air filter DODGE RAM 2001 Service Manual Online

WARNING: THE FUEL INJECTION PUMP SUPPLIES
EXTREMELY HIGH FUEL PRESSURE TO EACH INDI-
VIDUAL INJECTOR THROUGH THE HIGH-PRES-
SURE LINES. FUEL UNDER THIS AMOUNT OF
PRESSURE CAN PENETRATE THE SKIN AND
CAUSE PERSONAL INJURY. WEAR SAFETY GOG-
GLES AND ADEQUATE PROTECTIVE CLOTHING
AND AVOID CONTACT WITH FUEL SPRAY WHEN
BLEEDING HIGH-PRESSURE FUEL LINES.
WARNING: ENGINE MAY START WHILE CRANKING
STARTER MOTOR.
Engine may start, may run erratically and be
very noisy for a few minutes. This is a normal
condition.
(9) Thoroughly clean area around injector fittings
where they join injector connector tubes.
(10) Bleed air by loosening high-pressure fuel line
fittings (Fig. 3) at cylinders number 3, 4 and 5.
(11) Continue bleeding injectors until engine runs
smoothly. It may take a few minutes for engine to
run smooth.
(12) Tighten fuel line(s) at injector(s) to 38 N´m
(28 ft. lbs.) torque.
SPECIFICATIONS
FUEL SYSTEM PRESSURESÐDIESEL ENGINES
DESCRIPTION PRESSURE
Fuel Transfer (Lift) Pump Pressure With Engine
RunningMinimum 69 kPa (10 psi)
Fuel Transfer (Lift) Pump Pressure With Engine
CrankingMinimum 48 kPa (7 psi)
Fuel Injector ªPop Offº Pressure 31,026 kPa (310 bars) or (4500 psi6250 psi)
Fuel Injector Leak-Down Pressure Approximately 20 bars (291 psi) lower than pop
pressure
Fuel Pressure Drop Across Fuel Filter Test Ports 34 kPa max. (5 psi. max.) at 2500 rpm (rated rpm)
Overflow Valve Release Pressure 97 kPa max. (14 psi.) at 2500 rpm (rated rpm)
FUEL INJECTOR FIRING ORDERÐDIESEL
1±5±3±6±2±4
Fig. 3 Bleeding High-Pressure Fuel Lines at
Injectors
1 - HIGH-PRESSURE FUEL LINE
14 - 58 FUEL DELIVERY - DIESELBR/BE
FUEL DELIVERY - DIESEL (Continued)

(c) Check condition of o-ring.(d) Inspect the 2 WIF sensor probes. Carefully
clean contaminants from sensor probes with a cloth
if necessary. Replace sensor if probes are covered
with contaminants and will not clean up.
(7)Fuel Heater Element Replacement:The
heater element is located in the fuel filter housing
(Fig. 6).
(a) Remove fuel filter. See previous steps.
(b) Disconnect electrical connector from fuel tem-
perature sensor housing at side of fuel filter hous-
ing (Fig. 8).
(c) Remove 2 temperature sensor housing
mounting screws and carefully remove sensor
housing from fuel filter housing.
(d) Pry round wiring connector from fuel filter
housing and heater element. This connector passes
through the fuel filter housing and is plugged
directly into the heater element.
(e) Unlock heater element fingers and pry heater
element from filter housing.
(8)Drain Valve Replacement:The drain valve is
located on the side of the fuel filter housing (Fig. 6).
(a) Disconnect drain hose (Fig. 5) at bottom of
drain valve.
(b) Remove 4 drain valve mounting screws.
(c) Remove drain valve from filter housing.
(d) Remove 2 drain valve o-rings from filter
housing.
INSTALLATION
Refer to maintenance schedules in this manual for
recommended fuel filter replacement intervals.
(1) Thoroughly clean inside of filter housing, filter
cap and all related components.
(2)Fuel Filter:
(a) Fill fuel filter housing with clean diesel fuel.
If filter housing (canister) is not filled with
clean diesel fuel before installation, manual
air bleeding of fuel system may be necessary
(temporary rough engine running may occur).
If necessary, refer to Air Bleed Procedures.
