Distributorless ignition system (DIS) is controlled by PCM. PCM receives signals from mass airflow sensor, engine coolant temperature sensor, crankshaft position sensor, camshaft position sensor, knock sensor, throttle position sensor and park/neutral position switch to operate engine at optimum efficiency. Ignition timing is also determined by PCM which immediately transmits a primary current off signal to the power transistor (distributor ignitor) to control ignition timing. Ignition timing is fixed at 10 degrees during a starting condition.
IGNITION TIMING CONTROL SYSTEM
Ignition Timing Advance Control
On all models, ignition timing advance is controlled by PCM. Based on sensor input signals, PCM adjusts ignition timing to preprogrammed advance and retard specifications.
Camshaft Position (CMP) Sensor
Sensor is located on camshaft support on left cylinder bank. Based on signals received from CMP sensor, PCM identifies cylinder No. 1. PCM then uses these signals to trigger ignition system and fuel injectors. This device may also be referred to as cam angle sensor.
Crankshaft Position (CKP) Sensor
Sensor is located on oil pump, at front center of cylinder block. Based on signals received from CKP sensor, PCM determines crankshaft angle and triggers ignition system and fuel injectors. This device may also be referred to as a crank angle sensor.
Monday, November 1st, 2010 AT 7:09 PM