from the 02 sen­
sor.

CAUTION:
When
disconnecting
the
sensor
electrical

connector,
do not
pull directly
on
wire
going
into

sensor.

(3) Remove the 02 sensor from the exhaust mani­
fold.

INSTALLATION
Threads of new oxygen sensors are factory coated
with anti-seize compound to aid in removal. DO NOT add any additional anti-seize compound to
the threads of a new oxygen sensor.

•

FUEL SYSTEM
14-73 (1) Install the 02 sensor into the exhaust manifold.
Tighten to 30 N*m (22 ft. lbs.) torque.
(2) Connect the 02 sensor wire connector.
(3) Lower the vehicle.

PARK/NEUTRAL
SWITCH
Refer to Group 21, Transmission and Transfer Case
for removal/installation procedures.

POWERTRAIN CONTROL MODULE
(PCM) The powertrain control module (PCM) is located in
the engine compartment behind the battery (Fig. 28).

REMOVAL
DATA LINK CONTROL
CONNECTOR MODULE
J9314-164

Fig.
28 Powertrain Control
Module
(PCM) Location (1) Disconnect negative battery cable at battery.
(2) Carefully remove 60-way wiring connector from
PCM (one screw) (Fig. 29).
PCM

MOUNTING

PCM CONNECTOR CONNECTOR
MOUNTING
BOLT
J9314-165

Fig.
29 Powertrain Control
Module
(PCM) (3) Remove three mounting bolts (Fig. 29).
(4) Remove PCM from vehicle.

INSTALLATION
(1) Install PCM to inner fender.
(2) Check inside of 60-way wiring harness connec­
tor for bent pins or corrosion. Repair as necessary.
(3) Install 60-way connector to PCM. Tighten
mounting screw to 4 Nem (35 in. lbs.), torque.
(4) Install battery cable to battery.

QUICK-CONNECT
FITTINGS
Refer to the Fuel Delivery System section of this
group for removal/installation procedures.

THROTTLE
BODY
A (factory adjusted) set screw is used to mechani­
cally limit the position of the throttle body throttle
plate. Never attempt to adjust the engine idle speed using this screw. All idle speed functions are
controlled by the powertrain control module (PCM).

REMOVAL
(1) Remove the air cleaner.
(2) Disconnect throttle body electrical connectors
at MAP sensor, IAC motor and TPS (Fig. 30).

MANIFOLD ABSOLUTE
Fig.
30
Sensor
Electrical Connectors—Typical
(3) Remove vacuum line at throttle body.
(4) Remove (unsnap) all control cables from throt­
tle body (lever) arm. Refer to the Accelerator Pedal and Throttle Cable section of this group for addi­
tional information.
(5) Remove four throttle body mounting bolts (Fig.

31).
(6) Remove throttle body from intake manifold.

14
- 74
FUEL
SYSTEM

•

THROTTLE
THROTTLE BODY
MOUNTING BOLTS J9214-31
Fig.
31
Throttle
Body
Mounting
Bolts—Typical (7) Discard old throttle body-to-intake manifold
gasket.
INSTALLATION (1) Clean the mating surfaces of the throttle body
and the intake manifold.
(2) Install new throttle body-to-intake manifold
gasket.
(3) Install throttle body to intake manifold.
(4) Install four mounting bolts. Tighten bolts to 23
N»m (200 in. lbs.) torque. (5) Install control cables.
(6) Install vacuum line to throttle body.
(7) Install electrical connectors.
(8) Install air cleaner.

THROTTLE
POSITION
SENSOR
(TPS)
REMOVAL
The TPS is located on the side of the throttle body
(Fig. 30).
(1) Remove air intake tube at throttle body. (2) Disconnect TPS electrical connector.
(3) Remove two TPS mounting screws (Fig. 32).
(4) Remove TPS from throttle body.
INSTALLATION The throttle shaft end of the throttle body slides
into a socket in the TPS (Fig. 33). The TPS must be
installed so that it can be rotated a few degrees. If
the sensor will not rotate, install the sensor with the
throttle shaft on the other side of the socket tangs.
The TPS will be under slight tension when rotated.
(1) Install the TPS and two retaining screws. (2) Tighten screws to 7 N»m (60 in. lbs.) torque.
THROTTLE
Fig.
32 TPS
Mounting
Screws THROTTLE THROTTLE

BODY
POSITION
THROTTLE SOCKET LOCATING
SHAFT
TANGS
J9214-52

Fig.
33 TPS
Installation—Typical

(3) Manually operate the throttle control lever by
hand to check for any binding of the TPS. (4) Connect TPS electrical connector to TPS.
(5) Install air intake tube.