(b) Snap new filter into locking fingers on cap.
Hole in filter should face downward.
(c) Install new o-ring to cap.
(d) Apply a light film of clean diesel oil to cap
o-ring seal.
(e) Load filter and cap into housing.
(f) Tighten cap to 25 ft. lbs. torque. Do not over-
tighten cap.
(3)Water-In-Fuel (WIF) Sensor:
(a) Install new o-ring seal to WIF sensor.
(b) Apply a light film of clean diesel oil to o-ring
seal.
(c) Install sensor into housing.
(d) Tighten sensor to 2±3 N´m (15±20 in. lbs.)
torque.
Fig. 7 Water-In-Fuel Sensor
1 - WATER-IN-FUEL (WIF) SENSOR
2 - FUEL FILTER/WATER SEPARATOR
3 - WIF SENSOR CONNECTOR
Fig. 8 Fuel Filter/Water Separator Location
1 - FUEL HEATER AND TEMP. SENSOR
2 - FUEL FILTER/WATER SEPARATOR
3 - FUEL HEATER ELECTRICAL CONNECTOR
BR/BEFUEL DELIVERY - DIESEL 14 - 61
FUEL FILTER / WATER SEPARATOR (Continued)

Voltage to operate the fuel heater element is sup-
plied from the ignition switch, through the fuel
heater relay (also refer to Fuel Heater Relay), to the
fuel temperature sensor and on to the fuel heater ele-
ment.
The heater element operates on 12 volts, 300 watts
at 0 degrees F. As temperature increases, power
requirements decrease.
A minimum of 7 volts is required to operate the
fuel heater. The resistance value of the heater ele-
ment is less than 1 ohm (cold) and up to 1000 ohms
warm.
TESTING
(1) Disconnect electrical connector at sensor (Fig.
10).
Turn key to ON position. 12 volts should be
present at red wire. If not, check fuel heater relay
and related wiring. Refer to Relay TestÐFuel Heater.
If OK, proceed.
Turn key OFF. Check black wire in connector for
ground continuity with an ohmmeter. If continuity is
not present, correct open ground circuit. This test can
also be performed with a voltmeter by backprobing
black wire with it connected to sensor. Reconnect
electrical connector and turn key ON. Voltage drop
should not exceed 2 volts (2 volts lower than checked
at 12V+ connector). If voltage is lower, check for dirtyor corroded ground connection and repair. If OK, pro-
ceed.
(2) With electrical connector disconnected at sen-
sor and key OFF, check electrical/mechanical opera-
tion of fuel temperature sensor. Proceed to next step:
(3) Using an ohmmeter, check for continuity across
two terminals in electrical connector at side of sen-
sor. Sensor circuit should be open if fuel temperature
has risen above 75 degrees68 degrees F. Sensor cir-
cuit should be closed if fuel temperature has dropped
below 45 degrees68 degrees F. If not, replace fuel
heater assembly. This same test can also be per-
formed using a voltmeter, with key ON, and by back-
probing connector.
REMOVAL/INSTALLATION
The fuel heater/element/sensor assembly is located
inside of the fuel filter housing. Refer to Fuel Filter/
Water Separator Removal/Installation for procedures.
FUEL HEATER RELAY
DESCRIPTION
The fuel heater relay is located in Power Distribu-
tion Center (PDC) (Fig. 11). Refer to label on inside
of PDC cover for relay location.
OPERATION
Battery voltage to operate the fuel heater element
is supplied from the ignition switch through the fuel
heater relay.The fuel heater element and fuel
heater relay are not computer controlled.
Fig. 10 Fuel Heater Location
1 - FUEL HEATER AND TEMP. SENSOR
2 - FUEL FILTER/WATER SEPARATOR
3 - FUEL HEATER ELECTRICAL CONNECTOR
Fig. 11 Power Distribution Center Location
1 - CLIP
2 - BATTERY
3 - TRAY
4 - NEGATIVE CABLE
5 - POSITIVE CABLE
6 - CLIP
7 - FENDER INNER SHIELD
8 - POWER DISTRIBUTION CENTER
BR/BEFUEL DELIVERY - DIESEL 14 - 63
FUEL HEATER (Continued)

(1) Remove hose clamp and crankcase vent hose at
crankcase breather (Fig. 17). Remove crankcase
breather from gear cover. Breather threads into
cover.
