2002 DODGE RAM power

DIAGNOSIS AND TESTING - FUEL HEATER
RELAY
The fuel heater relay is located in the Power Dis-
tribution Center (PDC). Refer to label under PDC
cover for relay location.
To test the fuel heater, refer to Fuel Heater Test.
To test the heater relay only, refer to following:
The relay terminal numbers from (Fig. 21) can be
found on the bottom of the relay.
²Terminal number 30 is connected to battery volt-
age and can be switched or B+ (hot) at all times.
²The center terminal number 87A is connected (a
circuit is formed) to terminal 30 in the de-energized
(normally OFF) position.
²Terminal number 87 is connected (a circuit is
formed) to terminal 30 in the energized (ON) posi-
tion. Terminal number 87 then supplies battery volt-
age to the component being operated.
²Terminal number 86 is connected to a switched
(+) power source.
²Terminal number 85 is grounded by the power-
train control module (PCM).
TESTING
(1) Remove relay before testing.
(2) Using an ohmmeter, perform a resistance test
between terminals 85 and 86. Resistance value
(ohms) should be 75  5 ohms for resistor equipped
relays.
(3)
Connect the ohmmeter between terminals number
87A and 30. Continuity should be present at this time.
(4) Connect the ohmmeter between terminals num-
ber 87 and 30. Continuity should not be present at
this time.
(5) Use a set of jumper wires (16 gauge or small-
er). Connect one jumper wire between terminal num-
ber 85 (on the relay) to the ground side (-) of a 12
Volt power source.
(6) Attach the other jumper wire to the positive
side (+) of a 12V power source. Do not connect this
jumper wire to relay at this time.
CAUTION: Do not allow the ohmmeter to contact
terminals 85 or 86 during these tests. Damage to
ohmmeter may result.
Fig. 21 Relay Terminals
14 - 68 FUEL DELIVERY - DIESELBR/BE
FUEL HEATER RELAY (Continued)

(7) Attach the other jumper wire (12V +) to termi-
nal number 86. This will activate the relay. Continu-
ity should now be present between terminals number
87 and 30. Continuity should not be present between
terminals number 87A and 30.
(8) Disconnect jumper wires from relay and 12 Volt
power source.
(9) If continuity or resistance tests did not pass,
replace relay. If tests passed, refer to 8, Wiring Dia-
grams for (fuel system) relay wiring schematics and
for additional circuit information.
REMOVAL
The fuel heater relay is located in the Power Dis-
tribution Center (PDC) (Fig. 22). Refer to label under
PDC cover for relay location.
(1) Remove PDC cover.
(2) Remove relay from PDC.
(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. 22). Refer to label under
PDC cover for relay location.
(1) Install relay to PDC.
(2) Install cover to PDC.
FUEL INJECTION PUMP
DESCRIPTION
DESCRIPTIONÐFUEL PUMP 245 H.P.
Although the fuel injection pump on the 245 horse-
power engine appears similar to other VP 44 injec-
tion pumps, there are internal differences that make
it unique. If pump replacement is necessary, be sure
to verify pump number. The pump number can be
found on the Fuel Injection Pump Data Plate (Fig.
23).
DESCRIPTIONÐFUEL PUMP 235 H.P.
The fuel injection pump is mounted to the rear of
the timing gear housing on the left side of engine
(Fig. 24).
Fig. 22 Power Distribution Center (PDC) Location
1 - CLIP
2 - BATTERY
3 - TRAY
4 - NEGATIVE CABLE
5 - POSITIVE CABLE
6 - CLIP
7 - FENDER INNER SHIELD
8 - POWER DISTRIBUTION CENTER
Fig. 23 Fuel Injection Pump Data Plate Location
1 - PUMP DATA PLATE
BR/BEFUEL DELIVERY - DIESEL 14 - 69
FUEL HEATER RELAY (Continued)

FUEL INJECTION PUMP DATA
PLATE
SPECIFICATIONS
FUEL INJECTION PUMP DATA PLATE
Pertinent information about the fuel injection
pump is machined into a boss on the drivers side of
the fuel injection pump (Fig. 44).
FUEL LEVEL SENDING UNIT /
SENSOR
DESCRIPTION
The fuel gauge sending unit (fuel level sensor) is
attached to the side of the fuel tank module. The
sending unit consists of a float, an arm, and a vari-
able resistor track (card).
OPERATION
The fuel tank module on diesel powered models
has 3 different circuits (wires). Two of these circuits
are used at the fuel gauge sending unit for fuel
gauge operation. The other wire is used for a ground.
