2003 DODGE RAM engine

(4) Be sure pump is positioned flat to fuel filter
housing. Install mounting bolts and evenly tighten to
7 N´m (61 in. lbs.).
(5) Connect fuel line extension at fuel supply line.
(6) Connect electrical connector to pump.
(7)Prime System:Cycle key to actuate transfer
pump or use DRB II Scan Tool to actuate transfer
pump. Check for leaks.
(8) Operate engine and check for fuel leaks.
CASCADE OVERFLOW VALVE
DESCRIPTION
The cascade overflow valve is located on the top/
rear side of the fuel injection pump (Fig. 27).
OPERATION
When the fuel control actuator (FCA) is opened,
the maximum amount of fuel is being delivered to
the fuel injection pump. Any fuel that does not enter
the injection pump is directed to the cascade overflow
valve. The cascade valve regulates how much excess
fuel is used for lubrication of the injection pump, and
is also used to route excess fuel through the drain
circuit and back into the fuel tank.
REMOVAL
REMOVAL/INSTALLATION
The cascade overflow valve is not serviced sepa-
rately.
WATER IN FUEL SENSOR
DESCRIPTION
The Water-In-Fuel (WIF) sensor is located on the
side of the fuel filter/water separator canister (Fig.
28), or (Fig. 29).
Fig. 27 OVERFLOW VALVE
1 - BANJO BOLTS
2 - PUMP MOUNTING NUTS (3)
3 - FUEL INJECTION PUMP
4 - CASCADE OVERFLOW VALVE
Fig. 28 FILTER HOUSING (EARLY)
1 - FILTER HOUSING
2 - FUEL HEATER AND THERMOSTAT
3 - FUEL HEATER MOUNTING SCREWS
4 - FUEL HEATER ELEC. CONNECTOR
5 - DRAIN VALVE
6 - DRAIN VALVE MOUNTING SCREWS
7 - DRAIN HOSE
8 - WIF SENSOR
9 - WIF SENSOR ELEC. CONNECTOR
DRFUEL DELIVERY - DIESEL 14 - 77
FUEL TRANSFER PUMP (Continued)

OPERATION
The sensor sends an input to the Engine Control
Module (ECM) when it senses water in the fuel filter/
water separator. As the water level in the filter/sep-
arator increases, the resistance across the WIF
sensor decreases. This decrease in resistance is sent
as a signal to the ECM and compared to a high
water standard value. Once the value reaches 30 to
40 kilohms, the ECM will activate the water-in-fuel
warning lamp through CCD bus circuits. This all
takes place when the ignition key is initially put in
the ON position. The ECM continues to monitor the
input at the end of the intake manifold air heater
post-heat cycle.
REMOVAL
The Water-In-Fuel (WIF) sensor is located at the
side of fuel filter/water separator canister. Refer to
Fuel Filter/Water Separator Removal/Installation for
WIF sensor removal/installation procedures.
FUEL DRAIN CIRCUIT
OPERATION
The Fuel Drain Circuit incorporates several
sources of fuel return. Fuel travels from the fuel tank
to the fuel transfer pump and is forced through the
fuel filter. A portion of that fuel travels through the
fuel filter and into the fuel injection pump, while the
rest of the fuel flows through a passage in the fuel
filter housing. It then goes to a fuel drain line and
returns back to the fuel tank.
The fuel that flows to the fuel pump is pressurized
and sent into a passage in the fuel pump. At this
point the fuel is channeled into two passages. One
passage sends fuel to the FCA (Fuel Control Actua-
tor). The other passage sends fuel to the cascade
overflow valve. The overflow valve sends some fuel to
a lubrication passage. The rest of the fuel is sent to a
drain passage which connects to an external fuel
line. This fuel line is connected to the same fuel filter
housing passage that the fuel transfer pump is con-
nected to.
Fuel that travels through the FCA is pressurized
by the fuel injection pump and sent through an
external high pressure fuel line to the fuel rail. At
the fuel rail, fuel is sent to the fuel injectors. If fuel
pressure in the fuel rail becomes excessive, the pres-
sure limiting valve opens and sends fuel through an
external fuel line. This line is connected to the fuel
filter housing at the fuel pump drain.
At the fuel injector, fuel that is not injected is used
for lubrication of the fuel injectors. This fuel then
travels through an internal passage in the rear of the
cylinder head, an then into an external fuel line. This
line is connected to the vehicles fuel return line, and
returns excess fuel back to the fuel tank.
Fig. 29 FILTER HOUSING (LATE)
1 - FILTER HOUSING
2 - FUEL HEATER AND THERMOSTAT
3 - FUEL HEATER MOUNTING SCREWS
4 - FUEL HEATER ELEC. CONNECTOR
5 - WIF SENSOR
6 - WIF SENSOR ELEC. CONNECTOR
7 - DRAIN HOSE
8 - DRAIN VALVE MOUNTING SCREWS
9 - DRAIN VALVE
14 - 78 FUEL DELIVERY - DIESELDR
WATER IN FUEL SENSOR (Continued)

