GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Aveo 🢒 Brakes 🢒 Hydraulic Brakes 🢒 Brake Warning System Check

Test Description

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

  1. There are 3 possible symptoms of a problem: the brake warning lamp is always ON, the brake warning lamp is never ON, or the brake warning lamp will not operate for a particular function. This test takes you to the appropriate starting point in the procedure.

    2.

  2. This test checks whether the Antilock Brake System (ABS) has turned ON the brake warning lamp. If the vehicle is not equipped with ABS, the answer will be NO.

    3.

  3. This step tests for simple conditions that can turn ON the brake warning lamp.

    4.

  4. This step tests for simple conditions that can turn ON the brake warning lamp.

    5.

  5. This checks whether the brake fluid level switch is faulty.

    6.

  6. This checks whether the parking brake switch is faulty.

    7.

  7. This removes the circuit to the electronic brake control module (EBCM) in a vehicle with ABS.

    8.

  8. This removes the parking brake switch circuit.

    9.

  9. This removes the brake fluid level switch circuit.

    10.

  10. This checks the only remaining circuitry that can activate the brake warning lamp.

    11.

  11. This tests for the presence of battery voltage used by both the oil pressure lamp and the brake warning lamp.

    12.

  12. This step begins a sequence that will restore voltage to the lamps.

    13.

  13. This checks for a burned out indicator lamp.

    14.

  14. This begins a sequence that will find the opening that prevents contact to ground needed to operate the lamp.

    15.

  15. This checks whether the ABS system has tried to turn ON the brake warning lamp and could not. If the vehicle is not equipped with ABS, the answer is no.

    16.

  16. This step begins a search for a problem in the parking brake switch circuit.

    17.

  17. This step begins a search for a problem in the brake fluid level switch circuit.

Step

Action

Values

Yes

No

A low brake fluid level in the master cylinder will turn the brake lamp ON. Refer to Diagnostic Starting Point - Hydraulic Brakes to test for fluid leaks.

1

Turn the ignition ON.

Is the brake warning lamp always ON?

--

Go to Step 2

Go to Step 19

2

Inspect the ABS warning lamp.

Is the ABS warning lamp also ON?

--

Go to Step 3

Go to Step 3

3

Use a scan tool to check for diagnostic trouble codes (DTCs) and follow the procedures for any DTCs found.

Is the lamp still ON?

--

Go to Step 4

System OK

4

Release the parking brake fully.

Is the lamp OFF?

--

System OK

Go to Step 5

5

Inspect the brake fluid level.

Is the fluid level acceptable?

--

Go to Step 7

Go to Step 6

6
  1. Fill the brake fluid reservoir with clean DOT 3 equivalent hydraulic fluid.
  2. Replace the cap on the brake fluid reservoir.

Is the lamp still ON?

--

Go to Step 7

System OK

7

Unplug the harness connector from the brake fluid sensor switch.

Is the lamp still ON?

--

Go to Step 9

Go to Step 8

8

Replace the parking brake lever switch.

Is the repair complete?

--

System OK

--

9

  1. Reconnect the brake fluid level switch.
  2. Remove the rear console cover to expose the parking brake mechanism.
  3. Release the brake completely.
  4. Slide off the terminal with the BN/BK wire from the wiring harness.

Does the lamp go out?

--

Go to Step 10

Go to Step 11

10

Replace the switch.

Is the repair complete?

--

System OK

--

11

Replace the terminal back onto the switch.

Is the vehicle equipped with ABS?

--

Go to Step 12

Go to Step 14

12

Unplug connector C201.

Does the lamp go out?

--

Go to Step 13

Go to Step 14

13

Repair the short to ground in circuit BN between terminal 5 of connector C201 and terminal 33 on the electronic brake control module (EBCM).

Is the repair complete?

--

System OK

--

14

Disconnect connector C213.

Is the lamp still ON?

--

Go to Step 16

Go to Step 15

15

Repair the short to ground in circuit BN between connector C213 and connector C201 or between connector C213 and the parking brake switch.

Is the repair complete?

--

System OK

--

16

Disconnect connector C201.

Does the lamp go out?

--

Go to Step 17

Go to Step 18

17

Repair the short to ground in circuit BN between connector C201 and the brake fluid level switch.

Is the repair complete?

--

System OK

--

18

Repair the short to ground in circuit BN between terminal 11 of the instrument cluster ad connector C201 or connector C213.

Is the repair complete?

