QuestionHi Dennis, the air suspension on my 1993tdi classic has suddenly stopped working, the compressor runs normally and pressurises the tank, warning lights are performing normally,no air leaks obvious,underneath I notice that 3 of the bags have pressure in them but the nsf is empty and it's sitting tight on the bumpstop at this corner, the 3 corners with air in are just clear of the stops, any ideas? if it's the height sensor will it have to get plugged when I replace it? thanks,William.
AnswerIt sounds like a worn compressor has put it into soft fault, if the piston ring is worn out the compressor will run but not put air into the tank. there is a timer function in the ECU where it'll wait for the compressor to fill the tank to help raise the car, if you let it run beyond this time it will give you a fault.
A bad sensor can be replaced without plugging in most of the time, but it's hard to figure out if it's the sensor that's bad without plugging in.
Leave the door open with the engine running to see if compressor will fill the tank. if it shuts off on it's own (without showing a fault) then the comp is still good. if it runs for 15 minutes straight it's worn out and needs rebuilt.
