1998 DODGE RAM 1500 fuel filter location

(3) Check condition of relay terminals and PDC
connector terminals for damage or corrosion. Repair
if necessary before installing relay.
(4) Check for pin height (pin height should be the
same for all terminals within the PDC connector).
Repair if necessary before installing relay.
INSTALLATION
The fuel heater relay is located in the Power Dis-
tribution Center (PDC) (Fig. 6). Refer to label under
PDC cover for relay location.
(1) Install relay to PDC.
(2) Install cover to PDC.
FUEL INJECTION PUMP
DESCRIPTION
A Robert Bosch high-pressure fuel injection pump
is used. The pump is attached to the back of the tim-
ing gear cover at the left / rear side of the engine.
OPERATION
The fuel injection pump supplies high pressure to
the fuel rail independent of engine speed. This high
pressure is then accumulated in the fuel rail. High
pressure fuel is constantly supplied to the injectors
by the fuel rail. The Engine Control Module (ECM)
controls the fueling and timing of the engine by actu-
ating the injectors.
Fuel enters the system from the electric fuel trans-
fer (lift) pump, which is attached to the fuel filter
assembly. Fuel is forced through the fuel filter ele-
ment and then enters the Fuel Pump/Gear Pump,
which is attached to the rear of the fuel injection
pump. The Fuel Pump/Gear Pump is a low-pressure
pump and produce pressures ranging from 551.5 kpa
(80 psi) to 1241 kpa (180) psi. Fuel then enters the
fuel injection pump. Low pressure fuel is then sup-
plied to the FCA (Fuel Control Actuator).
The FCA is an electronically controlled solenoid
valve. The ECM controls the amount of fuel that
enters the high-pressure pumping chambers by open-
ing and closing the FCA based on a demanded fuel
pressure. The FPS (Fuel Pressure Sensor) on the fuel
rail provides the actual fuel pressure. When the
actuator is opened, the maximum amount of fuel is
being supplied to the fuel injection pump. Any fuel
that does not enter the injection pump is directed to
the cascade overflow valve. The cascade overflow
valve regulates how much excess fuel is used for
lubrication of the pump and how much is returned to
the tank through the drain manifold.
Fuel entering the injection pump is pressurized to
between 300-1600 bar (4351-23206 psi) by three
radial pumping chambers. The pressurized fuel is
then supplied to the fuel rail.
DIAGNOSIS AND TESTING - FUEL INJECTION
PUMP TIMING
With the Bosch injection pump, there are no
mechanical adjustments needed or necessary to
accomplish fuel injection timing. All timing and fuel
adjustments are electrically made by the engine
mounted Engine Control Module (ECM).
Fig. 6 POWER DISTRIBUTION CENTER LOCATION
1 - CLIP
2 - BATTERY
3 - TRAY
4 - NEGATIVE CABLE
5 - POSITIVE CABLE
6 - CLIP
7 - FENDER INNER SHIELD
8 - POWER DISTRIBUTION CENTER
DRFUEL DELIVERY - DIESEL 14 - 53
FUEL HEATER RELAY (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)

PUMPING ACTION
Action : During portions of this test, the PCM uses
the reed switch to monitor diaphragm movement.
The solenoid is only turned on by the PCM after the
reed switch changes from open to closed, indicating
that the diaphragm has moved down. At other times
during the test, the PCM will rapidly cycle the LDP
solenoid on and off to quickly pressurize the system.
During rapid cycling, the diaphragm will not move
enough to change the reed switch state. In the state
of rapid cycling, the PCM will use a fixed time inter-
val to cycle the solenoid. If the system does not pass
the EVAP Leak Detection Test, the following DTCs
may be set:
²P0442 - EVAP LEAK MONITOR 0.0409LEAK
DETECTED
²P0455 - EVAP LEAK MONITOR LARGE LEAK
DETECTED
²P0456 - EVAP LEAK MONITOR 0.0209LEAK
DETECTED
²P1486 - EVAP LEAK MON PINCHED HOSE
FOUND
²P1494 - LEAK DETECTION PUMP SW OR
MECH FAULT
²P1495 - LEAK DETECTION PUMP SOLENOID
CIRCUIT
REMOVAL
The Leak Detection Pump (LDP) and LDP filter
are attached to the front of the EVAP canister
mounting bracket (Fig. 9). This is located near the
front of the fuel tank. The LDP and LDP filter are
replaced (serviced) as one unit.
