Heating DODGE RAM 2001 Service Manual PDF

(10)Verify valve lash adjustment (Refer to 9 -
ENGINE/CYLINDER HEAD/INTAKE/EXHAUST
VALVES & SEATS - STANDARD PROCEDURE).
(11)
Install the cylinder head cover and reusable gas-
ket (Fig. 85) (Refer to 9 - ENGINE/CYLINDER HEAD/
CYLINDER HEAD COVER(S) - INSTALLATION).
(12) Install gear housing cover (Refer to 9 -
ENGINE/VALVE TIMING/GEAR HOUSING COVER
- INSTALLATION).
(13) Install the crankshaft damper (Fig. 83) (Refer
to 9 - ENGINE/ENGINE BLOCK/VIBRATION
DAMPER - INSTALLATION).
(14) Install the fan support/hub assembly (Fig. 82)
and tighten bolts to 24 N´m (18 ft. lbs.) torque.
(15) Install the crankcase breather housing (Refer
to 9 - ENGINE - INSTALLATION).
(16) Install the charge air cooler (with a/c con-
denser and auxiliary transmission oil cooler, if
equipped) and tighten the mounting bolts to 2 N´m
(17 in. lbs.) torque.
(17) Connect charge air cooler inlet and outlet
pipes. Tighten clamps to 10 N´m (100 in. lbs.) torque.
(18) Install the radiator upper support panel.
(19) Close radiator petcock and lower the radiator
into the engine compartment. Tighten the mounting
bolts to 11 N´m (95 in. lbs.) torque.
(20) Raise vehicle on hoist.
(21)
Connect radiator lower hose and install clamp.
(22) Connect transmission auxiliary oil cooler lines
(if equipped).
(23) Lower vehicle.
(24) Install the fan shroud and tighten the mount-
ing screws to 6 N´m (50 in. lbs.) torque.(25) Install the viscous fan/drive assembly (Refer
to 7 - COOLING/ENGINE/RADIATOR FAN -
INSTALLATION).
(26) Install the coolant recovery and windshield
washer fluid reservoirs to the fan shroud.
(27) Connect the coolant recovery hose to the radi-
ator filler neck.
(28) Install the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(29) Install the front bumper assembly (Refer to 13
- FRAMES & BUMPERS/BUMPERS/FRONT
BUMPER - INSTALLATION).
(30) Add engine coolant (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(31) Charge A/C system with refrigerant (if A/C
equipped) (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - STANDARD PROCEDURE).
(32) Connect the battery negative cables.
(33) Start engine and check for engine oil and cool-
ant leaks.
CONNECTING ROD BEARINGS
STANDARD PROCEDUREÐCONNECTING ROD
BEARING AND CRANKSHAFT JOURNAL
CLEARANCE
Measure the connecting rod bore with the bearings
installed and the bolts tightened to 100 N´m (73 ft.
lbs.) torque.
Record the smaller diameter.
Measure the diameter of the rod journal at the
location shown (Fig. 99). Calculate the average diam-
eter for each side of the journal.
The clearance is the difference between the con-
necting rod bore (smallest diameter) and the average
diameter for each side of the crankshaft journal.
CONNECTING ROD JOURNAL DIAMETER
LIMITS CHART
DESCRIPTION MEASUREMENT
CRANKSHAFT ROD
JOURNAL DIAMETERMINIMUM 68.962 mm
(2.715 in.)
MAXIMUM 69.013 mm
(2.717 in.)
OUT-OF-ROUND MAXIMUM 0.050 mm
(0.002 in.)
TAPER MAXIMUM 0.013 mm
(0.0005 in.)
BEARING CLEARANCE MAXIMUM 0.089 mm
(0.0035 in.)