The diesel engine does not have a fuel tank module
mounted electric fuel pump. The electric fuel pump
(fuel transfer pump) is mounted to the engine.
For Fuel Gauge Operation:A constant input
voltage source of about 12 volts (battery voltage) is
supplied to the resistor track on the fuel gauge send-
ing unit. This is fed directly from the Powertrain
Control Module (PCM).NOTE: For diagnostic pur-
poses, this 12V power source can only be veri-
fied with the circuit opened (fuel tank module
electrical connector unplugged). With the con-
nectors plugged, output voltages will vary from
about .6 volts at FULL, to about 7.0 volts at
EMPTY.The resistor track is used to vary the volt-
age (resistance) depending on fuel tank float level. As
fuel level increases, the float and arm move up,
which decreases voltage. As fuel level decreases, the
float and arm move down, which increases voltage.
The varied voltage signal is returned back to the
PCM through the sensor return circuit.
Both of the electrical circuits between the fuel
gauge sending unit and the PCM are hard-wired (not
multi-plexed). After the voltage signal is sent from
the resistor track, and back to the PCM, the PCM
will interpret the resistance (voltage) data and send
a message across the multi-plex bus circuits to the
instrument panel cluster. Here it is translated into
the appropriate fuel gauge level reading. Refer to
Instrument Panel for additional information.
FUEL LINES
DESCRIPTION
DESCRIPTION
All fuel lines up to the fuel injection pump are con-
sidered low-pressure. This includes the fuel lines
from: the fuel tank to the fuel transfer pump, and
the fuel transfer pump to the fuel injection pump.
The fuel return lines, the fuel drain manifold and the
fuel drain manifold lines are also considered low-
pressure lines. High-pressure lines are used between
the fuel injection pump and the fuel injectors. Also
refer to High-Pressure Fuel Lines Description/Opera-
tion.
Fig. 44 Fuel Injection Pump Data Plate Location
1 - PUMP DATA PLATE
BR/BEFUEL DELIVERY - DIESEL 14 - 77

CAUTION: Be sure that the high-pressure fuel lines
are installed in the same order that they were
removed.
(1) Lubricate threads of injector line fittings with
clean engine oil.
(2) Loosen, but do not remove, all fuel line support
bracket bolts.
(3) Installrearinjection line bundle beginning
with cylinder head (fuel injector) connections, fol-
lowed by injection pump connections. Tighten all fit-
tings finger tight.
(4) Tighten fittings at fuel injector ends for cylin-
ders number 6 and 5 to 38 N´m (28 ft. lbs.) torque.
Do not tighten number 3 line at this time. It
will be tightened during bleeding procedure.
(5) Tighten 3 fittings at fuel injection pump ends
to 24 N´m (18 ft. lbs.) torque.
(6) Installfrontinjection line bundle beginning
with cylinder head (fuel injector) connections, fol-
lowed by injection pump connections. Tighten all fit-
tings finger tight.
(7) Tighten fitting at fuel injector end for cylinder
number 2 to 38 N´m (28 ft. lbs.) torque.Do not
tighten lines number 1 or 4 at this time. They
will be tightened during bleeding procedure.
(8) Tighten remaining 3 fittings at fuel injection
pump ends to 24 N´m (18 ft. lbs.) torque.
(9) Install fuel line support bracket bolts to intake
manifold and tighten to 24 N´m (18 ft. lbs.) torque.
CAUTION: Be sure fuel lines are not contacting
each other or any other component. Noise will
result.
(10) Install engine lifting bracket at rear of intake
manifold. Tighten 2 bolts to 77 N´m (57 ft. lbs.)
torque.
(11) Install cable bracket housing/cable assembly
and tighten 3 mounting bolts to 24 N´m (18 ft. lbs.)
torque.
(12) Clean any old gasket material below and
above intake manifold air heater element block. Also
clean mating areas at intake manifold and air intake
housing.
(13) Using new gaskets, position intake manifold
air heater element block to engine.
(14) Install air intake housing and position ground
cable. Install 4 mounting bolts and tighten to 24 N´m
(18 ft. lbs.) torque.
(15) Install air tube (intake manifold-to-charge air
cooler) (Fig. 49). Tighten clamps to 8 N´m (72 in. lbs.)
torque.
(16) Install engine oil dipstick tube support mount-
ing bolt and tighten to 24 N´m (18 ft. lbs.) torque.
(17) Install engine oil dipstick to engine.(18) Connect 2 electrical cables to cable mounting
studs.
