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Dodge Durango (DN). Manual - part 8

TORQUE SPECIFICATIONS

DESCRIPTION

TORQUE

Front axle skid plate-to-front

x-member bolt . . . . . . . . . . . . 23 N·m (17 ft. lbs.)

Front axle skid plate-to-trans

x-member bolt . . . . . . . . . . . . 23 N·m (17 ft. lbs.)

Front bumper brkt-to-frame nut . . . . . . . . . 94 N·m

(70 ft. lbs.)

Front bumper outer brace bolt . . . . . . . . . . 94 N·m

(70 ft. lbs.)

Fuel tank skid plate-to-frame rail bolt . . . . 23 N·m

(17 ft. lbs.)

Fuel tank skid plate-to-x-member screw . . . 41 N·m

(30 ft. lbs.)

Rear bumper bracket-to-frame nut . . . . . . . 54 N·m

(40 ft. lbs.)

Spare tire winch bolt . . . . . . . . . 18 N·m (13 ft. lbs.)
Transfer case skid

plate-to-x-member bolt . . . . . 23 N·m (17 ft. lbs.)

Trailer hitch nut . . . . . . . . . . . 108 N·m (80 ft. lbs.)

13 - 10

FRAME AND BUMPERS

SPECIFICATIONS (Continued)

FUEL SYSTEM

TABLE OF CONTENTS

page

FUEL DELIVERY SYSTEM. . . . . . . . . . . . . . . . . . . . 1

FUEL INJECTION SYSTEM . . . . . . . . . . . . . . . . . . 27

FUEL DELIVERY SYSTEM

TABLE OF CONTENTS

page

DESCRIPTION AND OPERATION

DIAGNOSIS AND TESTING

FUEL PUMP PRESSURE TEST . . . . . . . . . . . . . . . 6
FUEL PUMP CAPACITY TEST . . . . . . . . . . . . . . . . 7
FUEL PRESSURE LEAK DOWN TEST . . . . . . . . . . 7
FUEL PUMP AMPERAGE TEST . . . . . . . . . . . . . . . 8
FUEL GAUGE SENDING UNIT . . . . . . . . . . . . . . . . 9
FUEL INJECTOR TEST . . . . . . . . . . . . . . . . . . . . 10

SERVICE PROCEDURES

FUEL SYSTEM PRESSURE RELEASE

PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . 10

QUICK-CONNECT FITTINGS . . . . . . . . . . . . . . . . 11

REMOVAL AND INSTALLATION

SPECIFICATIONS

FUEL TANK CAPACITY . . . . . . . . . . . . . . . . . . . . 24
FUEL SYSTEM PRESSURE . . . . . . . . . . . . . . . . . 24
FUEL REQUIREMENTS . . . . . . . . . . . . . . . . . . . . 24
TORQUE CHART . . . . . . . . . . . . . . . . . . . . . . . . . 26

DESCRIPTION AND OPERATION

PCM VIN REPROGRAMMING

OPERATION

USE THE DRB SCAN TOOL TO REPROGRAM

THE NEW POWERTRAIN CONTROL MODULE

(PCM) WITH THE VEHICLES ORIGINAL IDEN-
TIFICATION NUMBER (VIN) AND THE VEHI-
CLES ORIGINAL MILEAGE. IF THIS STEP IS
NOT DONE, A DIAGNOSTIC TROUBLE CODE
(DTC) MAY BE SET.

FUEL SYSTEM

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FUEL DELIVERY SYSTEM

DESCRIPTION

The fuel delivery system consists of:
• the fuel pump module containing the electric

fuel pump, fuel filter/fuel pressure regulator, fuel
gauge sending unit (fuel level sensor) and a separate
fuel filter located at bottom of pump module

• fuel tubes/lines/hoses

• quick-connect fittings

• fuel injector rail

• fuel injectors

• fuel tank

• fuel tank filler/vent tube assembly

• fuel tank filler tube cap

• accelerator pedal

• throttle cable

OPERATION

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.

The fuel tank assembly consists of: the fuel tank,

fuel pump module assembly, fuel pump module metal
lockring and gasket, and rollover valve (refer to
Group 25, Emission 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 Group 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.

FUEL PUMP MODULE

DESCRIPTION

The fuel pump module on all models/all engines is

installed in the top of the fuel tank (Fig. 1). The fuel
pump module contains the following components
(Fig. 2):

• A combination fuel filter/fuel pressure regulator

• Electric fuel pump

• Fuel pump reservoir

• A separate in-tank fuel filter (at bottom of mod-

ule)

• Fuel gauge sending unit (fuel level sensor)

• Fuel supply line connection at filter/regulator

• A metal lockring to retain pump module to fuel

tank

• A gasket between tank flange and module
The fuel gauge sending unit (fuel level sensor), and

pick-up filter (at bottom of module) may be serviced
separately. If the electrical fuel pump requires ser-
vice, the entire fuel pump module must be replaced.

OPERATION

Refer to Fuel Pump, Fuel Filter/Fuel Pressure Reg-

ulator and Fuel Gauge Sending Unit.

FUEL PUMP

DESCRIPTION

The fuel pump is located inside of the fuel pump

module. A 12 volt, permanent magnet, electric motor
powers the fuel pump.

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 pump outlet con-

tains a one-way check valve to prevent fuel flow back
into the tank and to maintain fuel supply line pres-
sure (engine warm) when pump is not operational. It
is also used to keep the fuel supply line full of gaso-
line 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

Fig. 1 Fuel Pump Module/Fuel Tank (Top View)

1 – FUEL PUMP MODULE
2 – FRONT ROLLOVER VALVE
3 – FUEL FILTER/FUEL PRESSURE REGULATOR
4 – FUEL TANK
5 – EVAP LINE
6 – REAR ROLLOVER VALVE

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FUEL SYSTEM

DESCRIPTION AND OPERATION (Continued)

injectors. Fuel pressure that has dropped to 0
psi on a cooled down vehicle (engine off) is a
normal condition. Refer to the Fuel Pressure Leak
Down Test for more information.

FUEL GAUGE SENDING UNIT

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).

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.

FUEL FILTER/FUEL PRESSURE REGULATOR

DESCRIPTION

A combination fuel filter and fuel pressure regula-

tor (Fig. 3) 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

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 kPa

6 34

kPa (49.2 psi

6 5 psi) at the fuel injectors. It con-

tains a diaphragm, calibrated springs and a fuel
return valve. The internal fuel filter (Fig. 3) is also
part of the assembly.

Fig. 2 Fuel Pump Module Components (Typical

Pump Module Shown)

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)

FUEL SYSTEM

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DESCRIPTION AND OPERATION (Continued)

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