For 1990-2009 cars

Step | Action | Yes | No
--- | --- | --- | ---
SCHEMATIC REFERENCE: Brake Warning System Schematics
1 | Did you perform the Hydraulic Brake Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Hydraulic Brakes
2 |

1. Turn OFF the ignition.
2. Turn ON the ignition, with the engine OFF.
3. Observe the brake warning indicator.

Does the brake warning indicator illuminate briefly during the bulb check?

Go to Step 3

Go to Step 12

3 | Apply the park brake. Does the brake warning indicator illuminate? | Go to Step 4 | Go to Step 5
4 |

1. Turn OFF the ignition.
2. Release the park brake.
3. Disconnect the brake fluid level switch.
4. Connect a 3A fused jumper wire between the signal circuit of the brake fluid level switch and the ground circuit of the brake fluid level switch.
5. Turn ON the ignition with the engine OFF.

Does the brake warning indicator illuminate?

Go to Step 10

Go to Step 7

5 |

1. Turn OFF the ignition.
2. Release the park brake.
3. Disconnect the park brake switch.
4. Connect a 3A fused jumper wire between the signal circuit of the park brake switch and a good ground.
5. Turn ON the ignition with the engine OFF.

Does the brake warning indicator illuminate?

Go to Step 9

Go to Step 6

6 | Test the signal circuit of the park brake switch for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 17 | Go to Step 11
7 | Test the signal circuit of the brake fluid level switch for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 17 | Go to Step 8
8 | Test the ground circuit of the brake fluid level switch for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 17 | Go to Step 12
9 | Inspect for poor connections or a poor case ground at the park brake switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 17 | Go to Step 13
10 | Inspect for poor connections at the harness connector of the brake fluid level switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 17 | Go to Step 14
11 | Inspect for poor connections at the harness connector of the body control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 17 | Go to Step 15
12 | Inspect for poor connections at the harness connector of the electronic brake control module (EBCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 17 | Go to Step 16
13 | Replace the park brake switch. Refer to Parking Brake Indicator Switch Replacement in Park Brake. Did you complete the repair? | Go to Step 17 | --
14 | Replace the brake fluid level switch. Refer to Brake Fluid Level Indicator Switch Replacement . Did you complete the repair? | Go to Step 17 | --
15 | Replace the body control module. Refer to Body Control Module Replacement in Body Control System. Did you complete the repair? | Go to Step 17 | --
16 | Replace the EBCM. Refer to Electronic Brake Control Module Replacement in Antilock Brake System. Did you complete the repair? | Go to Step 17 | --
17 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2