Valve Test

Valve test
Explanation of valve test
1. Select the valve test for the respective wheel from the Activate menu.

IMPORTANT: The test can only be performed when the car is stationary.

2. Spin the wheel by hand. It should spin freely. Answer YES and the inlet valve will be closed. The passage between the master cylinder and wheel cylinder is closed.
3. The inlet valve is closed. The valve has moved to the HOLDING PRESSURE position. The passage is closed and no brake pressure to the wheels is obtained.
4. The wheel should spin freely. Answer YES and the inlet valve and passage should open. Brake pressure can be applied to the wheel.
5. The wheel should be locked. Answer YES and the outlet valve opens and the return pump starts running. Brake-fluid pressure is retuned from the wheel cylinder by means of the pump.
6. The wheel should spin freely.
7. The last message on the display indicates that the test has been completed.
8. If a fault occurs whilst the test is running or if you answer NO to any of the questions, the following message will be displayed. "Valve test faulty. See Service Manual, Brakes (ABS 5.4)". Refer to Hydraulic Control Assembly; Service and Repair.