1998 DODGE RAM 1500 battery temp

FUEL INJECTION - DIESEL
TABLE OF CONTENTS
page page
ACCELERATOR PEDAL POSITION SENSOR
DESCRIPTION.........................68
OPERATION...........................68
REMOVAL.............................68
INSTALLATION.........................71
CAMSHAFT POSITION SENSOR
DESCRIPTION.........................71
OPERATION...........................71
REMOVAL.............................72
INSTALLATION.........................72
CRANKSHAFT POSITION SENSOR
DESCRIPTION.........................72
OPERATION...........................72
REMOVAL.............................73
INSTALLATION.........................73
FUEL CONTROL ACTUATOR
DESCRIPTION.........................74
OPERATION...........................74
REMOVAL.............................74
FUEL INJECTOR
DESCRIPTION.........................74
OPERATION...........................74
REMOVAL.............................75
INSTALLATION.........................77
FUEL INJECTOR RAIL
DESCRIPTION.........................78
OPERATION...........................78
REMOVAL.............................78
INSTALLATION.........................78INLET AIR TEMPERATURE SENSOR/
PRESSURE SENSOR
DESCRIPTION.........................79
OPERATION...........................79
REMOVAL.............................79
INSTALLATION.........................79
INTAKE AIR HEATER
DESCRIPTION.........................80
OPERATION...........................80
REMOVAL.............................80
INSTALLATION.........................80
INTAKE AIR HEATER RELAY
DESCRIPTION.........................82
OPERATION...........................82
REMOVAL.............................82
INSTALLATION.........................82
INTAKE AIR TEMPERATURE SENSOR/MAP
SENSOR
DESCRIPTION.........................82
OPERATION...........................82
REMOVAL.............................82
INSTALLATION.........................82
MAP SENSOR
DESCRIPTION.........................83
THROTTLE CONTROL CABLE
REMOVAL.............................83
INSTALLATION.........................84
PTO SWITCH
DESCRIPTION.........................85
OPERATION...........................85
ACCELERATOR PEDAL
POSITION SENSOR
DESCRIPTION
Engine Mounted Sensor:The APPS assembly is
located at the top-left-front of the engine. A plastic
cover is used to cover the assembly. The actual sen-
sor is located behind its mounting bracket.
Battery Tray Mounted Sensor:The Accelerator
Pedal Position Sensor (APPS) assembly is located
under the vehicle battery tray. A cable connects the
assembly to the accelerator pedal. A plastic cover
with a movable door is used to cover the assembly.
OPERATION
Engine Mounted Sensor:The Accelerator Pedal
Position Sensor (APPS) is a linear potentiometer. Itprovides the Engine Control Module (ECM) with a
DC voltage signal proportional to the angle, or posi-
tion of the accelerator pedal.
Battery Tray Mounted Sensor:The APPS pro-
vides the ECM with two DC voltage signals which
change as the position of the accelerator changes.
One of the DC voltage signals will be half the voltage
of the other signal.
REMOVAL
Engine Mounted Sensor :
The APPS is serviced (replaced) as one assembly
including the lever, brackets and sensor. The APPS is
calibrated to its mounting bracket. The APPS assem-
bly is located at left-front of engine below plastic
cable/lever/linkage cover (Fig. 1).
14 - 68 FUEL INJECTION - DIESELDR

CAUTION: Do not attempt to remove sensor from
its mounting bracket as electronic calibration will
be destroyed (sensor-to-bracket mounting screws
are permanently attached). Two accelerator lever
set screws (Fig. 3) are used to position lever. Do
not attempt to alter positions of these set screws as
electronic calibration will be destroyed.
(1) Disconnect both negative battery cables at both
batteries.
(2) Remove cable cover (Fig. 1). Cable cover is
attached with 2 Phillips screws, 2 plastic retention
clips and 2 push tabs (Fig. 1). Remove 2 Phillips
screws and carefully pry out 2 retention clips. After
clip removal, push rearward on front tab, and
upward on lower tab for cover removal.
(3) Using finger pressure only, disconnect end of
speed control servo cable from throttle lever pin by
pulling forward on connector while holding lever
rearward (Fig. 2).DO NOT try to pull connector
off perpendicular to lever pin. Connector will
be broken.
(4) Using two small screwdrivers, pry throttle
cable connector socket from throttle lever ball (Fig.
2).Be very careful not to bend throttle lever
arm.
(5) Disconnect transmission control cable at lever
arm (if equipped). Refer to 21, Transmission.
(6) Squeeze pinch tabs on speed control cable (Fig.
2) and pull cable rearward to remove from cable
mounting bracket.
