GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Engine Controls Schematics in Engine Controls-4.6L (LH2)

Connector End View Reference: Engine Control Module Connector End Views in Engine Controls-4.6L (LH2) or Power and Grounding Connector End Views in Wiring Systems

1

Did you perform the Vehicle Diagnostic System Check?

Go to Step 2

Go to Diagnostic Starting Point - Computer/Integrating Systems in Computer/Integrating Systems

2

Turn ON the ignition, with the engine OFF.

Does the battery charge indicator illuminate?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

  1. Install a scan tool.
  2. With a scan tool, command the lamp and gages On and Off.

Does the charge indicator turn On and Off with each command?

Go to Step 4

Go to Step 7

4

Test the generator turn on signal circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 8

Go to Step 5

5

Inspect for poor connections at the harness connector of the ECM. Refer to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 8

Go to Step 6

6

Important: The replacement ECM must be programmed.

Replace the ECM. Refer to Engine Control Module Replacement in Engine Controls-4.6L (LH2).

Did you complete the replacement?

Go to Step 8

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7

Replace the instrument panel cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gages and Console.

Did you complete the replacement?

Go to Step 8

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8

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2