Fig. 98 Camshaft Backlash and End Clearance
1 - CAMSHAFT GEAR
2 - CAMSHAFT GEAR BACKLASH
3 - CAMSHAFT GEAR CLEARANCE
BACKLASH Ð 0.152Ð0.33 mm
(0.006Ð0.013 inch)
CLEARANCE Ð 0.1Ð0.46 mm
(0.004Ð0.0182 inch)
9 - 274 ENGINE 5.9L DIESELBR/BE
CAMSHAFT & BEARINGS (IN BLOCK) (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
(3.9L/5.2L/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
Nuts8Ð72
Heat ShieldÐNuts and Bolts 11 Ð 100
Turbocharger MountingÐ
Nuts32 24 Ð
Turbocharger Oil Drain
TubeÐBolts24 18 Ð
Turbocharger Oil Supply
LineÐFitting15 Ð 133
Turbocharger V-Band
ClampÐNut9Ð75
CATALYTIC CONVERTER -
3.9L/5.2L/5.9L
DESCRIPTION
The stainless steel catalytic converter is located
under the vehicle, integral to the exhaust pipe(s).
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.
REMOVAL
(1) Raise and support vehicle.
(2) Saturate the bolts and nuts with heat valve
lubricant. Allow 5 minutes for penetration.
(3) Remove clamps and nuts (Fig. 3) (Fig. 4).
(4) Remove the catalytic converter.
INSPECTION
Look at the stainless steel body of the converter,
inspect for bulging or other distortion that could be a
result of overheating. If the converter has a heat
shield attached make sure it is not bent or loose.
If you suspect internal damage to the catalyst, tap-
ping the bottom of the catalyst with a rubber mallet
may indicate a damaged core.
INSTALLATION
(1) Assemble converter and clamps loosely in
place.
Fig. 3 Catalytic Converter and Exhaust Pipe 3.9L,
5.2L and 5.9L Light Duty ( Federal )
1 - BOLT
2 - EXHAUST PIPE W/CONVERTER
3 - NUT
4 - RETAINER
BR/BEEXHAUST SYSTEM 11 - 5

INSPECTION
Look at the stainless steel body of the converter,
inspect for bulging or other distortion that could be a
result of overheating. If the converter has a heat
shield attached make sure it is not bent or loose.
If you suspect internal damage to the catalyst, tap-
ping the bottom of the catalyst with a rubber mallet
may indicate a damaged core.
INSTALLATION
(1) Assemble converter and clamps loosely in
place.
(2) Tighten all clamp nuts to 48 N´m (35 ft. lbs.)
torque.
(3) Lower the vehicle.
(4) Start the engine and inspect for exhaust leaks
and exhaust system contact with the body panels. A
minimum of 25.4 mm (1.0 in.) is required between
exhaust system components and body/frame parts.
Adjust the alignment, if needed.
EXHAUST PIPE - 3.9L/5.2L/
5.9L
REMOVAL
(1) Raise and support the vehicle.
(2) Saturate the bolts and nuts with heat valve
lubricant. Allow 5 minutes for penetration.
(3) Remove exhaust pipe to manifold bolts, retain-
ers and nuts (Fig. 7).
(4) Remove the clamp nuts (Fig. 7).
(5) Remove the exhaust pipe.
INSPECTION
Discard rusted clamps, broken or worn supports
and attaching parts. Replace a component with orig-inal equipment parts, or equivalent. This will assure
proper alignment with other parts in the system and
provide acceptable exhaust noise levels.
INSTALLATION
(1) Position the exhaust pipe for proper clearance
with the frame and underbody parts. A minimum
clearance of 25.4 mm (1.0 in.) is required.
(2) Position the exhaust pipe to manifold. Install
the bolts, retainers and nuts. Tighten the nuts to 31
N´m (23 ft. lbs.) torque.
(3) Tighten the clamp nuts to 48 N´m (35 ft. lbs.)
torque.
(4) Lower the vehicle.
(5) Start the engine and inspect for exhaust leaks
and exhaust system contact with the body panels.
Adjust the alignment, if needed.
Fig. 7 Exhaust Pipe 3.9L,5.2L, 5.9L Light Duty
1 - EXHAUST PIPE WITH CATALYTIC CONVERTER
2 - CLAMP
3 - MUFFLER
BR/BEEXHAUST SYSTEM 11 - 7
CATALYTIC CONVERTER - 5.9L HEAVY DUTY/8.0L (Continued)

(3) Remove the front support bracket.
