Ignition Timing Control System: Notes

The ignition system controls ignition timing by matching vehicle operating conditions to preprogrammed timing advance and retard specifications. These parameters are stored in the Electronic Control Unit (ECU) memory. The computer uses input from the crank angle sensor, coolant and various other sensors to determine advance requirements.

Ignition timing is controlled by the ECU according to engine operating conditions. Optimum ignition timing for various driving conditions is preprogrammed and stored in the ECU. ECU receives and processes electrical signals from various sensors to determine present driving conditions. ECU will then select the optimum timing signal for the present driving conditions and send voltage signal to the power transistor to control timing advance and detonation retard operation (if equipped).