fuel tank removal DODGE RAM 2001 Service Repair Manual

(2) Remove the nuts and spring clamp bolts that
attach the spring to the axle (Fig. 2) and (Fig. 3)and
(Fig. 4).
(3) Remove the nuts and bolts from the spring
front and rear shackle eyes.Note: To remove front
eye bolt on left side spring fuel tank must be
removed, (Refer to 14 - FUEL SYSTEM/FUEL
DELIVERY/FUEL TANK - REMOVAL).
(4) Remove the spring from the vehicle.
(5) Remove the shackle from the spring.
INSTALLATION
(1) Install shackle on rear spring eye and install
bolt and nut.
(2) Position spring on axle shaft tube so spring
center bolt is inserted into the locating hole in the
axle tube spring pad or spacer.
(3) Align spring front eye with bolt hole in the
front bracket. Install the eye pivot bolt and nut.
(4) Align shackle eye with bolt hole in rear
bracket. Install bolt and nut.
(5) Tighten the spring front and rear eye pivot bolt
snug do not torque.
(6) Install spring clamp bolts and the retaining
nuts.
(7) Align the auxiliary spring with the primary
spring if equipped. Tighten the nuts until they force
the plate flush against the axle tube.
(8) Remove the supports and lower the vehicle so
that the weight is being supported by the tires.
(9) Tighten the spring clamp retaining nuts to
specifications
(10) Tighten spring front and rear eye pivot bolt
nuts and shackle eye to specifications.
Fig. 2 Rear Spring - 4x2
1 - SPRING CLAMP BOLTS
2 - SPRING SEAT
3 - SPRING
4 - SHACKLE
5 - SPRING PLATE
Fig. 3 Rear Spring - 4x4
1 - SPRING CLAMP BOLT
2 - SPRING SEAT
3 - SPRING
4 - SHACKLE
5 - SPRING PLATE
6 - SPACER
Fig. 4 Rear Spring - Cab-Chassis 11000 GVW
1 - SPRING CLAMP BOLT
2 - SPRING SEAT
3 - AUXILIARY SPRING
4 - SPRING
5 - SHACKLE
6 - SPRING PLATE
7 - SPACER
BR/BEREAR 2 - 29
SPRING (Continued)

²More Than Full Percent Tank Full Message
- Each time the cluster receives a message from the
PCM indicating the percent tank full is more than
full, the gauge needle is moved to the far left (low)
end of the gauge scale and the low fuel indicator is
illuminated immediately. This message would indi-
cate that the fuel tank sender input to the PCM is an
open circuit.
²Message Failure- If the cluster fails to receive
a percent tank full message, it will hold the gauge
needle at the last indication until a new message is
received, or until the ignition switch is turned to the
Off position, whichever occurs first.
²Actuator Test- Each time the cluster is put
through the actuator test, the gauge needle will be
swept to several calibration points on the gauge scale
in a prescribed sequence in order to confirm the func-
tionality of the gauge and the cluster control cir-
cuitry.
The PCM continually monitors the fuel tank send-
ing unit, then sends the proper messages to the
instrument cluster. For further diagnosis of the fuel
gauge or the instrument cluster circuitry that con-
trols the gauge, (Refer to 8 - ELECTRICAL/INSTRU-
MENT CLUSTER - DIAGNOSIS AND TESTING).
For proper diagnosis of the fuel tank sending unit,
the PCM, the CCD data bus, or the message inputs
to the instrument cluster that control the fuel gauge,
a DRBIIItscan tool is required. Refer to the appro-
priate diagnostic information.
GEAR SELECTOR INDICATOR
DESCRIPTION
A mechanical automatic transmission gear selector
indicator is standard factory-installed equipment on
this model, when it is also equipped with an optional
automatic transmission. The gear selector indicator
consists of a molded black plastic housing with inte-
gral mounting tabs that is secured to the back of the
instrument cluster housing with two screws. A face
plate on the indicator housing is visible through a
rectangular cutout in the lower right corner of the
instrument cluster overlay, just below the fuel gauge.