(7) Squeeze pinch tabs on throttle cable (Fig. 2)
and pull cable rearward to remove from cable mount-
ing bracket.
(8) Refer to 21, Transmission for transmission con-
trol cable removal procedures.
(9) Disconnect wiring harness clip (Fig. 3) at bot-
tom of bracket.
(10) Remove 6 mounting bolts (Fig. 3) and par-
tially remove APPS assembly from engine. After
assembly is partially removed, disconnect electrical
connector from bottom of sensor by pushing on con-
nector tab (Fig. 4).
(11) Remove APPS assembly from engine.
Battery Tray Mounted Sensor :
The APPS is serviced (replaced) as one assembly
including the sensor, plastic housing and cable. The
APPS assembly is located under the left (drivers
side) vehicle battery tray (Fig. 5). Access to APPS is
gained from over top of left / front tire.
(1) Disconnect negative battery cable at battery.
(2) Disconnect APPS cable at accelerator pedal.
Refer to Accelerator Pedal Removal / Installation.
(3) Remove wheel house liner at left / front wheel.
Refer to Body.(4) Gain access to APPS electrical connector by
opening swing-down door (Fig. 6). Disconnect electri-
cal connector.
(5) Remove 3 mounting bolts (Fig. 6).
(6) Remove APPS assembly from battery tray.
Fig. 1 CABLE/LEVER/THROTTLE LINKAGE COVER
1 - CABLE/LEVER/LINKAGE COVER
2 - PUSH UP LOWER TAB
3 - SCREWS/CLIPS (2)
4 - TAB PUSH HERE
Fig. 2 SERVO CABLE AT THROTTLE LEVER
1 - PINCH (2) TABS
2 - CABLE MOUNTING BRACKET
3 - PINCH TABS (2)
4 - OFF
5 - THROTTLE CABLE
6 - THROTTLE LEVER
7 - THROTTLE LEVER PIN
8 - OFF
9 - CONNECTOR
10 - SPEED CONTROL CABLE
DRFUEL INJECTION - DIESEL 14 - 69
ACCELERATOR PEDAL POSITION SENSOR (Continued)

(8) Connect battery cables to both batteries.
(9) Start engine and check for leaks.
INLET AIR TEMPERATURE
SENSOR/PRESSURE SENSOR
DESCRIPTION
The combination, dual function Inlet Air Tempera-
ture/Pressure Sensor is located on the air cleaner (fil-
ter) cover.
OPERATION
The Inlet Air Temperature/Pressure Sensor is a
combination dual-function sensor. The sensor element
extends into the intake air stream at the top of the
air filter housing. Ambient air temperature as well as
barometric pressure is monitored by this sensor. The
Engine Control Module (ECM) monitors signals from
this sensor.
REMOVAL
The Inlet Air Temperature/Pressure Sensor is
located on the air cleaner cover (Fig. 23).
(1) Disconnect electrical connector at sensor (Fig.
24).
(2) Remove two Torx-type mounting screws.
(3) Remove sensor from air cleaner cover.
(4) Check condition of sensor o-ring (Fig. 25).
INSTALLATION
(1) Check condition of sensor o-ring.
(2) Position sensor into top of air cleaner cover
with a slight twisting action.
(3) Install 2 mounting screws.
(4) Install electrical connector.
Fig. 22 FUEL INJECTOR RAIL
1 - FUEL RAIL MOUNTING BOLTS (3)
2 - INSULATED CLAMPS
3 - FUEL INJECTOR RAIL
Fig. 23 IAT/PRESSURE SENSOR LOCATION - 5.9L
DIESEL
1 - CLIPS
2 - FILTER COVER
3 - FILTER MINDERŸ
4 - INLET AIR TEMPERATURE/ PRESSURE SENSOR
5 - FILTER HOUSING
DRFUEL INJECTION - DIESEL 14 - 79
FUEL INJECTOR RAIL (Continued)

INTAKE AIR HEATER
DESCRIPTION
The intake manifold air heater element assembly
is located in the top of the intake manifold.
OPERATION
The air heater elements are used to heat incoming
air to the intake manifold. This is done to help
engine starting and improve driveability with cool or
cold outside temperatures.
Electrical supply for the 2 air heater elements is
controlled by the Engine Control Module (ECM)
through the 2 air heater relays. Refer to Intake Man-
ifold Air Heater Relays for more information.
Two heavy-duty cables connect the 2 air heater ele-
ments to the 2 air heater relays. Each of these cables
will supply approximately 95 amps at 12 volts to an
individual heating element within the heater block
assembly.