(2) Remove injection pump nut and washer (Fig.
18). Locate keyway behind washer.
(3) Be sure keyway aligning fuel injection pump
shaft to injection pump gear is in proper position and
pump gear has not slipped on pump shaft.
The following steps will require removing timing
gear cover to gain access to timing gears. Refer to
Group 9, Engines for procedures.
(4) Use a T-type puller to separate injection pump
gear from pump shaft.
(5) Be sure keyway has been installed with arrow
pointed torearof pump (Fig. 19).
(6)Pump timing has been calibrated to pump
keyway. Be sure 3±digit number on pump key-
way (Fig. 19) matches 3±digit number on fuel
injection pump data plate. Plate is located on
side of injection pump (Fig. 20). Twenty±one dif-
ferent calibrated keyways/pumps are available.
(7) Verify timing marks on crank, cam and pump
are aligned (Fig. 21).
(8) Perform necessary gear alignment/repairs as
needed.
(9) Install crankcase breather to gear cover. Install
hose clamp and crankcase vent hose to breather (Fig.
17).
(10) After repairs are completed, erase DTC using
DRB Scan Tool.
REMOVAL
CAUTION: Refer to Cleaning Fuel System Parts.
(1) Disconnect both negative battery cables at both
batteries. Cover and isolate ends of cables.
(2) Thoroughly clean fuel lines at cylinder head
and injection pump ends. Thoroughly clean fuel injec-
tion pump and supply/return lines at side of pump.
(3) Disconnect 9±way electrical connector at Fuel
Pump Control Module (FPCM) (Fig. 22).
(4) Remove fuel return line at side of injection
pump by removing overflow valve (Fig. 23). Place rag
beneath overflow valve to catch excess fuel.
(5) Remove fuel supply line at side of injection
pump by removing banjo bolt (Fig. 23). Also remove
same line at top of fuel filter housing (banjo bolt).
(6) Remove all high-pressure fuel lines, intake air
tube, accelerator pedal position sensor, air intake
housing, engine oil dipstick tube, wiring clips, electri-
cal cables at intake heaters and engine lifting
bracket. Refer to High-Pressure Fuel Line Removal/
Installation. All of these items are covered in this
procedure.
(7) Remove hose clamp at crankcase vent hose
(Fig. 24) and remove hose from canister.
(8) Remove (unscrew) canister (Fig. 24) from gear
cover.
Fig. 21 Checking Fuel Injection Pump Gear Timing
1 - PUMP SHAFT
2 - KEYWAY
3 - PUMP GEAR
4 - CAM GEAR
5 - CRANKSHAFT GEAR
Fig. 22 FPCM 9±Way Connector
1 - FPCM ELECTRICAL CONNECTOR
2 - HIGH-PRESSURE FUEL LINES
3 - FITTINGS
4 - FUEL INJECTION PUMP
5 - FPCM
14 - 68 FUEL DELIVERY - DIESELBR/BE
FUEL INJECTION PUMP (Continued)

(5) Clean pump gear and pump shaft at machined
tapers (Fig. 34) with an evaporative type cleaner
such as brake cleaner.
Keyway Installation:
(6) The pump/gear keyway has an arrow and a
3±digit number stamped at top edge (Fig. 33). Posi-
tion keyway into pump shaft witharrow pointed to
rear of pump.Also be sure 3±digit number stamped
to top of keyway is same as 3±digit number stamped
to injection pump data plate (Fig. 35). If wrong key-
way is installed, a diagnostic trouble code may be
set.
(7) Position pump assembly to mounting flange on
gear cover while aligning injection pump shaft
through back of injection pump gear. When installing
pump, dowel (Fig. 34) on mounting flange must align
to hole in front of pump.
(8) After pump is positioned flat to mounting
flange, install four pump mounting nuts and tighten
finger tight only. Do not attempt a final tightening at
this time.Do not attempt to tighten (pull) pump
to gear cover using mounting nuts. Damage to
pump or gear cover may occur. The pump must
be positioned flat to its mounting flange before
attempting to tighten mounting nuts.
