GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2004 🢒 Epica 🢒 Brakes 🢒 Hydraulic Brakes 🢒 Brake Warning System Check

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step begins the test sequence for a BRAKE warning lamp that stays on when the engine is running.

    2.

  2. This step begins the test sequence for a BRAKE warning lamp that never turns on.

Step

Action

Values

Yes

No

1

Start the engine and leave it running.

Does the BRAKE warning lamp stay on?

--

Go to Step 2

Go to Step 10

2

With the engine running, release the parking brake.

Is the BRAKE warning lamp OFF?

--

System OK

Go to Step 3

3

Inspect the brake fluid level.

Is the fluid level OK?

--

Go to Step 5

Go to Step 4

4
  1. Fill the brake fluid reservoir with clean DOT 3 or DOT 4 hydraulic fluid.
  2. Replace the cap on the fluid reservoir.
  3. Start the engine and leave it running.

Is the BRAKE warning lamp ON?

--

Go to Step 5

System OK

5

Disconnect the wiring harness connector from the brake fluid level switch at the master cylinder reservoir.

Is the BRAKE warning lamp ON?

--

Go to Step 7

Go to Step 6

6

Replace the brake fluid level switch.

Is the repair complete?

--

System OK

--

7
  1. Connect the brake fluid level switch.
  2. Disconnect the parking brake lever switch.
  3. Start the engine and leave it running.

Is the BRAKE warning lamp ON?

--

Go to Step 9

Go to Step 8

8

Replace the parking brake lever switch.

Is the repair complete?

--

System OK

--

9

Repair the short circuit in the instrument wiring harness between terminal C2 of the instrument cluster and ground.

Is the repair complete?

--

System OK

--

10
  1. Disconnect the electrical connector from the fluid level switch at the master cylinder reservoir.
  2. Connect a jumper wire between ground and terminal 1 of the fluid level switch harness connector.

Does the BRAKE warning lamp turn ON?

--

Go to Step 11

Go to Step 13

11
  1. Disconnect the electrical connector from the fluid level switch at the master cylinder reservoir.
  2. Connect a jumper wire between terminals 1 and 2 of the fluid level switch harness connector.

Does the BRAKE warning lamp turn ON?

--

Go to Step 12

Go to Step 13

12

Replace the brake fluid level switch on the master cylinder reservoir. The switch can be removed and replaced without draining the brake fluid from the reservoir.

Is the repair complete?

--

System OK

--

13
  1. Turn ON the ignition, with the engine OFF.
  2. Apply the parking brake.

Does the BRAKE warning lamp turn ON?

--

Go to Step 27

Go to Step 14

14

Inspect fuse F12.

Is fuse F12 open?

--

Go to Step 15

Go to Step 16

15
  1. Test for a short circuit and repair it, if necessary.
  2. Replace fuse F12.

Is the repair complete?

--

System OK

--

16
  1. Turn ON the ignition, with the engine OFF.
  2. Test the voltage at F12.

Is the voltage equal to the specified value?

11-14 V

Go to Step 18

Go to Step 17

17

Repair the power supply to fuse F12.

Is the repair complete?

--

System OK

--

18
  1. Disconnect terminal B14 of the instrument cluster.
  2. Turn ON the ignition, with the engine OFF.
  3. Use a voltmeter to test the voltage at terminal B14.

Is the voltage equal to the specified value?

11-14 V

Go to Step 20

Go to Step 19

19

Repair the open circuit between terminal B14 of the instrument cluster and fuse F12.

Is the repair complete?

--

System OK

--

20
  1. Reconnect terminal B14 of the instrument cluster.
  2. Turn ON the ignition, with the engine OFF.
  3. Use a voltmeter to backprobe terminal C2 of the instrument cluster.

Is the voltage equal to the specified value?

11-14 V

Go to Step 24

Go to Step 21

21
  1. Remove the BRAKE warning lamp from its socket.
  2. Test the BRAKE warning lamp.

Is the BRAKE warning lamp OK?

--

Go to Step 22

Go to Step 23

22

Replace the instrument cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gages and Console.

Is the repair complete?

--

System OK

--

23

Replace the BRAKE warning lamp.

Is the repair complete?

--

System OK

--

24
  1. Disconnect the parking brake switch connector.
  2. Connect a jumper wire between the switch connector and ground.
  3. Turn ON the ignition, with the engine OFF.

Is the BRAKE warning lamp ON?

--

Go to Step 25

Go to Step 26

25

Replace the PARK BRAKE warning lamp switch.

Is the repair complete?

--

System OK

--

26

Repair the open circuit between the PARK BRAKE warning lamp switch and terminal C2 of the instrument cluster.

Is the repair complete?

--

System OK

--

27
  1. Disconnect the brake fluid level switch at the master cylinder reservoir.
  2. Use an ohmmeter to measure the resistance between terminal 2 of the switch connector and ground.

Is the resistance equal to the specified value?

∞ ohms

Go to Step 28

Go to Step 29

28

Repair the open circuit between ground and the brake fluid level switch.

Is the repair complete?

--

System OK

--

29

Repair the open circuit between terminal 1 of the brake fluid level switch and terminal C2 of the instrument cluster.

Is the repair complete?

--

System OK

--