GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Brake Warning System Schematics

1

Did you review the hydraulic brakes operation and perform the necessary inspection?

Go to Step 2

Go to Symptoms - Hydraulic Brakes

2

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

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

Go to Step 3

Go to Step 11

3

  1. Turn ON the ignition, with the engine OFF.
  2. Apply the park brake.

Does the brake warning indicator illuminate?

Go to Step 4

Go to Step 7

4

  1. Turn OFF the ignition.
  2. Release the park brake.
  3. Disconnect the brake fluid level indicator switch.
  4. Connect a 3-amp fused jumper wire between the signal circuit of the brake fluid level indicator switch and a good ground.

Does the brake warning indicator illuminate?

Go to Step 5

Go to Step 9

5

Inspect for poor connections or a poor ground at the brake fluid level indicator switch.

Did you find and correct the condition?

Go to Step 17

Go to Step 6

6

Inspect brake fluid level indicator switch for proper operation.

Does the brake fluid level indicator switch work properly?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 15

7

  1. Disconnect the park brake warning lamp switch.
  2. Connect a 3-amp fused jumper wire between the signal circuit of the park brake warning lamp switch and ground.

Does the brake warning indicator illuminate?

Go to Step 10

Go to Step 8

8

  1. Turn OFF the ignition.
  2. Disconnect the body control module (BCM).
  3. Test the signal circuit of the park brake warning lamp switch for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 17

Go to Step 12

9

  1. Turn OFF the ignition.
  2. Disconnect the instrument panel cluster (IPC).
  3. Test the signal circuit of the brake fluid level indicator switch for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 17

Go to Step 11

10

Inspect for poor connections or a poor case ground at the park brake warning lamp switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 17

Go to Step 13

11

Inspect for poor connections at the harness connector of the IPC. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 17

Go to Step 14

12

Inspect for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 17

Go to Step 16

13

Replace the park brake warning lamp switch. Refer to Parking Brake Indicator Switch Replacement .

Did you complete the repair?

Go to Step 17

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14

Replace the IPC. Refer to Instrument Cluster Replacement .

Did you complete the repair?

Go to Step 17

--

15

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

Did you complete the repair?

Go to Step 17

--

16

Replace the BCM. Refer to Body Control Module Replacement for replacement, setup, and programming.

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