Refer to the Powertrain Diagnostic Procedures
manual for electrical operation and complete descrip-
tion of the intake heaters, including pre-heat and
post-heat cycles.
REMOVAL
If servicing either of the heater elements, the
entire block/element assembly must be replaced.
(1) Disconnect both negative battery cables at both
batteries. Cover and isolate ends of both cables.
(2) Remove both the intake manifold air intake
tube (above injection pump), and its rubber connector
hose (Fig. 26).
(3) Lift 2 rubber covers (Fig. 27) to gain access to 2
positive (+) cable nuts. Remove these 2 nuts (Fig. 28)
and remove 2 cables from studs.
(4) Disconnect ground strap (Fig. 27) at heater ele-
ment stud.
(5) Remove wiring harness clips.
(6) Remove engine oil dipstick tube bracket from
air inlet connection and fuel filter housing.
(7) Remove 4 housing mounting bolts (Fig. 27) and
remove heater element assembly.
INSTALLATION
If servicing either of the heater elements, the
entire block/element assembly must be replaced.
(1) Using 2 new gaskets, position element assem-
bly and air housing to intake manifold.
(2) Install ground cable to air housing.
(3) Install 4 housing bolts and tighten to 24 N´m
(18 ft. lbs.) torque.
(4) Connect 2 positive (+) heater cables at cable
mounting studs.Do not allow either of the cable
eyelets to contact any other metal source other
than the cable nuts/studs.
Fig. 24 INLET/PRESSURE SENSOR REMOVAL/
INSTALLATION
1 - INLET/PRESSURE SENSOR
2 - ELEC. CONNECTOR
3 - SENSOR MOUNTING SCREWS (2)
4 - TOP OF AIR FILTER COVER
Fig. 25 SENSOR O-RING
1 - IAT/PRESSURE SENSOR
2 - O-RING
14 - 80 FUEL INJECTION - DIESELDR
INLET AIR TEMPERATURE SENSOR/PRESSURE SENSOR (Continued)

INTAKE AIR HEATER RELAY
DESCRIPTION
The 2 intake manifold air heater relays are located
in the engine compartment. They are attached to a
common bracket. This bracket is attached to the
right battery tray (Fig. 29).
OPERATION
The Engine Control Module (ECM) operates the 2
heating elements through the 2 intake manifold air
heater relays.
Refer to Powertrain Diagnostic Procedures for an
electrical operation and complete description of the
intake heaters, including pre-heat and post-heat
cycles.
REMOVAL
The 2 intake manifold air heater relays are located
in the engine compartment. They are attached to a
common bracket. This bracket is attached to the
right battery tray (Fig. 29).
The mounting bracket and both relays are replaced
as an assembly.
(1) Disconnect both negative battery cables at both
batteries.
(2) Disconnect four relay trigger wires at both
relays. Note position of wiring before removing.
(3) Lift four rubber shields from all 4 cables.(4) Remove four nuts at cable connectors. Note
position of wiring before removing.
(5) Remove relay mounting bracket bolts and
remove relay assembly.
INSTALLATION
(1) Install relay assembly to battery tray. Tighten
mounting bolts to 4.5 N´m (40 in. lbs.) torque.
(2) Connect eight electrical connectors to relays.
(3) Connect battery cables to both batteries.
INTAKE AIR TEMPERATURE
SENSOR/MAP SENSOR
DESCRIPTION
The combination, dual function Intake Manifold
Air Temperature Sensor/MAP Sensor is installed into
the top of the intake manifold.
OPERATION
The combination, dual function Intake Manifold
Air Temperature Sensor/MAP Sensor is installed into
the top of the intake manifold with the sensor ele-
ment extending into the air stream.
The IAT portion of the sensor provides an input
voltage to the Engine Control Module (ECM) indicat-
ing intake manifold air temperature. The MAP por-
tion of the sensor provides an input voltage to the
ECM indicating turbocharger boost pressure.
REMOVAL
The combination, dual function Intake Manifold
Air Temperature Sensor/MAP (IAT/MAP) sensor is
installed into the top of the intake manifold (Fig. 30).
(1) Clean area around sensor.
(2) Disconnect electrical connector from IAT/MAP
sensor.
(3) Remove two T-15 Torx headed screws.
(4) Remove sensor from intake manifold.
(5) Check condition of sensor o-ring (Fig. 31).
INSTALLATION
(1) Check condition of sensor o-ring.
(2) Lubricate sensor o-ring with clean engine oil.
(3) Clean sensor mounting area at intake mani-
fold.
(4) Position sensor into intake manifold.
(5) Install and tighten 2 sensor mounting screws
to 1 N´m (9 in. lbs.) torque.
(6) Connect electrical connector to sensor.
