Removal Procedure

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2004 Oldsmobile Bravada, 2004 GMC Envoy XUV, 2004 GMC Envoy XL, 2004 GMC Envoy, and 2004 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.

Drain the engine coolant. Refer to Draining and Filling Cooling System (LL8) or Draining and Filling Cooling System (LM4) .

Fig 1: View Of PCM Assembly

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Remove the powertrain control module (PCM) retaining bolts (3) and nuts (6).
Remove the PCM mounting studs (5) and position the PCM out of the way.

Fig 2: View Of Engine Coolant Temperature Electrical Connector

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Disconnect the engine coolant temperature (ECT) sensor electrical connector (1).

NOTE: Refer to Fuel and Evaporative Emission (EVAP) Hose/Pipe Connection Cleaning Notice in Cautions and Notices.

Disconnect the fuel feed (1) and fuel return (2) pipes from the fuel rail. Refer to Quick Connect Fitting(s) Service (Metal Collar) in Engine Controls - 4.2L.
Disconnect the integral clip (3) from the wire harness bracket.

Fig 3: Fuel Feed And Fuel Return Pipes (Left Side Of Engine)
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Fig 4: Removing/Installing Engine Wire Harness Bracket

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Remove the engine wire harness bracket bolt.
Position the engine electrical wire harness bracket with wires attached out of the way.

Fig 5: Removing/Installing Coolant Heater Cord From Heater

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Remove the coolant heater cord from the heater (2).

Fig 6: Removing/Installing Coolant Heater From Block

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IMPORTANT: Do not score the surface of the engine block hole when removing the coolant heater.

Remove the coolant heater from the block.