heater DODGE RAM 2003 Service Repair Manual

(2) Insert MopartGEN II Silicone Rubber Adhe-
sive Sealant, or equivalent, into the four corner joints
an excessive amount of sealant is not required to
ensure a leak proof seal. However, an excessive
amount of sealant may reduce the effectiveness of
the flange gasket. The sealant should be approxi-
mately 5 mm (0.2 in.) in diameter. (Fig. 70).
(3) Position the cross-over gaskets and press firmly
onto the block (Fig. 70).BE SURE THE BLOCK IS
OIL FREE..
(4) The lower intake manifold MUST be installed
within 3 minutes of sealant application. Carefully
lower intake manifold into position on the cylinder
block and heads. After intake manifold is in place,
inspect to make sure seals and gaskets are in place.
Finger start all the lower intake bolts.
(5) Tighten the lower intake manifold bolts in
sequence to 54 N´m (40 ft. lbs.) torque (Fig. 69).
Recheck all bolts are tightened to 54 N´m (40 ft. lbs.)
torque.
(6) Using a new gasket, position the upper intake
manifold onto the lower intake manifold.
(7) Finger start all bolts, alternate one side to the
other.
(8) Tighten upper intake manifold bolts in
sequence to 22 N´m (16 ft. lbs.) torque (Fig. 68).
(9) Using a new gasket, install the throttle body
onto the upper intake manifold. Tighten the bolts to
23 N´m (200 in. lbs.) torque.
(10) Install closed crankcase ventilation and evap-
oration control systems.
(11) Connect the heater hoses and bypass hose.
(12) Connect the vacuum lines.
(13) Install the coil assemblies and the ignition
wires.
(14) Connect the accelerator linkage and if so
equipped, the speed control and transmission kick-
down cables.(15) Install the fuel lines (Refer to 14 - FUEL SYS-
TEM/FUEL DELIVERY/QUICK CONNECT FIT-
TING - STANDARD PROCEDURE).
(16) Using a new gasket, install the air cleaner
housing. Tighten the nuts to 11 N´m (96 in. lbs.)
torque. Install the air cleaner filter and cover.
(17) Install the A/C compressor (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING/A/C
COMPRESSOR - INSTALLATION). Position the com-
pressor brace and install the bolts. Tighten the brace
bolts to 41 N´m (30 ft. lbs.) torque.
(18) Install the generator (Refer to 8 - ELECTRI-
CAL/CHARGING/GENERATOR - INSTALLATION).
Position the generator brace and install the bolts.
Tighten the brace bolts to 41 N´m (30 ft. lbs.) torque.
(19) Install the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(20) Fill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(21) Connect the negative cable to the battery.
(22) Start engine check for leaks.
EXHAUST MANIFOLD
DESCRIPTION
Engine exhaust manifolds (Fig. 72) are made of
high molybdenum ductile cast iron. A special ribbed
design helps control permanent dimensional changes
during heat cycles.
OPERATION
The exhaust manifolds collect the engine exhaust
exiting the combustion chambers, then channels the
exhaust gases to the exhaust pipes attached to the
manifolds.
Fig. 71 Intake Manifold Flange
1 - LOCATOR DOWELS
2 - INTAKE MANIFOLD GASKETS
3 - LOCATOR DOWELS
Fig. 72 Exhaust ManifoldÐ8.0L Engine
1 - EXHAUST MANIFOLD
DRENGINE 8.0L 9 - 403
INTAKE MANIFOLD (Continued)

SPECIFICATIONS - TORQUE
DESCRIPTION N´m Ft. In.
Lbs. Lbs.
