2003 DODGE RAM service

(Fig. 12) or (Fig. 13). Type-1 is tethered to fuel line
and type-2 is not. A special tool will be necessary to
disconnect fuel line after latch clip is removed. The
latch clip may be used on certain fuel line/fuel rail
connection, or to join fuel lines together.
(a) Type 1: Pry up on latch clip with a screw-
driver (Fig. 12).
(b) Type 2: Separate and unlatch 2 small arms
on end of clip (Fig. 13) and swing away from fuel
line.(c) Slide latch clip toward fuel rail while lifting
with screwdriver.
(d) Insert special fuel line removal tool (Snap-On
number FIH 9055-1 or equivalent) into fuel line
(Fig. 14). Use tool to release locking fingers in end
of line.
(e) With special tool still inserted, pull fuel line
from fuel rail.
(f)
After disconnection, locking fingers will remain
within quick-connect fitting at end of fuel line.
(10) Disconnect quick-connect fitting from fuel sys-
tem component being serviced.
CONNECTING
(1) Inspect quick-connect fitting body and fuel sys-
tem component for damage. Replace as necessary.
(2) Prior to connecting quick-connect fitting to
component being serviced, check condition of fitting
and component. Clean parts with a lint-free cloth.
Lubricate with clean engine oil.
(3) Insert quick-connect fitting into fuel tube or
fuel system component until built-on stop on fuel
tube or component rests against back of fitting.
(4) Continue pushing until a click is felt.
(5) Single-tab type fitting: Push new tab down
until it locks into place in quick-connect fitting.
(6) Verify a locked condition by firmly pulling on
fuel tube and fitting (15-30 lbs.).
(7) Latch Clip Equipped: Install latch clip (snaps
into position).If latch clip will not fit, this indi-
cates fuel line is not properly installed to fuel
rail (or other fuel line). Recheck fuel line con-
nection.
(8) Connect negative cable to battery.
(9) Start engine and check for leaks.
Fig. 12 LATCH CLIP-TYPE 1
1 - TETHER STRAP
2 - FUEL LINE
3 - SCREWDRIVER
4 - LATCH CLIP
5 - FUEL RAIL
Fig. 13 LATCH CLIP-TYPE 2
1 - LATCH CLIP
Fig. 14 FUEL LINE DISCONNECTION USING
SPECIAL TOOL
1 - SPECIAL FUEL LINE TOOL
2 - FUEL LINE
3 - FUEL RAIL
DRFUEL DELIVERY - GAS 14 - 11
QUICK CONNECT FITTING (Continued)

FUEL PUMP
DESCRIPTION
The electric fuel pump is located inside of the fuel
pump module. A 12 volt, permanent magnet, electric
motor powers the fuel pump. The electric fuel pump
is not a separate, serviceable component.
OPERATION
Voltage to operate the electric pump is supplied
through the fuel pump relay.
Fuel is drawn in through a filter at the bottom of
the module and pushed through the electric motor
gearset to the pump outlet.
Check Valve Operation:The bottom section of
the fuel pump module contains a one-way check
valve to prevent fuel flow back into the tank and to
maintain fuel supply line pressure (engine warm)
when pump is not operational. It is also used to keep
the fuel supply line full of gasoline when pump is not
operational. After the vehicle has cooled down, fuel
pressure may drop to 0 psi (cold fluid contracts), but
liquid gasoline will remain in fuel supply line
between the check valve and fuel injectors.Fuel
pressure that has dropped to 0 psi on a cooled
down vehicle (engine off) is a normal condition.
The electric fuel pump is not a separate, service-
able component.
FUEL PUMP MODULE
DESCRIPTION
The fuel pump module assembly is located on the
top of the fuel tank (Fig. 1). The complete assembly
contains the following components:
²A combination fuel filter/fuel pressure regulator
²A separate fuel pick-up, or inlet filter
²An electric fuel pump
²A lockring to retain pump module to tank
²A soft gasket between tank flange and module
²A fuel gauge sending unit (fuel level sensor)
²Fuel line connection
The fuel gauge sending unit may be serviced sepa-
rately. If the electrical fuel pump, primary inlet filter,
fuel filter or fuel pressure regulator require service,
the fuel pump module must be replaced.
