Pilot Valve Test

The test indicates whether the pilot valve in the modulator valve assembly moves to the position which blocks pressure to the master cylinder. The pilot valve blocks pressure to the master cylinder before pump motor activation and fluid pressure application to the rear wheel circuits during ASR activation.

1. With ignition switch in Off position.
2. Connect Tech 1 scan tool with appropriate brake cartridge.
3. Turn ignition switch to On position.
4. Raise and support vehicle with wheels about six inches from floor.
5. Select F4, Misc. Tests.
6. Select F3, Pilot Valve Test.
7. Have assistant depress Tech 1 up arrow, then depress and hold brake pedal.
8. Attempt to move rear wheel by hand, no movement should be indicated.