GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Instrument Cluster Schematics

Connector End View Reference: Engine Control Module Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Start the engine.

Does the LOW OIL LEVEL message display in the radio?

Go to Step 3

Go to Testing for Intermittent Conditions and Poor Connections

3

  1. Install a scan tool.
  2. With the scan tool, observe the Engine Oil Level Switch parameter in the ECM data lists.

Does the Engine Oil Level Switch parameter display OK?

Go to Step 11

Go to Step 4

4

  1. Turn the ignition OFF.
  2. Disconnect the engine oil level switch.
  3. Connect a 3-amp fused jumper wire between the engine oil level switch signal circuit and a good ground.
  4. Start the engine.
  5. With the scan tool, observe the Engine Oil Level Switch parameter.

Does the Engine Oil Level parameter display OK?

Go to Step 6

Go to Step 5

5

Test the signal circuit of the engine oil level switch for an open, for a high resistance or for a short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 12

Go to Step 7

6

Test the low reference circuit or the ground circuit of the engine oil level switch for an open or for a high resistance. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 12

Go to Step 8

7

Inspect for poor connections at the harness connector of the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 12

Go to Step 9

8

Inspect for poor connections at the harness connector of the engine oil level switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 12

Go to Step 10

9

Replace the ECM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 12

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10

Replace the engine oil level switch. Refer to Engine Oil Level Sensor and/or Switch Replacement .

Did you complete the replacement?

Go to Step 12

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11

Replace the radio. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 12

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12

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2