(9) To prevent damage or cracking of components,
tighten nuts/bolts in the following sequence:
(a) Install injection pump shaft washer and nut
to pump shaft. Tighten nutfinger tight only.
(b) Install 2 rear/lower pump mounting bolts
finger tight only.(c) Do preliminary tightening of injection pump
shaft nut to 30 N´m (15±22 ft. lbs.) torque.This is
not the final torque.
(d) Tighten 4 pump mounting nuts to 43 N´m
(32 ft. lbs.) torque.
(e) Tighten 2 rear/lower pump bracket-to-pump
bolts 24 N´m (18 ft. lbs.) torque.
(f) Do final tightening of injection pump shaft
nut to 170 N´m (125 ft. lbs.) torque. Use barring
tool to prevent engine from rotating when tighten-
ing gear.
(10) Install canister (Fig. 24) to gear cover.
(11) Install crankcase vent hose (Fig. 24) to canis-
ter and install hose clamp.
(12) Using new gaskets, install fuel return line
and overflow valve to side of injection pump (Fig. 23).
Tighten overflow valve to 24 N´m (18 ft. lbs.) torque.
(13)
Using new gaskets, install fuel supply line to
side of injection pump and top of fuel filter housing (Fig.
23). Tighten banjo bolts to 24 N´m (18 ft. lbs.) torque.
(14)Install all high-pressure fuel lines, intake air
tube, accelerator pedal position sensor, air intake hous-
ing, engine oil dipstick tube, wiring clips, electrical
cables at intake heaters and engine lifting bracket.
Refer to High-Pressure Fuel Line Removal/Installation.
All of these items are covered in this procedure.
Fig. 34 Injection Pump Installation
1 - DOWEL
2 - PUMP
3 - PUMP SHAFT TAPER
4 - INJECTION PUMP GEAR TAPER
Fig. 35 Injection Pump Data Plate Location
1 - PUMP DATA PLATE
14 - 72 FUEL DELIVERY - DIESELBR/BE
FUEL INJECTION PUMP (Continued)

(3) Installrearinjection line bundle beginning
with cylinder head (fuel injector) connections, fol-
lowed by injection pump connections. Tighten all fit-
tings finger tight.
(4) Tighten fittings at fuel injector ends for cylin-
ders number 6 and 5 to 38 N´m (28 ft. lbs.) torque.
Do not tighten number 3 line at this time. It
will be tightened during bleeding procedure.
(5) Tighten 3 fittings at fuel injection pump ends
to 24 N´m (18 ft. lbs.) torque.
(6) Installfrontinjection line bundle beginning
with cylinder head (fuel injector) connections, fol-
lowed by injection pump connections. Tighten all fit-
tings finger tight.
(7) Tighten fitting at fuel injector end for cylinder
number 2 to 38 N´m (28 ft. lbs.) torque.Do not
tighten lines number 1 or 4 at this time. They
will be tightened during bleeding procedure.
(8) Tighten remaining 3 fittings at fuel injection
pump ends to 24 N´m (18 ft. lbs.) torque.
(9) Install fuel line support bracket bolts to intake
manifold and tighten to 24 N´m (18 ft. lbs.) torque.
CAUTION: Be sure fuel lines are not contacting
each other or any other component. Noise will
result.
(10) Install engine lifting bracket at rear of intake
manifold. Tighten 2 bolts to 77 N´m (57 ft. lbs.)
torque.
(11) Install cable bracket housing/cable assembly
and tighten 3 mounting bolts to 24 N´m (18 ft. lbs.)
torque.
(12) Clean any old gasket material below and
above intake manifold air heater element block. Also
clean mating areas at intake manifold and air intake
housing.
(13) Using new gaskets, position intake manifold
air heater element block to engine.
(14) Install air intake housing and position ground
cable. Install 4 mounting bolts and tighten to 24 N´m
(18 ft. lbs.) torque.
(15) Install air tube (intake manifold-to-charge air
cooler) (Fig. 41). Tighten clamps to 8 N´m (72 in. lbs.)
torque.
