GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the Instrument Cluster Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - Instrument Cluster

2

Verify the fault is present.

Does the system operate normally?

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

Go to Step 3

3

Does the oil pressure gauge remain past 80 psi?

--

Go to Step 6

Go to Step 4

4

Does the oil pressure gauge stay at 0 psi?

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Go to Step 8

Go to Step 5

5

  1. Ensure that the engine oil level is correct.
  2. Ensure that the engine develops adequate oil pressure. Refer to Oil Pressure Diagnosis and Testing in Engine Mechanical for 4.3L engines or Oil Pressure Diagnosis and Testing in Engine Mechanical for 4.8L, 5.3L, and 6.0L engines.
  3. Disconnect the oil pressure switch connector. Refer to Circuit Testing in wiring repairs.
  4. Connect a J 33431-C between the oil pressure switch connector terminal A and a good ground.
  5. Turn ON the ignition, with the engine OFF.
  6. Vary the resistance on the J 33431-C back and forth from 1ohms to 100 ohms of resistance.

Does the oil pressure gauge operate normally?

    • 0 ohms = no oil pressure
    • 88 ohms = maximum oil pressure

Go to Step 12

Go to Step 13

6

  1. Ensure that the engine oil level is correct.
  2. Ensure that the engine develops normal oil pressure. Refer to Oil Pressure Diagnosis and Testing in Engine Mechanical for 4.3L engines or Oil Pressure Diagnosis and Testing in Engine Mechanical for 4.8L, 5.3L, and 6.0L engines.
  3. Disconnect the oil pressure switch connector. Refer to Circuit Testing in wiring repairs.
  4. Turn ON the ignition, with the engine OFF.
  5. With a digital multimeter (DMM), measure the voltage between the oil pressure sensor signal circuit and a good ground. Refer to Circuit Testing in wiring systems.

Does the voltage measure within the specified range?

7-9.5 V

Go to Step 12

Go to Step 7

7

  1. In order to prevent damage to the terminal on the instrument cluster connector, backprobe with a DMM. Refer to Instrument Cluster Replacement and also refer to Circuit Testing in wiring systems.
  2. Measure the voltage between the oil pressure sensor signal circuit and a good ground. Refer to Circuit Testing in wiring systems.

Does the voltage measure within the specified range?

7-9.5 V

Go to Step 11

Go to Step 13

8

  1. Ensure that the engine oil level is correct.
  2. Ensure that the engine develops adequate oil pressure. Refer to Oil Pressure Diagnosis and Testing in Engine Mechanical for 4.3L engines or Oil Pressure Diagnosis and Testing in Engine Mechanical for 4.8L, 5.3L, and 6.0L engines.
  3. Turn ON the ignition, with the engine OFF.
  4. Disconnect the oil pressure sensor connector.

Does the oil pressure gauge remain past 80 psi?

--

Go to Step 12

Go to Step 9

9

  1. Disconnect the instrument cluster connector. Refer to Instrument Cluster Replacement .
  2. Remove the instrument cluster connector comb.
  3. Using a test lamp, test between a good power source and the oil pressure sensor signal circuit. Refer to Circuit Testing in wiring systems.

Does the test lamp illuminate?

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Go to Step 10

Go to Step 14

10

Repair the short to ground in the oil pressure sensor signal circuit. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 16

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11

Repair the open in the oil pressure sensor signal circuit. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 16

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12

Replace the oil pressure switch. Refer to Engine Oil Pressure Sensor and/or Switch Replacement in Engine Mechanical for 4.3L engines or Engine Oil Pressure Sensor and/or Switch Replacement in Engine Mechanical for 4.8L, 5.3L, and 6.0L engines.

Did you complete the replacement?

--

Go to Step 16

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13

  1. Disconnect the instrument cluster connector. Refer to Instrument Cluster Replacement .
  2. Remove the instrument cluster connector comb.
  3. Using a DMM, test for voltage between the oil pressure sensor signal circuit and a good ground. Refer to Circuit Testing in wiring systems.

Did you find a short to battery voltage?

--

Go to Step 15

Go to Step 14

14

Replace the instrument cluster. Refer to Instrument Cluster Replacement .

Did you complete the replacement?

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Go to Step 16

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15

Repair the short to battery voltage in the oil pressure sensor signal circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 16

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16

Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 3