Adjusting StrapÐBolt 23 Ð 200
Air Heater Power SupplyÐ
Nuts14 Ð 124
Air Inlet HousingÐBolts 24 18 Ð
Cab Heater Supply/Return
LineÐNuts24 18 Ð
Exhaust ClampÐNuts 48 35 Ð
Exhaust Manifold to Cylinder
HeadÐBolts
(Diesel Engine) 43 32 Ð
Exhaust Manifold to Cylinder
HeadÐBolts
(5.9L) 31 23 Ð
Exhaust Manifold to Cylinder
HeadÐBolts
(8.0L) 22 Ð 195
Exhaust Pipe to ManifoldÐ
Bolts31 23 Ð
Generator MountingÐBolts 41 30 Ð
Charge Air Cooler
MountingÐBolts2Ð17
Charge Air Cooler DuctÐ
Nuts11 Ð 9 5
Heat ShieldÐNuts and Bolts 11 Ð 95
Turbocharger flange studs 24 18 Ð
Turbocharger MountingÐ
Nuts43 32 Ð
Turbocharger Oil Drain
TubeÐBolts24 18 Ð
Turbocharger Oil Supply
LineÐFitting24 18 Ð
Turbocharger V-Band
ClampÐNut9Ð75
Turbocharger Oil Supply
fitting (at Turbocharger)36 27 Ð
Turbocharger Oil Supply
fitting (at lube filter head)24 18 Ð
Turbocharger Drain Hose
Clamps8Ð71
SPECIAL TOOLS
CATALYTIC CONVERTER
DESCRIPTION - CATALYTIC CONVERTER
WARNING: THE NORMAL OPERATING TEMPERA-
TURE OF THE EXHAUST SYSTEM IS VERY HIGH.
THEREFORE, NEVER WORK AROUND OR ATTEMPT
TO SERVICE ANY PART OF THE EXHAUST SYSTEM
UNTIL IT IS COOLED. SPECIAL CARE SHOULD BE
TAKEN WHEN WORKING NEAR THE CATALYTIC
CONVERTER. THE TEMPERATURE OF THE CON-
VERTER RISES TO A HIGH LEVEL AFTER A SHORT
PERIOD OF ENGINE OPERATION TIME.
CAUTION: DO NOT remove spark plug wires from
plugs or by any other means short out cylinders.
Failure of the catalytic converter can occur due to a
temperature increase caused by unburned fuel
passing through the converter.
The stainless steel catalytic converter body is
designed to last the life of the vehicle. Excessive heat
can result in bulging or other distortion, but exces-
sive heat will not be the fault of the converter. If
unburned fuel enters the converter, overheating may
occur. If a converter is heat-damaged, correct the
cause of the damage at the same time the converter
is replaced. Also, inspect all other components of the
exhaust system for heat damage.
Unleaded gasoline must be used to avoid con-
taminating the catalyst core.
50 State emission vehicles incorporate two mini
catalytic converters located after the exhaust mani-
folds and before the inline catalytic converter.
OPERATION
The catalytic converter captures and burns any
unburned fuel mixture exiting the combustion cham-
bers during the exhaust stroke of the engine. This
process aids in reducing emissions output.
TURBOCHARGER TESTER 9022
11 - 4 EXHAUST SYSTEMDR
EXHAUST SYSTEM (Continued)

(3)Pre-lube the turbocharger.Pour 50 to 60 cc
(2 to 3 oz.) clean engine oil in the oil supply line fit-
ting. Carefully rotate the turbocharger impeller by
hand to distribute the oil thoroughly.
(4) Install and tighten the oil supply line to 24
N´m (18 ft. lbs.) torque.
(5) Position the charge air cooler inlet pipe to the
turbocharger. With the clamp in position, tighten the
clamp nut to 11 N´m (95 in. lbs.) torque.
(6) Position the air inlet hose to the turbocharger
(Fig. 18). Tighten the clamp to 11 N´m (95 in. lbs.)
torque.
(7) Raise vehicle on hoist.
(8) Connect the exhaust pipe to the turbocharger
and tighten the bolts to 34 N´m (25 ft. lbs.) torque.
(9) Lower the vehicle.
(10) Connect the battery negative cables.
(11) Start the engine to check for leaks.
CHARGE AIR COOLER AND
PLUMBING
DESCRIPTION
The charge air system (Fig. 23) consists of the
charge air cooler piping, charge air cooler and intake
air grid heater.
The charge air cooler is a heat exchanger that uses
air flow from vehicle motion to dissipate heat from
the intake air. As the turbocharger increases air
pressure, the air temperature increases. Lowering
the intake air temperature increases engine effi-
ciency and power.
