Page 2393 of 5267
INSTALLATION
1. Clean any dirt/debris from top of intake manifold
and bottom of fuel rail.
2. Position fuel rail to top of manifold and install 3
mounting bolts (1) finger tight.
3. Install all high-pressure lines to rail (Refer to 14 -
FUEL SYSTEM/FUEL DELIVERY/FUEL LINES -
REMOVAL) (Refer to 14 - FUEL SYSTEM/FUEL
DELIVERY/FUEL LINES - INSTALLATION). Torque
to 30 Nꞏm (22 ft. lbs.).
4. Tighten 3 mounting bolts at fuel rail. Torque bolts to
24 Nꞏm (18 ft. lbs.).
5. Reposition wiring harness to intake elbow and
install nut.
6. Install and tighten fuel limiting valve banjo bolt.
Copper washer against fuel limiting valve, rubber
seal against banjo bolt. Torque to 24 Nꞏm (18 ft.
lbs.).
7. Connect electrical connector to fuel pressure sen-
sor.
8. Position 2 positive (+) cables to intake heater
studs. Install 2 nuts.
9. Connect battery cables to both batteries.
10. Start engine and check for leaks.
Page 2394 of 5267
SENSOR-TEMPERATURE/PRESSURE-INTAKE
DESCRIPTION
The combination, dual function Inlet Air Temperature/
Pressure Sensor (4) is located on the air cleaner (fil-
ter) cover.
OPERATION
The Inlet Air Temperature/Pressure Sensor is a combination dual-function sensor. The sensor element extends into
the intake air stream at the top of the air filter housing. Ambient air temperature as well as barometric pressure is
monitored by this sensor. The Engine Control Module (ECM) monitors signals from this sensor.
REMOVAL
The Inlet Air Temperature/Pressure Sensor is located
on the air cleaner cover.
Page 2395 of 5267
1. Disconnect electrical connector at sensor.
2. Remove two Torx-type mounting screws (3).
3. Remove sensor from air cleaner cover.
4. Check condition of sensor O-ring (2).
Page 2396 of 5267
INSTALLATION
1. Check condition of sensor O-ring.
2. Position sensor into top of air cleaner cover with a
slight twisting action.
3. Install 2 mounting screws (3).
4. Install electrical connector (2).
Page 2397 of 5267

HEATER - INTAKE AIR
DESCRIPTION
The intake manifold air heater element assembly is located in the top of theintake manifold.
OPERATION
The air heater element is 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 air heater element is controlled by the Engine Control Module (ECM) through the air heater
relay. Refer to Intake Manifold Air Heater Relay for more information.
One heavy-duty cable connects the air heater element to the air heater relay. This cable will supply 12 volts to an
individual heating element within the heater block assembly.
CAUTION: The heater elements are no longer grounded using an external ground strap. Grounding is now
accomplished using two electrically conductive gaskets. Failure to use these gaskets will result in faulty
heater element operation.
Refer to the Powertrain Diagnostic Procedures manual for electrical operation and complete description of the intake
heaters, including pre-heat and post-heat cycles.
REMOVAL
If servicing the heater element, the entire block/ele-
ment assembly must be replaced.
1. Disconnect both negative battery cables at both
batteries. Cover and isolate ends of both cables.
2. Remove both the intake manifold air intake tube
(above injection pump), and its rubber connector
hose (2).
Page 2398 of 5267
3. Lift 2 rubber covers (3) to gain access to 2 positive
(+) cable nuts.
4. Remove cable nut (6) (Fig #. ) and remove cable
from stud.
5. Remove wiring harness clips.
6. Remove engine oil dipstick tube bracket from air
inlet connection and fuel filter housing.
7. Remove four housing mounting bolts (1) and
remove heater element assembly.
Page 2399 of 5267
INSTALLATION
If servicing the heater element, the entire block/ele-
ment assembly must be replaced.
CAUTION: The heater elements are no longer
grounded using an external ground strap. Ground-
ing is now accomplished using two electrically
conductive gaskets. Failure to use these gaskets
will result in faulty heater element operation.
1. Using 2 new gaskets, position element assembly
and air housing to intake manifold (2).
2. Install wire harness clips to intake connection stud.
3. Install 4 housing bolts (1) and tighten to 24 Nꞏm
(18 ft. lbs.) torque.
4. Connect 2 positive (+) heater cables (6) at cable
mounting studs.Do not allow either of the cable
eyelets to contact any other metal source other
than the cable nuts/studs.
5. Install engine oil dipstick tube and mounting bolt
(5).
6. Connect rubber connector hose and intake tube to
air intake housing. Tighten clamp bolts to 11 Nꞏm
(100 in. lbs.) torque.
7. Connect both negative battery cables at both
batteries.
Page 2400 of 5267

RELAY - INTAKE AIR HEATER
DESCRIPTION
The intake manifold air heater relay (4) is located in
the engine compartment.
OPERATION
The Engine Control Module (ECM) operates the heating element through the intake manifold air heater relay. Refer
to Powertrain Diagnostic Procedures for an electrical operation and complete description of the intake heater, includ-
ing pre-heat and post-heat cycles.
REMOVAL
The two intake manifold air heater relays (4) are
located in the engine compartment. They are attached
to a common bracket. This bracket is attached to the
right battery tray.
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.
Note position of wiring before removing.
3. Lift four rubber shields from all 4 cables.
4. Remove four nuts at cable connectors. Note posi-
tion of wiring before removing.
5. Remove relay mounting bracket bolts and remove
relay assembly.