For 1990-2009 cars

## Engine Oil Pressure Gage Inaccurate or Inoperative Buick

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the Instrument Panel System Check performed? | -- | Go to Step 2 | Go to Instrument Cluster System Check
2 |

1. Turn the ignition switch to the OFF position.
2. Disconnect the oil pressure sensor/switch connector.
3. Connect 2 red leads from the J 33431-C tester to terminal A and terminal B.
4. Turn the ignition switch to the RUN position.
5. Set the tester resistance dial to 0 ohms (0 psi).
6. Set the tester resistance dial to 90 ohms (80 psi.

Does the scan tool display show the specified values?

• | 0 psi at 0 ohms

• | 120 psi at 90 ohms

Go to Step 4

Go to Step 3

3 | Inspect CKT 31 (TAN) for a short to ground, an open, or high resistance. Is the wiring OK? | -- | Go to Step 10 | Go to Step 9
4 | Inspect the oil pressure sensor/switch connector terminal A and terminal B for proper terminal contact. Is the contact OK? | -- | Go to Step 6 | Go to Step 8
5 | Inspect the following terminals for proper contact:

1. Connector C101 terminal A1
2. Connector C101 terminal A4
3. The instrument cluster connector terminal B10

Are the contacts OK?

--

Go to Step 7

Go to Step 12

6 | Replace the oil pressure sensor/switch. Refer to Engine Controls. Is the replacement complete? | -- | Go to Instrument Cluster System Check | --
7 | Replace the instrument cluster. Refer to the appropriate procedure:

• | Instrument Cluster Replacement

• | Instrument Cluster Replacement

• | Instrument Cluster Replacement

Is the replacement complete?

--

Go to Instrument Cluster System Check

--

8 | Repair poor terminal contact. Refer to Terminal Repairs in Wiring Systems. Is the repair complete? | -- | Go to Instrument Cluster System Check | --
9 | Repair the short to ground, open or high resistance in CKT 31 (TAN). Refer to Repairing Damaged Wire Insulation in Wiring Systems. Is the repair complete? | -- | Go to Instrument Cluster System Check | --
10 | Inspect CKT 251 (BLK/WHT) for an open or high resistance. Is the wiring OK? | -- | Go to Step 7 | Go to Step 11
11 | Repair the open or high resistance in CKT 251 (BLK/WHT). Refer to Repairing Damaged Wire Insulation in Wiring Systems. | -- | Go to Instrument Cluster System Check | --
12 | Repair the poor terminal contact. Refer to Terminal Repairs in Wiring Systems. Is the repair complete? | -- | Go to Instrument Cluster System Check | --

## Engine Oil Pressure Gage Inaccurate or Inoperative Oldsmobile

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the Instrument Panel System Check performed? | -- | Go to Step 2 | Go to Instrument Cluster System Check
2 |

1. Turn the ignition switch to the RUN position.
2. Use a scan tool IPC function. Read the diagnostic trouble codes (DTCs).

Does the scan tool display DTC B0029?

--

Go to Step 4

Go to Step 3

3 |

1. Turn the ignition switch to the OFF position.
2. Disconnect the oil pressure sensor/switch connector.
3. Connect 2 red leads from the J 33431-C tester to terminal A and terminal B.
4. Turn the ignition switch to the RUN position.
5. Use the scan tool IPC data list. Select "Oil Pressure".
6. Set the tester resistance dial to 0 ohms (0 psi).
7. Set the tester resistance dial to open circuit.

Does the scan tool display show the specified values?

• | Less than 2 psi at 0 ohms

• | 2-6 psi at open circuit

Go to Step 10

Go to Step 9

4 |

1. Turn the ignition switch to the OFF position.
2. Disconnect the oil pressure sensor/switch connector.
3. Connect a jumper from the oil pressure sensor/switch harness connector terminal A (TAN) to ground.
4. Turn the ignition switch to the RUN position.

Does the oil pressure indicator light?

--

Go to Step 6

Go to Step 5

5 | Inspect CKT 31 for an open or high resistance. Is the wiring OK? | -- | Go to Step 7 | Go to Step 14
6 | Inspect CKT 251 (BLK/WHT) for an open or high resistance. Is the wiring OK? | -- | Go to Step 8 | Go to Step 16
7 | Inspect the following terminals for proper contact:

1. Connector C101 terminal A4
2. The instrument cluster connector C2 terminal E2

Are the contacts OK?

--

Go to Step 13

Go to Step 15

8 | Inspect the following terminals for proper contact:

1. Connector C101 terminal A1
2. The oil pressure sensor/switch connector terminal A
3. The oil pressure sensor/switch connector terminal B

Are the contacts OK?

