
REMOVAL
WARNING: THE FUEL SYSTEM IS UNDER A CON-
STANT PRESSURE (EVEN WITH THE ENGINE OFF).
BEFORE SERVICING THE ROLLOVER VALVE, FUEL
SYSTEM PRESSURE MUST BE RELEASED (GASO-
LINE POWERED ENGINES ONLY). REFER TO THE
FUEL PRESSURE RELEASE PROCEDURE IN
GROUP 14, FUEL SYSTEM.
(1)Diesel Powered Engine:One rollover valve is
used. The valve is located on top of fuel tank module
(Fig. 52) and may be serviced separately.
(a) Disconnect both negative battery cables at
both batteries.
(b) Remove fuel filler cap and drain fuel tank.
(c) Remove fuel tank. Refer to Fuel Tank Remov-
al/Installation in Fuel System.
(d) The rollover valve is seated into a rubber
grommet. Remove valve by prying one side upward
and then roll valve out of grommet.
(e) Discard old grommet.
Fig. 50 Rollover Valve LocationsÐGas
1 - FUEL FILTER/PRESSURE REGULATOR
2 - FUEL SUPPLY FITTING
3 - REAR ROLLOVER VALVE
4 - ELECTRICAL CONNECTOR
5 - FUEL PUMP MODULE
6 - FRONT ROLLOVER VALVE
7 - LOCKNUT
Fig. 51 Rollover Valve LocationsÐGas Powered
with 35 Gallon Tank
1 - FRONT ROLLOVER VALVE
2 - FUEL PUMP MODULE
3 - REAR ROLLOVER VALVE
4 - FUEL TANK
Fig. 52 Rollover Valve Location - Diesel Powered
1 - AUXILIARY CAPPED FITTING
2 - FUEL PUMP MODULE
3 - FUEL SUPPLY/RETURN FITTINGS
4 - ELECTRICAL CONNECTOR
5 - LOCKNUT
6 - ROLLOVER VALVE
14 - 26 FUEL DELIVERY - GASOLINEBR/BE
ROLLOVER VALVE (Continued)

(2)Gasoline Powered Engines:If equipped with
a 26 or 34 gallon fuel tank, two rollover valves are
used. One of the valves is permanently mounted to
top of fuel tank (Fig. 53). If replacement of this par-
ticular valve is necessary, fuel tank must be replaced.
Refer to Fuel Tank Removal/Installation in Group 14,
Fuel System. The other rollover valve is located on
top of fuel pump module (Fig. 53). This valve may be
serviced separately. Refer to following steps for pro-
cedures.
If equipped with a 35 gallon fuel tank, two rollover
valves are also used, but both valves are perma-
nently mounted to top of fuel tank (Fig. 54). If
replacement is necessary, fuel tank must be replaced.
Refer to Fuel Tank Removal/Installation in Group 14,
Fuel System.
(a) Disconnect negative battery cable at battery.
(b) Remove fuel filler cap and drain fuel tank.
(c) Remove fuel tank. Refer to Fuel Tank Remov-
al/Installation in Fuel System.
(d) Disconnect tube (line) at valve.
(e) The rollover valve is seated into a rubber
grommet. Remove valve by prying one side upward
and then roll valve out of grommet.
(f) Discard old grommet.
INSTALLATION
(1) Install new grommet into fuel pump (or fuel
tank) module.
(2) Using finger pressure only, press valve into
place.
(3) Install fuel tank. Refer to Fuel Tank Installa-
tion.
(4) Fill fuel tank. Install fuel tank filler cap.
(5) Connect negative battery cable(s).
(6) Start vehicle and check for leaks.
Fig. 53 Rollover Valve Locations - Gas Powered -
26/34 Gallon Tank
1 - FUEL FILTER/PRESSURE REGULATOR
2 - FUEL SUPPLY FITTING
3 - REAR ROLLOVER VALVE
4 - ELECTRICAL CONNECTOR
5 - FUEL PUMP MODULE
6 - FRONT ROLLOVER VALVE
7 - LOCKNUT
Fig. 54 Rollover Valve Locations - Gas Powered
with 35 Gallon Tank
1 - FRONT ROLLOVER VALVE
2 - FUEL PUMP MODULE
3 - REAR ROLLOVER VALVE
4 - FUEL TANK
BR/BEFUEL DELIVERY - GASOLINE 14 - 27
ROLLOVER VALVE (Continued)

