For 1990-2009 cars

### Diagnostic Aids

The BRAKE lamp glows brightly when the ignition is ON and either the parking brake lever switch or the brake fluid level switch is closed. If neither switch is closed, the BRAKE lamp receives a ground through the generator, and it glows dimly when the ignition is ON and the engine is off. When the engine starts, the generator creates voltage. With voltage on both sides of the lamp, the lamp turns off.

### Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. This step begins the test sequence for a BRAKE warning lamp that stays on when the engine is running.

2. This step begins the test sequence for a BRAKE warning lamp that never turns on.

Step | Action | Values | Yes | No
--- | --- | --- | --- | ---
1 | Start the engine and leave it running. Does the BRAKE warning lamp stay on? | -- | Go to Step 2 | Go to Step 10
2 | With the engine running, release the parking brake. Is the BRAKE warning lamp off? | -- | System OK | Go to Step 3
3 | Check the brake fluid level. Is the fluid level OK? | -- | Go to Step 5 | Go to Step 4
4 |

1. Fill the brake fluid reservoir with clean DOT-4 hydraulic fluid.
2. Replace the cap on the fluid reservoir.
3. Start the engine and leave it running.

Is the BRAKE warning lamp on?

--

Go to Step 5

System OK

5 | Disconnect the wiring harness connector from the brake fluid level switch at the master cylinder reservoir. Is the BRAKE warning lamp on? | -- | Go to Step 7 | Go to Step 6
6 | Replace the brake fluid level switch. Is the repair complete? | -- | System OK | --
7 |

1. Connect the brake fluid level switch.
2. Disconnect the parking brake lever switch.
3. Start the engine and leave it running.

Is the BRAKE warning lamp on?

--

Go to Step 9

Go to Step 8

8 | Replace the parking brake lever switch. Is the repair complete? | -- | System OK | --
9 | Repair the short circuit in the instrument wiring harness between terminal 14 of the instrument cluster and ground. Is the repair complete? | -- | System OK | --
10 |

1. Disconnect the electrical connector from the fluid level switch at the master cylinder reservoir.
2. Connect a jumper wire between ground and terminal 1 of the fluid level switch harness connector.

Does the BRAKE warning lamp turn on?

--

Go to Step 11

Go to Step 13

11 |

1. Disconnect the electrical connector from the fluid level switch at the master cylinder reservoir.
2. Connect a jumper wire between terminal 1 and 2 of the fluid level switch harness connector.

Does the BRAKE warning lamp turn on?

--

Go to Step 12

Go to Step 13

12 | Replace the brake fluid level switch on the master cylinder reservoir. The switch can be removed and replaced without draining the brake fluid from the reservoir. Is the repair complete? | -- | System OK | --
13 |

1. Turn the ignition ON.
2. Apply the parking brake.

Does the BRAKE warning lamp turn on?

--

Go to Step 27

Go to Step 14

14 | Check fuse F28 and F13. Is fuse F12 blown? | -- | Go to Step 15 | Go to Step 16
15 |

1. Check for a short circuit and repair it, if necessary.
2. Replace fuse F28 and F13.

Is the repair complete?

--

System OK

--

16 |

1. Turn the ignition ON.
2. Check the voltage at F28 and F13.

Is the voltage equal to the specified value?

11-14 V

Go to Step 18

Go to Step 17

17 | Repair the power supply to fuse F28 and F13. Is the repair complete? | -- | System OK | --
18 |

1. Disconnect terminal 1 and 2 of the instrument cluster.
2. Turn the ignition ON.
3. Use a voltmeter to check the voltage at terminal 1 and 2.

Is the voltage equal to the specified value?

11-14 V

Go to Step 20

Go to Step 19

19 | Repair the open circuit between terminal 1 and 2 of the instrument cluster and fuse F28 and F13. Is the repair complete? | -- | System OK | --
20 |

1. Reconnect terminal 1 and 2 of the instrument cluster.
2. Turn the ignition ON.
3. Use a voltmeter to backprobe terminal 14 of the instrument cluster.

Is the voltage equal to the specified value?

11-14 V

Go to Step 24

Go to Step 24

21 |

1. Remove the BRAKE warning lamp from its socket.
2. Test the BRAKE warning lamp.

Is the BRAKE warning lamp OK?

--

Go to Step 22

Go to Step 23

22 | Replace the instrument cluster. Is the repair complete? | -- | System OK | --
23 | Replace the BRAKE warning lamp. Is the repair complete? | -- | System OK | --
24 |

1. Disconnect the parking brake switch connector.
2. Connect a jumper wire between the switch connector and ground.
3. Turn the ignition ON.

Is the BRAKE warning lamp on?

--

Go to Step 25

Go to Step 26

25 | Replace the BRAKE warning lamp switch. Is the repair complete? | -- | System OK | --
26 | Repair the open circuit between the BRAKE warning lamp switch and terminal 14 of the instrument cluster. Is the repair complete? | -- | System OK | --
27 |

1. Disconnect the brake fluid level switch at the master cylinder reservoir.
2. Use an ohmmeter to check the resistance between terminal 2 of the switch connector and ground.

Is the resistance equal to the specified value?

0 ohms

Go to Step 28

Go to Step 29

28 | Repair the open circuit between ground and the brake fluid level switch. Is the repair complete? | -- | System OK | --
29 | Repair the open circuit between terminal 1 of the brake fluid level switch and terminal 14 of the instrument cluster. Is the repair complete? | -- | System OK | --