8W-02 COMPONENT INDEX
Component Page
A/C Compressor Clutch................. 8W-42
A/C Compressor Clutch Relay............ 8W-42
A/C Pressure Transducer................ 8W-42
A/C-Heater Control.................... 8W-42
Accelerator Pedal Position Sensor......... 8W-30
Adjustable Pedal Motor................. 8W-30
Adjustable Pedal Relay................. 8W-30
Adjustable Pedal Switch................ 8W-30
Airbag Control Module................. 8W-43
Airbag-Squibs........................ 8W-43
Airbag-Curtains....................... 8W-43
Airbag-Passenger On/Off Switch.......... 8W-43
Ambient Temperature Sensor............ 8W-49
Amplifier Audio....................... 8W-47
Ashtray Lamp........................ 8W-44
Auto Shut Down Relay................. 8W-30
Automatic Day/Night Mirror.......... 8W-49, 55
Auxiliary Battery..................... 8W-20
Backup Lamp Switch.................. 8W-51
Battery............................. 8W-20
Battery Temperature Sensor............. 8W-30
Blend Door Actuators.................. 8W-42
Blower Motor......................... 8W-42
Blower Motor Resistor Block............. 8W-42
Brake Fluid Level Switch............ 8W-34, 35
Brake Lamp Switch.................... 8W-33
Brake Transmission Shift Interlock
Solenoid........................... 8W-40
Camshaft Position Sensor............... 8W-30
Capacitor............................ 8W-30
Center High Mounted Stop Lamp-
Aftermarket........................ 8W-51
Center High Mounted Stop Lamp/Cargo
Lamp.......................... 8W-44, 51
Cigar Lighter Outlet................... 8W-41
Circuit Breaker....................... 8W-10
Clearance Lamps...................... 8W-50
Clockspring................. 8W-33, 41, 43, 47
Clutch Interlock Brake Switch........... 8W-21
Coil On Plugs........................ 8W-30
Compass/Mini-Trip Computer............ 8W-49
Condenser Fan....................... 8W-42
Condenser Fan Relay.................. 8W-42
Controller Antilock Brake............ 8W-34, 35
Crankshaft Position Sensor.............. 8W-30
Cylinder Lock Switch-Driver............. 8W-61
Data Link Connector................... 8W-18
Data Link Connector-Engine............. 8W-18
Dome Lamp....................... 8W-44, 49
Door Ajar Switches.................... 8W-40
Door Lock Motor/Ajar Switches........ 8W-40, 61
Door Lock Switch-Passenger............. 8W-61Component Page
Door Module................... 8W-60, 61, 62
EGR Solenoid........................ 8W-30
Electric Backlight..................... 8W-48
Electric Brake Provision................ 8W-54
Electronic Throttle Control Module........ 8W-30
Engine Control Module................. 8W-30
Engine Coolant Temperature Sensor....... 8W-30
Engine Oil Pressure Switch.............. 8W-30
EVAP/Purge Solenoid.................. 8W-30
Evaporator Temperature Sensor.......... 8W-42
Fender Lamps........................ 8W-51
Fog Lamp Relay...................... 8W-50
Fog Lamps.......................... 8W-50
Front Control Module.................. 8W-10
Fuel Control Actuator.................. 8W-30
Fuel Heater.......................... 8W-30
Fuel Heater Relay..................... 8W-30
Fuel Injector Packs.................... 8W-30
Fuel Injectors........................ 8W-30
Fuel Pump Module.................... 8W-30
Fuel Pump Motor..................... 8W-30
Fuel Pump Relay...................... 8W-30
Fuses............................ 8W-10, 33
Fusible Link......................... 8W-10
Generator........................... 8W-20
