GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Instrument Cluster Schematics

Connector End View Reference: Master Electrical Component List

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Install a scan tool.
  2. Turn the ignition ON, with the engine OFF.
  3. With the scan tool, observe the Engine Oil Level Switch parameter in the PCM Engine Data 2 data list or the PCM Engine Data 1 data list 6.6L diesel.

Does the Engine Oil Level Switch parameter display OK?

Go to Step 3

Go to Step 4

3

Does the CHECK ENG OIL LEVEL indicator remain illuminated after the displays test?

Go to Step 11

Go to Testing for Intermittent Conditions and Poor Connections

4

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

Does the Engine Oil Level Switch parameter display OK?

Go to Step 6

Go to Step 5

5

Test the signal circuit of the engine oil level switch for a short to battery voltage, 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

6

Test 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 7

7

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 9

8

Inspect for poor connections at the harness connector of the powertrain control module (PCM). 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 engine oil level switch. Refer to the following procedures:

    •  Engine Oil Level Sensor and/or Switch Replacement for the 4.3L engine
    •  Engine Oil Level Sensor and/or Switch Replacement for the 4.8L, 5.3L and 6.0L engine
    •  Engine Oil Level Sensor and/or Switch Replacement for the 6.6L (LLY) engine
    •  Engine Oil Level Sensor and/or Switch Replacement for the 8.1L engine

Did you complete the replacement?

Go to Step 12

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10

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

Did you complete the replacement?

Go to Step 12

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11

Replace the instrument panel cluster (IPC). 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