OPERATION
Refer to Fuel Pump, Inlet Filter, Fuel Filter / Fuel
Pressure Regulator and Fuel Gauge Sending Unit.
REMOVAL
WARNING: THE FUEL SYSTEM IS UNDER A CON-
STANT PRESSURE (EVEN WITH THE ENGINE OFF).BEFORE SERVICING THE FUEL PUMP MODULE, THE
FUEL SYSTEM PRESSURE MUST BE RELEASED.
(1) Drain and remove fuel tank. Refer to Fuel
Tank Removal/Installation.
(2) The plastic fuel pump module locknut (Fig. 15)
is threaded onto fuel tank. Install Special Tool 6856
to locknut and remove locknut (Fig. 16). The fuel
pump module will spring up slightly when locknut is
removed.
(3) Remove module from fuel tank.
Fig. 15 FUEL PUMP MODULE (TOP)
1 - FUEL FILTER / FUEL PRESSURE REGULATOR
2 - ALIGNMENT ARROW
3 - TOP OF PUMP MODULE
4 - LOCKNUT
5 - ALIGNMENT MARKS
Fig. 16 LOCKNUT REMOVAL/INSTALLATION -
TYPICAL
1 - SPECIAL TOOL 6856
2 - LOCKNUT
14 - 12 FUEL DELIVERY - GASDR

FUEL INJECTION - GAS
TABLE OF CONTENTS
page page
ACCELERATOR PEDAL
REMOVAL.............................24
INSTALLATION.........................24
ACCELERATOR PEDAL POSITION SENSOR
DESCRIPTION.........................25
OPERATION...........................25
REMOVAL.............................25
INSTALLATION.........................25
CRANKSHAFT POSITION SENSOR
DESCRIPTION.........................26
OPERATION...........................26
REMOVAL.............................29
INSTALLATION.........................30
FUEL INJECTOR
DESCRIPTION.........................32
OPERATION
OPERATION - FUEL INJECTOR..........32
OPERATION - PCM OUTPUT............32
REMOVAL.............................32
INSTALLATION.........................33
FUEL PUMP RELAY
DESCRIPTION.........................33
OPERATION...........................33
REMOVAL.............................33
INSTALLATION.........................33
IDLE AIR CONTROL MOTOR
DESCRIPTION.........................33
OPERATION...........................33
REMOVAL.............................34INSTALLATION.........................35
INTAKE AIR TEMPERATURE SENSOR
DESCRIPTION.........................36
OPERATION...........................36
REMOVAL.............................36
INSTALLATION.........................38
MAP SENSOR
DESCRIPTION.........................39
OPERATION...........................39
REMOVAL.............................40
INSTALLATION.........................42
OXYGEN SENSOR
DESCRIPTION.........................43
OPERATION...........................43
REMOVAL.............................44
INSTALLATION.........................45
THROTTLE BODY
DESCRIPTION.........................45
OPERATION...........................45
REMOVAL.............................45
INSTALLATION.........................47
THROTTLE CONTROL CABLE
REMOVAL.............................49
INSTALLATION.........................51
THROTTLE POSITION SENSOR
DESCRIPTION.........................52
OPERATION...........................52
REMOVAL.............................53
INSTALLATION.........................54
ACCELERATOR PEDAL
REMOVAL
The following procedure applies only to vehicles
without the Adjustable Pedal Package (code XAP).
The accelerator pedal is serviced as a complete
assembly including the bracket.
The accelerator cable is connected to the upper
part of the accelerator pedal arm by a plastic
retainer (clip) (Fig. 1). This plastic retainer snaps
into the top of the accelerator pedal arm.
(1) From inside the vehicle, hold up accelerator
pedal. Remove plastic cable retainer (clip) and throt-
tle cable core wire from upper end of accelerator
pedal arm (Fig. 1). Plastic cable retainer (clip) snaps
into pedal arm.(2) Remove 2 accelerator pedal mounting bracket
nuts. Remove accelerator pedal assembly.INSTALLATION
(1) Place accelerator pedal assembly over 2 studs.
