Ignition, basic function
- Idling speed ignition timing
When idle speed control is active, the ignition timing is adjusted to stabilize idling speed. The value is sent to box 3.
- Normal ignition timing
When the idle speed control is not active, the ignition timing is obtained from a load and speed-dependent matrix. The matrix value is optimized for the lowest fuel consumption (best torque). The value is sent to box 3.
- Selection of ignition timing
One of the ignition timing calculations is selected, depending on which function is active. The value is sent to box 6.
- Catalytic converter heating ignition
In order to heat the catalytic converter as fast as possible after starting, the ignition will be retarded. The value is load and engine speed dependent.
- Engagement of catalytic converter heating ignition
The function is active when the coolant temperature is above -8°C and below +35°C.
- Total
The value from box 5 is added to the value from box 3.
- Compensation
The ignition timing is corrected depending on the engine coolant temperature and intake air temperature. The value is sent to box 6.
- Knock control
If knocking occurs, the amount by which the ignition should be retarded is calculated. The value is sent to box 6.
- Total
The compensation angle and knock retardation are added to the current ignition timing. The value is sent to box 7.
- Selection of ignition timing
Starting ignition timing is selected when the engine has not yet started. The value is sent to box 9.
- Starting ignition timing
Starting ignition timing is calculated depending on intake air temperature and engine coolant temperature. The value is sent to box 9 via box 7.
- Activate relevant trigger
At the calculated crankshaft angle, the microprocessor controls the transistor for the trigger which is next in the firing order.