(16) Install engine oil dipstick tube support mount-
ing bolt and tighten to 24 N´m (18 ft. lbs.) torque.
(17) Install engine oil dipstick to engine.
(18) Connect 2 electrical cables to cable mounting
studs.
(19) Connect electrical connector to bottom of
APPS by pushing connector upward until it snaps
into position.
(20) Connect wiring harness (clip) at bottom of
Accelerator Pedal Position Sensor (APPS) mounting
bracket (Fig. 40).(21) Connect front wiring clip (Fig. 41) to cable
bracket housing.
(22) Install cable cover (Fig. 39).
(23) Connect both negative battery cables to both
batteries.
(24) Bleed air from fuel system. Do this at fuel
injector ends of lines. Use cylinders numbers 1, 3 and
4 for bleeding . (Refer to 14 - FUEL SYSTEM/FUEL
DELIVERY - STANDARD PROCEDURE). After
bleeding, tighten fittings to 38 N´m (28 ft. lbs.)
torque.
(25) Check lines/fittings for leaks.
FUEL TANK
DESCRIPTION - DIESEL FUEL TANK
The fuel tank is similar to the tank used with gas-
oline powered models. The tank is equipped with a
separate fuel return line and a different fuel tank
module for diesel powered models. A fuel tank
mounted, electric fuel pump is not used with diesel
powered models. Refer to Fuel Tank Module for addi-
tional information.
For removal and installation procedures, refer to
Fuel Tank - Gasoline Engines.
FUEL TANK MODULE
DESCRIPTION
An electric fuel pump isnot usedin the fuel tank
module for diesel powered engines. Fuel is supplied
by the engine mounted fuel transfer pump and the
fuel injection pump.
The fuel tank module is installed in the top of the
fuel tank (Fig. 48). The fuel tank module (Fig. 48)
contains the following components:
²Fuel reservoir
²A separate in-tank fuel filter
²Rollover valve
²Fuel gauge sending unit (fuel level sensor)
²Fuel supply line connection
²Fuel return line connection
²Auxiliary non-pressurized fuel supply fitting
OPERATION
Refer to Fuel Gauge Sending Unit.
REMOVAL
(1) Drain and remove fuel tank. Refer to Fuel
Tank Removal/Installation.
(2) Thoroughly clean area around tank module at
top of tank.
14 - 78 FUEL DELIVERY - DIESELBR/BE
FUEL LINES (Continued)

The transfer pump is self-priming: When the key is
first turned on (without cranking engine), the pump
will operate for approximately 2 seconds and then
shut off. The pump will also operate for up to 25 sec-
onds after the starter is engaged, and then disen-
gaged and the engine is not running. The pump
shuts off immediately if the key is on and the engine
stops running.
The fuel volume of the transfer pump will always
provide more fuel than the fuel injection pump
requires. Excess fuel is returned from the injection
pump through an overflow valve. The valve is located
on the side of the injection pump (Fig. 52). It is also
used to connect the fuel return line to the side of the
injection pump. This valve opens at approximately 97
kPa (14 psi) and returns fuel to the fuel tank
through the fuel return line.
DIAGNOSIS AND TESTING - FUEL TRANSFER
PUMP PRESSURE
The following tests will include: pressures
tests of fuel transfer pump (engine running and
engine cranking), a pressure drop test of fuel
filter, a test for supply side restrictions, and a
test for air in fuel supply side.
Fig. 50 Fuel Transfer Pump Location
1 - OIL PRESSURE SENSOR
2 - PUMP BRACKET NUTS (3)
3 - SUPPORT BRACKET BOLT
4 - BANJO BOLT (REAR)
5 - FUEL SUPPLY LINE
6 - ELECTRICAL CONNECTOR
7 - BANJO BOLT (FRONT)
8 - FUEL TRANSFER PUMP
Fig. 51 Engine Control Module (ECM) Location
1 - ENGINE CONTROL MODULE (ECM)
2 - HEX HEADED BOLT
3 - 50-WAY CONNECTOR
4 - FUEL TRANSFER PUMP
5 - MOUNTING BOLTS (3)
Fig. 52 Injection Pump Overflow Valve Location
1 - FUEL SUPPLY LINE
2 - FUEL RETURN LINE
3 - BANJO BOLT (TEST PORT FITTING)
4 - OVERFLOW VALVE
5 - BANJO FITTING
14 - 80 FUEL DELIVERY - DIESELBR/BE
FUEL TRANSFER PUMP (Continued)

(5) Using key, crank engine over while observing
gauge. Pressure should be 5±7 psi.