•

FUEL
SYSTEM
14-75
VEHICLE SPEED SENSOR

The vehicle speed sensor (Fig. 34) is located on the
extension housing of the transmission on 2WD mod­

els.
It is located on the transfer case on 4WD models.
REMOVAL Fig. 34 Vehicle Speed Sensor Location—Typical
(1) Raise and support vehicle.
(2) Disconnect the electrical connector from the
sensor. (3) Remove (unscrew) the speedometer cable (if
equipped) from the sensor (Fig. 35). (4) Loosen the sensor mounting nut (Fig. 35). Fig. 35 Sensor and Components—Typical
(5) Remove the sensor.
INSTALLATION

(1) Install new sensor into speedometer adapter.
(2) Tighten sensor mounting nut.
(3) Connect electrical connector to sensor.
(4) Connect the speedometer cable (if equipped).

DIESEL
FUEL
INJECTION—COMPONENT
DESCRIPTION/SYSTEM
OPERATION

NDEX

page

Air
Conditioning (A/C) Clutch
Relay-PCM
Output
. 81

Air
Conditioning (A/C)
Controls-PCM
Input
.... 77

Air
Intake Heater
Relays—PCM
Output
........ 81

Auto
Shut
Down
(ASD)
Relay-PCM
Output
.... 82
Automatic
Shut
Down
(ASD)
Sense-PCM
input
. 78
Battery
Voltage-PCM
Input
78

Brake
Switch—PCM
Input
....... 78

Charge
Air
Temperature
Sensor—PCM
Input
... 78
Engine
Speed
Sensor—PCM
Input
........... 78

Fuel
Drain Manifold
83

Fuel
Heater
83

Fuel
Injection
Pump
83

Fuel
Injectors
84

Fuel
Solenoid
84

Fuel/Water
Separator
Filter ................. 84

General
Information
76

Generator
Field-PCM
Output
. 81

High
Pressure
Fuel
Lines
85
Ignition
Sense—PCM
Input
78

KSB
Solenoid
....... 85

Malfunction Indicator
Lamp—PCM
Output
...... 82

Manual
Shut
Down
Lever
.................. 85

GENERAL
INFORMATION

The fuel system of the 5.9L (in-line six-cylinder)
turbo-diesel engine (Fig. 1) consists of the following components:
• Fuel tank
• Low and high pressure fuel supply lines
• Mechanical lift pump
• Fuel/water separator filter
• Fuel heater
• Fuel injection pump
• Fuel injectors • Fuel return lines For information regarding fuel requirements of the
5.9L turbo-diesel engine, refer to the Fuel Require­
ments—Diesel Engines paragraph at the front of this group. Although various components, relays and switches
are operated by the powertrain control module (PCM), the diesel fuel injection system (Fig. 1) is not
directly regulated by the PCM. Refer to the proceed­
ing Powertrain Control Module section for additional
information.

SYSTEM
DIAGNOSIS
The 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 Diesel Fuel Injection—General Diagnosis section of
page

Mechanical
Lift
Pump
86

Overdrive
Indicator
Lamp—PCM
Output
....... 82

Overdrive
Solenoid-PCM
Output
............ 82

Overdrive/Override
Switch—PCM
Input
........ 79
Park/Neutral
Switch-PCM
Input
79

Power
Ground-PCM
Input
. 79
Powertrain Control Module
(PCM)
76

SCI
Receive-PCM
Input
. . 80

SCI
Transmit-PCM
Output
. . . 82

Sensor
Return-PCM
Input
................. 80

Signal
Ground-PCM
Input
. 80

Speed
Control-PCM
Input
80

Speed
Control-PCM
Output
82

System
Diagnosis
76

System
Operation
86

Tachometer-PCM
Output
82

Throttle
Position
Sensor
(TPS)-PCM
Input
80

Vehicle
Speed
Sensor-PCM
Input
80

Wait-To-Start
Lamp-PCM
Output
82

Water-ln-Fuel
Lamp-PCM
Output
83

Water-ln-Fuel
Sensor-PCM
input
80
this group for DTC information. The DRB II scan tool can be used to access the DTC messages stored in the PCM memory.