OPERATION
Intake air is drawn through the air cleaner and
into the turbocharger compressor housing. Pressur-ized air from the turbocharger then flows forward
through the charge air cooler located in front of the
radiator. From the charge air cooler the air flows
back into the intake manifold.
DIAGNOSIS AND TESTING - CHARGE AIR
COOLER SYSTEM - LEAKS
Low turbocharger boost pressure and low engine
performance can be caused by leaks in the charge air
cooler or it's plumbing. Fuel staining on the exhaust
manifold can also be an indication that there are
leaks in the air system.The following procedure out-
lines how to check for leaks in the charge air cooler
system.
(1) Loosen clamp and remove air inlet hose from
turbocharger.
(2)
Insert Special Tool 9022 Adapter into the turbo-
charger inlet. Tighten tool clamp to 8 N´m (72 in. lbs.).
CAUTION: Do not apply more than 138 kPa (20 psi)
air pressure to the charge air cooler system, sever
damage to the charge air cooler system may occur.
(3) Connect a regulated air supply to air fitting on
Special Tool 9022 Adapter. Set air pressure to a Max-
imum of 138 kPa (20 psi).
(4) Using soapy water check the rubber sleeves,
charge air cooler and intake manifold for leaks.
REMOVAL
WARNING: IF THE ENGINE WAS JUST TURNED
OFF, THE AIR INTAKE SYSTEM TUBES MAY BE
HOT.
Fig. 22 Measure Turbocharger Bearing Radial
Clearance
1 - FEELER GAUGE
Fig. 23 Intake Air Circulation
1 - CHARGE AIR COOLER
2 - AIRFILTER
3 - TURBOCHARGER
DREXHAUST SYSTEM 11 - 15
TURBOCHARGER (Continued)

OXYGEN SENSOR
DESCRIPTION
The Oxygen Sensors (O2S) are attached to, and
protrude into the vehicle exhaust system. Depending
on the engine or emission package, the vehicle may
use a total of either 2 or 4 sensors.
Federal Emission Packages :Two sensors are
used: upstream (referred to as 1/1) and downstream
(referred to as 1/2). With this emission package, the
upstream sensor (1/1) is located just before the main
catalytic convertor. The downstream sensor (1/2) is
located just after the main catalytic convertor.
California Emission Packages:On this emis-
sions package, 4 sensors are used: 2 upstream
(referred to as 1/1 and 2/1) and 2 downstream
(referred to as 1/2 and 2/2). With this emission pack-
age, the right upstream sensor (2/1) is located in the
right exhaust downpipe just before the mini-catalytic
convertor. The left upstream sensor (1/1) is located in
the left exhaust downpipe just before the mini-cata-
lytic convertor. The right downstream sensor (2/2) is
located in the right exhaust downpipe just after the
mini-catalytic convertor, and before the main cata-
lytic convertor. The left downstream sensor (1/2) is
located in the left exhaust downpipe just after the
mini-catalytic convertor, and before the main cata-
lytic convertor.
OPERATION
An O2 sensor is a galvanic battery that provides
the PCM with a voltage signal (0-1 volt) inversely
proportional to the amount of oxygen in the exhaust.
In other words, if the oxygen content is low, the volt-
age output is high; if the oxygen content is high the
output voltage is low. The PCM uses this information
to adjust injector pulse-width to achieve the
14.7±to±1 air/fuel ratio necessary for proper engine
operation and to control emissions.
The O2 sensor must have a source of oxygen from
outside of the exhaust stream for comparison. Cur-
rent O2 sensors receive their fresh oxygen (outside
air) supply through the O2 sensor case housing.
Four wires (circuits) are used on each O2 sensor: a
12±volt feed circuit for the sensor heating element; a
ground circuit for the heater element; a low-noise
sensor return circuit to the PCM, and an input cir-
cuit from the sensor back to the PCM to detect sen-
sor operation.
Oxygen Sensor Heater Relay - 5.9L/8.0L:If 4
oxygen sensors are used, a separate heater relay is
used to supply voltage to the sensors heating ele-
ments for only the 1/2 and 2/2 downstream sensors.
Voltage for the other 2 sensor heating elements is
supplied directly from the Powertrain Control Mod-ule (PCM) through a Pulse Width Module (PWM)
method.
