Pressure Switch / Brake Switch Circuits

When monitored: Continuously.

Set condition: The pressure switch input is used by the CAB to determine when the brakes have been applied. It is located in the HCU. When the brakes are applied, pressure from the master cylinder primary circuit causes the normally closed pressure switch to open. If the brakes are applied, the CAB will not enter the traction control mode. The CAB sends a signal through the pressure switch circuit. If it does not see the proper signal return, this code is set.

Possible causes:

> Brake switch output circuit open
> Brake switch sticking or out of adjustment
> Pedal travel sensor connector disconnected
> High pressure in the primary brake hydraulic channel
> Valve block pressure switch sticking or internal wiring