By-Pass Air Control (BAC) Valve

BAC valve is mounted to dynamic chamber, near throttle body. See Fig 1 . Remove BAC valve. Circulate cold water in BAC valve coolant input hose to cool valve. Circulate hot water in BAC valve coolant input hose and ensure air valve operates. Replace BAC valve as necessary.

Fig 1: Identifying BAC Valve

Courtesy of MAZDA MOTORS CORP.