Glove Box Lamp And Switch............. 8W-44
Grounds............................ 8W-15
Hands Free Module.................... 8W-55
Headlamp Switch.................. 8W-40, 50
Headlamps.......................... 8W-50
Heated Mirror Relay................... 8W-62
Heated Seat Cushions.................. 8W-63
Horn Relay.......................... 8W-41
Horn Switch......................... 8W-41
Horn-High Note....................... 8W-41
Horn-Low Note....................... 8W-41
Idle Air Control Motor.................. 8W-30
Ignition Switch....................... 8W-10
Inlet Air Temperature Sensor............ 8W-30
Input Speed Sensor.................... 8W-31
Instrument Cluster.................... 8W-40
Intake Air Heater Relays............... 8W-30
Intake Air Temperature Sensor........... 8W-30
Intake Air Temperature/Manifold Absolute
Pressure Sensor..................... 8W-30
Integrated Power Module............... 8W-10
Knock Sensosr........................ 8W-30
License Lamps....................... 8W-51
Lift Pump Motor...................... 8W-30
Line Pressure Sensor................ 8W-30, 31
Lumbar Motors....................... 8W-63
Lumbar Switch....................... 8W-63
DR8W-02 COMPONENT INDEX 8W - 02 - 1
8W-42 AIR CONDITIONING
Component Page
A/C Compressor Clutch............... 8W-42-7
A/C Compressor Clutch Relay.......... 8W-42-7
A/C Pressure Transducer............ 8W-42-8, 9
A/C-Heater Control........... 8W-42-2, 3, 4, 5, 6
Blend Door Actuator.................. 8W-42-6
Blower Motor....................... 8W-42-2
Blower Motor Resistor Block........... 8W-42-2
Condenser Fan..................... 8W-42-10
Condenser Fan Relay................ 8W-42-10
Data Link Connector............. 8W-42-3, 4, 8
Driver Blend Door Actuator............ 8W-42-5
Engine Control Module.............. 8W-42-7, 9
EVAPorator Temperature Sensor........ 8W-42-4
Fuse 12........................... 8W-42-10
Fuse 16............................ 8W-42-7Component Page
Fuse 36.......................... 8W-42-3, 4
G104............................. 8W-42-10
G107.............................. 8W-42-7
G120.............................. 8W-42-7
G202.......................... 8W-42-2, 3, 4
Heated Mirror Relay............... 8W-42-3, 4
Ignition Switch...................... 8W-42-2
Instrument Cluster................... 8W-42-2
Integrated Power Module....... 8W-42-3, 4, 7, 10
Mode Door Actuator 1............... 8W-42-5, 6
Mode Door Actuator 2............... 8W-42-5, 6
Passenger Blend Door Actuator......... 8W-42-5
Powertrain Control Module........ 8W-42-7, 8, 10
PTCNo.1.......................... 8W-42-7
Recirculation Door Actuator.......... 8W-42-5, 6
DR8W-42 AIR CONDITIONING 8W - 42 - 1
8W-80 CONNECTOR PIN-OUTS
Component Page
4WD Switch (Manual Transfer Case)..... 8W-80-5
A/C Compressor Clutch (Diesel)......... 8W-80-5
A/C Compressor Clutch (Gas)........... 8W-80-5
A/C Heater Control C1................ 8W-80-5
A/C Heater Control C2................ 8W-80-6
A/C Pressure Transducer (Diesel)........ 8W-80-6
A/C Pressure Transducer (NGC)......... 8W-80-6
Accelerator Pedal Position Sensor (5.7L) . . 8W-80-6
Accelerator Pedal Position Sensor
(Diesel M/T)...................... 8W-80-7
Accelerator Pedel Position Sensor
(Diesel A/T)....................... 8W-80-7
Adjustable Pedal Motor (Except Memory) . 8W-80-7
Adjustable Pedal Switch (Except Memory) . 8W-80-8
Airbag Control Module C1............. 8W-80-8
Airbag Control Module C2............. 8W-80-9
