Clearing Past Malfunction DTCS
WARNING: This page is about a different car, the 2003 Mazda Protege5 and 2003 Mazda Protege. However, it is still accessible from the selected car via links, so may be relevant.
Turn ignition on. Using a jumper wire, short DLC terminal SCN (Gray/Black wire) to ground for 0.5-1.5 seconds 3 times. See Figure. Then ground DLC terminal SCN and ensure past malfunction DTCs are not displayed. Repeat if past malfunction DTCs are displayed. If DTCs are not displayed, disconnect jumper wire and turn ignition off.