FUEL INJECTION - DIESEL
TABLE OF CONTENTS
page page
ACCELERATOR PEDAL POSITION SENSOR
DESCRIPTION
DESCRIPTION (EARLY)................79
DESCRIPTION (LATE)..................79
OPERATION...........................79
REMOVAL.............................79
INSTALLATION.........................82
CAMSHAFT POSITION SENSOR
DESCRIPTION.........................82
OPERATION...........................82
REMOVAL.............................83
INSTALLATION.........................83
CRANKSHAFT POSITION SENSOR
DESCRIPTION.........................83
OPERATION...........................83
REMOVAL.............................84
INSTALLATION.........................84
FUEL CONTROL ACTUATOR
DESCRIPTION.........................85
OPERATION...........................85
REMOVAL.............................85
INSTALLATION.........................85
FUEL INJECTOR
DESCRIPTION.........................85
OPERATION...........................86
REMOVAL.............................87
INSTALLATION.........................87
FUEL INJECTOR RAIL
DESCRIPTION.........................89
OPERATION...........................89REMOVAL.............................89
INSTALLATION.........................90
INLET AIR TEMPERATURE SENSOR/
PRESSURE SENSOR
DESCRIPTION.........................90
OPERATION...........................90
REMOVAL.............................90
INSTALLATION.........................90
INTAKE AIR HEATER
DESCRIPTION.........................91
OPERATION...........................91
REMOVAL.............................91
INSTALLATION.........................91
INTAKE AIR HEATER RELAY
DESCRIPTION.........................92
OPERATION...........................92
REMOVAL.............................93
INSTALLATION.........................93
INTAKE AIR TEMPERATURE SENSOR/MAP
SENSOR
DESCRIPTION.........................93
OPERATION...........................93
REMOVAL.............................93
INSTALLATION.........................94
MAP SENSOR
DESCRIPTION.........................94
THROTTLE CONTROL CABLE
REMOVAL.............................94
INSTALLATION.........................96
ACCELERATOR PEDAL
POSITION SENSOR
DESCRIPTION
DESCRIPTION (EARLY)
The APPS assembly is located at the top-left-front
of the engine. A plastic cover is used to cover the
assembly. The actual sensor is located behind its
mounting bracket.
DESCRIPTION (LATE)
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
The Accelerator Pedal Position Sensor (APPS) is a
linear potentiometer. It provides the Engine Control
Module (ECM) with a DC voltage signal proportional
to the angle, or position of the accelerator pedal.
REMOVAL
Early Diesel Engines
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).
DRFUEL INJECTION - DIESEL 14 - 79

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) If equipped with an automatic transmission,
refer to 21, Transmission for transmission control
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.
Late Diesel Engines
The APPS is serviced (replaced) as one assembly
including the sensor, plastic housing and cable. The
APPS assembly is located under the left vehicle bat-
tery 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
14 - 80 FUEL INJECTION - DIESELDR
ACCELERATOR PEDAL POSITION SENSOR (Continued)

