Abstract: A control unit of a vehicle navigation system receives a voice input signal collected from a microphone included in a voice input unit when a synthesized voice is outputted from a voice output unit. An analog-to-digital converter of the control unit converts the voice input signal to a digital signal and a voice recognition circuit performs voice recognition on the digital signal. The control unit compares a result of the voice recognition with voice data. A synthesized voice signal produced by an output control circuit of the control unit via a digital-to-analog convert of the control unit is inputted to the analog-to-digital converter. The voice recognition circuit performs voice recognition on the synthesized voice signal. The control unit compares a result of the voice recognition with voice data. The control unit detects failures based on the results and the detected failures are stored in a data storage.

Abstract: An air conditioner system for an automotive vehicle is particularly adapted to insolation dependent correction of a discharge rate of the conditioning air in cold weather, such as in the winter so that an excessive flow rate of relatively cool air will never be discharged in response to insolation.