Acceleration/Accelerometer Sensor

On 850 turbo, acceleration/accelerometer is mounted to firewall at right rear of engine compartment. Sensor consists of a piezoelectric vibration pick-up that detects vertical acceleration of vehicle, for example driving on a bumpy road. ECM uses this sensor signal to determine if irregularities in crankshaft rotation are due to cylinder misfiring or due to driving on an uneven road surface.