Pulse Width Module (PWM) - 5.9L/8.0L:Voltage
to the O2 sensor heating elements is supplied
directly from the Powertrain Control Module (PCM)
through two separate Pulse Width Module (PWM)
low side drivers. PWM is used on both the upstream
and downstream O2 sensors if equipped with a Fed-
eral Emissions Package, and only on the 2 upstream
sensors (1/1 and 2/1) if equipped with a California
Emissions Package. The main objective for a PWM
driver is to avoid overheating of the O2 sensor heater
element. With exhaust temperatures increasing with
time and engine speed, it's not required to have a
full-voltage duty-cycle on the O2 heater elements.
To avoid the large simultaneous current surge
needed to operate all 4 sensors, power is delayed to
the 2 downstream heater elements by the PCM for
approximately 2 seconds.
Oxygen Sensor Heater Elements:
The O2 sensor uses a Positive Thermal Co-efficient
(PTC) heater element. As temperature increases,
resistance increases. At ambient temperatures
around 70ÉF, the resistance of the heating element is
approximately 13 ohms. As the sensor's temperature
increases, resistance in the heater element increases.
This allows the heater to maintain the optimum
operating temperature of approximately 930É-1100ÉF
(500É-600É C). Although the sensors operate the
same, there are physical differences, due to the envi-
ronment that they operate in, that keep them from
being interchangeable.
Maintaining correct sensor temperature at all
times allows the system to enter into closed loop
operation sooner. Also, it allows the system to remain
in closed loop operation during periods of extended
idle.
In Closed Loop operation, the PCM monitors cer-
tain O2 sensor input(s) along with other inputs, and
adjusts the injector pulse width accordingly. During
Open Loop operation, the PCM ignores the O2 sensor
input. The PCM adjusts injector pulse width based
on preprogrammed (fixed) values and inputs from
other sensors.
Upstream Sensor - Federal Emissions Pack-
age :The upstream sensor (1/1) provides an input
voltage to the PCM. The input tells the PCM the oxy-
gen content of the exhaust gas. The PCM uses this
information to fine tune fuel delivery to maintain the
correct oxygen content at the downstream oxygen
sensor. The PCM will change the air/fuel ratio until
the upstream sensor inputs a voltage that the PCM
has determined will make the downstream sensor
output (oxygen content) correct.
The upstream oxygen sensor also provides an input
to determine catalytic convertor efficiency.
DRFUEL INJECTION - GAS 14 - 43

FUEL DELIVERY - DIESEL
TABLE OF CONTENTS
page page
FUEL DELIVERY - DIESEL
DESCRIPTION - DIESEL FUEL SYSTEM.....57
STANDARD PROCEDURE
STANDARD PROCEDURES - WATER
DRAINING AT FUEL FILTER..............57
STANDARD PROCEDURES - CLEANING
FUEL SYSTEM PARTS.................58
STANDARD PROCEDURE - FUEL SYSTEM
PRIMING............................59
SPECIFICATIONS
FUEL SYSTEM PRESSURE - DIESEL......60
FUEL INJECTOR FIRING ORDER - DIESEL . 60
SPECIAL TOOLS
DIESEL FUEL SYSTEM.................60
FUEL FILTER / WATER SEPARATOR
DESCRIPTION.........................61
OPERATION...........................61
REMOVAL.............................61
INSTALLATION.........................62
FUEL HEATER
DESCRIPTION.........................63
OPERATION...........................63
DIAGNOSIS AND TESTING - FUEL HEATER . . . 63
REMOVAL
REMOVAL/INSTALLATION...............64
FUEL HEATER RELAY
DESCRIPTION.........................64
OPERATION...........................64
REMOVAL.............................64
INSTALLATION.........................64
FUEL INJECTION PUMP
DESCRIPTION.........................64
OPERATION...........................64
DIAGNOSIS AND TESTING - FUEL INJECTION
PUMP TIMING........................65
REMOVAL.............................65
INSTALLATION.........................67
FUEL LEVEL SENDING UNIT / SENSOR
DESCRIPTION.........................68
OPERATION...........................68
REMOVAL
REMOVAL/INSTALLATION...............68FUEL LINES
DESCRIPTION.........................69
