[JFP in PA]

Originally Posted by kalasend

Thanks JFP. The way I understand this is that, as long as the ABS naturally opens up the valves then it is possible to flush the brake fluids. Is this what you imply?

No. The ABS/PSM control network consists of a pump, valves, and passageways that need to be cycled open and closed during the flushing cycle to assure air trapped inside will be removed. But if there is no air trapped in the system, nothing needs to be activated, just flush the system. Most dealers do not activate the system unless they suspect air has gotten into the control network.