Airbag-Left Curtain.................. 8W-80-9
Airbag-Passenger On/Off Switch....... 8W-80-10
Airbag-Passenger Squib.............. 8W-80-10
Airbag-Right Curtain................ 8W-80-10
Ambient Temperature Sensor.......... 8W-80-10
Amplifier Audio C1 (Premium)......... 8W-80-11
Amplifier Audio C2 (Premium)......... 8W-80-11
Ashtray Lamp...................... 8W-80-11
Automatic Day/Night Mirror C1 (Except
Base).......................... 8W-80-12
Automatic Day/Night Mirror C2
(Telematics)..................... 8W-80-12
Back-Up Lamp Switch............... 8W-80-12
Battery Temperature Sensor........... 8W-80-12
Blend Door Actuator (Single Zone)...... 8W-80-13
Blower Motor...................... 8W-80-13
Blower Motor Resistor Block.......... 8W-80-13
Brake Fluid Level Switch............. 8W-80-13
Brake Lamp Switch................. 8W-80-13
Brake Transmission Shift Interlock
Solenoid........................ 8W-80-14
C102 (NGC)....................... 8W-80-14
C103............................. 8W-80-14
C106 (5.7L A/T).................... 8W-80-14
C106 (5.7L A/T).................... 8W-80-15
C107 (5.7L)........................ 8W-80-15
C107 (5.7L)........................ 8W-80-16
C108 (Diesel)...................... 8W-80-16
C108 (Diesel)...................... 8W-80-16
C109 (Diesel)...................... 8W-80-17
C109 (Diesel)...................... 8W-80-17
C110 (Diesel)...................... 8W-80-17
C110 (Diesel)...................... 8W-80-18
C112 (Diesel M/T)................... 8W-80-18
C112 (Diesel M/T)................... 8W-80-18
C112 (Diesel A/T)................... 8W-80-18Component Page
C112 (Diesel A/T)................... 8W-80-19
C130 (Diesel)...................... 8W-80-19
C131 (4.7L Electronic Transfer Case).... 8W-80-20
C131 (4.7L Electronic Transfer Case).... 8W-80-20
C131 (5.7L/Diesel).................. 8W-80-20
C131 (5.7L/Diesel).................. 8W-80-21
C131 (3.7L/4.7L Except Electronic
Transfer Case)................... 8W-80-21
C131 (3.7L/4.7L Except Electronic
Transfer Case)................... 8W-80-22
C200............................. 8W-80-22
C200............................. 8W-80-23
C201............................. 8W-80-23
C201............................. 8W-80-23
C202............................. 8W-80-24
C202............................. 8W-80-24
C206............................. 8W-80-24
C206............................. 8W-80-24
C207............................. 8W-80-24
C207............................. 8W-80-25
C216............................. 8W-80-25
C216............................. 8W-80-25
C217............................. 8W-80-26
C217............................. 8W-80-26
C218............................. 8W-80-26
C218............................. 8W-80-27
C219............................. 8W-80-27
C219............................. 8W-80-29
C220............................. 8W-80-30
C220............................. 8W-80-31
C250 (Hands Free).................. 8W-80-31
C250 (Hands Free).................. 8W-80-32
C301............................. 8W-80-32
C301............................. 8W-80-32
C301............................. 8W-80-33
C302............................. 8W-80-33
C302 (SLT)........................ 8W-80-34
C304............................. 8W-80-34
C304............................. 8W-80-34
C305 (SLT)........................ 8W-80-35
C305 (SLT)........................ 8W-80-35
C306............................. 8W-80-36
C306............................. 8W-80-36
