GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Brake Warning System Schematics

Connector End View Reference: Hydraulic Brake Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Install a scan tool.
  2. Select the body control module (BCM) Special Functions menu on the scan tool.
  3. Command the instrument panel warning lamps ON.

Does the brake warning indicator illuminate?

Go to Step 3

Go to Step 10

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 3-amp fused jumper wire between the brake fluid level switch connector terminals.
  5. Turn ON the ignition with the engine OFF.

Does the brake warning indicator illuminate?

Go to Step 12

Go to Step 7

5

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

Does the brake warning indicator illuminate?

Go to Step 11

Go to Step 6

6

Test the park brake switch signal circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 14

Go to Step 9

7

Test the brake fluid level sensor signal circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 14

Go to Step 8

8

Inspect for poor connections at the following harness connectors:

    • BCM harness connector
    • Brake fluid level switch harness connector
    • Ground splice pack connector

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 14

Go to Step 13

9

Inspect for poor connections at the following harness connectors:

    • BCM harness connector
    • Park brake switch harness connector
    • Park brake switch case ground

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 14

Go to Step 13

10

Replace the instrument panel cluster (IPC). Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 14

--

11

Replace the park brake switch. Refer to Parking Brake Lever Pedal Assembly Replacement in Park Brake.

Did you complete the replacement?

Go to Step 14

--

12

Replace the brake fluid level switch. Refer to Brake Fluid Level Indicator Switch Replacement .

Did you complete the replacement?

Go to Step 14

--

13

Replace the BCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 14

--

14

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2