ABC Light is OFF when I start the car in the morning then when I start again in the afternoon comes ON. Let sit for 3 or 4 hours OFF again. Height of the car stays the same all the time. When light is OFF car still lifts and lowers. Last week resvoirs over flowed a couple of times not anymore. Sounds like air is in the system for a couple seconds at start up in the morning. Is this the pump or a valve issue?