GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Hydraulic Brake Schematics

1

Did you review the brake warning system circuit description and perform the necessary inspections?

Go to Step 2

Go to Symptoms - Hydraulic Brakes

2

With the ignition switch ON, observe the brake warning indicator and perform a brake warning system test by meeting each of the conditions described in the circuit description.

Did the brake indicator illuminate and turn OFF for each condition?

Go to Testing for Electrical Intermittents

Go to Step 3

3

Disconnect the brake fluid level switch connector.

Did the brake indicator turn OFF?

Go to Step 4

Go to Step 5

4

Replace the brake fluid reservoir (which contains the fluid level switch). Refer to Master Cylinder Reservoir Replacement .

Did you complete the repair?

Go to Step 11

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5

Disconnect the DRL control module connector.

Did the brake indicator turn OFF?

Go to Step 7

Go to Step 6

6

Repair the short to ground in the brake indicator control circuit. Refer to Circuit Testing and to Wiring Repairs .

Did you correct the condition?

Go to Step 11

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7

  1. Disconnect the park brake switch connector.
  2. Test the park brake signal circuit for a short to ground. Refer to Circuit Testing and to Wiring Repairs .

Did you find and correct the condition?

Go to Step 11

Go to Step 8

8

Test the park brake switch for a short to ground. Refer to Circuit Testing and to Wiring Repairs .

Did you find the condition?

Go to Step 9

Go to Step 10

9

Replace the park brake switch.

Did you complete the repair?

Go to Step 11

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10

Replace the DRL control module. Refer to Daytime Running Lights (DRL) Control Module Replacement .

Did you complete the repair?

Go to Step 11

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11

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3