(23) Inspect for exhaust system restrictions such
as pinched exhaust pipes, collapsed muffler or
plugged catalytic convertor.
(24) If equipped with automatic transmission, ver-
ify that electrical harness is firmly connected to park/
neutral switch. Refer to 21, Automatic Transmission.
(25) Verify electrical harness is firmly connected to
rear wheel speed sensor. Verify rear wheel speed sen-sor is firmly attached to rear axle with proper air
gap. Refer to 5, Brakes for information.
(26) If equipped with 4±wheel antilock brake sys-
tem, verify electrical harness is firmly connected to
each front wheel speed sensor. Verify both front
wheel speed sensors are firmly attached. Refer to 5,
Brakes for information.
(27) Verify that fuel pump/gauge sender unit wire
connector is firmly connected to harness connector.
(28) Inspect fuel hoses at fuel pump/gauge sender
unit for cracks or leaks.
(29) Inspect transmission torque convertor housing
(automatic transmission) or clutch housing (manual
transmission) for damage to timing ring on drive
plate/flywheel.
(30) Verify that battery cable and solenoid feed
wire connections to the starter solenoid are tight and
clean. Inspect for chaffed wires or wires rubbing up
against other components.
Fig. 8 Engine Coolant Temperature
1 - GENERATOR
2 - A/C COMPRESSOR
3 - ENGINE COOLANT TEMPERATURE SENSOR
4 - ELEC. CONN.
Fig. 9 Left/Right Oxygen SensorsÐHDC Engines
1 - DUAL OXYGEN SENSORS
2 - TOP OF TRANSMISSION
Fig. 10 Pre-Catalyst/Post-Catalyst Sensors
1 - POST CATALYST OXYGEN SENSOR (1/3)
2 - PRE-CATALYST OXYGEN SENSOR (1/2)
Fig. 11 Oxygen Sensors
BR/BEFUEL INJECTION - GASOLINE 14 - 31
FUEL INJECTION - GASOLINE (Continued)

(25) Verify electrical harness is firmly connected to
rear wheel speed sensor. Verify rear wheel speed sen-
sor is firmly attached to rear axle with proper air
gap. Refer to 5, Brakes for information.
(26) If equipped with 4±wheel antilock brake sys-
tem, verify electrical harness is firmly connected to
each front wheel speed sensor. Verify both front
wheel speed sensors are firmly attached. Refer to 5,
Brakes for information.
(27) Verify that fuel pump/gauge sender unit wire
connector is firmly connected to harness connector.
(28) Inspect fuel hoses at fuel pump/gauge sender
unit for cracks or leaks.
(29) Inspect transmission torque convertor housing
(automatic transmission) or clutch housing (manual
transmission) for damage to timing ring on drive
plate/flywheel.
(30) Verify that battery cable and solenoid feed
wire connections to the starter solenoid are tight and
clean. Inspect for chaffed wires or wires rubbing up
against other components.
Fig. 18 Upstream/Downstream Oxygen Sensors
1 - DOWN STREAM OXYGEN SENSOR (1/2)
2 - UP STREAM OXYGEN SENSOR (1/1)
Fig. 19 Left/Right
1 - DUAL OXYGEN SENSORS
2 - TOP OF TRANSMISSION
Fig. 20 Pre-Catalyst/Post Catalyst Oxygen Sensors
1 - POST CATALYST OXYGEN SENSOR (1/3)
2 - PRE-CATALYST OXYGEN SENSOR (1/2)
14 - 34 FUEL INJECTION - GASOLINEBR/BE
FUEL INJECTION - GASOLINE (Continued)

