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specification. See TORQUE SPECIFICATIONS.
Removal & Installation (3.1L & 3.4L)
Disconnect negative battery cable. Raise and support vehicle.
Disconnect knock sensor electrical connector. Remove knock sensor. To
install, reverse removal procedure. Tighten knock sensor to
specification. See TORQUE SPECIFICATIONS.
Removal & Installation (3.5L)
Disconnect negative battery cable. Remove right front wheel.
Disconnect and reposition jumper harness connector. Disconnect knock
sensor electrical connector. Remove knock sensor. To install, reverse
removal procedure. Tighten knock sensor to specification. See
TORQUE SPECIFICATIONS.
Removal & Installation (3.8L - Knock Sensor 1)
Disconnect negative battery cable. Drain cooling system.
Raise and support vehicle. Disconnect knock sensor electrical
connector. Remove knock sensor. To install, reverse removal procedure.
Tighten knock sensor to specification. See TORQUE SPECIFICATIONS.
Removal & Installation (3.8L - Knock Sensor 2)
Disconnect negative battery cable. Drain cooling system.
Raise and support vehicle. Remove splash shield bolts. Remove knock
sensor heat shield. Disconnect knock sensor electrical connector.
Remove knock sensor. To install, reverse removal procedure. Tighten
knock sensor to specification. See TORQUE SPECIFICATIONS.
Removal & Installation (4.0L, 4.6L & 5.7L)
Disconnect negative battery cable. Remove intake manifold.
See appropriate article in ENGINES. Disconnect knock sensor electrical
connector. Remove knock sensor. To install, reverse removal procedure.
Tighten knock sensor to specification. See TORQUE SPECIFICATIONS.
FUEL SYSTEMS
FUEL SYSTEM PRESSURE RELEASE (CNG)
WARNING: Always relieve fuel pressure before disconnecting any fuel
injection-related component. DO NOT allow fuel to contact
engine or electrical components.
NOTE:
Replace all "O" rings that are disconnected or loosened.
1) Connect scan tool to Data Link Connector (DLC). Clear all
existing DTC's. Start engine and verify engine is operating on CNG.
Using scan tool, select High Pressure Lock-Off (HPL) output control.
See Fig. 13. Close HPL and observe the Fuel Pressure Sensor parameter
on scan tool. If Fuel Pressure Sensor parameter fails to decrease, go
to next step. When engine stalls, turn ignition off. Remove CNG 20-amp
fuse. Slowly open fuel line fittings in order to release remaining
pressure.
2) Remove fuel tank cover dust plug. Close manual lock-down
screw located on HPL manual shutoff fitting by rotating the Allen
screw clockwise until fully seated. Turn ignition off. Disconnect
negative battery cable. Loosen fuel line fitting at Low Pressure Lock-
Off (LPL) inlet port several turns. Do not remove fitting. If fuel is
not venting with LPL inlet fitting loosened, relieve fuel line tension
by pulling line away from LPL.
3) Loosen fuel line fitting at HPL inlet port several turns.
Do not remove fitting. Relieve fuel line tension by pulling line away
from HPL. Pressure is released when fuel line can be pulled away from
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