(1) Raise and support vehicle.
(2) Carefully remove hose at LDP filter.
(3) Remove LDP filter mounting bolt and remove
from vehicle.
(4) Carefully remove vapor/vacuum lines at LDP.
(5) Disconnect electrical connector at LDP.
(6) Remove LDP mounting bolt and remove LDP
from vehicle.
INSTALLATION
The LDP and LDP filter are attached to the front
of the EVAP canister mounting bracket. The LDP
and LDP filter are replaced (serviced) as one unit.
(1) Install LDP to mounting bracket. Refer to
Torque Specifications.
(2) Install LDP filter to mounting bracket. Refer to
Torque Specifications.
(3) Carefully install vapor/vacuum lines to LDP,
and install hose to LDP filter.The vapor/vacuum
lines and hoses must be firmly connected.
Fig. 8 DIAPHRAGM DOWNWARD MOVEMENT
1 - Diaphragm
2 - Inlet Check Valve (Closed)
3 - Vent Valve (Closed)
4 - From Air Filter
5 - To Canister
6 - Outlet Check Valve (Open)
7 - Engine Vacuum (Closed)
Fig. 9 LDP AND LDP FILTER LOCATION
1 - LDP
2 - LDP MOUNTING BOLT
3 - ELEC. CONNEC.
4 - FILTER MOUNTING BOLT
5 - LDP FILTER
6 - CONNECTING HOSE
7 - EVAP CANISTER MOUNTING BRACKET
8 - EVAP CANISTERS (2)
25 - 16 EVAPORATIVE EMISSIONSDR
LEAK DETECTION PUMP (Continued)

5.7L V-8
(1) Clean out intake manifold opening.
(2) Check condition of 2 o-rings on PCV valve.
(3) Apply engine oil to 2 o-rings.
(4) Place PCV valve into intake manifold and
rotate 90 degrees clockwise for installation.
VACUUM LINES
DESCRIPTION
A vacuum schematic for emission related items can
be found on the vehicles VECI label. Refer to Vehicle
Emission Control Information (VECI) Label for label
location.
VAPOR CANISTER
DESCRIPTION
Two, maintenance free, EVAP canisters are used.
Both canisters are mounted into a two-piece support
bracket located near the front of the fuel tank (Fig.
23).
OPERATION
Two, maintenance free, EVAP canisters are
used.The EVAP canisters are filled with granules of
an activated carbon mixture. Fuel vapors entering
the EVAP canisters are absorbed by the charcoal
granules.
Fuel tank pressure vents into the EVAP canisters.
Fuel vapors are temporarily held in the canisters
until they can be drawn into the intake manifold.
The duty cycle EVAP canister purge solenoid allows
the EVAP canisters to be purged at predetermined
times and at certain engine operating conditions.
REMOVAL
Two, maintenance free, EVAP canisters are used.
Both canisters are mounted into a two-piece support
bracket located near the front of the fuel tank (Fig.
23).
(1) Raise and support vehicle.
(2) Remove fuel tubes/lines at each EVAP canister.
Note location of tubes/lines before removal for easier
installation.
(3) Remove lower support bracket (Fig. 24).
(4) Remove mounting nuts at top of each canister
(Fig. 24).
(5) Remove each canister from upper support
bracket.
INSTALLATION
(1) Place each canister into upper support bracket
and install nuts. Refer to Torque Specifications.
(2) Install lower support bracket. Refer to Torque
Specifications.
(3) Carefully install vapor/vacuum lines.The
vapor/vacuum lines and hoses must be firmly
connected. Also check the vapor/vacuum lines
at the LDP, LDP filter and EVAP canister purge
solenoid for damage or leaks. If a leak is
present, a Diagnostic Trouble Code (DTC) may
be set.