Vehicles with a manual transmission have a block-off
plate mounted to the back of the instrument cluster
behind this cutout in the overlay, in place of the gear
selector indicator. Near the top of this face plate the
following characters are imprinted from left to right:
ªP,º ªR,º ªN,º ªD,º ª2,º and ª1.º Respectively, these
characters represent the park, reverse, neutral,
drive, second gear, and first gear positions of the
transmission gear selector lever on the steering col-
umn. Directly below each character on the face plateis a small, rectangular window, and behind these
windows is a single, movable red pointer.
The gear selector indicator graphics are white
against a black field except for the single red pointer,
making them clearly visible within the instrument
cluster in daylight. When illuminated from behind by
the panel lamps dimmer controlled cluster illumina-
tion lighting with the exterior lamps turned On, the
white graphics appear blue-green, while the red
pointer still appears red. Indicator illumination is
provided by replaceable incandescent bulb and bulb
holder units located on the instrument cluster elec-
tronic circuit board. The gear selector indicator is
available for service replacement separate from the
instrument cluster. The instrument cluster must be
removed from the instrument panel for service access
to the gear selector indicator. (Refer to 8 - ELECTRI-
CAL/INSTRUMENT CLUSTER - REMOVAL).
OPERATION
The mechanical gear selector indicator gives an
indication of the transmission gear that has been
selected with the automatic transmission gear selec-
tor lever. A red pointer appears in a window below
the character in the indicator representing the trans-
mission gear that has been selected. The small,
spring-loaded pointer moves on a track through a
trolley-like mechanism within the indicator housing.
A short length of small diameter stranded cable is
attached to one side of the pointer trolley and is
encased in a tubular plastic housing that exits the
right side of the indicator. The cable is routed
through the instrument panel and under the steering
column to the left side of the column. The looped end
of the cable is hooked over the end of the PRNDL
driver lever on the steering column gearshift mecha-
nism, and the cable housing is secured in a molded
plastic adjuster and bracket on the column housing.
When the gear selector lever is moved the PRNDL
driver lever moves, which moves the pointer through
the mechanical actuator cable. The cable adjuster
and bracket unit mounted on the steering column
housing provides a mechanical means of calibrating
the gear selector indicator mechanism. (Refer to 19 -
STEERING/COLUMN - INSTALLATION).
HIGH BEAM INDICATOR
DESCRIPTION
A high beam indicator is standard equipment on
all instrument clusters. The high beam indicator is
located near the upper edge of the instrument cluster
overlay, between the tachometer and the speedome-
ter. The high beam indicator consists of a stenciled
cutout of the International Control and Display Sym-
BR/BEINSTRUMENT CLUSTER 8J - 21
FUEL GAUGE (Continued)

EXCESSIVE BLACK SMOKE
POSSIBLE CAUSE CORRECTION
Raw fuel in intake manifold. Fuel injectors leaking on engine shutdown. Do Fuel
Injector Test (Refer to 14 - FUEL SYSTEM/FUEL
INJECTION/FUEL INJECTOR - DIAGNOSIS AND
TESTING).
Static timing not correct. A DTC should have been set. If so, refer to Powertrain
Diagnostic Procedures Information. Also (Refer to 14 -
FUEL SYSTEM/FUEL DELIVERY/FUEL INJECTION
PUMP - DIAGNOSIS AND TESTING).
Turbocharger air intake restriction. Remove restriction.
Turbocharger damaged. (Refer to 11 - EXHAUST SYSTEM/TURBOCHARGER
SYSTEM/TURBOCHARGER - INSPECTION).
Turbocharger has excess build up on compressor
wheel and/or diffuser vanes.(Refer to 11 - EXHAUST SYSTEM/TURBOCHARGER
SYSTEM/TURBOCHARGER - CLEANING).
Turbocharger wheel clearance out of specification. (Refer to 11 - EXHAUST SYSTEM/TURBOCHARGER
SYSTEM/TURBOCHARGER - INSPECTION).
EXCESSIVE WHITE SMOKE
POSSIBLE CAUSE CORRECTION
Air in fuel supply: Possible leak in fuel supply side
(between transfer pump and fuel tank module).(Refer to 14 - FUEL SYSTEM/FUEL DELIVERY/FUEL
TRANSFER PUMP - DIAGNOSIS AND TESTING).
Coolant leaking into combustion chamber. Do pressure test of cooling system (Refer to 7 -
COOLING - DIAGNOSIS AND TESTING).
