GM Service Manual Online
For 1990-2009 cars only

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Action

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Schematic Reference: Instrument Cluster Schematics

Connector End View Reference: Master Electrical Component List in Wiring Systems

1

Did you perform the Instrument Cluster Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Instrument Cluster

2

  1. Install a scan tool.
  2. Turn the ignition ON, with the engine OFF.
  3. With a scan tool, observe one of the following Engine Oil Level Switch parameters:
  4. • Engine Oil Level Switch in the ECM Engine Data 1 data list (LB7 and LG4).
    • Engine Oil Level Switch in the PCM Engine Data 2 data list (L18).

Does the Engine Oil Level Switch parameter display Ok?

Go to Step 3

Go to Step 4

3

Does the low engine oil level indicator remain illuminated after the displays test?

Go to Step 11

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

4

  1. Turn the ignition OFF.
  2. Disconnect the engine oil level switch.
  3. Connect a 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 to Wiring Repairs in Wiring Systems.

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 to Wiring Repairs in Wiring Systems.

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 to Connector Repairs in Wiring Systems.

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 PCM. 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 12

Go to Step 10

9

Replace the engine oil level switch. Refer to:

    •  Engine Oil Level Sensor and/or Switch Replacement in Engine Mechanical - 6.6L
    •  Engine Oil Level Sensor and/or Switch Replacement in Engine Mechanical - 8.1L
    • Engine Oil Level Sensor/Switch Replacement in Engine Mechanical - LG4

Did you complete the replacement?

Go to Step 12

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10

Important: Program the replacement PCM.

Replace the PCM. Refer to:

    •  Engine Control Module Replacement in Engine Controls - 6.6L
    •  Engine Control Module Replacement/Restore Fuel Rate Data in Engine Controls - 7.8L
    •  Powertrain Control Module Replacement in Engine Controls - 8.1L

Did you complete the replacement?

Go to Step 12

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11

Important: Program the replacement IPC.

Replace the IPC. Refer to Instrument Cluster Replacement .

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