(4) Discharge the A/C system (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - STAN-
DARD PROCEDURE) and remove the A/C condenser
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING/A/C CONDENSER - REMOVAL) (Fig.
29) (if A/C equipped) .
(5) Remove the transmission auxiliary cooler (Fig.
29) (Refer to 7 - COOLING/TRANSMISSION/TRANS
COOLER - REMOVAL).
(6) Remove the boost tubes from the charge air
cooler (Fig. 30).
(7) Remove the charge air cooler bolts. Pivot the
charge air cooler forward and up to remove.
CLEANING
CAUTION: Do not use caustic cleaners to clean the
charge air cooler. Damage to the charge air cooler
will result.
NOTE: If internal debris cannot be removed from
the cooler, the charge air cooler MUST be replaced.
(1) If the engine experiences a turbocharger failure
or any other situation where oil or debris get into the
charge air cooler, the charge air cooler must be
cleaned internally.
(2) Position the charge air cooler so the inlet and
outlet tubes are vertical.
(3) Flush the cooler internally with solvent in the
direction opposite of normal air flow.(4) Shake the cooler and lightly tap on the end
tanks with a rubber mallet to dislodge trapped
debris.
(5) Continue flushing until all debris or oil are
removed.
(6) Rinse the cooler with hot soapy water to
remove any remaining solvent.
(7) Rinse thoroughly with clean water and blow
dry with compressed air.
INSPECTION
Visually inspect the charge air cooler for cracks,
holes, or damage. Inspect the tubes, fins, and welds
for tears, breaks, or other damage. Replace the
charge air cooler if damage is found.
Pressure test the charge air cooler, using Charge
Air Cooler Tester Kit #3824556. This kit is available
through CumminstService Products. Instructions
are provided with the kit.
INSTALLATION
(1) Position the charge air cooler. Install the bolts
and tighten to 2 N´m (17 in. lbs.) torque.
Fig. 29 Condenser and Transmission Auxiliary
Cooler
1 - A/C CONDENSOR
2 - TRANSMISSION COOLER
3 - INTERCOOLER
Fig. 30 Air Intake System Tubes
1 - CLAMP
2 - INTERCOOLER INLET DUCT
3 - CLAMP
4 - VALVE COVER
5 - AIR INLET HOUSING
6 - CLAMP
7 - INTERCOOLER OUTLET DUCT
8 - CLAMP
9 - INTERCOOLER
11 - 18 EXHAUST SYSTEMBR/BE
CHARGE AIR COOLER AND PLUMBING (Continued)

(2) Install the air intake system tubes to the
charge air cooler . With the clamps in position,
tighten the clamps to 11 N´m (95 in. lbs.) torque.
(3) Install the transmission auxiliary cooler (if
equipped) (Refer to 7 - COOLING/TRANSMISSION/
TRANS COOLER - INSTALLATION).
(4) Install the A/C condenser (if A/C equipped)
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING/A/C CONDENSER - INSTALLATION).
Recharge A/C system (Refer to 24 - HEATING & AIRCONDITIONING/PLUMBING - STANDARD PRO-
CEDURE).
(5) Install the front support bracket. Install and
tighten the bolts.
(6) Install the front bumper (Refer to 13 -
FRAMES & BUMPERS/BUMPERS/FRONT
BUMPER - INSTALLATION).
(7) Connect the battery negative cables.
(8) Start engine and check for boost system leaks.
BR/BEEXHAUST SYSTEM 11 - 19
CHARGE AIR COOLER AND PLUMBING (Continued)

(3) Install MAP sensor mounting bolts (screws).
Tighten screws to 3 N´m (25 in. lbs.) torque.
(4) Install air cleaner.
INSTALLATION - 8.0L
The MAP sensor is mounted into the right upper
side of the intake manifold (Fig. 38). A rubber gasket
is used to seal the sensor to the intake manifold. The
rubber gasket is part of the sensor and is not ser-
viced separately.
(1) Check the condition of the sensor seal. Clean
the sensor and lubricate the rubber gasket with clean
engine oil.
(2) Clean the sensor opening in the intake mani-
fold.
