4.0L
Ignition timing and spark distribution are controlled by PCM according to sensor inputs. Ignition timing is controlled primarily as a function of engine load and speed. Engine load is sensed by Mass Airflow (MAF) sensor. Engine speed is sensed by a Crankshaft Position (CKP) sensor. The PCM processes inputs from the sensors and accesses ignition timing from the ignition timing strategy. Individual ignition coils are located above each spark plug (total of 6 coils). PCM incorporates the primary circuit for each coil and provides switching for each primary circuit. The correct firing sequence and timing of the 6 coils is determined by PCM from cylinder synchronization input provided by the Camshaft Position (CMP) sensor.
Jan 10, 2010 at 5:49 AM
