Abstract: A system and method of diagnosing and/or mitigating the effects of a malfunctioning brake valve configured to supply pressurized fluid to a brake unit via a pressure delivery line during automated braking operations including detecting a period of no braking activity, venting the pressure delivery line to atmosphere during the period of no braking activity, monitoring pressure in the pressure delivery line to detect a pressure change resulting from the venting, and generating an error signal if a detected pressure change exceeds a threshold value. The pressure modulating valve can be periodically cycled once a fault is detected to reduce the effects thereof.