Fig. 23 LOCATION, EVAP CANISTERS
1 - LDP
2 - LDP MOUNTING BOLT
3 - ELEC. CONNEC.
4 - FILTER MOUNTING BOLT
5 - LDP FILTER
6 - CONNECTING HOSE
7 - EVAP CANISTER MOUNTING BRACKET
8 - EVAP CANISTERS (2)
25 - 22 EVAPORATIVE EMISSIONSDR
PCV VALVE (Continued)

The NVLD device is designed with a normally open
vacuum switch, a normally closed solenoid, and a
seal, which is actuated by both the solenoid and a
diaphragm. The NVLD is located on the atmospheric
vent side of the canister. The NVLD assembly may
be mounted on top of the canister outlet, or in-line
between the canister and atmospheric vent filter. The
normally open vacuum switch will close with about 19
H2O (0.25 KPA) vacuum in the evaporative system.
The diaphragm actuates the switch. This is above the
opening point of the fuel inlet check valve in the fill
tube so cap off leaks can be detected. Submerged fill
systems must have recirculation lines that do not
have the in-line normally closed check valve that pro-
tects the system from failed nozzle liquid ingestion,
in order to detect cap off conditions.
The normally closed valve in the NVLD is intended
to maintain the seal on the evaporative system dur-
ing the engine off condition. If vacuum in the evapo-
rative system exceeds 39to 69H2O (0.75 to 1.5 KPA),
the valve will be pulled off the seat, opening the seal.
This will protect the system from excessive vacuum
as well as allowing sufficient purge flow in the event
that the solenoid was to become inoperative.
The solenoid actuates the valve to unseal the can-
ister vent while the engine is running. It also will be
used to close the vent during the medium and large
leak tests and during the purge flow check. This sole-
noid requires initial 1.5 amps of current to pull the
valve open but after 100 ms. will be duty cycled down
to an average of about 150 mA for the remainder of
the drive cycle.
Another feature in the device is a diaphragm that
will open the seal in the NVLD with pressure in the
evaporative system. The device will9blow off9at
about 0.59H2O (0.12 KPA) pressure to permit the
venting of vapors during refueling. An added benefit
to this is that it will also allow the tank to9breathe9
during increasing temperatures, thus limiting the
pressure in the tank to this low level. This is benefi-
cial because the induced vacuum during a subse-
quent declining temperature will achieve the switch
closed (pass threshold) sooner than if the tank had to
decay from a built up pressure.
The device itself has 3 wires: Switch sense, sole-
noid driver and ground. It also includes a resistor to
protect the switch from a short to battery or a short
to ground. The NGC utilizes a high-side driver to
energize and duty-cycle the solenoid.REMOVAL
The NVLD pump and filter are attached to the
front of the EVAP canister mounting bracket (Fig.
25). This is located near the front of the fuel tank.
The pump and filter are replaced (serviced) as one
unit.
(1) Raise and support vehicle.
(2) Carefully remove pump hose clamp and hose at
filter.
(3) Carefully remove other vapor/vacuum hose at
pump.
(4) Disconnect 3±way electrical connector at pump.
(5) The NVLD pump snaps onto the EVAP canister
mounting bracket. Press on release tab (Fig. 26)
while sliding pump from bracket.
