For 1990-2009 cars

## Tachometer Inoperative Buick

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the Instrument Cluster 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 ignition control module connector.
3. Plug the J 33431-C IP Tester into a wall outlet.
4. Connect the J 33431-C harness adapter to the IP Tester.
5. Connect the J 33431-C harness adapter black lead to ground.
6. Connect the red lead to the ignition control module connector terminal E.
7. Set the J 33431-C IP Tester to 54 mph (60 Hz).
8. Turn the power switch to the ON position.
9. Turn the ignition switch to the RUN position.

Does the tachometer read approximately the specified value?

1350 RPM

Go to Step 5

Go to Step 3

3 | Inspect CKT 121 (WHT) for an open or a short to ground. Is the wiring OK? | -- | Go to Step 6 | Go to Step 4
4 |

1. Inspect the Instrument Cluster terminal B15 (UB3) or connector C2 terminal B9 (U5O or U2F) for proper terminal contact.
2. If OK, replace the instrument cluster. Refer to Instrument Cluster Replacement .

Is the repair complete?

--

Go to Instrument Cluster System Check

--

5 | Inspect connector C101 for proper terminal contact at terminal J7. Is the contact OK? | -- | Go to Instrument Cluster System Check | --
6 | Inspect connector C200 for proper terminal contact at terminal A6. Is the contact OK? | -- | Go to Instrument Cluster System Check | --
7 | Inspect the instrument cluster connector for proper terminal contact at terminal B4. Is the contact OK? | -- | Go to Step 8 | --
8 | Replace the instrument cluster. Is the repair complete? | -- | Go to Instrument Cluster System Check | --
9 | Inspect the ignition control module connector for proper terminal contact. Is the contact OK? | -- | Go to Step 10 | --
10 | Replace the ignition control module. Refer to Ignition Control Module Replacement in Engine Controls. Is the replacement complete? | -- | Go to Instrument Cluster System Check | --

## Tachometer Inoperative Pontiac

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the Instrument Cluster 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 ignition control module connector.
3. Plug the J 33431-C IP Tester into a wall outlet.
4. Connect the J 33431-C harness adapter to the IP Tester.
5. Connect the J 33431-C harness adapter black lead to ground.
6. Connect the red lead to the ignition control module connector terminal E.
7. Set the J 33431-C IP Tester to 54 mph (60 Hz).
8. Turn the power switch to the ON position.
9. Turn the ignition switch to the RUN position.

Does the tachometer read approximately the specified value?

1350 RPM

Go to Step 5

Go to Step 3

3 | Inspect CKT 121 (WHT) for an open or a short to ground. Is the wiring OK? | -- | Go to Step 6 | Go to Step 4
4 |

1. Inspect the instrument cluster terminal B15 (UB3) or connector C2 terminal B9 (U50) or (U2F) for proper terminal contact.
2. If the terminal is OK, replace the instrument cluster. Refer to Instrument Cluster Replacement .

Is the repair complete?

--

Go to Instrument Cluster System Check

--

5 |

1. Inspect the ignition control module connector for proper terminal contact.
2. If OK, replace the ignition control module. Refer to Ignition Control Module Replacement in Engine Controls.

Is the repair complete?

--

Go to Instrument Cluster System Check

--

6 | Repair an open or short to ground in CKT 121 (WHT). Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Instrument Cluster System Check | --

## Tachometer Inoperative Oldsmobile

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the Instrument Cluster 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 ignition control module connector.
3. Plug the J 33431-C IP Tester into a wall outlet.
4. Connect the J 33431-C harness adapter to the IP Tester.
5. Connect the J 33431-C harness adapter black lead to ground.
6. Connect the red lead to the ignition control module connector terminal E.
7. Set the J 33431-C IP Tester to 54 mph (60 Hz).
8. Turn the power switch to the ON position.
9. Turn the ignition switch to the RUN position.

Does the tachometer read approximately the specified value?

1350 RPM

Go to Step 6

Go to Step 3

3 | Inspect CKT 121 (WHT) for an open or a short to ground. Did you find an open or short to ground in CKT 121? | -- | Go to Step 4 | --
4 |

1. Inspect the instrument cluster connector C2 terminal E8 (OLDSMOBILE) or terminal B4 (BUICK) for proper terminal contact.
2. If the terminal is OK, replace the instrument cluster. Refer to Instrument Cluster Replacement .

Is the repair complete?

--

Go to Instrument Cluster System Check

--

5 |

1. Inspect the ignition control module connector for proper terminal contact.
2. If the connector is OK, replace the ignition control module. Refer to Ignition Control Module Replacement in Engine Controls.

Did you complete the repair?

--

Go to Instrument Cluster System Check

--

6 | Repair an open or short to ground in CKT 121 (WHT). Refer to Repairing Damaged Wire Insulation in Wiring Systems. Did you complete the repair? | -- | Go to Instrument Cluster System Check | --