GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The engine oil level switch grounds when the oil level is at the proper level. With the ignition ON, and the engine OFF, the PCM should detect a low voltage input on the switch circuit (full oil level). With the engine running, the PCM should detect a transition from a low voltage to a high voltage input on the oil level switch signal circuit.

Conditions for Running the DTC

    • The vehicle is travelling at a speed greater than 5 km/h (3 mph).
    • The throttle position is greater than 5%.
    • The engine speed is greater than 2000 RPM.
    • The vehicle is cruising (no acceleration).
    • The following DTCs are not set:
       - P0502
       - P0503
       - P0121
       - P0122
       - P0123

Conditions for Setting the DTC

    • The PCM detects that the engine oil level signal circuit is low.
    • The above condition is present for greater than 8 seconds.
    • The PCM detects a low signal voltage, and/or the PCM does not detect a switch transition with the engine running

Action Taken When the DTC Sets

The PCM records the operating conditions at the time the diagnostic fails. The PCM displays this information in the Failure Records on the scan tool.

Conditions for Clearing the DTC

    • The DTC becomes history when the conditions for setting the DTC are no longer present.
    • The history DTC clears after 40 malfunction free warm-up cycles.
    • The PCM receives a clear code command from the scan tool.

Diagnostic Aids

Using the Failure Records data may aid in locating an intermittent condition. If you cannot duplicate the DTC, the information included in the Failure Records data can aid in determining how many miles since the DTC set. The Fail Counter and Pass Counter can also aid determining how many ignition cycles the diagnostic reported a pass and/or a fail.

Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Step

Action

Values

Yes

No

Schematic Reference: Driver Information System Schematics

1

Did you perform the Driver Information Center Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - Driver Information Systems

2

Important: Verify proper engine oil level as indicated on the engine oil level indicator, correct as necessary.

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

Does the Engine Oil Level Switch parameter display OK?

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Go to Diagnostic Aids

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Disconnect the engine oil level switch.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the Engine Oil Level Switch parameter in the PCM Engine Data 2 data list.

Does the Engine Oil Level Switch parameter display Low?

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Go to Step 6

Go to Step 4

4

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

Did you find and correct the condition?

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Go to Step 8

Go to Step 5

5

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?

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Go to Step 8

Go to Step 7

6

Replace the engine oil level switch. Refer to Engine Oil Level Sensor Replacement .

Did you complete the replacement?

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Go to Step 8

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7

Important: Program the replacement PCM.

Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls - 3.5L or Powertrain Control Module Replacement in Engine Controls - 4.0L.

Did you complete the replacement?

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Go to Step 8

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8

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

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Go to Step 2

System OK