GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Instrument Cluster Schematics

Connector End View Reference: Powertrain Control Module Connector End Views in Engine Controls 3.8 L

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

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 ON the ignition, with the engine OFF.
  3. With a scan tool, observe the Engine Oil Pressure Switch parameter in the powertrain control module (PCM) Engine Data List or the IPC PCM Data List.

Does the Engine Oil Pressure Switch parameter display OK?

Go to Step 10

Go to Step 4

4

  1. Turn OFF the ignition.
  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 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 of the engine oil pressure switch. 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 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 - 3.8 L.

Did you complete the replacement?

Go to Step 11

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9

Replace the PCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 11

--

10

Replace the instrument panel cluster (IPC). Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

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