Ignition Timing Control
ECM has complete control of ignition timing. Timing is controlled in response to signals from various sensors. Input signals from TDC, CRANK and CYL, throttle angle, coolant temperature, and MAP sensors are all used by ECM to determine optimum ignition timing control.
Battery voltage is supplied through ignition switch to ignition coil and Ignition Control Module (ICM). ECM triggers ICM based upon signals from TDC, CRANK and/or CYL and other sensors. High voltage from ignition coil is distributed to each spark plug by distributor.