Theory Of Operation

The Active Noise Cancellation Module (ANC) performs the creation of sound waves from the vehicle's speakers to cancel engine related noises from the passenger compartment. The module creates these sound waves in proportion to engine RPM and inputs from the interior microphones. The ANC module receives engine RPM signals from a direct hardwired engine RPM signal circuit from the PCM. The ANC module uses 4 microphones located in the headliner for ANC inputs to listen for engine noises in the interior compartment. The ANC module monitors the CAN bus, speaker, crankshaft pulse, and microphone inputs for concerns.