Patent ID: 6381545
Filing Date: 2002-04-30
Classification: B60H

Abstract:
A diagnostic method for an automotive air conditioning system including a refrigerant compressor, a clutch coupling the compressor to a rotary drive source, a pressure transducer response to a refrigerant pressure produced by the compressor, and a control unit responsive to an output signal produced by said pressure transducer for selectively activating said clutch to operate the compressor and de-activating said clutch to turn off the compressor, the diagnostic method including the steps of:isolating a pulsating component of the pressure transducer output signal, the pulsating component corresponding to pressure pulses produced during operation of said compressor, and producing pulses based on said pulsating component; detecting activation of said clutch by said control unit; and monitoring the produced pulses to verify that the compressor is actually operating in response to the detected activation of said clutch.