GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Visually inspect the system for any signs of external fluid leaks.

Any leaks found?

--

Go to Step 2

Go to Step 3

2

Repair any leaks that were found.

Is the repair complete?

--

System OK

--

3

  1. Disconnect the park brake pressure solenoid valve.
  2. Disengage the park brake.
  3. Connect a test lamp from the park brake pressure solenoid valve connector terminal A to ground.

Does the test lamp light?

--

Go to Step 4

Go to Step 7

4

Refer to

CAUTION:: This system operates using fluid pressure up to 12 400 kPa (1800 psi). Some malfunctions can cause this pressure to be trapped in the system. Use caution when loosening pipe fittings on a system that does not work or personal injury can result.

in Cautions and Notices.

  1. Reconnect the park brake pressure solenoid valve.
  2. Engage the park brake.
  3. Remove the pipe fitting from the park brake pressure solenoid valve to the park brake pump motor assembly.
  4. Observe the pipe fitting while disengaging the park brake.

Does any fluid leak out of the fitting?

--

Go to Step 5

Go to Step 6

5

Replace the park brake pressure solenoid valve. Refer to Park Brake Solenoid Valve Replacement .

Is the repair complete?

--

System OK

--

6

Replace the park brake pump motor assembly. Refer to Park Brake Pump Replacement .

Is the repair complete?

--

System OK

--

7

  1. Backprobe the park brake switch with a test lamp from terminal 1 to ground.
  2. Turn the ignition switch to the RUN position.

Does the test lamp light?

--

Go to Step 8

Go to Step 15

8

  1. Engage the park brake.
  2. Backprobe the park brake switch with a test lamp from terminal 3 to ground.

Does the test lamp light?

--

Go to Step 9

Go to Step 16

9

Backprobe the park brake relay with a test lamp from terminal 86 to ground.

Does the test lamp light?

--

Go to Step 10

Go to Step 17

10

Backprobe the park brake relay with a test lamp from terminal 85 to terminal B+.

Does the test lamp light?

--

Go to Step 11

Go to Step 18

11

Backprobe the park brake relay with a test lamp from terminal 30 to ground.

Does the test lamp light?

--

Go to Step 12

Go to Step 19

12

Backprobe the park brake relay with a test lamp from terminal 87 to ground.

Does the test lamp light?

--

Go to Step 13

Go to Step 14

13

Locate and repair the open in CKT 1931 (YEL/BLK), or CKT 504 (YEL/BLK) between the park brake relay and the park brake pressure solenoid valve.

Is the repair complete?

--

System OK

--

14

Replace the park brake relay. Refer to Parking Brake Relay Switch Replacement .

Is the repair complete?

--

System OK

--

15

Locate and repair the open in CKT 1 (ORN), or CKT 502 (ORN), or CKT 522 (ORN) between the I/P fuseblock and the park brake switch.

Is the repair complete?

--

System OK

--

16

Replace the park brake switch.

Is the repair complete?

--

System OK

--

17

Locate and repair the open in CKT 3 (YEL/BLK), or CKT 518 (YEL/BLK), or CKT 523 (YEL/BLK) between the park brake relay and the park brake switch.

Is the repair complete?

--

System OK

--

18

Locate and repair the open in CKT 524 (BLK) between the park brake relay and G105.

Is the repair complete?

--

System OK

--

19

Locate and repair the open in CKT 145 (PNK), or CKT 516 (PNK) between the park brake relay and the I/P fuseblock.

Is the repair complete?

--

System OK

--