OPERATION...........................69
DIAGNOSIS AND TESTING - HIGH-
PRESSURE FUEL LINE LEAKS...........69
REMOVAL.............................69
INSTALLATION.........................71
FUEL PRESSURE SENSOR
DESCRIPTION.........................72
OPERATION...........................72
REMOVAL.............................72
INSTALLATION.........................72
FUEL PRESSURE LIMITING VALVE
DESCRIPTION.........................72
OPERATION...........................72
REMOVAL.............................72
INSTALLATION.........................73
FUEL TANK
DESCRIPTION - DIESEL..................73
REMOVAL - DIESEL.....................73
INSTALLATION - DIESEL.................74
FUEL TANK MODULE
DESCRIPTION.........................75
OPERATION...........................75
REMOVAL.............................75
INSTALLATION.........................75
FUEL TRANSFER PUMP
DESCRIPTION.........................75
OPERATION...........................76
REMOVAL.............................76
INSTALLATION.........................76
CASCADE OVERFLOW VALVE
DESCRIPTION.........................77
OPERATION...........................77
REMOVAL
REMOVAL/INSTALLATION...............77
WATER IN FUEL SENSOR
DESCRIPTION.........................77
OPERATION...........................78
REMOVAL.............................78
FUEL DRAIN CIRCUIT
OPERATION...........................78
14 - 56 FUEL DELIVERY - DIESELDR

FUEL DELIVERY - DIESEL
DESCRIPTION - DIESEL FUEL SYSTEM
The fuel system used on the Cummins engine is an
electronically controlled, Bosch HPCR (High-Pressure
Common Rail) system. The HPCR system consists of
five main components:
²Electric Fuel Transfer (lift) Pump
²Fuel Pump/Gear Pump (attached to fuel injec-
tion pump)
²High-Pressure Fuel Injection Pump
²Fuel Injection Rail
²Fuel Injectors
Also to be considered as part of the overall fuel
system are:
²Accelerator Pedal
²Air Cleaner Housing/Element
²Fuel Drain Manifold (passage)
²Fuel Drain Valve (at filter)
²Fuel Filter/Water Separator
²Fuel Heater
²Fuel Heater Relay
²Fuel Level (gauge) Sending Unit
²Fuel Tank
²Fuel Tank Module (containing fuel gauge send-
ing unit and separate fuel filter located at bottom of
tank module)
²Fuel Tank Filler/Vent Tube Assembly
²Fuel Tank Filler Tube Cap
²Fuel Tubes/Lines/Hoses
²High-Pressure Fuel Injector Lines
²In-Tank Fuel Filter (at bottom of fuel tank mod-
ule)
²Low-Pressure Fuel Supply Lines
²Low-Pressure Fuel Return Line
²Overflow Valve
²Quick-Connect Fuel Line Fittings
²Throttle Cable
²Water Draining (maintenance)
²Water-In-Fuel (WIF) Sensor
The fuel injection pump supplies high pressure to
the fuel rail independent of engine speed. This high
pressure is then accumulated in the fuel rail. High
pressure fuel is constantly supplied to the injectors
by the fuel rail. The Engine Control Module (ECM)
controls the fueling and timing of the engine by actu-
ating the injectors.Fuel enters the system from the electric fuel trans-
fer (lift) pump, which is attached to the fuel filter
assembly. Fuel is forced through the fuel filter ele-
ment and then enters the Fuel Pump/Gear Pump,
which is attached to the rear of the fuel injection
pump. The Fuel Pump/Gear Pump is a low-pressure
pump and produce pressures ranging from 551.5 kpa
(80 psi) to 1241 kpa (180) psi. Fuel then enters the
fuel injection pump. Low pressure fuel is then sup-
plied to the FCA (Fuel Control Actuator).
The FCA is an electronically controlled solenoid
valve. The ECM controls the amount of fuel that
enters the high-pressure pumping chambers by open-
ing and closing the FCA based on a demanded fuel
pressure. The FPS (Fuel Pressure Sensor) on the fuel
rail provides the actual fuel pressure. When the
actuator is opened, the maximum amount of fuel is
being supplied to the fuel injection pump. Any fuel
that does not enter the injection pump is directed to
the overflow valve. The overflow valve regulates how
much excess fuel is used for lubrication of the pump
and how much is returned to the tank through the
drain manifold.