Fig. 29 INTAKE MANIFOLD AIR HEATER RELAYS
1 - BATTERY
2 - CABLES TO INTAKE HEATERS
3 - RELAY TRIGGER WIRES
4 - INTAKE AIR HEATER RELAYS (2)
14 - 82 FUEL INJECTION - DIESELDR

MAP SENSOR
DESCRIPTION
A combination, dual function Intake Manifold Air
Temperature Sensor/MAP Sensor is used. Refer to
Intake Air Temperature Sensor/MAP Sensor for infor-
mation.
THROTTLE CONTROL CABLE
REMOVAL
If Equipped With Engine Mounted Accelerator Pedal
Position Sensor
(1) Disconnect both negative battery cables at both
batteries.
(2) From inside vehicle, hold up accelerator pedal.
Remove plastic cable retainer and throttle cable core
wire from upper end of pedal arm (Fig. 32). The plas-
tic cable retainer snaps into pedal arm.
(3) From inside vehicle, remove cable clip (Fig. 32).
(4) Remove cable core wire at pedal arm.
(5) Remove cable housing from dash panel and
pull cable into engine compartment.
(6) Remove cable cover (Fig. 33). Cable cover is
attached with 2 Phillips screws, 2 plastic retention
clips and 2 push tabs (Fig. 33). Remove 2 Phillips
screws and carefully pry out 2 retention clips. After
clip removal, push rearward on front tab, and
upward on lower tab for cover removal.
(7) Using 2 screwdrivers, pry cable connector
socket from throttle lever ball (Fig. 34).Be very
careful not to bend throttle lever arm.
If Equipped With Battery Tray Mounted Accelerator Pedal
Position Sensor
The Throttle Control Cable connects the accelera-
tor pedal to the Accelerator Pedal Position Sensor
(APPS). A separate mechanical cable is not routed to
the throttle body.
CAUTION: Be careful not to damage or kink cable
core wire (within cable sheathing) while servicing
accelerator pedal, cables or APPS.
(1) Disconnect both negative battery cables at both
batteries.
(2) From inside vehicle, hold up accelerator pedal.
Remove plastic cable retainer and throttle cable core
wire from upper end of pedal arm (Fig. 35). The plas-
tic cable retainer snaps into pedal arm.
(3) Remove cable core wire at pedal arm.
(4) Remove APPS. Refer to (Diesel) Accelerator
Pedal Position Sensor (APPS) Removal / Installation.
(5) From inside vehicle, remove cable clip (Fig. 35).
Fig. 30 INTAKE/MAP SENSOR
1 - TOP OF INTAKE MANIFOLD
2 - IAT/MAP SENSOR
3 - ELEC. CONNECTOR
4 - MOUNTING BOLTS (2)
Fig. 31 SENSOR O-RING
1 - IAT/MAP SENSOR
2 - O-RING
DRFUEL INJECTION - DIESEL 14 - 83
INTAKE AIR TEMPERATURE SENSOR/MAP SENSOR (Continued)

COLUMN
TABLE OF CONTENTS
page page
COLUMN
DESCRIPTION..........................6
DIAGNOSIS AND TESTING - STEERING
COLUMN.............................7
REMOVAL.............................7
INSTALLATION..........................9
IGNITION SWITCH
DESCRIPTION..........................9
OPERATION............................9
DIAGNOSIS AND TESTING - IGNITION
SWITCH.............................9
REMOVAL.............................10
INSTALLATION.........................11
KEY-IN IGNITION SWITCH
DESCRIPTION.........................11
DIAGNOSIS AND TESTING - IGNITION
SWITCH AND KEY LOCK CYLINDER.......11
KEY CYLINDER
REMOVAL.............................12
INSTALLATION.........................12GEAR SHIFT LEVER
REMOVAL.............................12
INSTALLATION.........................12
UPPER STEERING COUPLING
REMOVAL.............................13
INSTALLATION.........................13
LOWER STEERING COUPLING
REMOVAL
REMOVAL - ALL LD & HD EXCEPT 4X4 HD . 14
REMOVAL - 4X4 HD...................14
INSTALLATION
INSTALLATION - ALL LD & HD EXCEPT 4X4
HD.................................14
INSTALLATION - 4X4 HD................15
STEERING WHEEL
REMOVAL.............................15
INSTALLATION.........................15
TILT LEVER KNOB RELEASE
REMOVAL.............................16
INSTALLATION.........................16
COLUMN
DESCRIPTION
NOTE: The steering column on vehicles with an
automatic transmission may not be equipped with
an internal locking shaft that allows the ignition key
cylinder to be locked with the key. Alternative meth-
ods of locking the steering wheel for service will
have to be used.