C308............................. 8W-80-36
C308............................. 8W-80-37
C309............................. 8W-80-37
C309............................. 8W-80-37
C311 ............................. 8W-80-38
C311 ............................. 8W-80-38
C313............................. 8W-80-38
C313............................. 8W-80-39
C315............................. 8W-80-39
DR8W-80 CONNECTOR PIN-OUTS 8W - 80 - 1
BLEND DOOR ACTUATOR (SINGLE ZONE)-2WAY
CAV CIRCUIT FUNCTION
1 C34 20DB/LB COMMON DOOR DRIVER
2 C61 20DB/LG BLEND DOOR DRIVER
BLOWER MOTOR - BLACK 2 WAY
CAV CIRCUIT FUNCTION
1 C70 10DB/YL BLOWER MOTOR HIGH DRIVER
2 C7 10DB BLOWER MOTOR FEED
BLOWER MOTOR RESISTOR BLOCK - BLACK 4 WAY
CAV CIRCUIT FUNCTION
1 C72 16DB/OR BLOWER MOTOR M1 DRIVER
2 C70 12DB/YL BLOWER MOTOR HIGH DRIVER
3 C71 16DB/BR BLOWER MOTOR LOW DRIVER
4 C73 14DB/VT BLOWER MOTOR M2 DRIVER
BRAKE FLUID LEVEL SWITCH - BLACK 2 WAY
CAV CIRCUIT FUNCTION
1 B20 20DG/OR BRAKE FLUID LEVEL SWITCH SENSE
2 Z420 20BK/OR GROUND
BRAKE LAMP SWITCH-6WAY
CAV CIRCUIT FUNCTION
1 A103 18GY/RD FUSED B(+)
2 L50 18WT/TN BRAKE LAMP SWITCH OUTPUT
3 V30 20VT/WT S/C BRAKE SWITCH OUTPUT
3 V30 20VT/WT (5.7L) FUSED IGNITION SWITCH (RUN-START)
4 V32 20VT/YL SPEED CONTROL SUPPLY
4 V32 20VT/YL (5.7L) BRAKE SWITCH NO. 2 SIGNAL
5 Z429 20BK/OR GROUND
6 B29 20DG/WT BRAKE SWITCH SIGNAL
6 B29 20DG/WT (5.7L) BRAKE SWITCH NO. 1 SIGNAL
DR8W-80 CONNECTOR PIN-OUTS 8W - 80 - 13
CONNECTOR NAME/NUMBER COLOR LOCATION FIG.
Battery Temperature Sensor BK Below Battery Tray 22, 25, 26, 28
Blend Door Actuator (Single Zone) BK Behind Right Side of Instrument
PanelN/S
Blower Motor BK Behind Right Side of Instrument
PanelN/S
Blower Motor Resistor Block BK Behind Right Side of Instrument
PanelN/S
Brake Lamp Switch BK Top of Brake Pedal Arm 30, 35, 38
Brake Transmission Shift Interlock
SolenoidBK Near Steering Column 31, 35, 38
C102 Near Integrated Power Module 25
C106 BK Left Rear Engine 7
C107 (5.7L) BK Left Rear Engine 7
C112 (Diesel) BK Near T/O for Water In Fuel Sensor N/S
C113 BK Left Side Engine 10
C114 BK Left side Engine 10
C115 (Diesel) BK Left Side Engine 10
C130 BK Left Rear of Engine 4, 8, 21
C131 Right Rear Engine Compartment 4, 8, 21
C200 GY Under Instrument Panel 39
C201 WT Near Left Instrument Panel
Speaker35, 38
C202 BK Left Rear Side of Engine
Compartment27
C206 BK Right Instrument Panel 35, 39, 48
C207 Rear Engine Compartment 22
C216 BK Middle Left Frame 22, 25, 50
C217 BK Middle Left Frame 22, 25, 50
C218 WT Left Side of Instrument Panel 22, 24, 40, 44, 46
C219 GY Left Side of Instrument Panel 22, 24, 31, 35, 38, 40,
44
C220 WT Left Side of Instrument Panel 35, 38, 40, 44, 46
C250 Seft Side Instrument Panel 35
C301 WT Right Kick Panel 40, 42, 45, 47
C302 BK Left Front Door 40, 42, 45, 47
C304 WT Left Side of Instrument Panel 41, 44, 46
C305 BK At Left Front Door 41, 44, 46
C306 WT Middle Front of Door 43, 46
C308 WT Under Instrument Panel 39, 40, 45, 47
C309 WT Left Side of Instrument Panel 35, 38, 40, 44, 46
C311 BK Left Rear of Frame 44, 46
C312 WT Under Seat 47
C313 DK GY At Driver Seat N/S
C314 DK GY At Driver Seat N/S
8W - 91 - 2 8W-91 CONNECTOR/GROUND/SPLICE LOCATIONDR
CONNECTOR/GROUND/SPLICE LOCATION (Continued)
SPECIAL TOOLS
POWER DISTRIBUTION SYSTEMS
CIGAR LIGHTER OUTLET
DESCRIPTION
On models equipped a cigar lighter outlet is
installed to the left of the center stack area in the
lower instrument panel. The cigar lighter outlet is
secured by a snap fit within the bezel.