(2) Install and tighten 2 mounting nuts. Refer to
Torque Specifications.
(3) Slide throttle cable into opening slot in top of
pedal arm.
(4) Push plastic cable retainer (clip) into accelera-
tor pedal arm opening until it snaps into place.
(5) Before starting engine, operate accelerator
pedal to check for any binding.
14 - 24 FUEL INJECTION - GASDR

ACCELERATOR PEDAL
POSITION SENSOR
DESCRIPTION
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.
The APPS is used only with the 5.7L V-8 engine.
OPERATION
The Accelerator Pedal Position Sensor (APPS) is a
linear potentiometer. It provides the Powertrain Con-
trol Module (PCM) with a DC voltage signal propor-
tional to the angle, or position of the accelerator
pedal. The APPS signal is translated (along with
other sensors) to place the throttle plate (within the
throttle body) to a pre-determined position.
A mechanical cable is used between the accelerator
pedal and the APPS assembly. Although a cable is
used between the pedal and APPS, a mechanical
cable is not used at the throttle body. Throttle plate
position is electrically determined.
REMOVAL
The APPS is serviced (replaced) as one assembly
including the sensor, plastic housing and cable. The
APPS assembly is located under the vehicle battery
tray (Fig. 2). 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. 3). Disconnect electri-
cal connector.
(5) Remove 3 mounting bolts (Fig. 3).
(6) Remove APPS assembly from battery tray.
(7) If cable is to be separated at APPS, unsnap
cable clip from ball socket (Fig. 4). Release cable from
plastic housing by pressing on small cable release tab
(Fig. 3).
INSTALLATION
(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.
Fig. 1 ACCELERATOR PEDAL MOUNTING
1 - ACCELERATOR CABLE
2 - PLASTIC RETAINER (CLIP)
3 - THROTTLE PEDAL ARM
4 - PEDAL / BRACKET ASSEMBLY
5 - CABLE CLIP
Fig. 2 APPS LOCATION
1 - BATTERY TRAY
2 - APPS LOCATION
3 - APPS MOUNTING BOLTS
DRFUEL INJECTION - GAS 14 - 25
ACCELERATOR PEDAL (Continued)

5.7L V-8
The IAC motor is not serviceable on the 5.7L V-8
engine.
5.9L V-8
The IAC motor is located on the back of the throt-
tle body (Fig. 22).
(1) Remove air resonator box at throttle body.
(2) Disconnect electrical connector from IAC motor.
(3) Remove two mounting bolts (screws) (Fig. 22).
(4) Remove IAC motor from throttle body.
8.0L V-10
The IAC motor is located on the back of the throt-
tle body (Fig. 23).
(1) Remove the air cleaner cover.
(2) Remove the 4 air cleaner housing mounting
nuts and remove housing from throttle body.
(3) Disconnect electrical connector from IAC motor.
(4) Remove two mounting bolts (screw).
(5) Remove IAC motor from throttle body.
INSTALLATION
3.7L V-6
The Idle Air Control (IAC) motor is located on the
side of the throttle body (Fig. 20).
(1) Install IAC motor to throttle body.
(2) Install and tighten two mounting bolts (screws)
to 7 N´m (60 in. lbs.) torque.
(3) Install electrical connector.
(4) Install air resonator to throttle body.
4.7L V-8
The Idle Air Control (IAC) motor is located on the
side of the throttle body (Fig. 21).
(1) Install IAC motor to throttle body.
Fig. 21 IDLE AIR CONTROL MOTOR - 4.7L V-8
1 - THROTTLE BODY
2 - TPS
3 - IAC MOTOR
4 - IAT SENSOR
5 - MOUNTING SCREWS
Fig. 22 IDLE AIR CONTROL MOTOR - 5.9L V-8
1 - MOUNTING SCREWS
2 - IDLE AIR CONTROL MOTOR
Fig. 23 IAC MOTOR - 8.0L V-10
1 - IDLE AIR CONTROL MOTOR
2 - INTAKE MANIFOLD (UPPER HALF)
3 - THROTTLE POSITION SENSOR
4 - THROTTLE BODY
DRFUEL INJECTION - GAS 14 - 35
IDLE AIR CONTROL MOTOR (Continued)

(2) Install and tighten two mounting bolts (screws)
to 7 N´m (60 in. lbs.) torque.