POWERTRAIN
CONTROL
MODULE
(PCM)
The powertrain control module (PCM) (Fig. 2) was
formerly referred to as the SBEC or engine control­ ler. The PCM is a pre-programmed, dual micropro­
cessor digital computer. The PCM is located in the engine compartment be­
hind the battery and under the left front fender (Fig.
2).
The PCM contains a voltage convertor, which con­
verts battery voltage to a regulated 8.0 volts. This is used to power the engine speed sensor. The PCM also
provides a 5 volt supply for the throttle position sen­sor (TPS). The TPS is not used if equipped with a
manual transmission.
Various sensors, switches and relays provide the
inputs necessary for operation of the PCM.
The PCM Inputs are from:

9
Air conditioning control switch
• Automatic shut down (ASD) sense circuit
• Battery voltage
• Brake light switch • Charge air temperature sensor ® Coolant temperature sensor (Auto, trans, only)
• Engine speed sensor
• Ignition
• Overdrive/override switch
• Park/neutral switch (Auto, trans, only)

•

FUEL
SYSTEM
14-77

FUEL FROM SUPPLY TANK

LIFT
PUMP
LOW
PRESSURE
SUPPLY LINE
FUEL/WATER SEPARATOR FILTER
4A. FUEL HEATER
4B. FUEL/WATER DRAIN VALVE
FUEL/WATER SEPARATOR FILTER
W.I.F. (WATER
IN
FUEL) SENSOR
CHARGE
AIR
TEMP. SENSOR
BLEED
SCREW
LOW
PRESSURE
SUPPLY LINE
INJECTION PUMP
TURBO BOOST CONTROL LINE POWERTRAIN CONTROL MODULE
FUEL DRAIN MANIFOLD
(RETURN FUEL
TO
TANK)
HIGH
PRESSURE
LINES
INJECTORS

KSB
SOLENOID
MANUAL SHUT DOWN LEVER
TDC TIMING
PIN

AIR TEMP. SWITCH
NOTE: #10 CONTROLS INTAKE HEATER,
KSB
VALVE, FUEL HEATER,
WIF
SENSOR
J9314-179

Fig.
1
Diesel
Fuel
System
Components

TORQUE CONVERTER CLUTCH RELAY
A/C
CLUTCH RELAY STARTER RELAY
AUTO SHUTDOWN RELAY FUEL PUMP RELAY DATA UNK
CONNECTOR POWERTRAIN
CONTROL
MODULE
J9314-164

Fig.
2 PCM Location—Typical Power ground
SCI receive (DRB II connection)
Sensor return
Signal ground
Speed control switch
Throttle position sensor (Auto, trans, only)
Transmission thermo-switch (Auto, trans, only)
Vehicle speed sensor
Water-in-fuel sensor Based on these inputs, the PCM regulates various
engine and vehicle operations through different sys­
tem components. These are called PCM outputs.
PCM outputs are to the:
• A/C compressor clutch relay
• Air intake heater relays
• Generator field control
• ASD relay
• Malfunction indicator lamp
• Overdrive indicator lamp
• Overdrive solenoid
• SCI transmit
• Speed control functions
• Tachometer (if equipped)
• Water-in-fuel indicator lamp • Wait-to-start indicator lamp

AIR CONDITIONING
(A/C)
CONTROLS-PCM
INPUT
The A/C control system information applies to fac­
tory installed air conditioning units only.

A/C
REQUEST SIGNAL

Once A/C has been selected, the 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).

14-78
FUEL SYSTEM

• 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 evaporator switch opens, (indicating that evapo­
rator
is not in
proper temperature range),
PCM
will
not receive
the A/C
request signal.
The PCM
will
then remove
the
ground from
the A/C
relay, deacti­
vating
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.
3).
It is
used
to power
a
circuit
to the
generator field winding.
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.
3
Relay Location—Typical

BATTERY VOLTAGE-PC! INPUT
The battery input provides power
to
operate
the

PCM. Battery voltage
is
needed
to
keep
PCM
mem­
ory alive.
The
memory stores diagnostic trouble code (DTC) messages
and the
minimum
TPS
value from
the previous key-on,
BRAKE
SWITCH-PCM INPUT

If
the PCM
receives
a
brake switch input while
the

speed control system
is on, it
will disable speed con­
trol.