The cigar lighter outlet, plastic cap and the knob
and heating element unit are available for service
replacement. These components cannot be repaired
and, if faulty or damaged, they must be replaced.
OPERATION
The cigar lighter consists of two major components:
a knob and heating element unit, and the cigar
lighter base or outlet shell. The receptacle shell is
connected to ground, and an insulated contact in the
bottom of the shell is connected to battery current.
The cigar lighter receives battery voltage from a fuse
in the junction block when the ignition switch is in
the Accessory or Run positions.
The cigar lighter knob and heating element are
encased within a spring-loaded housing, which also
features a sliding protective heat shield. When the
knob and heating element are inserted in the outlet
shell, the heating element resistor coil is grounded
through its housing to the outlet shell. If the cigar
lighter knob is pushed inward, the heat shield slides
up toward the knob exposing the heating element,
and the heating element extends from the housing
toward the insulated contact in the bottom of the
outlet shell.
Two small spring-clip retainers are located on
either side of the insulated contact inside the bottom
of the outlet shell. These clips engage and hold the
heating element against the insulated contact longenough for the resistor coil to heat up. When the
heating element is engaged with the contact, battery
current can flow through the resistor coil to ground,
causing the resistor coil to heat.
When the resistor coil becomes sufficiently heated,
excess heat radiates from the heating element caus-
ing the spring-clips to expand. Once the spring-clips
expand far enough to release the heating element,
the spring-loaded housing forces the knob and heat-
ing element to pop back outward to their relaxed
position. When the cigar lighter knob and element
are pulled out of the outlet shell, the protective heat
shield slides downward on the housing so that the
heating element is recessed and shielded around its
circumference for safety.
DIAGNOSIS AND TESTING - CIGAR LIGHTER
OUTLET
For complete circuit diagrams, refer toWiring
Diagrams.
(1) Check the fused B(+) fuse in the integrated
power module. If OK, go to Step 2. If not OK, repair
the shorted circuit or component as required and
replace the faulty fuse.
(2) Turn the ignition switch to the Run position.
Check for battery voltage at the fused B(+) fuse in
the integrated power module. If OK, go to Step 3. If
not OK, repair the open or short as required.
(3) Remove the cigar lighter knob and element
from the cigar lighter outlet shell. Check for continu-
ity between the inside circumference of the cigar
lighter outlet shell and a good ground. there should
be continuity. If OK, go to Step 4. If not OK, go to
Step 5.
(4) Turn the ignition switch to the Run position.
Check for battery voltage at the insulated contact
located at the back of the cigar lighter outlet shell. If
OK, replace the faulty cigar lighter knob and ele-
ment. If not OK, go to Step 5.
(5) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Check for continuity between the ground circuit cav-
ity of the cigar lighter wire harness connector and a
good ground. There should be continuity. If OK, go to
Step 6. If not OK, repair the open ground circuit to
ground as required.
(6) Connect the battery negative cable. Turn the
ignition switch to the Accessory or Run positions.
Check for battery voltage at the fused B(+) circuit
cavity of the cigar lighter wire harness connector. If
OK, replace the faulty cigar lighter outlet. If not OK,
repair the open fused B(+) circuit to the integrated
power module fuse as required.Terminal Pick Kit 6680
8W - 97 - 2 8W-97 POWER DISTRIBUTIONDR
POWER DISTRIBUTION (Continued)
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 58 2 psi at the
fuel injectors. It contains a diaphragm, calibrated
springs and a fuel return valve. The internal fuel fil-
ter (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 Pump - Description and
Operation for more information.
If fuel pressure at the pressure regulator exceeds
approximately 60 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.
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 is supplied to the resistor track on the fuel
gauge sending unit. This is fed directly from the
Powertrain Control Module (PCM).NOTE: For
diagnostic purposes, this 12V power source can
only be verified with the circuit opened (fuel
pump module electrical connector unplugged).