(19) Connect electrical connector to bottom of
APPS by pushing connector upward until it snaps
into position.
(20) Connect wiring harness (clip) at bottom of
Accelerator Pedal Position Sensor (APPS) mounting
bracket (Fig. 48).
(21) Connect front wiring clip (Fig. 49) to cable
bracket housing.
(22) Install cable cover (Fig. 47).
(23) Connect both negative battery cables to both
batteries.
(24) Bleed air from fuel system. Do this at fuel
injector ends of lines. Use cylinders numbers 1, 3 and
4 for bleeding. (Refer to 14 - FUEL SYSTEM/FUEL
DELIVERY - STANDARD PROCEDURE). After
bleeding, tighten fittings to 38 N´m (28 ft. lbs.)
torque.
(25) Check lines/fittings for leaks.
FUEL TANK
DESCRIPTION - DIESEL FUEL TANK
The fuel tank is similar to the tank used with gas-
oline powered models. The tank is equipped with a
separate fuel return line and a different fuel tank
module for diesel powered models. A fuel tank
mounted, electric fuel pump is not used with diesel
powered models. Refer to Fuel Tank Module for addi-
tional information.
For removal and installation procedures, refer to
Fuel Tank - Gasoline Engines.
FUEL TANK MODULE
DESCRIPTION
An electric fuel pump isnot usedin the fuel tank
module for diesel powered engines. Fuel is supplied
by the engine mounted fuel transfer pump and the
fuel injection pump.
The fuel tank module is installed in the top of the
fuel tank (Fig. 56). The fuel tank module (Fig. 56)
contains the following components:
²Fuel reservoir
²A separate in-tank fuel filter
²Rollover valve
²Fuel gauge sending unit (fuel level sensor)
²Fuel supply line connection
²Fuel return line connection
²Auxiliary non-pressurized fuel supply fitting
OPERATION
Refer to Fuel Gauge Sending Unit.
14 - 82 FUEL DELIVERY - DIESELBR/BE
FUEL LINES (Continued)

Refer to Fuel Transfer Pump Description/Operation
for an operational description of transfer pump.
The fuel transfer (lift) pump is located on left side
of engine and above starter motor (Fig. 61).
An improperly operating fuel transfer pump, a
plugged or dirty fuel filter, or a defective overflow
valve can cause low engine power, excessive white
smoke and/or hard engine starting.
Before performing following tests, inspect fuel sup-
ply and return lines for restrictions, kinks or leaks.
Fuel leaking from pump casing indicates a leaking
pump which must be replaced.
Pressure Test:Because the transfer pump is oper-
ating at two different pressure cycles (engine running
and engine cranking), two different pressure tests
will be performed.
(1) Remove protective cap at test port (Fig. 62).
Clean area around cap/fitting before cap removal.
(2) Install Special Fuel Pressure Test Gauge 6828
(or equivalent) to fitting at test port (Fig. 62).
(3) To prevent engine from starting, remove fuel
system relay (fuel injection pump relay). Relay is
located in Power Distribution Center (PDC). Refer to
label under PDC cover for relay location.(4) Using key, crank engine over while observing
gauge. Pressure should be 5±7 psi.
(5) Re-install fuel system relay to PDC.
(6) Start engine and record fuel pressure. Pressure
should be aminimumof 69 kPa (10 psi) at idle
speed.
Fig. 61 Fuel Transfer Pump Location
1 - OIL PRESSURE SENSOR
2 - PUMP BRACKET NUTS (3)
3 - SUPPORT BRACKET BOLT
4 - BANJO BOLT (REAR)
5 - FUEL SUPPLY LINE
6 - ELECTRICAL CONNECTOR
7 - BANJO BOLT (FRONT)
8 - FUEL TRANSFER PUMP
Fig. 62 Fuel Pressure Test Port Fitting
1 - FUEL PRESSURE TEST PORT
Fig. 63 Fuel Return and Supply Line Quick-Connect
Locations
1 - FUEL RETURN LINE
2 - QUICK-CONNECT FITTINGS
3 - FUEL SUPPLY LINE
BR/BEFUEL DELIVERY - DIESEL 14 - 85
FUEL TRANSFER PUMP (Continued)

(7) Because fuel pump relay was removed, a Diag-
nostic Trouble Code (DTC) may have been set. After
testing is completed, and relay has been installed,
use DRB scan tool to remove DTC.
Fuel Supply Restriction Test:
Due to very small vacuum specifications, the DRB
scan tool along with the Periphal Expansion Port
(PEP) Module and 0±15 psi transducer must be used.