The tilt and standard column (Fig. 1) has been
designed to be serviced as an assembly; less wiring,
switches, shrouds, steering wheel, etc. Most steering
column components can be serviced without remov-
ing the steering column from the vehicle.
To service the steering wheel, switches or airbag,
refer to Restraints and follow all WARNINGS and
CAUTIONS.
WARNING: THE AIRBAG SYSTEM IS A SENSITIVE,
COMPLEX ELECTRO-MECHANICAL UNIT. BEFORE
ATTEMPTING TO DIAGNOSE, REMOVE OR INSTALL
THE AIRBAG SYSTEM COMPONENTS YOU MUST
FIRST DISCONNECT AND ISOLATE THE BATTERY
NEGATIVE (GROUND) CABLE. THEN WAIT TWO
MINUTES FOR THE SYSTEM CAPACITOR TO DIS-
CHARGE. FAILURE TO DO SO COULD RESULT INACCIDENTAL DEPLOYMENT OF THE AIRBAG AND
POSSIBLE PERSONAL INJURY. THE FASTENERS,
SCREWS, AND BOLTS, ORIGINALLY USED FOR
THE AIRBAG COMPONENTS, HAVE SPECIAL COAT-
INGS AND ARE SPECIFICALLY DESIGNED FOR THE
AIRBAG SYSTEM. THEY MUST NEVER BE
REPLACED WITH ANY SUBSTITUTES. ANYTIME A
NEW FASTENER IS NEEDED, REPLACE WITH THE
CORRECT FASTENERS PROVIDED IN THE SERVICE
PACKAGE OR FASTENERS LISTED IN THE PARTS
BOOKS.
CAUTION: Do not hammer on steering column
shaft. This may cause damage to the shaft or bear-
ing.
CAUTION: Do not attempt to remove the pivot bolts
to disassemble the tilting mechanism. Do not
remove shaft lock plate or plate retainer. This will
damage the column.
CAUTION: Do not attempt to remove or modify the
park lock slider or link.
19 - 6 COLUMNDR

NOTE: When servicing the steering wheel after
removing the old bolt a new bolt must be used
when installing.
NOTE: When servicing the coupler a new bolt must
be used when installing.
DIAGNOSIS AND TESTING - STEERING
COLUMN
If the vehicle is involved in a front end collision/the
air bag has deployed the column must be inspected.
This inspection will determine if the Column has col-
lapsed. Inspect the column mounting capsules visu-
ally and manually push and pull them to check for
separation or fractures. If capsules are fractured or
have moved the column MUST be replaced.
REMOVAL
WARNING: BEFORE SERVICING THE STEERING
COLUMN THE AIRBAG SYSTEM MUST BE DIS-
ARMED. REFER TO ELECTRICAL RESTRAINT SYS-
TEM FOR SERVICE PROCEDURES. FAILURE TO DO
SO MAY RESULT IN ACCIDENTAL DEPLOYMENT OF
THE AIRBAG AND POSSIBLE PERSONAL INJURY.CAUTION: All fasteners must be torqued to specifi-
cation to ensure proper operation of the steering
column.
(1) Position the front wheelsstraight ahead.
(2) Disconnect the negative (ground) cable from
the battery.
(3) Remove the two switches from the steering
wheel.
(4) Remove the airbag, (Refer to 8 - ELECTRICAL/
RESTRAINTS/DRIVER AIRBAG - REMOVAL).
(5) Remove the steering wheel with special tool
CJ98±1 or an appropriate steering wheel puller.
CAUTION: Ensure the puller bolts are fully engaged
into the steering wheel and not into the clock-
spring, before attempting to remove the wheel. Fail-
ure to do so may damage the steering wheel/
clockspring.
(6) Remove the steering column opening cover
(Refer to 23 - BODY/INSTRUMENT PANEL/STEER-
ING COLUMN OPENING COVER - REMOVAL).
(7) Remove the tilt lever.
(8) Remove the column shrouds (Fig. 2).
(9) Remove the clock spring, (Refer to 8 - ELEC-
TRICAL/RESTRAINTS/CLOCKSPRING -
REMOVAL).
(10) Disconnect the wiring harness to the column.
Fig. 1 STEERING COLUMN
1 - LOCK CYLINDER
2 - GEAR SHIFT LEVER
3 - MOUNTING HOLES
4 - STEERING COLUMN
5 - TILT LEVER
Fig. 2 UPPER & LOWER SHROUDS
1 - UPPER SHROUD
2 - LOWER SHROUD
DRCOLUMN 19 - 7
COLUMN (Continued)