(6) Re-install fuel system relay to PDC.
(7) Start engine and record fuel pressure. Pressure
should be aminimumof 69 kPa (10 psi) at idle
speed.
(8) Because fuel pump relay was removed, a Diag-
nostic Trouble Code (DTC) may have been set. After
testing is completed, and relay has been installed,
use DRB scan tool to remove DTC.
Pressure Drop Test:
(9) Shut engine off and remove test gauge from
inlet port test fitting. Re-attach 6828 test gauge to
outlet port (Fig. 55). Start engine and record fuel
pressure. Pressure should not be more than 34 kPa
(5 psi) lower than inlet port pressure test. If so,
replace fuel filter.
Fuel Supply Restriction Test:
Due to very small vacuum specifications, the DRB
scan tool along with the Periphal Expansion Port
(PEP) Module and 0±15 psi transducer must be used.
(10) Verify transfer pump pressure is OK before
performing restriction test.
(11) Locate and disconnect fuel supply line quick-
connect fitting at left-rear of engine (Fig. 56). After
disconnecting line, plastic clip will remain attached
to metal fuel line at engine. Carefully remove clip
from metal line. Snap same clip into fuel supply
hose.
(12) Install Special Rubber Adapter Hose Tool
6631 (3/8º) into ends of disconnected fuel supply line.(13) Install transducer from PEP module to brass
ªTº fitting on tool 6631.
(14) Hook up DRB scan tool to transducer.
WARNING: DO NOT STAND IN LINE WITH THE
COOLING FAN FOR THE FOLLOWING STEPS.
(15) Start engine and record vacuum reading with
engine speed at high-idle (high-idle means engine
speed is at 100 percent throttle and no load). The
fuel restriction testMUSTbe done with engine speed
at high-idle.
(16) If vacuum reading islessthan 6 in/hg. (0±152
mm hg.), test is OK. If vacuum reading ishigher
than 6 in/hg. (152 mm hg.), restriction exists in fuel
supply line or in fuel tank module. Check fuel supply
line for damage, dents or kinking. If OK, remove
module and check module and lines for blockage.
Also check fuel pump inlet filter at bottom of module
for obstructions.
Testing For Air Leaks in Fuel Supply Side:
(17) A 3±foot section of 3/8º I.D. clear tubing is
required for this test.
(18) Using a tire core valve removal tool, carefully
remove core valve from inlet fitting test port.
(19) Attach and clamp the 3/8ºclear hose to fitting
nipple.
(20) Place other end of hose into a large clear con-
tainer. Allow hose to loop as high as possibleabove
test port.
(21) The fuel transfer pump can be put into a 25
second run (test) mode if key is quickly turned to
crank position and released back to run position
without starting engine.
To prevent engine from starting in this test, first
remove fuel system relay (fuel injection pump relay).
Relay is located in Power Distribution Center (PDC).
Refer to label under PDC cover for relay location.
Because fuel pump relay was removed, a Diagnos-
tic Trouble Code (DTC) may have been set. After test-
ing is completed, and relay has been installed, use
DRB scan tool to remove DTC.
(22) Allow air to purge from empty hose before
examining for air bubbles. Air bubbles should not be
present.
(23) If bubbles are present, check for leaks in sup-
ply line to fuel tank.
(24) If supply line is not leaking, remove fuel tank
module and remove filter at bottom of module (filter
snaps to module). Check for leaks between supply
nipple at top of module, and filter opening at bottom
of module. Replace module if necessary.
(25) After performing test, install core back into
test fitting. Before installing protective cap, be sure
fitting is not leaking.