CHARGE AIR TEMPERATURE SENSOR—PCM INPUT
The charge
air
temperature sensor
is
located
on top

of
the
intake manifold
(Fig. 4). It
provides
an
input
to
the PCM
that indicates
air
temperature
in the
manifold. Based
on the
charge
air
temperature input,
the
PCM
determines
if and how
long
to
energize
the
air intake heaters. Refer
to Air
Intake Heaters
in

this section. AIR

TEMPERATURE
SWITCH

(KSB
SOLENOID)

j9114-235

Fig.
4
Charge
Air
Temperature Sensor

ENGINE
SPEED
SENSOR-PCM
INPUT
The engine speed sensor (sometimes referred
to as

the crankshaft position sensor)
is
mounted
to the

front
of
engine
(Fig. 5). It
generates
an rpm
signal
to

the
PCM. The
engine speed sensor input
is
used along with
the
vehicle speed sensor
and
throttle
po­

sition sensor inputs
to
determine when
to
shift
the

automatic transmission into
and out of
overdrive.
The speed sensor signal
is
also used
as an
input
for
the
ASD
relay
(for
control
of
generator field), vehicle speed control
and
instrument panel mounted tachom­
eter.

SENSOR
MOUNTING BOLTS
VIBRATION
DAMPER
J9214-69

Fig.
5
Engine Speed Sensor
IGNITION
SENSE-PCM
INPUT
The ignition circuit
(J2)
sense input informs
the

PCM that
the
ignition switch
is in the run
position.

•

FUEL SYSTEM
14-79
OVERDRIVE/OVERRIDE SWITCH-PCM
INPUT

The overdrive/override switch is not used with
manual transmissions. On vehicles equipped with overdrive, the PCM reg­
ulates the 3-4 overdrive upshift and downshift
through the overdrive solenoid. An override switch is located on the instrument panel. The overdrive/override switch is a momentary con­
tact switch. The switch contacts are normally open. When the switch is activated, the PCM will receive a ground signal. The transmission will not enter over­
drive when the operator presses the override switch.
The transmission downshifts if the operator presses
the override switch while in overdrive.
COOLANT TEMPERATURE SENSOR The coolant temperature sensor is not used with
manual transmissions.
The coolant temperature sensor (Fig. 6) monitors
engine coolant temperature. This input is used to in­
hibit transmission upshift into overdrive when the
engine coolant temperature is below 16 degrees C (60
degrees F).

Fig.
6 Coolant
Temperature
Sensor

TRANSMISSION THERMO-SWITCH The transmission thermo-switch is not used with
manual transmissions.
The transmission thermo-switch opens when the
transmission fluid temperature is above 134°C (273°F). When the thermo-switch opens, the trans­
mission will not shift into overdrive. The transmis­ sion downshifts if it is in overdrive when the thermo-
switch opens. Once the thermo-switch opens, it will
not close until transmission fluid temperature drops
to 116°C (240°F). The switch is located in the trans­ mission-to-radiator cooling line (Fig. 7).

PARK/NEUTRAL SWITCH-PCM
INPUT
The park/neutral switch (Fig. 8) is located on the
automatic transmission housing. It provides an input
THERMO SWITCH
J9214-62

Fig.
7
Transmission
Thermo-Switch—Typical to the PCM. The input indicates if the automatic
transmission is in park, neutral or a drive gear se­ lection.
If transmission is in overdrive and operator shifts
vehicle into neutral, the overdrive solenoid will be de-energized. Normal PCM operation will resume
when the transmission is shifted back into drive po­ sition.
The PCM uses the park/neutral switch input when
determining speed control strategy. The PCM will
disable the speed control if the operator shifts the
transmission into neutral. The speed control will
have to be reset once the vehicle is placed back into drive.
The park/neutral switch is sometimes referred to as
the neutral safety switch. Refer to Group 21 Trans­ missions for adjustment, replacement and test infor­
mation.

Fig.
8 Park/Neutral Switch—Typical

POWER
GROUND-PCM
INPUT
Provides a common ground for power devices (sole­
noid and relay).