The cam sensor interrupter (magnet) may become demagnetized and/or fall off of the camshaft gear causing the Check Engine Light (Service Engine Soon) light to illuminate. On higher mileage vehicles it would be advisable to replace the timing chain and gears if this problem were to occur as the timing cover must be removed to replace the interrupter.Google+
Car Problem Reports
Pontiac Bonneville Check Engine Light Due to Cam Sensor Interrupter Falling off Camshaft Gear
Pontiac Bonneville Problem
Engine Affected: 3.8L V6
Visitor, 1992 Pontiac Bonneville, 3.8L V6, 100,025 mi
Hasn't been fixed. Engine light came on. Scanned and got code 41 cam sensor. Kept driving and engine cuts off but will crank back up. After about two weeks is cutting off more often and now doesn't want to start.