(3) Install electrical connector.
(4) Install air resonator to throttle body.
5.7L V-8
The IAC motor is not serviceable on the 5.7L V-8
engine.
5.9L V-8
The IAC motor is located on the back of the throt-
tle body (Fig. 22).
(1) Install IAC motor to throttle body.
(2) Install and tighten two mounting bolts (screws)
to 7 N´m (60 in. lbs.) torque.
(3) Install electrical connector.
(4) Install air resonator to throttle body.
8.0L V-10
The IAC motor is located on the back of the throt-
tle body (Fig. 23).
(1) Install IAC motor to throttle body.
(2) Install and tighten two mounting bolts (screws)
to 7 N´m (60 in. lbs.) torque.
(3) Install electrical connector.
(4) Install air cleaner housing to throttle body.
(5) Install 4 air cleaner housing mounting nuts.
Tighten nuts to 11 N´m (96 in. lbs.) torque.
(6) Install air cleaner housing cover.
INTAKE AIR TEMPERATURE
SENSOR
DESCRIPTION
The 2±wire Intake Manifold Air Temperature (IAT)
sensor is installed in the intake manifold with the
sensor element extending into the air stream.
The IAT sensor is a two-wire Negative Thermal
Coefficient (NTC) sensor. Meaning, as intake mani-
fold temperature increases, resistance (voltage) in the
sensor decreases. As temperature decreases, resis-
tance (voltage) in the sensor increases.
OPERATION
The IAT sensor provides an input voltage to the
Powertrain Control Module (PCM) indicating the
density of the air entering the intake manifold based
upon intake manifold temperature. At key-on, a
5±volt power circuit is supplied to the sensor from
the PCM. The sensor is grounded at the PCM
through a low-noise, sensor-return circuit.
The PCM uses this input to calculate the following:
²Injector pulse-width²Adjustment of spark timing (to help prevent
spark knock with high intake manifold air-charge
temperatures)
The resistance values of the IAT sensor is the same
as for the Engine Coolant Temperature (ECT) sensor.
REMOVAL
3.7L V-6
The intake manifold air temperature (IAT) sensor
is installed into the left side of intake manifold ple-
num (Fig. 24).
(1) Disconnect electrical connector from IAT sen-
sor.
(2) Clean dirt from intake manifold at sensor base.
(3) Gently lift on small plastic release tab (Fig. 24)
or (Fig. 25) and rotate sensor about 1/4 turn counter-
clockwise for removal.
(4) Check condition of sensor o-ring.
4.7L V-8
The intake manifold air temperature (IAT) sensor
is installed into the left side of intake manifold ple-
num (Fig. 26).
(1) Disconnect electrical connector from IAT sen-
sor.
(2) Clean dirt from intake manifold at sensor base.
(3) Gently lift on small plastic release tab (Fig. 25)
or (Fig. 26) and rotate sensor about 1/4 turn counter-
clockwise for removal.
Fig. 24 IAT SENSOR LOCATION - 3.7L V-6
1 - IAT SENSOR
2 - RELEASE TAB
3 - ELECTRICAL CONNECTOR
14 - 36 FUEL INJECTION - GASDR
IDLE AIR CONTROL MOTOR (Continued)

5.7L V-8
The Manifold Absolute Pressure (MAP) sensor is
mounted to the front of the intake manifold air ple-
num box (Fig. 34).
(1) Disconnect electrical connector at sensor by
sliding release lock out (Fig. 35). Press down on lock
tab for removal.
(2) Rotate sensor 1/4 turn counter-clockwise for
removal.
(3) Check condition of sensor o-ring.