Fuel entering the injection pump is pressurized to
between 300 - 1600 bar by three radial pumping
chambers. The pressurized fuel is then supplied to
the fuel rail.
Some fuel system components are shown in.
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.
Certain fuel system components can be found in
(Fig. 1), or (Fig. 2).
STANDARD PROCEDURE
STANDARD PROCEDURES - WATER DRAINING
AT FUEL FILTER
Refer to Fuel Filter/Water Separator removal/in-
stallation for procedures.
DRFUEL DELIVERY - DIESEL 14 - 57

STANDARD PROCEDURES - CLEANING FUEL
SYSTEM PARTS
CAUTION: Cleanliness cannot be overemphasized
when handling or replacing diesel fuel system com-
ponents. This especially includes the fuel injectors,
high-pressure fuel lines and fuel injection pump.
Very tight tolerances are used with these parts. Dirt
contamination could cause rapid part wear and pos-
sible plugging of fuel injector nozzle tip holes. This
in turn could lead to possible engine misfire.Always wash/clean any fuel system component
thoroughly before disassembly and then air dry.
Cap or cover any open part after disassembly.
Before assembly, examine each part for dirt, grease
or other contaminants and clean if necessary. When
installing new parts, lubricate them with clean
engine oil or clean diesel fuel only.
Fig. 1 DIESEL FUEL SYSTEM COMPONENTS
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 RETURN LINE CONNECTION (TO FUEL TANK)
3 - INTAKE MANIFOLD AIR HEATER/ELEMENTS 16 - FUEL DRAIN TUBE
4 - FUEL PRESSURE SENSOR 17 - OIL PRESSURE SENSOR
5 - FUEL LIMITING VALVE 18 - ENGINE CONTROL MODULE (ECM)
6 - HIGH-PRESSURE FUEL LINES 19 - FUEL INJECTION PUMP
7 - FUEL HEATER 20 - CRANKSHAFT POSITION (ENGINE SPEED) SENSOR
8 - HIGH-PRESSURE FUEL INJECTOR RAIL 21 - CAMSHAFT POSITION SENSOR (CMP)
9 - FUEL HEATER TEMPERATURE SENSOR (THERMOSTAT) 22 - FUEL CONTROL ACTUATOR (FCA)
10 - FUEL FILTER/WATER SEPARATOR 23 - CASCADE OVERFLOW VALVE
11 - FUEL TRANSFER (LIFT) PUMP
12 - FUEL DRAIN MANIFOLD
13 - DRAIN VALVE
14 - 58 FUEL DELIVERY - DIESELDR
FUEL DELIVERY - DIESEL (Continued)

FUEL FILTER / WATER
SEPARATOR
DESCRIPTION
The fuel filter/water separator assembly is located
on left side of engine above starter motor. The assem-
bly also includes the fuel heater and Water-In-Fuel
(WIF) sensor, and fuel transfer pump.
OPERATION
The fuel filter/water separator protects the fuel
injection pump by removing water and contaminants
from the fuel. The construction of the filter/separator
allows fuel to pass through it, but helps prevent
moisture (water) from doing so. Moisture collects at
the bottom of the canister.
Refer to the maintenance schedules for the recom-
mended fuel filter replacement intervals.
For draining of water from canister, refer to Fuel
Filter/Water Separator Removal/Installation section.A Water-In-Fuel (WIF) sensor is attached to side of
canister. Refer to Water-In-Fuel Sensor Description/
Operation.
The fuel heater is installed into the top of the fil-
ter/separator housing. Refer to Fuel Heater Descrip-
tion/Operation.
REMOVAL
Refer to maintenance schedules in this manual for
recommended fuel filter replacement intervals.
Draining water from fuel filter/water separa-
tor housing:
The housing drain valve (Fig. 3) or (Fig. 4) serves
two purposes. One is topartiallydrain filter hous-
ing of excess water. The other is tocompletelydrain
housing for fuel filter, drain valve, heater element, ,
water-in-fuel sensor replacement or transfer pump
replacement.
