suspension mode

Failures in the Hydractive system (generally problems with sensors or their wiring) can force the suspension to be stuck in hard mode. To diagnose the fault, it would be convenient to know which mode the car is currently in. As H II systems use a 1 kHz chopper to form the current operating the valves, this leads to an interesting way to learn the current status of the suspension: this chopped current actually disturbs the radio reception. Tune your radio to a spot somewhere near 700 kHz where there is no incoming broadcast.