ACCELERATOR PEDAL
REMOVAL
CAUTION: Be careful not to damage or kink the
cable core wire (within the cable sheathing) while
servicing accelerator pedal or cables.
(1) From inside vehicle, hold up accelerator pedal.
Remove plastic cable retainer and throttle cable core
wire from upper end of pedal arm (Fig. 21). The plas-
tic cable retainer snaps into pedal arm.
(2) Insert a small screwdriver into square holes
located on pivots/bushings (Fig. 22). Twist screw-
driver to disengage pivot locks from pivot pin. Pivots
will be damaged when removing. Discard old pivots.
(3) Remove pedal/bracket assembly from vehicle.
INSTALLATION
(1) Position pedal/bracket assembly over pivot pin
(Fig. 22).
(2) Install two new pivots/bushings. Using large
pliers, press both bushings together until they bot-
tom on sides of pedal/bracket assembly. Bushing
retaining ears will snap into position when properly
installed.
(3) From inside vehicle, hold up accelerator pedal.
Install throttle cable core wire and plastic cable
retainer into and through upper end of pedal arm
(the plastic retainer is snapped into pedal arm).
When installing plastic retainer to accelerator pedal
arm, note index tab on pedal arm (Fig. 21). Align
index slot on plastic cable retainer to this index tab.
Fig. 21 Cable Removal/Installation at Pedal
1 - PINCH TWO TABS FOR CABLE REMOVAL
2 - DASH PANEL
3 - CABLE CORE WIRE
4 - THROTTLE PEDAL ARM
5 - INDEX TAB
6 - CABLE RETAINER
7 - CABLE STOP
Fig. 22 Accelerator PedalÐRemoval or Installation
1 - PEDAL MOUNTING BRACKET
2 - PIVOTS/BUSHINGS
3 - PEDAL/BRACKET
4 - PIVOT PIN
BR/BEFUEL INJECTION - GASOLINE 14 - 37

CRANKSHAFT POSITION
SENSOR
DESCRIPTION - 3.9L
The Crankshaft Position (CKP) sensor is located
near the outer edge of the flywheel (starter ringear).
DESCRIPTION - 5.2L/5.9L
The Crankshaft Position (CKP) sensor is located
near the outer edge of the flywheel (starter ringear).
DESCRIPTION - 8.0L
The Crankshaft Position (CKP) sensor is located on
the right-lower side of the cylinder block, forward of
the right engine mount, just above the oil pan rail
(Fig. 23).
OPERATION - 3.9L
Engine speed and crankshaft position are provided
through the CKP sensor. The sensor generates pulses
that are the input sent to the Powertrain Control
Module (PCM). The PCM interprets the sensor input
to determine the crankshaft position. The PCM then
uses this position, along with other inputs, to deter-
mine injector sequence and ignition timing.
The sensor is a hall effect device combined with an
internal magnet. It is also sensitive to steel within a
certain distance from it.The flywheel/drive plate has groups of notches at
its outer edge. On 3.9L V-6 engines, there are three
sets of double notches and three sets of single
notches (Fig. 24).
The notches cause a pulse to be generated when
they pass under the sensor. The pulses are the input
to the PCM.
The engine will not operate if the PCM does not
receive a CKP sensor input.
OPERATION - 5.2L/5.9L
Engine speed and crankshaft position are provided
through the CKP sensor. The sensor generates pulses
that are the input sent to the Powertrain Control
Module (PCM). The PCM interprets the sensor input
to determine the crankshaft position. The PCM then
uses this position, along with other inputs, to deter-
mine injector sequence and ignition timing.
The sensor is a hall effect device combined with an
internal magnet. It is also sensitive to steel within a
certain distance from it.
On 5.2/5.9L V-8 engines, the flywheel/drive plate
has 8 single notches, spaced every 45 degrees, at its
outer edge (Fig. 25).
The notches cause a pulse to be generated when
they pass under the sensor. The pulses are the input
to the PCM. For each engine revolution, there are 8
pulses generated on V-8 engines.
Fig. 23 CKP Sensor LocationÐ8.0L V-10 Engine
1 - CRANKSHAFT POSITION SENSOR
2 - HOLE
3 - OIL FILTER
4 - PLASTIC TIE STRAP
5 - PIGTAIL HARNESS
Fig. 24 CKP Sensor OperationÐ3.9L Engine
1 - FLYWHEEL
2 - NOTCHES
3 - CRANKSHAFT POSITION SENSOR
14 - 38 FUEL INJECTION - GASOLINEBR/BE