(3) Install the sensor into the intake manifold.
(4) Install sensor mounting bolts. Tighten bolts to
2 N´m (20 in. lbs.) torque.
(5) Install the electrical connector to sensor.
O2 SENSOR
DESCRIPTION
The Oxygen Sensors (O2S) are attached to, and
protrude into the vehicle exhaust system. Depending
on the emission package, the vehicle may use a total
of either 2 or 4 sensors.
3.9L/5.2L/Light Duty 5.9L Engine:Four 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 package, 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-catalytic convertor. The right down-
stream sensor (2/2) is located in the right exhaust
downpipe just after the mini-catalytic convertor, and
before the main catalytic convertor. The left down-
stream sensor (1/2) is located in the left exhaust
downpipe just after the mini-catalytic convertor, and
before the main catalytic convertor.
Medium and Heavy Duty 8.0L V-10 Engine:
Four sensors are used (2 upstream, 1 pre-catalyst
and 1 post-catalyst). With this emission package, the
1/1 upstream sensor (left side) is located in the left
exhaust downpipe before both the pre-catalyst sensor
(1/2), and the main catalytic convertor. The 2/1
upstream sensor (right side) is located in the right
exhaust downpipe before both the pre-catalyst sensor
(1/2), and the main catalytic convertor. The pre-cata-
lyst sensor (1/2) is located after the 1/1 and 2/1 sen-
sors, and just before the main catalytic convertor.
The post-catalyst sensor (1/3) is located just after the
main catalytic convertor.Heavy Duty 5.9L Engine:Two sensors are used.
They arebothreferred to as upstream sensors (left
side is referred to as 1/1 and right side is referred to
as 2/1). With this emission package, a sensor is
located in each of the exhaust downpipes before the
main catalytic 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 wire harness. This is why it
is important to never solder an O2 sensor connector,
or pack the connector with grease.
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 Heaters/Heater Relays:
Depending on the emissions package, the heating ele-
ments within the sensors will be supplied voltage
from either the ASD relay, or 2 separate oxygen sen-
sor relays. Refer to 8, Wiring Diagrams to determine
which relays are used.
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 4.5 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
14 - 46 FUEL INJECTION - GASOLINEBR/BE
MANIFOLD ABSOLUTE PRESSURE SENSOR (Continued)

(3) Once injector has been found to be malfunc-
tioning, remove it from engine and test it. Refer to
Fuel Injector Removal/Installation.
WARNING: FUEL INJECTOR TESTERS CAN
DEVELOP EXTREMELY HIGH PRESSURES. FUEL
UNDER THIS AMOUNT OF PRESSURE CAN PENE-
TRATE SKIN AND CAUSE PERSONAL INJURY.
WEAR SAFETY GOGGLES AND ADEQUATE PRO-TECTIVE CLOTHING. AVOID CONTACT WITH FUEL
SPRAY WHEN OPERATING INJECTOR TESTOR.
(4) After injector has been removed, obtain bench-
mount fuel injector tester OTCt(SPXt) part number
4210 (Fig. 16) (or equivalent). Install Special Tool
number 8301 (Fuel Injector Adapter) to 4210 tester.
Install fuel injector into 8301 adapter. Be sure tip of
adapter tool 8301 is aligned to inlet hole at side of
injector (Fig. 17) before tightening tool. Tighten tool
8301 to injector. Position container below injector
before testing.
(5) Refer to operating instructions supplied with
pressure tester for procedures.
(a) Check opening pressure or ªpopº pressure.
Pressure should be approximately 31,026 kPa (310
bars) or (4500 psi6250 psi). If fuel injector needle
valve is opening (popping) too early or too late,
replace injector.
(b) Perform a leak-down test on injector. Apply
pressure with injector tester. The injector should
not leak (drip) fuel with pressure at approximately
20 bars (291 psi) lower than pop pressure.
(c) Operate tester lever quickly several times to
check injector spray pattern. Verify fuel is spraying
from each injector nozzle hole. Injector should also
spray evenly from each nozzle hole.