5.9L V-8
The MAP sensor is located on the front of the
throttle body (Fig. 36). An L-shaped rubber fitting is
used to connect the MAP sensor to throttle body (Fig.
37).
(1) Clean area around MAP sensor.
(2) Remove two MAP sensor mounting bolts
(screws) (Fig. 36).
(3) While removing MAP sensor, slide the vacuum
rubber L-shaped fitting (Fig. 37) from the throttle
body.
(4) Remove rubber L-shaped fitting from MAP sen-
sor.
8.0L V-10
The MAP sensor is mounted into the right upper
side of intake manifold (Fig. 38). A rubber gasket is
used to seal sensor to intake manifold. The rubber
gasket is part of sensor and is not serviced sepa-
rately.(1) Remove electrical connector at sensor.
(2) Clean area around sensor before removal.
(3) Remove two sensor mounting bolts.
(4) Remove sensor from intake manifold.
Fig. 34 5.7L MAP SENSOR LOCATION
1 - MAP SENSOR
2 - FRONT OF INTAKE MANIFOLD
Fig. 35 5.7L MAP SENSOR R/I
1 - PRESS DOWN
2 - SLIDE RELEASE LOCK
3 - MAP SENSOR
Fig. 36 MAP SENSOR - 5.9L V-8
1 - MAP SENSOR
2 - MOUNTING SCREWS (2)
DRFUEL INJECTION - GAS 14 - 41
MAP SENSOR (Continued)

INSTALLATION
3.7L V-6
The Manifold Absolute Pressure (MAP) sensor is
mounted into the front of the intake manifold (Fig.
31). An o-ring is used to seal the sensor to the intake
manifold (Fig. 32).
(1) Clean MAP sensor mounting hole at intake
manifold.
(2) Check MAP sensor o-ring seal for cuts or tears.
(3) Position sensor into manifold.(4) Install MAP sensor mounting bolts (screws).
Refer to Torque Specifications.
(5) Connect electrical connector.
4.7L V-8
The MAP sensor is located on the front of the
intake manifold (Fig. 33). An o-ring seals the sensor
to the intake manifold (Fig. 32).
(1) Clean MAP sensor mounting hole at intake
manifold.
(2) Check MAP sensor o-ring seal for cuts or tears.
(3) Position sensor into manifold.
(4) Install MAP sensor mounting bolts (screws).
Refer to Torque Specifications.
(5) Connect electrical connector.
5.7L V-8
The Manifold Absolute Pressure (MAP) sensor is
mounted to the front of the intake manifold air ple-
num box (Fig. 34).
(1) Clean MAP sensor mounting hole at intake
manifold.
(2) Check MAP sensor o-ring seal for cuts or tears.
(3) Position sensor into manifold.
(4) Rotate sensor 1/4 turn clockwise for installa-
tion.
(5) Connect electrical connector.
5.9L V-8
The MAP sensor is located on the front of the
throttle body (Fig. 36). An L-shaped rubber fitting is
used to connect the MAP sensor to throttle body (Fig.
37).
(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).
Refer to Torque Specifications.
(4) Install air resonator box.
8.0L V-10
The MAP sensor is mounted into the right upper
side of intake manifold (Fig. 38). A rubber gasket is
used to seal sensor to intake manifold. The rubber
gasket is part of sensor and is not serviced sepa-
rately.
(1) Check condition of sensor seal. Clean sensor
and lubricate rubber gasket with clean engine oil.
(2) Clean sensor opening in intake manifold.
(3) Install sensor into intake manifold.
(4) Install sensor mounting bolts. Refer to Torque
Specifications.
(5) Install electrical connector to sensor.
Fig. 37 MAP SENSOR L-SHAPED RUBBER FITTING
- 5.9L V-8
1 - MAP SENSOR
2 - RUBBER FITTING
3 - IDLE AIR PASSAGE
Fig. 38 MAP SENSOR LOCATION - 8.0L V-10
1 - MAP SENSOR
2 - MOUNTING BOLTS
3 - THROTTLE BODY
14 - 42 FUEL INJECTION - GASDR
MAP SENSOR (Continued)