With the connectors plugged, output voltages
will vary from about 0.6 volts at FULL, to about
8.6 volts at EMPTY (about 8.6 volts at EMPTY
for Jeep models, and about 7.0 volts at EMPTY
for Dodge Truck models).The resistor track is
used to vary the voltage (resistance) depending 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 sensor return
circuit.
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.
Fig. 2 SIDE VIEW - FILTER/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
14 - 6 FUEL DELIVERY - GASDR
FUEL FILTER/PRESSURE REGULATOR (Continued)
FUEL LEVEL SENDING UNIT /
SENSOR
DESCRIPTION
The fuel gauge sending unit (fuel level sensor) is
attached to the side of the fuel tank module. The
sending unit consists of a float, an arm, and a vari-
able resistor track (card).
OPERATION
The fuel tank module on diesel powered models
has 2 different circuits (wires). Two of these circuits
are used at the fuel gauge sending unit for fuel
gauge operation. The diesel engine does not have a
fuel tank module mounted electric fuel pump. The
electric fuel pump (fuel transfer pump) is mounted to
the engine.
For Fuel Gauge Operation:A constant input
voltage source of about 12 volts (battery voltage) is
supplied to the resistor track on the fuel gauge send-
ing unit. This is fed directly from the Engine Control
Module (ECM).NOTE: For diagnostic purposes,
this 12V power source can only be verified with
the circuit opened (fuel tank module electrical
connector unplugged). With the connectors
plugged, output voltages will vary from about .6
volts at FULL, to about 7.0 volts at EMPTY.The
resistor track is used to vary the voltage (resistance)
depending 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 ECM
through the sensor return circuit.
Both of the electrical circuits between the fuel
gauge sending unit and the ECM are hard-wired (not
multi-plexed). After the voltage signal is sent from
the resistor track, and back to the ECM, the ECM
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.
REMOVAL
REMOVAL/INSTALLATION
For diesel removal and installation procedures,
refer to the gas section of Fuel System/Fuel Delivery.
See Fuel Level Sending Unit/Sensor Removal/Instal-
lation.
FUEL LINES
DESCRIPTION
Low-Pressure Lines Are:
²the fuel supply line from fuel tank to fuel trans-
fer (lift) pump.
²the fuel return line back to fuel tank.
²the fuel drain (manifold) line at rear of cylinder
head.
²the fuel supply line from fuel filter to fuel injec-
tion pump.
²the fuel injection pump return line.
High-Pressure Lines Are:
²the fuel line from fuel injection pump to fuel
rail.
²the 6 fuel lines from fuel rail up to injector con-
nector tubes
WARNING: HIGH-PRESSURE FUEL LINES DELIVER
DIESEL FUEL UNDER EXTREME PRESSURE FROM
THE INJECTION PUMP TO THE FUEL INJECTORS.
THIS MAY BE AS HIGH AS 160,000 KPA (23,206
PSI). USE EXTREME CAUTION WHEN INSPECTING
FOR HIGH-PRESSURE FUEL LEAKS. INSPECT FOR
HIGH-PRESSURE FUEL LEAKS WITH A SHEET OF
CARDBOARD. HIGH FUEL INJECTION PRESSURE
CAN CAUSE PERSONAL INJURY IF CONTACT IS
MADE WITH THE SKIN.
OPERATION
High-Pressure Lines
CAUTION: The high-pressure fuel lines must be
held securely in place in their holders. The lines
cannot contact each other or other components. Do
not attempt to weld high-pressure fuel lines or to
repair lines that are damaged. If lines are ever
kinked or bent, they must be replaced. Use only the
recommended lines when replacement of high-pres-
sure fuel line is necessary.
High-pressure fuel lines deliver fuel (under pres-
sure) of up to approximately 160,000 kPa (23,206
PSI) from the injection pump to the fuel injectors.
The lines expand and contract from the high-pres-
sure fuel pulses generated during the injection pro-
cess. All high-pressure fuel lines are of the same
length and inside diameter. Correct high-pressure
fuel line usage and installation is critical to smooth
engine operation.
DRFUEL DELIVERY - DIESEL 14 - 57