--

Go to Step 12

Go to Step 15

9 | Inspect CKT 31 for a short to ground, an open or high resistance. Is the wiring OK? | -- | Go to Step 18 | Go to Step 17
10 | Inspect for proper terminal contact at the oil pressure sensor/switch connector terminal A and terminal B. Are the contacts OK? | -- | Go to Step 12 | Go to Step 15
11 | Inspect the following terminals for proper terminal contact:

1. Connector C101 terminal A1
2. Connector C101 terminal A4
3. The instrument cluster connector C2 terminal E2

Are the contacts OK?

--

Go to Step 13

Go to Step 15

12 | Replace the oil pressure sensor/switch. Refer to Engine Controls. Is the replacement complete? | -- | Go to Instrument Cluster System Check | --
13 | Replace the instrument cluster. Refer to the appropriate procedure:

• | Instrument Cluster Replacement

• | Instrument Cluster Replacement

• | Instrument Cluster Replacement

Is the replacement complete?

--

Go to Instrument Cluster System Check

--

14 | Repair the open or high resistance on CKT 31 (TAN) Refer to Repairing Damaged Wire Insulation in Wiring Systems. Is the repair complete? | -- | Go to Instrument Cluster System Check | --
15 | Repair the poor terminal contacts. Refer to Terminal Repairs in Wiring Systems. Is the repair complete? | -- | Go to Instrument Cluster System Check | --
16 | Repair the open or high resistance on CKT 251 (BLK/WHT). Refer to Repairing Damaged Wire Insulation in Wiring Systems. Is the repair complete? | -- | Go to Instrument Cluster System Check | --
17 | Repair the open, short to ground or high resistance on CKT 31 (TAN). Refer to Repairing Damaged Wire Insulation in Wiring Systems. Is the repair complete? | -- | Go to Instrument Cluster System Check | --
18 | Inspect CKT 251 (BLK/WHT) for an open or high resistance. Is the wiring OK? | -- | Go to Step 11 | Go to Step 19
19 | Repair the open or high resistance on CKT 251 (BLK/WHT). Refer to Repairing Damaged Wire Insulation in Wiring Systems. Is the repair complete? | -- | Go to Instrument Cluster System Check | --

## Engine Oil Pressure Gage Inaccurate or Inoperative Pontiac

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the Instrument Panel System Check? | -- | Go to Step 2 | Go to Instrument Cluster System Check
2 |

1. Turn the ignition switch to the OFF position.
2. Disconnect the oil pressure sensor/switch connector.
3. Connect 2 red leads from the J 33431-C tester to terminal A and terminal B.
4. Turn the ignition switch to the RUN position.
5. Set the tester resistance dial to 0 ohms (0 psi).
6. Set the tester resistance dial to 90 ohms (120 psi.

Does the scan tool display show the specified values?

• | 0 psi at 0 ohms

• | 120 psi at 90 ohms

Go to Step 4

Go to Step 3

3 | Inspect CKT 31 (TAN) for a short to ground, an open, or high resistance. Is the wiring OK? | -- | Go to Step 10 | Go to Step 9
4 | Inspect the oil pressure sensor/switch connector terminal A and terminal B for proper terminal contact. Is the contact OK? | -- | Go to Step 6 | Go to Step 8
5 | Inspect the following terminals for proper contact:

1. Connector C101 terminal A1
2. Connector C101 terminal A4
3. Connector C200 terminal A5
4. Either of the following terminals:

• | For UB3, inspect the instrument cluster connector terminal A2.

• | For U5O or U2F, inspect the instrument cluster connector C2 terminal B1.

Are the contacts OK?

--

Go to Step 7

Go to Step 12

6 | Replace the oil pressure sensor/switch. Refer to Engine Controls. Is the replacement complete? | -- | Go to Instrument Cluster System Check | --
7 | Replace the instrument cluster. Refer to the appropriate procedure:

• | Instrument Cluster Replacement

• | Instrument Cluster Replacement

• | Instrument Cluster Replacement

Is the replacement complete?

--

Go to Instrument Cluster System Check

--

8 | Repair the poor terminal contact. Refer to Terminal Repairs in Wiring Systems. Is the repair complete? | -- | Go to Instrument Cluster System Check | --
9 | Repair the short to ground open or high resistance in CKT 31 (TAN) Refer to Repairing Damaged Wire Insulation in Wiring Systems. Is the repair complete? | -- | Go to Instrument Cluster System Check | --
10 | Inspect CKT 251 (BLK/WHT) for an open or high resistance. Is the wiring OK? | -- | Go to Step 7 | Go to Step 11
11 | Repair the open or high resistance in CKT 251(BLK/WHT). Refer to Repairing Damaged Wire Insulation in Wiring Systems. Is the repair complete? | -- | Go to Instrument Cluster System Check | --
12 | Repair the poor terminal contact. Refer to Terminal Repairs in Wiring Systems. Is the repair complete? | -- | Go to Instrument Cluster System Check | --