Fig. 56 Fuel Return and Supply Line Quick-Connect
Locations
1 - FUEL RETURN LINE
2 - QUICK-CONNECT FITTINGS
3 - FUEL SUPPLY LINE
14 - 82 FUEL DELIVERY - DIESELBR/BE
FUEL TRANSFER PUMP (Continued)

(1) Clean area around overflow valve and fuel
return line at injection pump before removal.
(2) Remove valve from pump and banjo fitting.
(3) Discard old sealing gaskets.
INSTALLATION
The overflow valve (pressure relief valve) is located
at the outside of fuel injection pump (Fig. 60). It con-
nects the fuel return line (banjo fitting) to the pump.
The valve has no internal serviceable parts and must
be replaced as an assembly. Two sealing gaskets are
used. One gasket is located between pump and banjo
fitting. The other is located between the banjo fitting
and end of valve.
(1) Install new sealing gaskets to valve.
(2) Install valve through banjo fitting and into
pump.
(3) Tighten to 30 N´m (24 ft. lbs.) torque.
WATER IN FUEL SENSOR
DESCRIPTION
The WIF sensor is located on the side of the fuel
filter/water separator canister (Fig. 61).
OPERATION
The sensor sends an input to the Engine Control
Module (ECM) when it senses water in the fuel filter/
water separator. As the water level in the filter/sep-
arator increases, the resistance across the WIF
sensor decreases. This decrease in resistance is sent
as a signal to the ECM and compared to a high
water standard value. Once the value reaches 30 to
40 kilohms, the ECM will activate the water-in-fuel
warning lamp through CCD bus circuits. This all
takes place when the ignition key is initially put in
the ON position. The ECM continues to monitor the
input at the end of the intake manifold air heater
post-heat cycle.
REMOVAL
The Water-In-Fuel (WIF) sensor is located at the
side of fuel filter/water separator canister. Refer to
Fuel Filter/Water Separator Removal/Installation for
WIF sensor removal/installation procedures.
Fig. 60 Overflow Valve Location
1 - FUEL SUPPLY LINE
2 - FUEL RETURN LINE
3 - BANJO BOLT (TEST PORT FITTING)
4 - OVERFLOW VALVE
5 - BANJO FITTING
Fig. 61 Water-in-Fuel Sensor Location
1 - WATER-IN-FUEL (WIF) SENSOR
2 - FUEL FILTER/WATER SEPARATOR
3 - WIF SENSOR CONNECTOR
BR/BEFUEL DELIVERY - DIESEL 14 - 85
OVERFLOW VALVE (Continued)

Fig. 1 Fuel System Components - Diesel
1 - ENGINE COOLANT TEMPERATURE (ECT) SENSOR 14 - FUEL SUPPLY LINE (LOW-PRESSURE, TO ENGINE)
2 - THROTTLE LEVER BELLCRANK AND APPS (ACCELERATOR
PEDAL POSITION SENSOR)15 - FUEL TRANSFER (LIFT) PUMP
3 - INTAKE MANIFOLD AIR HEATER/ELEMENTS 16 - OIL PRESSURE SENSOR
4 - HIGH-PRESSURE FUEL LINES 17 - FUEL FILTER/WATER SEPARATOR
5 - FUEL HEATER 18 - DRAIN TUBE
6 - FUEL PRESSURE TEST PORT 19 - WATER-IN-FUEL (WIF) SENSOR
7 - MAP (BOOST) SENSOR 20 - ENGINE CONTROL MODULE (ECM)
8 - FUEL INJECTORS 21 - FUEL PRESSURE TEST PORT
9 - FUEL INJECTOR CONNECTOR 22 - CAMSHAFT POSITION SENSOR (CMP)
10 - INTAKE AIR TEMPERATURE (IAT) SENSOR 23 - OVERFLOW VALVE
11 - FUEL DRAIN MANIFOLD 24 - FUEL INJECTION PUMP
12 - DRAIN VALVE 25 - FUEL HEATER TEMPERATURE SENSOR (THERMOSTAT)
13 - FUEL RETURN LINE (TO FUEL TANK)
14 - 88 FUEL INJECTION - DIESELBR/BE
FUEL INJECTION - DIESEL (Continued)