For 1990-2009 cars

## Brake Warning Indicator Inoperative Buick

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the Brake Warning System Check? | -- | Go to Step 2 | Go to Brake Warning System Check
2 | Did the BRAKE indicator illuminate briefly during the bulb check (when the ignition switch transitions from RUN to START)? | -- | Go to Step 19 | Go to Step 3
3 |

1. Disconnect the brake fluid level sensor.
2. Connect a DMM between terminal C of the brake fluid level sensor harness connector and ground.
3. Turn the ignition switch to the RUN position.

Is the measured voltage within the specified range?

10-15V

Go to Step 4

Go to Step 8

4 | Connect the DMM between the connector terminals C and B. Is the measured voltage within the specified range? | 10-15V | Go to Step 14 | Go to Step 8
5 | Connect the DMM between the connector terminal B and ground. Is the measured voltage within the specified range? | 10-15V | Go to Step 6 | Go to Step 7
6 | Repair CKT 875 (LT GRN/BLK) for a short to positive voltage. Did you complete the repair? | -- | Go to Brake Warning System Check | --
7 | Repair the open in CKT 875 (LT GRN/BLK). Did you complete the repair? | -- | Go to Brake Warning System Check | --
8 |

1. Turn the ignition switch to OFF.
2. Disconnect the instrument cluster connectors.
3. Connect a fused jumper between the instrument cluster harness connector C1, terminals E15 and E16.
4. Turn the ignition switch to RUN.

Is the measured voltage within the specified range?

10-15V

Go to Step 15

Go to Step 9

9 | Connect the fused jumper between the harness connector C1, terminal E16 and battery positive voltage. Is the measured voltage within the specified range? | 10-15V | Go to Step 13 | Go to Step 10
10 | Connect the fused jumper between the harness connector C1, terminal E16 and ground. Is the measured voltage within the specified range? | 10-15V | Go to Step 11 | Go to Step 12
11 | Repair the short to positive voltage in CKT 33 (TAN/WHT). Did you complete the repair? | -- | Go to Brake Warning System Check | --
12 | Repair the open in CKT 875 (LT GRN/BLK). Did you complete the repair? | -- | Go to Brake Warning System Check | --
13 | Repair the open in CKT 39 (PNK). Did you complete the repair? | -- | Go to Brake Warning System Check | --
14 | Replace the brake fluid level sensor. Did you complete the repair? | -- | Go to Brake Warning System Check | --
15 | Inspect the instrument cluster BRAKE indicator. Does an open exist? | -- | Go to Step 17 | Go to Step 16
16 | Inspect the instrument cluster BRAKE indicator circuit for an open. Does an open exist? | -- | Go to Step 18 | Go to Brake Warning System Check
17 | Replace the instrument cluster BRAKE indicator. Did you complete the repair? | -- | Go to Brake Warning System Check | --
18 | Replace the instrument cluster. Did you complete the repair? | -- | Go to Brake Warning System Check | --
19 |

1. Disconnect the park brake switch.
2. Connect a DMM between the park brake switch harness connector terminal A and ground.
3. Turn the ignition switch to the RUN position.

Is the measured voltage within the specified range?

10-15V

Go to Step 20

Go to Step 21

20 | Replace the park brake switch. Did you complete the repair? | -- | Go to Brake Warning System Check | --
21 | Repair the open in CKT 33 (TAN/WHT). Did you complete the repair? | -- | Go to Brake Warning System Check | --

## Brake Warning Indicator Inoperative Oldsmobile

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the Brake Warning System Check? | -- | Go to Step 2 | Go to Brake Warning System Check
2 | Did the PARK indicator illuminate briefly during the bulb check (when the ignition switch transitions from RUN to START)? | -- | Go to Step 3 | Go to Step 4
3 | Did the PARK indicator illuminate when the park brake was applied? | -- | Go to Step 11 | Go to Step 9
4 |

1. Disconnect the instrument cluster connectors.
2. Connect a DMM between the instrument cluster harness connector C2, terminals A9 and B11.
3. Briefly turn the ignition switch to START (do not start the engine).

Is the voltage within the specified range?

10-15V

Go to Step 20

Go to Step 5

5 | Connect the DMM between the connector terminal B11 and ground. Is the voltage within the specified range? | 10-15V | Go to Step 6 | Go to Step 16
6 |

1. Disconnect C202.
2. Connect the DMM between the instrument cluster harness connector C2, terminal A9 and C202 terminal B3 (body harness side).

Is the resistance less than the specified range?

5 ohms

Go to Step 7

Go to Step 8

7 | Repair open in CKT 33 (TAN/WHT) between C202 and the ignition switch. If the circuit is open, test for a short to positive voltage. Did you complete the repair? | -- | Go to Brake Warning System Check | --
8 | Repair open in CKT 33 (TAN/WHT) between C202 and the instrument cluster. If the circuit is open, test for a short to positive voltage. Did you complete the repair? | -- | Go to Brake Warning System Check | --
9 |

1. Disconnect the park brake switch connector.
2. Connect a DMM between the park brake switch harness connector terminal A and ground.
3. Turn the ignition switch to the RUN position.

Is the measured voltage within the specified range?

10-15V

Go to Step 17

Go to Step 10

10 | Repair open in CKT 33 (TAN/WHT) between S226 and the park brake switch. If the circuit is open, test for a short to positive voltage. Did you complete the repair? | -- | Go to Brake Warning System Check | --
11 |

1. Disconnect the brake fluid level sensor.
2. Connect a DMM between the brake fluid level sensor harness connector terminals C and B.
3. Briefly turn the ignition switch to START (do not start the engine).

Is the measured voltage within the specified range?

10-15V

Go to Step 18

Go to Step 12

12 |

1. Connect the DMM between the brake fluid level sensor harness connector terminal C and ground.
2. Turn the ignition switch to the RUN position.

Is the measured voltage within the specified range?

10-15V

Go to Step 19

Go to Step 13

13 |

1. Disconnect the remote indicator bank connector.
2. Connect a fused jumper between the brake fluid level sensor harness connector terminal C and ground.
3. Connect the DMM between the remote indicator bank connector terminals A1 and A3.
4. Turn the ignition switch to the RUN position.

Is the measured voltage within the specified range?

10-15V

Go to Step 21

Go to Step 14

14 |

1. Connect the DMM between the remote indicator bank connector terminals A1 and ground.
2. Turn the ignition switch to the RUN position.

Is the measured voltage within the specified range?

10-15V

Go to Step 15

Go to Step 16

15 | Repair open in CKT 33 (TAN/WHT). If the circuit is open, test for a short to positive voltage. Did you complete the repair? | -- | Go to Brake Warning System Check | --
16 | Repair open in CKT 39 (PNK). If the circuit is open, test for a short to positive voltage. Did you complete the repair? | -- | Go to Brake Warning System Check | --
17 | Replace the park brake switch. Did you complete the repair? | -- | Go to Brake Warning System Check | --
18 | Replace the brake fluid level sensor. Did you complete the repair? | -- | Go to Brake Warning System Check | --
19 | Repair open in CKT 875 (LT GRN/BLK). If the circuit is open, test for a short to positive voltage. Did you complete the repair? | -- | Go to Brake Warning System Check | --
20 | Check instrument cluster PARK indicator and the circuit for an open. Did you complete the repair? | -- | Go to Brake Warning System Check | --
21 | Check instrument cluster BRAKE FLUID indicator and the circuit for an open. Did you complete the repair? | -- | Go to Brake Warning System Check | --