INSTALLATION
Early Diesel Engines
The APPS is serviced (replaced) as one assembly
including the lever, brackets and sensor. The APPS is
calibrated to its mounting bracket.
(1) Snap electrical connector into bottom of sensor.
(2) Position APPS assembly to engine and install 6
bolts. Tighten bolts to 24 N´m (18 ft. lbs.) torque.
(3) Connect wiring harness clip at bottom of
bracket.
(4) If equipped with an automatic transmission,
refer to Group 21, Transmission for transmission con-
trol cable installation procedures.
(5) Install speed control cable into mounting
bracket. Be sure pinch tabs have secured cable.
(6) Install throttle cable into mounting bracket. Be
sure pinch tabs have secured cable.
(7) Connect throttle cable at lever (snaps on).
(8) Connect speed control cable to lever by pushing
cable connector rearward onto lever pin while hold-
ing lever forward.
(9) Install cable cover.
(10) Connect both negative battery cables to both
batteries.
(11)ECM Calibration:Turn key to ON position.
Without starting engine, slowly press throttle pedal
to floor and then slowly release. This step must bedone (one time) to ensure accelerator pedal position
sensor calibration has been learned by ECM. If not
done, possible DTC's may be set.
(12) Use DRB III scan tool to erase any DTC's
from ECM.
Late Diesel Engines
(1) Install Accelerator Pedal Position Sensor
(APPS) cable to accelerator pedal. Refer to Accelera-
tor Pedal Removal / Installation.
(2) Connect electrical connector to APPS.
(3) If necessary, connect cable to APPS lever ball
socket (snaps on).
(4) Snap APPS cable cover closed.
(5) Position APPS assembly to bottom of battery
tray and install 3 bolts. Refer to Torque Specifica-
tions.
(6) Install wheelhouse liner. Refer to Body.
(7) Perform the following procedure:
(a) Connect negative battery cables to both bat-
teries.
(b) Turn key switch ON, but do not crank
engine.
(c) Leave key switch ON for a minimum of 10
seconds. This will allow ECM to learn electrical
parameters.
(8) If necessary, use DRB IIItScan Tool to erase
any Diagnostic Trouble Codes (DTC's) from PCM.CAMSHAFT POSITION
SENSOR
DESCRIPTION
The Camshaft Position Sensor (CMP) on the 5.9L
diesel engine is located below the fuel injection
pump. It is bolted to the back of the timing gear
cover.
OPERATION
The diesel Camshaft Position Sensor (CMP) con-
tains a hall effect device. A rotating target wheel
(tonewheel) for the CMP is located on the front tim-
ing gear. This hall effect device detects notches
located on the tonewheel. As the tonewheel rotates,
the notches pass the tip of the CMP.
When the leading edge of the tonewheel notch
passes the tip of the CMP, the following occurs: The
interruption of magnetic field causes the voltage to
switch high resulting in a signal of approximately 5
volts.
When the trailing edge of the tonewheel notch
passes the tip of the CMP, the following occurs: The
change of the magnetic field causes the signal voltage
to switch low to 0 volts.
Fig. 7 APPS CABLE (LATE)
1 - APPS LEVER
2 - BALL SOCKET
3 - SWING-DOWN DOOR
4 - CABLE CLIP
5 - CABLE
14 - 82 FUEL INJECTION - DIESELDR
ACCELERATOR PEDAL POSITION SENSOR (Continued)

The CMP (Fig. 8) provides a signal to the Engine
Control Module (ECM) at all times when the engine
is running. The ECM uses the CMP information pri-
marily on engine start-up. Once the engine is run-
ning, the ECM uses the CMP as a backup sensor for
engine speed. The Crankshaft Position Sensor (CKP)
is the primary engine speed indicator for the engine
after the engine is running.
REMOVAL
The Camshaft Position Sensor (CMP) on the 5.9L
diesel engine is located below the fuel injection
pump. It is bolted to the back of the timing gear
cover (Fig. 9).
(1) Disconnect electrical connector at CMP sensor
(Fig. 9).
(2) Remove sensor mounting bolt.
(3) Carefully twist sensor from timing gear cover.
(4) Check condition of sensor o-ring.
INSTALLATION
(1) Clean out machined hole in back of timing gear
cover.
(2) Apply a small amount of engine oil to sensor
o-ring.
(3) Install sensor into timing gear cover with a
slight rocking action. Do not twist sensor into posi-
tion as damage to o-ring may result.CAUTION: Before tightening sensor mounting bolt,
be sure sensor is completely flush to back of timing
chain cover. If sensor is not flush, damage to sen-
sor mounting tang may result.
(4) Install mounting bolt and tighten. Refer to
Torque Specifications.
(5) Connect electrical connector to sensor.
CRANKSHAFT POSITION
SENSOR
DESCRIPTION
The Crankshaft Position Sensor (CKP) on the die-
sel engine is attached at the front / left side of the
engine next to the engine harmonic balancer.
OPERATION
The Crankshaft Position Sensor (CKP) is the pri-
mary engine speed indicator for the engine after the
engine is running (Fig. 10). The CKP contains a hall
effect device. A rotating, notched target wheel (tone-
wheel) for the CMP is located on the engine har-
monic balancer (Fig. 11). This hall effect device
detects notches located on the tonewheel. As the
Fig. 8 5.9L DIESEL CMP
1 - CMP
2 - FUEL INJECTION PUMP (BOTTOM)
3 - ELECTRONIC CONTROL MODULE (ECM)
4 - ECM ELEC. CONNECTOR
5 - CMP ELEC. CONNECTOR
6 - CMP MOUNTING BOLT
7 - BACK OF TIMING GEAR COVER
Fig. 9 5.9L DIESEL CMP
1 - CMP
2 - FUEL INJECTION PUMP (BOTTOM)
3 - ELECTRONIC CONTROL MODULE (ECM)
4 - ECM ELEC. CONNECTOR
5 - CMP ELEC. CONNECTOR
6 - CMP MOUNTING BOLT
7 - BACK OF TIMING GEAR COVER
DRFUEL INJECTION - DIESEL 14 - 83
CAMSHAFT POSITION SENSOR (Continued)