Diagnostic Trouble Codes (DTC's) active or multiple,
intermittent DTC's.Refer to Powertrain Diagnostic Procedures Information.
In very cold ambient temperatures, engine block heater
is malfunctioning (if equipped).(Refer to 7 - COOLING/ENGINE/ENGINE BLOCK
HEATER - REMOVAL).
Engine coolant temperature sensor malfunctioning. A DTC should have been set. Refer to Powertrain
Diagnostic Procedures Information. Also check
thermostat operation (Refer to 7 - COOLING/ENGINE/
ENGINE COOLANT THERMOSTAT - DIAGNOSIS AND
TESTING).
Engine Control Module (ECM) not calibrated or has
incorrect calibration.A DTC should have been set. Refer to Powertrain
Diagnostic Procedures Information.
Fuel filter plugged. Perform Fuel Pressure Drop Test (Refer to 14 - FUEL
SYSTEM/FUEL DELIVERY/FUEL TRANSFER PUMP -
DIAGNOSIS AND TESTING).
Fuel grade not correct or fuel quality is poor. Temporarily change fuel brands and note condition.
Change brand if necessary.
Fuel heater element or fuel heater temperature sensor
malfunctioning. This will cause wax type build-up in fuel
filter.Refer to Fuel Heater Testing (Refer to 14 - FUEL
SYSTEM/FUEL DELIVERY/FUEL HEATER -
DIAGNOSIS AND TESTING).
Fuel injector malfunctioning. A DTC should have been set. Perform9Cylinder
Balance Test9using DRB scan tool to isolate individual
cylinders. Also refer to Powertrain Diagnostic
Procedures Information and, (Refer to 14 - FUEL
SYSTEM/FUEL INJECTION/FUEL INJECTOR -
DIAGNOSIS AND TESTING).
Fuel injector hold-downs loose. Torque to specifications.
BR/BEENGINE 5.9L DIESEL 9 - 235
ENGINE 5.9L DIESEL (Continued)

(9) Remove viscous fan/drive assembly (Refer to 7 -
COOLING/ENGINE/RADIATOR FAN - REMOVAL).
Remove the cooling fan and shroud together.
(10) Disconnect the coolant recovery bottle hose
from the radiator filler neck and remove bottle from
fan shroud (Fig. 2).
(11) Disconnect heater core supply and return
hoses from the cylinder head fitting and coolant pipe.
(12) Raise vehicle on hoist.
(13) Remove transmission and transfer case (if
equipped.).
(14) Disconnect exhaust pipe from turbocharger
extension pipe (Fig. 3).
(15) Remove starter motor (Refer to 8 - ELECTRI-
CAL/STARTING/STARTER MOTOR - REMOVAL).
(16) Disconnect A/C suction/discharge hose from
the rear of the A/C compressor.
(17) Lower vehicle.
(18) Disconnect lower radiator hose from radiator
outlet.
(19)Automatic Transmission models:Discon-
nect transmission oil cooler lines from radiator using
special tool #6931.
(20) Remove radiator (Refer to 7 - COOLING/EN-
GINE/RADIATOR - REMOVAL).
(21) Remove upper radiator support panel.
(22)
Remove front bumper (Refer to 13 - FRAMES &
BUMPERS/BUMPERS/FRONT BUMPER - REMOVAL).
(23) If A/C equipped, disconnect A/C condenser
refrigerant lines.
(24) Disconnect charge air cooler piping.
(25) Remove the two charge air cooler mounting
bolts.
(26) Remove charge air cooler (and A/C condenser
if equipped) from vehicle.
(27) Disconnect engine block heater connector.
(28) Disconnect A/C compressor electrical connec-
tors.
(29) Remove the passenger battery ground cable
from the engine block.
(30) Disconnect power steering pump pressure and
return lines.
(31) Remove accelerator linkage cover.
(32) Leaving all cables attached, remove accelera-
tor pedal position sensor assy. (APPS) (Fig. 4) from
cylinder head bracket and secure out of the way.
(33) Disconnect APPS connector (Fig. 5).
(34) Disconnect vacuum pump supply hose (Fig. 6).
(35) Disconnect the engine harness and ground
cable from the PDC.
