GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

Schematic Reference: Instrument Cluster Schematics

Connector End View Reference: Engine Control Module Connector End Views for the 2.8L, 3.0L, 3.2L or 3.6L engine, or Engine Control Module Connector End Views for the 4.6L engine

1

Did you perform the Diagnostic System Check - Vehicle?

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Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Start the engine.

Does the OIL TEMP HIGH message display in the driver information center (DIC)?

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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 Temperature Calculated parameter in the IPC ECM data list.

Does the Engine Oil Temperature Calculated parameter display a value within the specified range?

30-140°C (86-284°F)

Go to Step 10

Go to Step 4

4

  1. Turn the ignition OFF.
  2. Disconnect the engine oil temperature switch.
  3. Start the engine.
  4. With the scan tool, observe the Engine Oil Temperature Switch parameter in the IPC ECM data list.

Does the Engine Oil Level parameter display at or below the specified value?

30°C (86°F)

Go to Step 6

Go to Step 5

5

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

Did you find and correct the condition?

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Go to Step 11

Go to Step 7

6

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

Did you find and correct the condition?

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Go to Step 11

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?

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Go to Step 11

Go to Step 9

8

Replace the engine oil temperature switch. Refer to the following:

Did you complete the replacement?

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Go to Step 11

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9

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

Did you complete the replacement?

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Go to Step 11

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10

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

Did you complete the replacement?

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Go to Step 11

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11

Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 2