(8) Verify transfer pump pressure is OK before
performing restriction test.
(9) Locate and disconnect fuel supply line quick-
connect fitting at left-rear of engine (Fig. 63). After
disconnecting line, plastic clip will remain attached
to metal fuel line at engine. Carefully remove clip
from metal line. Snap same clip into fuel supply
hose.
(10) Install Special Rubber Adapter Hose Tool
6631 (3/8º) into ends of disconnected fuel supply line.
(11) Install transducer from PEP module to brass
ªTº fitting on tool 6631.
(12) Hook up DRB scan tool to transducer.
WARNING: DO NOT STAND IN LINE WITH THE
COOLING FAN FOR THE FOLLOWING STEPS.
(13) Start engine and record vacuum reading with
engine speed at high-idle (high-idle means engine
speed is at 100 percent throttle and no load). The
fuel restriction testMUSTbe done with engine speed
at high-idle.
(14) If vacuum reading islessthan 6 in/hg. (0±152
mm hg.), test is OK. If vacuum reading ishigher
than 6 in/hg. (152 mm hg.), restriction exists in fuel
supply line or in fuel tank module. Check fuel supply
line for damage, dents or kinking. If OK, remove
module and check module and lines for blockage.
Also check fuel pump inlet filter at bottom of module
for obstructions.
Testing For Air Leaks in Fuel Supply Side:
(15) A 3±foot section of 3/8º I.D. clear tubing is
required for this test.
(16) Using a tire core valve removal tool, carefully
remove core valve from inlet fitting test port.
(17) Attach and clamp the 3/8ºclear hose to fitting
nipple.
(18) Place other end of hose into a large clear con-
tainer. Allow hose to loop as high as possibleabove
test port.
(19) The fuel transfer pump can be put into a 25
second run (test) mode if key is quickly turned to
crank position and released back to run position
without starting engine.
To prevent engine from starting in this test, first
remove fuel system relay (fuel injection pump relay).
Relay is located in Power Distribution Center (PDC).
Refer to label under PDC cover for relay location.
Because fuel pump relay was removed, a DiagnosticTrouble Code (DTC) may have been set. After testing
is completed, and relay has been installed, use DRB
scan tool to remove DTC.
(20) Allow air to purge from empty hose before
examining for air bubbles. Air bubbles should not be
present.
(21) If bubbles are present, check for leaks in sup-
ply line to fuel tank.
(22) If supply line is not leaking, remove fuel tank
module and remove filter at bottom of module (filter
snaps to module). Check for leaks between supply
nipple at top of module, and filter opening at bottom
of module. Replace module if necessary.
(23) After performing test, install core back into
test fitting. Before installing protective cap, be sure
fitting is not leaking.
REMOVAL
The fuel transfer pump (fuel lift pump) is located
on left side of engine, below and rearward of fuel fil-
ter (Fig. 64).
(1) Disconnect both negative battery cables at both
batteries.
Fig. 64 Fuel Transfer Pump Location
1 - OIL PRESSURE SENSOR
2 - PUMP BRACKET NUTS (3)
3 - SUPPORT BRACKET BOLT
4 - BANJO BOLT (REAR)
5 - FUEL SUPPLY LINE
6 - ELECTRICAL CONNECTOR
7 - BANJO BOLT (FRONT)
8 - FUEL TRANSFER PUMP
14 - 86 FUEL DELIVERY - DIESELBR/BE
FUEL TRANSFER PUMP (Continued)

within the assembly is sticking, low engine power or
hard starting may result.
If a Diagnostic Trouble Code (DTC) has been stored
for ªdecreased engine performance due to high injec-
tion pump fuel temperatureº, the overflow valve may
be stuck in closed position.
A rubber tipped blow gun with regulated air line
pressure is needed for this test.
(1) Clean area around overflow valve and fuel
return line at injection pump before removal.
(2) Remove valve from pump and banjo fitting.
(3) Discard old sealing gaskets.
(4) Set regulated air pressure to approximately 97
kPa (14±16 psi).
(5) Using blow gun, apply pressure to overflow
valve inlet end (end that goes into injection pump).
(6) Internal check valve should release, and air
should pass through valve at 97 kPa (14±16 psi). If
not, replace valve.
(7) Reduce regulated air pressure to 10 psi and
observe valve. Valve should stay shut. If not, replace
valve.
(8) Install new sealing gaskets to valve.
(9) Install valve through banjo fitting and into
pump.