(36) Disconnect the fuel supply and return hoses
(Fig. 7).
(37) Remove the cylinder head cover (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL).
(38) Remove the #5 and #6 cylinder intake and
exhaust rocker arms and pedestals (Fig. 8). Note the
original location for re-assembly.
(39) Loosen but do not remove engine mount
through bolts and nuts.
(40) Attach chain accross engine lift brackets.
(41)
Lift engine up and out of engine compartment.
(42) Install engine to suitable engine stand.
Fig. 2 Coolant Recovery Bottle
1 - T-SLOTS
2 - ALIGNMENT PIN
3 - FAN SHROUD
4 - COOLANT RESERVE/OVERFLOW TANK
Fig. 3 Exhaust Pipe Connection at Turbocharger
1 - EXHAUST PIPE
2 - TURBOCHARGER EXHAUST PIPE
BR/BEENGINE 5.9L DIESEL 9 - 239
ENGINE 5.9L DIESEL (Continued)

FUEL SYSTEM
TABLE OF CONTENTS
page page
FUEL DELIVERY - GASOLINE................1
FUEL INJECTION - GASOLINE..............28FUEL DELIVERY - DIESEL.................54
FUEL INJECTION - DIESEL.................87
FUEL DELIVERY - GASOLINE
TABLE OF CONTENTS
page page
FUEL DELIVERY - GASOLINE
DESCRIPTION............................2
OPERATION.............................2
DIAGNOSIS AND TESTING..................2
FUEL PRESSURE LEAK DOWN TEST........2
STANDARD PROCEDURE...................3
FUEL SYSTEM PRESSURE RELEASE
PROCEDURE...........................3
SPECIFICATIONS.........................4
SPECIAL TOOLS..........................4
FUEL FILTER/PRESSURE REGULATOR
DESCRIPTION............................5
OPERATION.............................5
REMOVAL...............................5
INSTALLATION............................6
FUEL LEVEL SENDING UNIT / SENSOR
DESCRIPTION............................7
OPERATION.............................7
DIAGNOSIS AND TESTING..................8
FUEL GAUGE SENDING UNIT..............8
REMOVAL...............................8
INSTALLATION............................9
FUEL LINES
DESCRIPTION............................9
FUEL PUMP
DESCRIPTION............................9
OPERATION.............................9
DIAGNOSIS AND TESTING..................9
FUEL PUMP CAPACITY TEST..............9FUEL PUMP PRESSURE TEST............10
FUEL PUMP AMPERAGE TEST............10
FUEL PUMP MODULE
DESCRIPTION...........................12
OPERATION.............................13
REMOVAL..............................13
INSTALLATION...........................13
FUEL RAIL
DESCRIPTION...........................15
OPERATION.............................15
REMOVAL..............................16
INSTALLATION...........................18
FUEL TANK
DESCRIPTION...........................19
OPERATION.............................19
REMOVAL..............................19
INSTALLATION...........................20
INLET FILTER
REMOVAL..............................22
INSTALLATION...........................22
QUICK CONNECT FITTING
DESCRIPTION...........................22
STANDARD PROCEDURE..................22
QUICK-CONNECT FITTINGS..............22
ROLLOVER VALVE
DESCRIPTION...........................25
REMOVAL..............................26
INSTALLATION...........................27
BR/BEFUEL SYSTEM 14 - 1

FUEL DELIVERY - GASOLINE
DESCRIPTION - FUEL DELIVERY SYSTEM
The fuel delivery system consists of:
²the fuel pump module containing the electric
fuel pump, fuel filter/fuel pressure regulator, rollover
valve (certain modules), fuel gauge sending unit (fuel
level sensor) and a separate fuel filter located at bot-
tom of pump module
²fuel tubes/lines/hoses
²quick-connect fittings
²fuel injector rail
²fuel injectors
²fuel tank
²fuel tank filler/vent tube assembly
²fuel tank filler tube cap
²accelerator pedal
²throttle cable
OPERATION - FUEL DELIVERY SYSTEM
Fuel is returned through the fuel pump module
and back into the fuel tank through the fuel filter/
fuel pressure regulator. A separate fuel return line
from the engine to the tank is not used with any gas-
oline powered engine.
