GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Instrument Cluster Schematics

1

Did you perform the Instrument Cluster Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Instrument Cluster

2

Start the engine.

Does the engine oil pressure indicator illuminate after the displays test?

Go to Step 3

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

3

  1. Install a scan tool.
  2. Turn the ignition ON, with the engine OFF.
  3. With a scan tool, observe the Engine Oil Pressure Switch parameter in the PCM Engine Data 2 data list.

Does the Engine Oil Pressure Switch parameter display OK?

Go to Step 10

Go to Step 4

4

  1. Turn the ignition OFF.
  2. Disconnect the engine oil pressure switch.
  3. Start the engine.
  4. With the scan tool, observe the Engine Oil Pressure Switch parameter.

Does the Engine Oil Pressure Switch parameter display OK?

Go to Step 6

Go to Step 5

5

Test the oil pressure switch signal circuit for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 7

6

Inspect for poor connections at the harness connector and the case ground of the engine oil pressure switch. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 8

7

Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 9

8

Replace the engine oil pressure switch. Refer to Engine Oil Pressure Sensor and/or Switch Replacement in Engine Mechanical -- 3.4L or to Engine Oil Pressure Sensor and/or Switch Replacement in Engine Mechanical -- 3.8L.

Did you complete the replacement?

Go to Step 11

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9

Important: Program the replacement PCM.

Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls - 3.4L or to Powertrain Control Module Replacement in Engine Controls -- 3.8L.

Did you complete the replacement?

Go to Step 11

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10

Replace the IPC. Refer to Instrument Cluster Replacement .

Did you complete the replacement?

Go to Step 11

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11

  1. Use the scan tool in order to clear the PCM DTCs.
  2. Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2