The engine will not operate if the PCM does not
receive a CKP sensor input.
OPERATION - 8.0L
The Crankshaft Position (CKP) sensor detects
notches machined into the middle of the crankshaft
(Fig. 26).There are five sets of notches. Each set contains
two notches. Basic ignition timing is determined by
the position of the last notch in each set of notches.
Once the Powertrain Control Module (PCM) senses
the last notch, it will determine crankshaft position
(which piston will next be at Top Dead Center). An
input from the camshaft position sensor is also
needed. It may take the module up to one complete
engine revolution to determine crankshaft position
during engine cranking.
The PCM uses the signal from the camshaft posi-
tion sensor to determine fuel injector sequence. Once
crankshaft position has been determined, the PCM
begins energizing a ground circuit to each fuel injec-
tor to provide injector operation.
REMOVAL - 3.9L/5.2L/5.9L
The sensor is bolted to the top of the cylinder block
near the rear of right cylinder head (Fig. 27).
(1) Remove the air cleaner intake tube.
(2) Disconnect crankshaft position sensor pigtail
harness from main wiring harness.
(3) Remove two sensor (recessed hex head) mount-
ing bolts (Fig. 27).
(4) Remove sensor from engine.
Fig. 25 CKP Sensor OperationÐ5.2L/5.9L Engine
1 - CRANKSHAFT POSITION SENSOR
2 - NOTCHES
3 - FLYWHEEL
Fig. 26 CKP Sensor OperationÐ8.0L V-10 Engine
1 - CRANKSHAFT NOTCHES
2 - CRANKSHAFT
3 - CRANKSHAFT POSITION SENSOR
Fig. 27 Crankshaft Position Sensor
1 - GROMMET
2 - MOUNTING BOLTS (2)
3 - CRANKSHAFT POSITION SENSOR
4 - RIGHT EXHAUST MANIFOLD
5 - TRANSMISSION BELL HOUSING
BR/BEFUEL INJECTION - GASOLINE 14 - 39
CRANKSHAFT POSITION SENSOR (Continued)

REMOVAL - 8.0L
The crankshaft position sensor is located on the
right-lower side of the cylinder block, forward of the
right engine mount, just above the oil pan rail (Fig.
28).
(1) Raise and support vehicle.
(2) Disconnect sensor pigtail harness from main
engine wiring harness.
(3) Remove sensor mounting bolt (Fig. 29).
(4) Cut plastic tie strap (Fig. 28) securing sensor
pigtail harness to side of engine block.
(5) Carefully pry sensor from cylinder block in a
rocking action with two small screwdrivers.
(6) Remove sensor from vehicle.
(7) Check condition of sensor o-ring (Fig. 30).
INSTALLATION - 3.9L/5.2L/5.9L
(1) Position crankshaft position sensor to engine.
(2) Install mounting bolts and tighten to 8 N´m (70
in. lbs.) torque.
(3) Connect main harness electrical connector to
sensor.
(4) Install air cleaner tube.
INSTALLATION - 8.0L
The crankshaft position sensor is located on the
right-lower side of the cylinder block, forward of the
right engine mount, just above the oil pan rail (Fig.
28).(1) Apply a small amount of engine oil to sensor
o-ring (Fig. 30).
(2) Install sensor into cylinder block with a slight
rocking action. Do not twist sensor into position as
damage to o-ring may result.
CAUTION: Before tightening sensor mounting bolt,
be sure sensor is completely flush to cylinder block
(Fig. 29). If sensor is not flush, damage to sensor
mounting tang may result.
(3) Install mounting bolt and tighten to 8 N´m (70
in. lbs.) torque.
(4) Connect sensor pigtail harness to main engine
wiring harness
Fig. 28 Crankshaft Position Sensor LocationÐ8.0L
V-10 Engine
1 - CRANKSHAFT POSITION SENSOR
2 - HOLE
3 - OIL FILTER
4 - PLASTIC TIE STRAP
5 - PIGTAIL HARNESS
Fig. 29 Sensor Removal/InstallationÐ8.0L V-10
Engine
1 - CRANKSHAFT POSITION SENSOR
2 - MOUNTING BOLT
3 - SENSOR POSITIONED FLUSH TO CYLINDER BLOCK
Fig. 30 Sensor O-RingÐ8.0L V-10 Engine
1 - CRANKSHAFT POSITION SENSOR O-RING
2 - ELECTRICAL CONNECTOR
3 - PIGTAIL HARNESS
14 - 40 FUEL INJECTION - GASOLINEBR/BE
CRANKSHAFT POSITION SENSOR (Continued)