GM Service Manual Online
For 1990-2009 cars only

Engine Oil Pressure Gauge Always Low Gasoline

Step

Action

Value(s)

Yes

No

1

Was the Instrument Cluster System Check performed?

--

Go to Step 2

Go to Instrument Cluster System Check

2

  1. With the engine in operation, measure the actual engine oil pressure.
  2. Compare the actual engine oil pressure with the specified value.

Is the difference between the actual engine oil pressure and the specified engine oil pressure less than 68.95 kPa (10 psi)?

68.95 kPa (10 psi)

Go to Step 3

Go to Step 4

3

The oil pressure gauge functions properly.

Inspect the engine for operating conditions, as necessary.

Does the engine oil pressure gauge operate properly?

--

Go to Instrument Cluster System Check

Go to Step 4

4

  1. Disconnect the connector at the fuel pump switch and the oil pressure gauge sensor.
  2. Place the ignition switch in the RUN position.
  3. Connect 1  red lead of a J 33431-C at the fuel pump switch and the oil pressure gauge, cavity A for CKT 31 (TAN).
  4. Connect the other lead to ground.
  5. Adjust the tester to 88 ohms.

Does the oil pressure gauge indicate pressure greater than the specified value?

211.60 kPa (80 psi)

Go to Step 5

Go to Step 6

5

Replace the fuel pump switch and the oil pressure gauge.

Does the engine oil pressure gauge operate properly?

--

Go to Instrument Cluster System Check

Go to Step 6

6

  1. Disconnect the connector at the instrument cluster.
  2. Connect a J 39200 between the instrument cluster connector, cavity B8 and ground.

Is continuity present?

--

Go to Step 7

Go to Step 8

7

Repair the short to ground in CKT 31 (TAN) between the instrument cluster and the fuel pump switch and the oil pressure gauge.

Does the engine oil pressure gauge operate properly?

--

Go to Instrument Cluster System Check

--

8

Replace the instrument cluster. Refer to Instrument Cluster Replacement .

Does the engine oil pressure gauge operate properly?

--

Go to Instrument Cluster System Check

--

Engine Oil Pressure Gauge Always Low Diesel

Step

Action

Value(s)

Yes

No

1

Was the Instrument Cluster System Check performed?

--

Go to Step 2

Go to Instrument Cluster System Check

2

  1. With the engine in operation, measure the actual engine oil pressure.
  2. Compare the actual engine oil pressure with the specified value.

Is the difference between the actual engine oil pressure and the specified engine oil pressure less than 68.95 kPa (10 psi)?

68.95 kPa (10 psi)

Go to Step 3

Go to Step 4

3

The oil pressure gauge functions properly.

Inspect the engine for operating conditions, as necessary.

Does the engine oil pressure gauge operate properly?

--

Go to Instrument Cluster System Check

Go to Step 4

4

  1. Disconnect the connector at the fuel pump switch and the engine oil pressure indicator sender.
  2. Place the ignition switch in the RUN position.
  3. Connect 1  red lead of a J 33431-C at the fuel pump switch and the engine oil pressure indicator sender, cavity A for CKT 31 (TAN).
  4. Connect the other lead to ground.
  5. Adjust the tester to 88 ohms.

Does the oil pressure gauge indicate pressure greater than the specified value?

211.60 kPa (80 psi)

Go to Step 5

Go to Step 6

5

Replace the fuel pump switch and the engine oil pressure indicator sender.

Does the engine oil pressure gauge operate properly?

--

Go to Instrument Cluster System Check

Go to Step 6

6

  1. Disconnect the connector at the instrument cluster.
  2. Connect a J 39200 between the instrument cluster connector, cavity B8 and ground.

Is continuity present?

--

Go to Step 7

Go to Step 8

7

Repair the short to ground in CKT 31 (TAN) between the instrument cluster and the fuel pump switch and the engine oil pressure indicator sender.

Does the engine oil pressure gauge operate properly?

--

Go to Instrument Cluster System Check

--

8

Replace the instrument cluster. Refer to Instrument Cluster Replacement .