(d) Pay attention to size and shape of spray
plumes. They should all be equal. If possible, com-
pare spray pattern to that of a new fuel injector
with same part number. Checking each plume for
consistency is an excellent indicator of injector per-
formance. Even if only one nozzle hole is plugged,
significant performance problems could result.
(e) Look for burrs on injector inlet.
(f) Check nozzle holes for hole erosion or plug-
ging.
(g) Inspect end of nozzle for burrs or rough
machine marks.
(h) Look for cracks at nozzle end.
(i) Check nozzle color for signs of overheating.
Overheating will cause nozzle to turn a dark yel-
low/tan or blue (depending on overheating temper-
ature).
(j) Look at end of injector tube where it meets
injector. A small, shiny band should be seen at this
point. The band should have a consistent thick-
ness. If not, injector could be leaking into fuel
return.
(k) If any of these conditions occur, replace injec-
tor.
REMOVAL
The fuel injectors are located in the top of the cyl-
inder head between the intake/exhaust valves (Fig.
18).
Fig. 16 Fuel
1 - FUEL INJECTOR
2 - ADAPTOR TOOL 8301
3 - POP PRESSURE TESTER
Fig. 17 Installing Injector to Adaptor Tool 8301
1 - ADAPTOR TOOL 8301
2 - TIP
3 - FUEL INJECTOR
4 - INLET AT SIDE OF INJECTOR
14 - 96 FUEL INJECTION - DIESELBR/BE
FUEL INJECTOR (Continued)

INSTALLATION
The fuel injectors are located in the top of the cyl-
inder head between the intake/exhaust valves (Fig.
18).
(1) Inspect fuel injector.
(a) If necessary, perform pressure test of injector.
Refer to Fuel Injector Testing.
(b) Look for burrs on injector inlet.(c) Check nozzle holes for hole erosion or plug-
ging.
(d) Inspect end of nozzle for burrs or rough
machine marks.
(e) Look for cracks at nozzle end.
(f) Check nozzle color for signs of overheating.
Overheating will cause nozzle to turn a dark yel-
low/tan or blue (depending on overheating temper-
ature).
Fig. 20 Fuel Injector Connector Tube Removal
1 - FUEL INJECTOR CONNECTOR TUBE
2 - SPECIAL TOOL 8324
3 - CYLINDER HEAD
Fig. 21 Fuel Injector Removal
1 - FUEL INJECTOR REMOVAL TOOL 8318
2 - TIGHTEN NUT FOR INJECTOR TERMINAL
3 - THREAD INTO INJECTOR
Fig. 22 Fuel Injector Sealing Washer (Shim)
Location
1 - FUEL INJECTOR
2 - COPPER SEALING WASHER (SHIM)
Fig. 23 Measuring Injector Sealing Washer (Shim)
1 - SHIM
14 - 98 FUEL INJECTION - DIESELBR/BE
FUEL INJECTOR (Continued)

OPERATION
The sensor located in the Bosch VP44 fuel injection
pump is used to check fuel temperature within the
injection pump and to set a Diagnostic Trouble Code
(DTC) if a specific high fuel temperature has been
reached. If high temperature has been reached,
engine power will be de-rated by the Engine Control
Module (ECM).
The sensor located in the top of the fuel filter hous-
ing is used to control the fuel heater element. Refer
to Fuel Heater Description and Operation for addi-
tional information.
INTAKE AIR HEATER
DESCRIPTION
The intake manifold air heater element assembly
is located in the top of the intake manifold (Fig. 25).
OPERATION
The air heater elements are used to heat incoming
air to the intake manifold. This is done to help
engine starting and improve driveability with cool or
cold outside temperatures.
Electrical supply for the 2 air heater elements is
controlled by the Engine Control Module (ECM)
through the 2 air heater relays. Refer to Intake Man-
ifold Air Heater Relays for more information.
Two heavy-duty cables connect the 2 air heater ele-
ments to the 2 air heater relays. Each of these cables will
supply approximately 95 amps at 12 volts to an individ-
ual heating element within the heater block assembly.
Refer to the Powertrain Diagnostic Procedures
manual for an electrical operation and complete
description of the intake heaters, including pre-heat
and post-heat cycles.