tonewheel rotates, the notches pass the tip of the
CKP.
When the leading edge of the tonewheel notch passes
the tip of the CKP, the following occurs: The interrup-
tion of magnetic field causes the voltage to switch high
resulting in a signal of approximately 5 volts.
When the trailing edge of the tonewheel notch
passes the tip of the CKP, the following occurs: The
change of the magnetic field causes the signal voltage
to switch low to 0 volts.
The Camshaft Position Sensor (CMP) also provides
a signal to the Engine Control Module (ECM) at all
times when the engine is running. The ECM uses
this CMP information primarily on engine start-up.
Once the engine is running, the ECM uses the CMP
as a backup sensor for engine speed.
REMOVAL
(1) Raise and support vehicle
(2) Disconnect electrical connector at CKP sensor
(Fig. 12).
(3) Remove 1 sensor mounting bolt.
(4) Remove CKP sensor.
INSTALLATION
(1) Position and install CKP sensor to engine.
(2) Install 1 sensor mounting bolt. Refer to Torque
Specifications.(3) Install electrical connector to CKP sensor (Fig.
12).
Fig. 10 5.9L DIESEL CKP
1 - ENGINE HARMONIC BALANCER
2 - FRONT OF TIMING GEAR COVER
3 - CKP MOUNTING BOLT
4 - ELEC. CONNECTOR
5 - CKP SENSOR
6 - NOTCHES
Fig. 11 CKP NOTCHED TONEWHEEL
1 - ENGINE HARMONIC BALANCER
2 - NOTCHED TONEWHEEL
3 - FRONT OF CRANKSHAFT
Fig. 12 5.9L DIESEL CKP
1 - ENGINE HARMONIC BALANCER
2 - FRONT OF TIMING GEAR COVER
3 - CKP MOUNTING BOLT
4 - ELEC. CONNECTOR
5 - CKP SENSOR
6 - NOTCHES
14 - 84 FUEL INJECTION - DIESELDR
CRANKSHAFT POSITION SENSOR (Continued)

FUEL CONTROL ACTUATOR
DESCRIPTION
The Fuel Control Actuator (FCA) is located at the
rear of the high-pressure, fuel injection pump.
OPERATION
The Fuel Control Actuator (FCA) is an electroni-
cally controlled solenoid valve. The ECM controls the
amount of fuel that enters the high-pressure pumping
chambers by opening and closing the FCA based on a
demanded fuel pressure. When the FCA 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 overflow valve. The
overflow valve regulates how much excess fuel is used
for lubrication of the pump and how much is returned
to the fuel tank through the drain manifold.
An audible click from the FCA is normal when
operating the key to either the ON or OFF positions.
REMOVAL
The Fuel Control Actuator (FCA) is located at the
rear of the high-pressure, fuel injection pump (Fig. 13).
(1) Clean FCA mounting area at rear of fuel injec-
tion pump with an evaporative-type cleaner.
(2) Disconnect electrical connector at FCA.
(3) Remove 2 FCA mounting bolts.
(4) Remove FCA from injection pump.
(5) After removal, inspect FCA for corrosion or
damage. Shake the FCA and listen for a rattle. If
FCA does not rattle, replace it.
INSTALLATION
(1) Install new o-rings to the Fuel Control Actua-
tor (FCA).
(2) Lubricate o-rings with clean, light grease.
(3) Using new mounting bolts, install FCA into
injection pump. Tighten the micro-encapsulated bolts
in two stages. First to 3 N´m (27 in. lbs.), and then to
7 N´m (62 in. lbs.) torque. Do not pause more than
two minutes between tightening stages as bolts may
lose their ability to retain torque.
(4) Ensure FCA is mounted flush to injection
pump.
(5) Connect electrical connector to FCA.
(6) Start engine and observe for leaks.
FUEL INJECTOR
DESCRIPTION
Six individual, solenoid actuated high-pressure fuel
injectors are used (Fig. 14). The injectors are vertically
mounted into a bored hole in the top of the cylinder
head. This bored hole is located between the intake/
exhaust valves. High-pressure connectors (Fig. 15),
mounted into the side of the cylinder head, connect
each fuel injector to each high-pressure fuel line.
Fig. 13 FUEL CONTROL ACTUATOR
1 - ACTUATOR MOUNTING BOLTS
2 - FCA (FUEL CONTROL ACTUATOR)
3 - ACTUATOR ELECTRICAL CONNECTOR
Fig. 14 FUEL INJECTOR - DIESEL
1 - SOLENOID ELECTRICAL CONNECTOR STUDS
2 - MOUNTING BOLTS
3 - MOUNTING PLATES
4- COPPER SEALING WASHER
5 - INJECTOR TIP
6 - INJECTOR O-RING
7 - INJECTOR ELECTRICAL SOLENOID
DRFUEL INJECTION - DIESEL 14 - 85