The fuel tank assembly consists of: the fuel tank,
fuel pump module assembly, fuel pump module lock-
nut/gasket and rollover valve(s) (refer to 25, Emis-
sion Control System for rollover valve information).
A fuel filler/vent tube assembly using a pressure/
vacuum, 1/4 turn fuel filler cap is used. The fuel
filler tube contains a flap door located below the fuel
fill cap.
Also to be considered part of the fuel system is the
evaporation control system. This is designed to
reduce the emission of fuel vapors into the atmo-
sphere. The description and function of the Evapora-
tive Control System is found in 25, Emission Control
Systems.
Both fuel filters (at bottom of fuel pump module
and within fuel pressure regulator) are designed for
extended service. They do not require normal sched-
uled maintenance. Filters should only be replaced if
a diagnostic procedure indicates to do so.
DIAGNOSIS AND TESTING - FUEL PRESSURE
LEAK DOWN TEST
Use this test in conjunction with the Fuel Pump
Pressure Test and Fuel Pump Capacity Test.
Check Valve Operation:The electric fuel pump
outlet 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 oper-
ational. It is also used to keep the fuel supply line
full of gasoline when pump is not operational. Afterthe 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.When the elec-
tric fuel pump is activated, fuel pressure should
immediately(1±2 seconds) rise to specification.
Abnormally long periods of cranking to restart a
hotengine that has been shut down for a short
period of time may be caused by:
²Fuel pressure bleeding past a fuel injector(s).
²Fuel pressure bleeding past the check valve in
the fuel pump module.
(1) Disconnect the fuel inlet line at fuel rail. Refer
to Fuel Tubes/Lines/Hoses and Clamps for proce-
dures. On some engines, air cleaner housing removal
may be necessary before fuel line disconnection.
(2) Obtain correct Fuel Line Pressure Test Adapter
Tool Hose. Tool number 6539 is used for 5/16º fuel
lines and tool number 6631 is used for 3/8º fuel lines.
(3) Connect correct Fuel Line Pressure Test
Adapter Tool Hose between disconnected fuel line
and fuel rail (Fig. 1).
Fig. 1 Connecting Adapter ToolÐTypical
1 - VEHICLE FUEL LINE
2 - TEST PORT ªTº
3 - SPECIAL TOOL 6923, 6631, 6541 OR 6539
4 - FUEL PRESSURE TEST GAUGE
5 - FUEL LINE CONNECTION AT RAIL
6 - FUEL RAIL
14 - 2 FUEL DELIVERY - GASOLINEBR/BE

FUEL FILTER/PRESSURE
REGULATOR
DESCRIPTION
A combination fuel filter and fuel pressure regula-
tor (Fig. 2) is used on all engines. It is located on the
top of the fuel pump module. A separate frame
mounted fuel filter is not used with any engine.
Both fuel filters (at bottom of fuel pump module
and within fuel pressure regulator) are designed for
extended service. They do not require normal sched-
uled maintenance. Filters should only be replaced if
a diagnostic procedure indicates to do so.
OPERATION
Fuel Pressure Regulator Operation:The pres-
sure regulator is a mechanical device that is not con-
trolled by engine vacuum or the powertrain control
module (PCM).
The regulator is calibrated to maintain fuel system
operating pressure of approximately 339 kPa634
kPa (49.2 psi65 psi) at the fuel injectors. It con-
tains a diaphragm, calibrated springs and a fuelreturn valve. The internal fuel filter (Fig. 2) is also
part of the assembly.
Fuel is supplied to the filter/regulator by the elec-
tric fuel pump through an opening tube at the bot-
tom of filter/regulator (Fig. 2).
The regulator acts as a check valve to maintain
some fuel pressure when the engine is not operating.
This will help to start the engine. A second check
valve is located at the outlet end of the electric fuel
pump.Refer to Fuel PumpÐDescription and
Operation for more information. Also refer to
the Fuel Pressure Leak Down Test and the Fuel
Pump Pressure Tests.
If fuel pressure at the pressure regulator exceeds
approximately 49.2 psi, an internal diaphragm opens
and excess fuel pressure is routed back into the tank
through the bottom of pressure regulator.