REMOVAL
The 2 intake manifold air heater elements are
attached to a metal block located at the top of the
intake manifold (Fig. 26). If servicing either of the
heater elements, the entire block/element assembly
must be replaced.
(1) Disconnect both negative battery cables at both
batteries.
(2) Disconnect clamp from rubber hose at air
intake housing.
(3) Disconnect rubber hose at air intake housing.
(4) Remove engine oil dipstick tube mounting bolt
(Fig. 28). Position dipstick tube to the side.
(5) Disconnect heater electrical cables at cable
mounting studs (Fig. 28).
(6) Disconnect ground cable bolt and ground cable
from housing (Fig. 27).
(7) Remove 4 housing bolts (Fig. 28).
(8) Remove air intake housing from top of heater
elements.
(9) Remove heater element assembly from intake
manifold.
(10) Clean old gasket material from air intake
housing and intake manifold.
(11) Clean old gasket material from both ends of
heater block (Fig. 26).
Fig. 25 Air Heater Elements Location
1 - AIR HEATER ELEMENTS
2 - LOWER GASKET
3 - BLOCK
4 - UPPER GASKET
Fig. 26 Intake Manifold Air Heater Element Location
1 - AIR HEATER ELEMENTS
2 - LOWER GASKET
3 - BLOCK
4 - UPPER GASKET
14 - 100 FUEL INJECTION - DIESELBR/BE
FUEL TEMPERATURE SENSOR (Continued)

OPERATION
The Engine Control Module (ECM) operates the 2
heating elements through the 2 intake manifold air
heater relays.
Refer to Powertrain Diagnostic Procedures for an
electrical operation and complete description of the
intake heaters, including pre-heat and post-heat
cycles.
REMOVAL
The relays are located in engine compartment,
bolted to left inner fender below left battery (Fig. 30).
The mounting bracket and both relays are replaced
as an assembly.
(1) Disconnect both negative battery cables at both
batteries.
(2) Disconnect four relay trigger wires at both
relays (Fig. 30). Note position of wiring before remov-
ing.
(3) Lift four rubber shields from all 4 cables (Fig.
30).
(4) Remove four nuts at cable connectors (Fig. 30).
Note position of wiring before removing.
(5) Remove three relay mounting bracket bolts
(Fig. 30) and remove relay assembly.
INSTALLATION
The relays are located in engine compartment,
bolted to left inner fender below left battery (Fig. 30).
(1) Install relay assembly to inner fender. Tighten
mounting bolts to 4.5 N´m (40 in. lbs.) torque.
(2) Connect eight electrical connectors to relays.
(3) Connect battery cables to both batteries.
INTAKE AIR TEMPERATURE
SENSOR
DESCRIPTION - DIESEL
The intake manifold air temperature sensor is
installed into the rear of the intake manifold (Fig.
31) with the sensor element extending into the air
stream.
OPERATION - DIESEL
The IAT provides an input voltage to the Engine
Control Module (ECM) indicating intake manifold air
temperature. The input is used along with inputs
from other sensors for intake air heater element
operation, for engine protection, fuel timing and fuel
control. As the temperature of the air-fuel stream in
the manifold varies, the sensor resistance changes.
This results in a different input voltage to the ECM.
Fig. 30 Intake Manifold Air Heater Relays
1 - BATTERY (LEFT SIDE)
2 - RELAY MOUNTING BOLTS (3)
3 - RELAY TRIGGER WIRES (4)
4 - INTAKE AIR HEATER RELAYS (2)
5 - RUBBER SHIELDS (4)
6 - CABLES TO BATTERY (+)
Fig. 31 Intake Manifold Air Temperature (IAT) Sensor
Location
1 - MANIFOLD AIR PRESSURE (MAP) SENSOR
2 - REAR OF CYLINDER HEAD
3 - IAT SENSOR
4 - ELECTRICAL CONNECTOR
5 - ELECTRICAL CONNECTOR
14 - 102 FUEL INJECTION - DIESELBR/BE
INTAKE AIR HEATER RELAY (Continued)