--

System OK

--

19

Inspect the brake lamp after doing each of the following functions:

    • Apply the parking brake.
    • Remove the cap from the brake fluid reservoir.
    • Command the lamp ON using a scan tool.

Does the brake warning lamp operate for any of these conditions?

--

Go to Step 32

Go to Step 20

20

Turn the ignition ON.

Does the oil pressure indicator light?

--

Go to Step 24

Go to Step 21

21

Inspect fuse 4.

Is the fuse in good condition?

--

Go to Step 23

Go to Step 22

22

Replace fuse 4 with another 10-amp fuse.

Does the brake warning lamp function now?

--

System OK

--

23

Inspect EF7 in the engine fuse block.

Is EF7 in good condition?

--

Go to Step 25

Go to Step 24

24

Replace EF7 with another 30-amp device.

Is the repair complete?

--

System OK

--

25
  1. Unplug C206 from the connection box behind the left-side kick panel. This is the large connector at the bottom of the box.
  2. Use a digital volt meter (DVM) to measure voltage from terminal 11 of the cluster.

Does the DVM indicate the specified voltage?

11-14 V

Go to Step 27

Go to Step 26

26

Repair the open in circuit PK from terminal 11 in the connection box fuse 4 in the instrument panel (I/P) fuse block.

Is the repair complete?

--

System OK

--

27
  1. Reconnect harness terminal 11 to the connection box.
  2. Gain access to the rear of the instrument cluster.
  3. Unplug the instrument 10-pin cluster connector.
  4. Use a DVM to measure the voltage from terminal 6 of the instrument cluster connector to ground.

Does the DVM show the specified value?

11-14 V

Go to Step 28

Go to Step 29

28

Repair the open in circuit PK between terminal 6 and 11 or from there in circuit BN to terminal 10 of connector C201.

Is the repair complete?

--

System OK

--

29

Remove the brake indicator lamp from its socket and examine it.

Is the lamp burned out?

--

Go to Step 30

Go to Step 31

30

Replace the brake indicator lamp.

Is the repair complete?

--

System OK

--

31

  1. Return the brake indicator lamp to its socket, the instrument cluster.
  2. Look for the opening in circuit BN between terminal 11 of the cluster and terminal 10 of connector C201.
  3. Repair any open found in circuit BN/BK.

Is the repair complete?

--

System OK

--

32

Check the ABS lamp.

Is the ABS lamp flashing?

--

Go to Step 33

Go to Step 34

33

Use a scan tool to determine what DTCs are present and repair them according to the tables for the DTCs involved.

Is the repair complete?

--

System OK

--

34

Try applying the parking brake fully.

Does the brake warning lamp fail to light when the parking brake is applied?

--

Go to Step 35

Go to Step 38

35

Expose the parking brake mechanism by removing the rear console. Use a jumper to short the terminal from the BN wire to ground.

Does the lamp come ON?

--

Go to Step 36

Go to Step 37

36

Replace the parking brake switch or repair the grounding between the parking brake switch and the brake handle mounting or between the brake handle mounting and the vehicle body.

Is the repair complete?

--

System OK

--

37

Repair the open in circuit BN. This will be in one of two places:

    • The I/P harness between terminal 6 of cluster and terminal 15 of connector C213
    • The floor harness between terminal 10 of connector C213 and the parking brake switch

Is the repair complete?

--

System OK

--

38

If the brake warning lamp is not indicating low brake fluid, remove the cap from the brake fluid reservoir to lift the sensor from the brake fluid.

Does the lamp come ON?

--

System OK

Go to Step 39

39
  1. Unplug the harness connector from the sensor on the brake fluid reservoir cap.
  2. Use a jumper to short the terminals in the harness connector together.

Does the lamp come ON?

--

Go to Step 40

Go to Step 41

40

Install a new fluid level sensor switch into the brake fluid reservoir.

Is the repair complete?

--

System OK

--

41

Use the jumper to short terminal 1 from the BN wire to ground.

Does the lamp come on?

--

Go to Step 42

Go to Step 43

42

Repair the open to ground in circuit BK between the terminal 2 from the BK wire of the harness connector for the level sensor switch and ground G104 at the left front corner of the vehicle.

Is the repair complete?

--

System OK

--

43

Repair the open in circuit BN. There are 2 possible locations for this open:

    • The I/P harness between terminal 6 of cluster and terminal 10 of connector C201
    • The front harness between terminal 10 of connector C201 and terminal 1 of the harness connector for the level sensor switch

Is the repair complete?

--

System OK

--