(10) Tighten to 30 N´m (24 ft. lbs.) torque.REMOVAL
The overflow valve (pressure relief valve) is located
at the outside of fuel injection pump (Fig. 67). It con-
nects the fuel return line (banjo fitting) to the pump.
The valve has no internal serviceable parts and must
be replaced as an assembly. Two sealing gaskets are
used. One gasket is located between pump and banjo
fitting. The other is located between the banjo fitting
and end of valve.
(1) Clean area around overflow valve and fuel
return line at injection pump before removal.
(2) Remove valve from pump and banjo fitting.
(3) Discard old sealing gaskets.
INSTALLATION
The overflow valve (pressure relief valve) is located
at the outside of fuel injection pump (Fig. 67). It con-
nects the fuel return line (banjo fitting) to the pump.
The valve has no internal serviceable parts and must
be replaced as an assembly. Two sealing gaskets are
used. One gasket is located between pump and banjo
fitting. The other is located between the banjo fitting
and end of valve.
(1) Install new sealing gaskets to valve.
(2) Install valve through banjo fitting and into
pump.
(3) Tighten to 30 N´m (24 ft. lbs.) torque.
Fig. 66 Overflow Valve Location
1 - FUEL SUPPLY LINE
2 - FUEL RETURN LINE
3 - BANJO BOLT (TEST PORT FITTING)
4 - OVERFLOW VALVE
5 - BANJO FITTING
Fig. 67 Overflow Valve Location
1 - FUEL SUPPLY LINE
2 - FUEL RETURN LINE
3 - BANJO BOLT (TEST PORT FITTING)
4 - OVERFLOW VALVE
5 - BANJO FITTING
14 - 88 FUEL DELIVERY - DIESELBR/BE
OVERFLOW VALVE (Continued)

FUEL INJECTION - DIESEL
TABLE OF CONTENTS
page page
FUEL INJECTION - DIESEL
DESCRIPTION - DIESEL FUEL INJECTION
SYSTEM............................91
DIAGNOSIS AND TESTING - BOOST
PRESSURE..........................93
SPECIFICATIONS
TORQUE - DIESEL ENGINE.............94
ACCELERATOR PEDAL POSITION SENSOR
DESCRIPTION.........................95
OPERATION...........................95
REMOVAL.............................95
INSTALLATION.........................97
FUEL INJECTOR
DESCRIPTION.........................97
OPERATION...........................98
DIAGNOSIS AND TESTINGÐFUEL INJECTOR
TEST...............................99
REMOVAL............................101
INSTALLATION........................102
FUEL INJECTION PUMP RELAY
DESCRIPTION........................103
OPERATION..........................103
FUEL TEMPERATURE SENSOR
DESCRIPTION........................104
OPERATION..........................104
INTAKE AIR HEATER
DESCRIPTION........................104OPERATION..........................104
REMOVAL............................104
INSTALLATION........................105
INTAKE AIR HEATER RELAY
DESCRIPTION........................105
OPERATION..........................105
REMOVAL............................106
INSTALLATION........................106
INTAKE AIR TEMPERATURE SENSOR
DESCRIPTION - DIESEL.................106
OPERATION - DIESEL..................106
REMOVAL - DIESEL....................107
INSTALLATION - DIESEL................107
MAP SENSOR
DESCRIPTION - DIESEL.................108
OPERATION - DIESEL..................108
REMOVAL - DIESEL....................108
INSTALLATION........................108
PTO SWITCH
DESCRIPTION
OPERATION........................108
THROTTLE CONTROL CABLE
REMOVAL............................109
INSTALLATION........................110
FUEL INJECTION - DIESEL
DESCRIPTION - DIESEL FUEL INJECTION
SYSTEM
The Engine Control Module (ECM) and Fuel Injec-
tion Pump Control Module (FPCM) are used prima-
rily for fuel system control. The ECM is a separate
replaceable component, while the FPCM is internal
to the fuel injection pump and is a non-serviceable
part. The ECM and FPCM are interconnected (wired
together) for fuel injection control.The Powertrain Control Module (PCM) is used to
regulate or control the A/C, charging and speed con-
trol systems. It is also used to partially control cer-
tain electronic automatic transmission components.
The PCM also has control over certain instrument
panel components.
Refer to either Powertrain Control Module (PCM)
or Engine Control Module (ECM) for additional infor-
mation. Refer to (Fig. 1) for a partial list of fuel sys-
tem components.
BR/BEFUEL INJECTION - DIESEL 14 - 91