Fig. 25 NVLD PUMP LOCATION
1 - EVAP CANISTER MOUNTING BRACKET
2 - NVLD PUMP
3 - FILTER
25 - 24 EVAPORATIVE EMISSIONSDR
NATURAL VAC LEAK DETECTION ASSY (Continued)

WATER PUMP BYPASS - DESCRIPTION....7-59
WATER PUMP BYPASS - OPERATION......7-60
WATER SEPARATOR - DESCRIPTION,
FUEL FILTER........................14-50
WATER SEPARATOR - INSTALLATION,
FUEL FILTER........................14-50
WATER SEPARATOR - OPERATION, FUEL
FILTER.............................14-50
WATER SEPARATOR - REMOVAL, FUEL
FILTER.............................14-50
WATER TO OIL COOLER - REMOVAL......7-69
WATERDAM - INSTALLATION......23-25,23-34
WATERDAM - REMOVAL..........23-25,23-34
WATER-IN-FUEL INDICATOR -
DESCRIPTION.......................8J-45
WATER-IN-FUEL INDICATOR -
OPERATION.........................8J-45
WATER-TO-AIR COOLER - INSTALLATION . . 7-70
WEAR - STANDARD PROCEDURE,
MEASURING TIMING CHAIN............9-167
WEAR INDICATORS - DIAGNOSIS AND
TESTING, TREAD......................22-8
WEAR PATTERNS - DIAGNOSIS AND
TESTING, TIRE.......................22-8
WEAR, STANDARD PROCEDURE -
MEASURING TIMING CHAIN.............9-77
WEATHERSTRIP - INSTALLATION, DRIP
RAIL..............................23-91
WEATHERSTRIP - INSTALLATION, FRONT
DOOR GLASS RUN...................23-92
WEATHERSTRIP - INSTALLATION, REAR
DOOR GLASS RUN.....................23-93
WEATHERSTRIP - REMOVAL, DRIP RAIL . . 23-91
WEATHERSTRIP - REMOVAL, FRONT
DOOR GLASS RUN...................23-92
WEATHERSTRIP - REMOVAL, REAR
DOOR GLASS RUN...................23-93
WEATHERSTRIP RETAINER -
INSTALLATION, A-PILLAR..............23-91
WEATHERSTRIP RETAINER -
INSTALLATION, DRIP RAIL.............23-92
WEATHERSTRIP RETAINER - REMOVAL,
A-PILLAR...........................23-91
WEATHERSTRIP RETAINER - REMOVAL,
DRIP RAIL..........................23-92
WELD LOCATIONS - SPECIFICATIONS . . . 23-120
WELD PROCESS - SPECIFICATIONS......13-15
WHEEL - INSTALLATION, STEERING
......19-15
WHEEL - REMOVAL, STEERING
.........19-15
WHEEL ALIGNMENT - DESCRIPTION
.......2-1
WHEEL ALIGNMENT - OPERATION
.........2-2
WHEEL ALIGNMENT, SPECIAL TOOLS
......2-7
WHEEL ANTILOCK - DIAGNOSIS AND
TESTING, REAR
.......................5-48
WHEEL BALANCE - STANDARD
PROCEDURE, TIRE
....................22-4
WHEEL COVER - REMOVAL
............22-14WHEEL INSPECTION, DIAGNOSIS AND
TESTING...........................22-11
WHEEL INSTALLATION - STANDARD
PROCEDURE, DUAL REAR.............22-12
WHEEL REPLACEMENT - STANDARD
PROCEDURE........................22-12
WHEEL RUNOUT - DIAGNOSIS AND
TESTING, TIRE.......................22-1
WHEEL SPEED SENSOR - DESCRIPTION,
FRONT..............................5-47
WHEEL SPEED SENSOR - DIAGNOSIS
AND TESTING, REAR...................5-49
WHEEL SPEED SENSOR -
INSTALLATION, FRONT.................5-48
WHEEL SPEED SENSOR -
INSTALLATION, REAR..................5-48
WHEEL SPEED SENSOR - OPERATION,
FRONT..............................5-47
WHEEL SPEED SENSOR - REMOVAL,
FRONT..............................5-48
WHEEL SPEED SENSOR - REMOVAL,
REAR...............................5-48
WHEEL WITH MATCHING TIRE -
DESCRIPTION, FULL SIZE, SPARE.......22-15
WHEELHOUSE SPLASH SHIELD -
INSTALLATION, FRONT................23-41
WHEELHOUSE SPLASH SHIELD -