Both fuel filters (at bottom of fuel pump module
and within fuel pressure regulator) are designed for
extended service. They do not require normal sched-
uled maintenance. Filters should only be replaced if
a diagnostic procedure indicates to do so.REMOVAL
WARNING: THE FUEL SYSTEM IS UNDER A CON-
STANT PRESSURE, EVEN WITH ENGINE OFF.
BEFORE SERVICING FUEL FILTER/FUEL PRES-
SURE REGULATOR, FUEL SYSTEM PRESSURE
MUST BE RELEASED.
Fig. 2 Side ViewÐFilter/Regulator
1 - INTERNAL FUEL FILTER
2 - FUEL FLOW TO FUEL INJECTORS
3 - FUEL FILTER/FUEL PRESSURE REGULATOR
4 - EXCESS FUEL BACK TO TANK
5 - FUEL INLET
6 - RUBBER GROMMET
7 - TOP OF PUMP MODULE
Test Kit, Fuel PressureÐ5069
Test Kit, Fuel PressureÐC-4799-B
Fuel Line Removal ToolÐ6782
BR/BEFUEL DELIVERY - GASOLINE 14 - 5
FUEL DELIVERY - GASOLINE (Continued)

Refer to Fuel System Pressure Release in Fuel
Delivery System section of this group.
The fuel filter/fuel pressure regulator (Fig. 3) is
located at top of fuel pump module (Fig. 4) or (Fig. 5).
Fuel pump module removal is not necessary.
(1) Drain fuel tank and remove tank. Refer to Fuel
Tank Removal/Installation.
(2) The fuel filter/regulator is pressed into a rub-
ber grommet. Remove by twisting and pulling
straight up (Fig. 6).
CAUTION: Do not pull filter/regulator more than
three inches from fuel pump module. Damage to
coiled fuel tube (line) may result.
(3) Gently cut old fuel tube (line) clamp (Fig. 7)
taking care not to damage plastic fuel tube. Remove
and discard old fuel tube clamp.
(4) Remove plastic fuel tube from filter/regulator
by gently pulling downward. Remove filter/regulator
from fuel pump module.
INSTALLATION
(1) Install a new clamp over plastic fuel tube.
(2) Install filter/regulator to fuel tube. Rotate fil-
ter/regulator in fuel tube (line) (Fig. 8) until it is
pointed to drivers side of vehicle (Fig. 4) or (Fig. 5).
(3) Tighten line clamp to fuel line using special
Hose Clamp Pliers number C-4124 or equivalent
(Fig. 8).Do not use conventional side cutters to
tighten this type of clamp.
Fig. 3 Fuel Filter/Fuel Pressure Regulator
1 - INTERNAL FUEL FILTER
2 - FUEL FLOW TO FUEL INJECTORS
3 - FUEL FILTER/FUEL PRESSURE REGULATOR
4 - EXCESS FUEL BACK TO TANK
5 - FUEL INLET
6 - RUBBER GROMMET
7 - TOP OF PUMP MODULE
Fig. 4 Filter/Regulator LocationÐWith 26 or 34
Gallon Fuel 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. 5 Filter/Regulator LocationÐWith 35 Gallon
Fuel Tank
1 - FUEL FILTER/PRESSURE REGULATOR
2 - FUEL SUPPLY FITTING
3 - ELECTRICAL CONNECTOR
4 - LOCKNUT
5 - FUEL PUMP MODULE
6 - AUXILIARY CAPPED FITTING
14 - 6 FUEL DELIVERY - GASOLINEBR/BE
FUEL FILTER/PRESSURE REGULATOR (Continued)

(4) Press filter/regulator (by hand) into rubber
grommet. The assembly should be pointed towards
drivers side of vehicle (Fig. 4) or (Fig. 5).
(5) Install fuel tank. Refer to Fuel Tank Removal/
Installation.
(6) Check for fuel leaks.
FUEL LEVEL SENDING UNIT /
SENSOR
DESCRIPTION
The fuel gauge sending unit (fuel level sensor) is
attached to the side of the fuel pump module. The
sending unit consists of a float, an arm, and a vari-
able resistor track (card).
OPERATION
The fuel pump module has 4 different circuits
(wires). Two of these circuits are used for the fuel
gauge sending unit for fuel gauge operation, and for
certain OBD II emission requirements. The other 2
wires are used for electric fuel pump operation.
