AHS CM receives information of ① IG key ON, ② Vehicle speed, ③ Air temperature and checks for CLUSTER’s existence through the high speed CAN line.

And it sends ① System error warning message, ② "FIRE" event warning message, ③ Not received CAN information message.

It receives "IG key ON" information from EMS message. Vehicle speed is received by monitoring the EMS message as a first priority.

AHS CM checks the reliability of EMS message when IG key ON during the self-diagnosis.

If EMS speed information message is not valid, AHS CM calculates the average speed of the each wheel from TCS, ABS message to use as vehicle speed.

Air temperature value is received from the air conditioning system message.