The filter housing should be partially drained
whenever water-in-fuel warning lamp remains illumi-
nated. (Note that lamp will be illuminated for
approximately two seconds when ignition key is ini-
tially placed in ON position for a bulb check).
(1) A drain hose (Fig. 3) or (Fig. 4) is located at
bottom of drain valve. Place drain pan under drain.
(2)With engine not running,rotate drain valve
handle rearward to OPEN (DRAIN) position. Hold
drain valve open until all water and contaminants
have been removed and clean fuel exits.
(3) If drain valve, fuel heater element or Water-In-
Fuel (WIF) sensor is being replaced, drain housing
completely. Dispose of mixture in drain pan according
to applicable regulations.
(4) After draining operation, push valve handle
forward to CLOSE position.
(5)Fuel Filter Replacement:The fuel filter is
located inside of the fuel filter housing.
(a) Clean all debris from around canister.
(b) Remove filter lid (Fig. 5) using a socket.
Attach socket to large hex on top of lid (Fig. 5).
Rotate counter-clockwise for removal. Remove
o-ring.
(c) Remove filter element by twisting element
sideways from filter lid.
(6)Water-In-Fuel (WIF) Sensor Replacement:
The WIF sensor is located on the side of the fuel fil-
ter housing (Fig. 3) or (Fig. 4).
(a) Disconnect electrical connector at sensor.
(b) Clean area around sensor.
(c) Remove sensor by rotating counter-clockwise.
(d) Check condition of sensor o-ring. Replace if
damaged.
(7)Fuel Heater Element Replacement:The
heater element is located in the fuel filter housing
(Fig. 3) or (Fig. 4).
(a) Remove fuel filter. See previous steps.
FUEL INJECTOR TUBE (CONNECTOR) REMOVER -
#9015
SPANNER WRENCH (FUEL TANK MODULE
REMOVAL/INSTALLATION) - #6856
ENGINE ROTATING (BARRING) TOOL - #7471B
(ALSO PART OF KIT #6860)
DRFUEL DELIVERY - DIESEL 14 - 61
FUEL DELIVERY - DIESEL (Continued)

(b) Disconnect electrical connector.
(c) Remove two T-15 Torx head mounting screws
from fuel heater element.
(d) Remove fuel filter cover and filter element.
(e) Remove fuel heater.
(8)Drain Valve Replacement:The drain valve
assembly is located on the side of the fuel filter hous-
ing (Fig. 3) or (Fig. 4).
(a) Disconnect drain hose from the fuel drain
valve.
(b) Remove 4 drain valve mounting screws (T-15
Torx head).
(c) Remove drain valve from filter housing.
INSTALLATION
Refer to maintenance schedules for recommended
fuel filter replacement intervals.
(1) Thoroughly clean inside of filter housing, filter
cap and all related components.
(2)Fuel Filter:
(a)The engine has a self-priming low-pres-
sure fuel system. Refer to Standard Proce-
dures-Fuel System Priming.
(b) Install new o-ring to canister lid and lubri-
cate o-ring with 30W oil.
Fig. 3 FILTER HOUSING (EARLY)
1 - FILTER HOUSING
2 - FUEL HEATER AND THERMOSTAT
3 - FUEL HEATER MOUNTING SCREWS
4 - FUEL HEATER ELEC. CONNECTOR
5 - DRAIN VALVE
6 - DRAIN VALVE MOUNTING SCREWS
7 - DRAIN HOSE
8 - WIF SENSOR
9 - WIF SENSOR ELEC. CONNECTOR
Fig. 4 FILTER HOUSING (LATE)
1 - FILTER HOUSING
2 - FUEL HEATER AND THERMOSTAT
3 - FUEL HEATER MOUNTING SCREWS
4 - FUEL HEATER ELEC. CONNECTOR
5 - WIF SENSOR
6 - WIF SENSOR ELEC. CONNECTOR
7 - DRAIN HOSE
8 - DRAIN VALVE MOUNTING SCREWS
9 - DRAIN VALVE
Fig. 5 FILTER COVER (LID)
1 - FILTER COVER
2 - ATTACH SOCKET HERE
14 - 62 FUEL DELIVERY - DIESELDR
FUEL FILTER / WATER SEPARATOR (Continued)

(c) Position new element to canister lid. Place
this assembly into canister by rotating clockwise.
