After-start ignition control will calculate and adjust ignition timing based on engine operating conditions. The calculation and adjustment of ignition timing is performed in a series of steps, beginning with basic ignition advance control.
Various corrections are added to the initial ignition timing angle and the basic ignition advance angle during normal operation.
After-start ignition control is carried out during normal operation.
The various corrections (that are based on signals from the relevant sensors) are added to the initial ignition timing angle and to the basic ignition advance angle (determined by the intake air volume signal or intake manifold pressure signal) and by the engine speed signal:
Ignition timing = initial ignition timing angle
• basic ignition advance angle
• corrective ignition advance angle
During normal operation of after-start ignition control, the Ignition Timing (IGT) signal calculated by the microprocessor in the ECM and is output through the back-up IC.
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