GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Brake Warning System Schematics

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. Turn OFF the ignition.
  2. Turn ON the ignition, with the engine OFF.
  3. Observe the red Brake indicator.

Does the red Brake indicator illuminate briefly during the bulb check?

Go to Step 3

Go to Step 11

3

Apply the park brake.

Does the red Brake 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 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 red Brake indicator illuminate?

Go to Step 10

Go to Step 7

5

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

Does the red Brake 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 15

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 15

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 15

Go to Step 11

9

Inspect for poor case ground or poor connections at the harness connector of 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 15

Go to Step 12

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 15

Go to Step 13

11

Inspect for poor connections at the harness connector of the body control module (BCM). 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 15

Go to Step 14

12

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

Did you complete the repair?

Go to Step 15

--

13

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

Did you complete the repair?

Go to Step 15

--

14

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

Did you complete the repair?

Go to Step 15

--

15

Operate the vehicle in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2