For Fuel Gauge Operation:A constant current
source of about 32 mA is supplied to the resistor
track on the fuel gauge sending unit. This is fed
directly from the Powertrain Control Module (PCM).
The resistor track is used to vary the voltage depend-
ing 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 sen-
sor return circuit. Output voltages will vary from
about .6 volts at FULL, to about 8.6 volts at EMPTY
(Jeep models), or, about 7.0 volts at EMPTY (Dodge
Truck models).NOTE: For diagnostic purposes,
this voltage can only be verified with the fuel
gauge sending unit circuit closed (i.e. having all
of the sending units electrical connectors con-
nected).
Fig. 6 Filter/Regulator Removal and InstallationÐ
TYPICAL
1 - RUBBER GROMMET
2 - FUEL FILTER/FUEL PRESSURE REGULATOR
Fig. 7 Fuel Tube and ClampÐTYPICAL
1 - FUEL FILTER/FUEL PRESSURE REGULATOR
2 - TUBE CLAMP
3 - FUEL TUBE
Fig. 8 Tightening Fuel Tube ClampÐTYPICAL
1 - TOOL C-4124
2 - TUBE CLAMP
3 - FUEL TUBE
BR/BEFUEL DELIVERY - GASOLINE 14 - 7
FUEL FILTER/PRESSURE REGULATOR (Continued)

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.
For OBD II Emission Monitor Requirements:
The PCM will monitor the voltage output sent from
the resistor track on the sending unit to indicate fuel
level. The purpose of this feature is to prevent the
OBD II system from recording/setting false misfire
and fuel system monitor diagnostic trouble codes.
The feature is activated if the fuel level in the tank
is less than approximately 15 percent of its rated
capacity. If equipped with a Leak Detection Pump
(EVAP system monitor), this feature will also be acti-
vated if the fuel level in the tank is more than
approximately 85 percent of its rated capacity.
DIAGNOSIS AND TESTING - FUEL GAUGE
SENDING UNIT
The fuel gauge sending unit contains a variable
resistor (track). As the float moves up or down, elec-
trical resistance will change. Refer to 8, Instrument
Panel and Gauges for Fuel Gauge testing. To test the
gauge sending unit only, it must be removed from
vehicle. The unit is part of the fuel pump module.
Refer to Fuel Pump Module Removal/Installation for
procedures. Measure the resistance across the send-
ing unit terminals. With float in up position, resis-
tance should be 20 ohms66 ohms. With float in
down position, resistance should be 220 ohms66
ohms.
REMOVAL
The fuel gauge sending unit (fuel level sensor) and
float assembly is located on the side of fuel pump
module (Fig. 9). The fuel pump module is located
inside of fuel tank.
(1) Remove fuel tank. Refer to Fuel Tank±All
Engines in the Removal/Installation section.
(2) Remove fuel pump module. Refer to Fuel Pump
Module Removal/Installation.
(3) Unplug 4±way electrical connector (Fig. 9).
(4) Disconnect 2 sending unit wires at 4±way con-
nector. The locking collar of connector must be
removed before wires can be released from connector.
Note location of wires within 4±way connector.
(5) The sending unit is retained to pump module
with a small lock tab and notch (Fig. 10). Carefully
push lock tab to the side and away from notch while
sliding sending unit downward on tracks for removal.
Note wire routing while removing unit from module.
Fig. 9 Fuel Gauge Sending Unit LocationÐTYPICAL
Module
1 - FUEL FILTER/PRESSURE REGULATOR
2 - ELECTRICAL CONNECTOR
3 - ELECTRIC FUEL PUMP
4 - FUEL GAUGE FLOAT
5 - FUEL PUMP INLET FILTER
6 - FUEL GAUGE SENDING UNIT
7 - MODULE LOCK TABS (3)
Fig. 10 Fuel Gauge Sending Unit Lock Tab/Tracks
1 - FUEL GAUGE SENDING UNIT
2 - LOCK TAB
3 - NOTCH
4 - TRACKS
14 - 8 FUEL DELIVERY - GASOLINEBR/BE
FUEL LEVEL SENDING UNIT / SENSOR (Continued)