Does the engine oil pressure gauge operate properly?

--

Go to Instrument Cluster System Check

--

Engine Oil Pressure Gauge Always Low Gasoline Export

Step

Action

Value(s)

Yes

No

1

Was the Instrument Cluster System Check performed?

--

Go to Step 2

Go to Instrument Cluster System Check

2

  1. Operate the vehicle.
  2. Inspect the actual engine oil pressure
  3. Inspect the oil pressure gauge.

Are the actual engine oil pressure and the oil pressure gauge readings within 10 psi of each other?

--

Go to Step 3

Go to Step 4

3

Inspect the engine for operating problems.

Is the repair complete?

--

Go to Instrument Cluster System Check

--

4

  1. Disconnect the connector at the fuel pump switch and oil pressure gauge sensor.
  2. Turn the ignition switch to the RUN position.
  3. Connect one red lead of the J 33431-C at the fuel pump switch and oil pressure gauge sensor connector cavity A for the CKT 31 (TAN) wire.
  4. Connect the other lead to ground.
  5. Adjust the J 33431-C to 88 ohms.
  6. Observe the oil pressure gauge.

Does the oil pressure gauge indicate approximately 80 ohms?

--

Go to Step 5

Go to Step 6

5

Replace the fuel pump switch and oil pressure gauge sensor.

Is the repair complete?

--

Go to Instrument Cluster System Check

--

6

  1. Disconnect the connector at the instrument cluster.
  2. Connect a J 39200 between the following components:
  3. • The instrument cluster connector cavity B8
    • Ground

Is continuity present?

--

Go to Step 7

Go to Step 8

7

  1. Locate the short to ground in the CKT 31 (TAN) wire between the following components:
  2. • The instrument cluster
    • The fuel pump switch and oil pressure gauge sensor
  3. Repair the short to ground in the CKT 31 (TAN) wire between the following components:
  4. • The instrument cluster
    • The fuel pump switch and oil pressure gauge sensor

Is the repair complete?

--

Go to Instrument Cluster System Check

--

8

Replace the instrument cluster.

Is the repair complete?

--

Go to Instrument Cluster System Check

--

Engine Oil Pressure Gauge Always Low Diesel Export

Step

Action

Value(s)

Yes

No

1

Was the Instrument Cluster System Check performed?

--

Go to Step 2

Go to Instrument Cluster System Check

2

  1. Operate the vehicle.
  2. Inspect the actual engine oil pressure
  3. Inspect the oil pressure gauge.

Are the actual engine oil pressure and the oil pressure gauge readings within 10 psi of each other?

--

Go to Step 3

Go to Step 4

3

Inspect the engine for operating problems.

Is the repair complete?

--

Go to Instrument Cluster System Check

--

4

  1. Disconnect the connector at the engine oil pressure indicator sender.
  2. Turn the ignition switch to the RUN position.
  3. Connect one red lead of the J 33431-C at the engine oil pressure indicator sender connector cavity A for the CKT 31 (TAN) wire.
  4. Connect the other lead to ground.
  5. Adjust the J 33431-C to 88 ohms.
  6. Observe the oil pressure gauge.

Does the oil pressure gauge indicate approximately 80 ohms?

--

Go to Step 5

Go to Step 6

5

Replace the engine oil pressure indicator sender.

Is the repair complete?

--

Go to Instrument Cluster System Check

--

6

  1. Disconnect the connector at the instrument cluster.
  2. Connect a J 39200 between the following components:
  3. • The instrument cluster connector cavity B8
    • Ground

Is continuity present?

--

Go to Step 7

Go to Step 8

7

  1. Locate the short to ground in the CKT 31 (TAN) wire between the following components:
  2. • The instrument cluster
    • The engine oil pressure indicator sender
  3. Repair the short to ground in the CKT 31 (TAN) wire between the following components:
  4. • The instrument cluster
    • The fuel pump switch and oil pressure gauge sensor

Is the repair complete?

--

Go to Instrument Cluster System Check

--

8

Replace the instrument cluster.

Is the repair complete?

--

Go to Instrument Cluster System Check

--