October 30: LEMON manuals on a temporary server, it is slow and having issues, download the manuals you need! Later in November we will switch back to the fast server.

By-Pass Air Control (BAC) Valve

Ensure air flows through port A when valve is cold. See Fig 1 . If not, replace BAC valve.
Measure resistance of Idle Speed Control (ISC) valve at 2 wire connector of BAC valve. Resistance should be between 10.8-12.3 ohms, at normal operating temperature. If not, replace BAC valve.

Fig 1: BAC Valve Testing

Courtesy of MAZDA MOTORS CORP.