INSTALLATION, REAR.................23-41
WHEELHOUSE SPLASH SHIELD -
REMOVAL, FRONT....................23-41
WHEELHOUSE SPLASH SHIELD -
REMOVAL, REAR.....................23-41
WHEELS - DESCRIPTION..............22-11
WHEELS - INSTALLATION, REAR DUAL....5-35
WHEELS - OPERATION................22-11
WHEELS - REMOVAL, REAR DUAL........5-34
WIND NOISE - DIAGNOSIS AND TESTING . . 23-2
WINDOW DEFOGGER RELAY -
DESCRIPTION, REAR..................8G-2
WINDOW DEFOGGER RELAY -
INSTALLATION, REAR..................8G-4
WINDOW DEFOGGER RELAY -
OPERATION, REAR....................8G-3
WINDOW DEFOGGER RELAY -
REMOVAL, REAR.....................8G-3
WINDOW DEFOGGER SWITCH -
DESCRIPTION, REAR..................8G-4
WINDOW DEFOGGER SWITCH -
OPERATION, REAR....................8G-4
WINDOW DEFOGGER SYSTEM -
DIAGNOSIS AND TESTING, REAR.........8G-2
WINDOW MOTOR - REMOVAL..........8N-20
WINDOW REGULATOR - MANUAL -
INSTALLATION..................23-27,23-35
WINDOW REGULATOR - MANUAL -
REMOVAL.....................23-26,23-35
WINDOW REGULATOR - POWER -
INSTALLATION..................23-26,23-34WINDOW REGULATOR - POWER -
REMOVAL.....................23-25,23-34
WINDOW SWITCH - DIAGNOSIS AND
TESTING...........................8N-20
WINDOW SWITCH - INSTALLATION......8N-21
WINDOW SWITCH - REMOVAL..........8N-20
WINDOWS - DESCRIPTION, POWER.....8N-19
WINDOWS - DIAGNOSIS AND TESTING,
POWER............................8N-19
WINDOWS - OPERATION, POWER.......8N-19
WINDSHIELD SAFETY PRECAUTIONS,
WARNING..........................23-88
WIPER & WASHER SYSTEM - CLEANING . . 8R-6
WIPER & WASHER SYSTEM -
DIAGNOSIS AND TESTING..............8R-6
WIPER & WASHER SYSTEM -
INSPECTION.........................8R-7
WIPER ARM - DESCRIPTION...........8R-17
WIPER ARM - INSTALLATION...........8R-18
WIPER ARM - OPERATION.............8R-18
WIPER ARM - REMOVAL..............8R-18
WIPER BLADE - DESCRIPTION..........8R-18
WIPER BLADE - INSTALLATION.........8R-20
WIPER BLADE - OPERATION...........8R-19
WIPER BLADE - REMOVAL.............8R-19
WIPER HIGH/LOW RELAY -
DESCRIPTION.......................8R-20
WIPER HIGH/LOW RELAY - DIAGNOSIS
AND TESTING.......................8R-21
WIPER HIGH/LOW RELAY -
INSTALLATION......................8R-22
WIPER HIGH/LOW RELAY - OPERATION . . 8R-20
WIPER HIGH/LOW RELAY - REMOVAL....8R-21
WIPER MODULE - DESCRIPTION........8R-22
WIPER MODULE - INSTALLATION.......8R-23
WIPER MODULE - OPERATION..........8R-23
WIPER MODULE - REMOVAL...........8R-23
WIPER ON/OFF RELAY - DESCRIPTION . . . 8R-24
WIPER ON/OFF RELAY - DIAGNOSIS AND
TESTING...........................8R-25
WIPER ON/OFF RELAY - INSTALLATION . . . 8R-26
WIPER ON/OFF RELAY - OPERATION.....8R-25
WIPER ON/OFF RELAY - REMOVAL......8R-26
WIPERS/WASHERS - DESCRIPTION
.......8R-1
WIPERS/WASHERS - OPERATION
........8R-4
WIRE SPLICING - STANDARD
PROCEDURE
.....................8W-01-15
WIRING - DESCRIPTION, TRAILER TOW
. . 8L-24
WIRING DIAGRAMS - DESCRIPTION,
HOW TO USE
.....................8W-01-1
WIRING HARNESS - DIAGNOSIS AND
TESTING
.........................8W-01-7
WIRING/TERMINAL, SPECIAL TOOLS
. . 8W-01-10
WORN THREADS - STANDARD
PROCEDURE, REPAIR
DAMAGED OR
...........9-190,9-240,9-9,9-94
DRINDEX 37
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