(d) Tighten cap to 34 N´m (25 ft. lbs.) torque. Do
not overtighten 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 4.5 N´m (39 in. lbs.) torque.
(e) Connect electrical connector to WIF sensor.
(4)Fuel Heater Element:
(a) Install fuel heater into fuel filter housing.
(b) Install fuel heater thermostat into fuel filter
housing.
(c) Install fuel heater mounting screws and
tighten to 1-1.5 N´m torque.
(d) Connect electrical connector to fuel heater
thermostat.
(e) Install new filter cover O-ring onto fuel filter
housing cover and lubricate with 30W oil.
(f) Tighten fuel filter housing cover (lid) to 34
N´m (25 ft. lbs.).
(5)Drain Valve:
(a) Install 2 new o-rings to valve and filter hous-
ing.
(b) Lubricate with silicon grease.
(c) Install fuel drain valve.
(d) Install 4 mounting screws and tighten to
1±1.5 N´m (8±13 in. lbs.) torque.
(e) Connect drain hose to drain valve.
(6) Start engine and check for leaks.
FUEL HEATER
DESCRIPTION
The fuel heater assembly is located on the side of
the fuel filter housing (Fig. 3) or (Fig. 4).
The heater/element assembly is equipped with a
temperature sensor (thermostat) that senses fuel
temperature. This sensor is attached to the fuel heat-
er/element assembly.
OPERATION
The fuel heater is used to prevent diesel fuel from
waxing during cold weather operation.
When the temperature is below 45  8 degrees F,
the temperature sensor allows current to flow to the
heater element warming the fuel. When the temper-
ature is above 75  8 degrees F, the sensor stops cur-
rent flow to the heater element.
Battery voltage to operate the fuel heater element
is supplied from the ignition switch and through the
fuel heater relay. Also refer to Fuel Heater Relay.The fuel heater element and fuel heater relay
are not computer controlled.
The heater element operates on 12 volts, 300 watts
at 0 degrees F.
DIAGNOSIS AND TESTING - FUEL HEATER
The fuel heater is used to prevent diesel fuel from
waxing during cold weather operation.
NOTE: The fuel heater element, fuel heater relay
and fuel heater temperature sensor are not con-
trolled by the Engine Control Module (ECM), or the
Powertrain Control Module (PCM).
A malfunctioning fuel heater can cause a wax
build-up in the fuel filter/water separator. Wax
build-up in the filter/separator can cause engine
starting problems and prevent the engine from rev-
ving up. It can also cause blue or white fog-like
exhaust. If the heater is not operating in cold tem-
peratures, the engine may not operate due to fuel
waxing.
The fuel heater assembly is located on the side of
fuel filter housing.
The heater assembly is equipped with a built-in
fuel temperature sensor (thermostat) that senses fuel
temperature. When fuel temperature drops below 45
degrees   8 degrees F, the sensor allows current to
flow to built-in heater element to warm fuel. When
fuel temperature rises above 75 degrees   8 degrees
F, the sensor stops current flow to heater element
(circuit is open).
Voltage to operate fuel heater element is supplied
from ignition switch, through fuel heater relay (also
refer to Fuel Heater Relay), to fuel temperature sen-
sor and on to fuel heater element.
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 fuel
heater. The resistance value of heater element is less
than 1 ohm (cold) and up to 1000 ohms warm.
TESTING
(1) Disconnect electrical connector from thermostat
(Fig. 3) or (Fig. 4).
Ambient temperature must be below circuit close
temperature, If necessary, induce this ambient tem-
perature by placing ice packs on thermostat to pro-
duce an effective ambient temperature below circuit
close temperature. For first check of thermostat you
can hear click of thermostat when circuit closes.
Measure resistance across two pins. Operating
range is 0.3 Ð 0.45 Ohms.
(2) If resistance is out of range, remove thermostat
and check resistance across terminal connections of
DRFUEL DELIVERY - DIESEL 14 - 63
FUEL FILTER / WATER SEPARATOR (Continued)