Method for controlling an ignition system of an internal combustion engine and an ignition system

An internal combustion engine system comprising:

• a spark ignition system including a device for detection of misfires;
• and
• a controller configured to:
• operate an internal combustion engine in a calibration mode, including controlling the spark ignition system to:
• perform stepwise reduction of spark ignition energy by changing a spark ignition parameter starting from an initial value,
• detect when a combustion failure limit is reached based on a signal of the detection device and again reducing the spark ignition energy if the combustion failure limit has not yet been reached, and
• store the spark ignition parameter at a point in time of reaching the combustion failure limit, selectively taking into account an operating offset value;
• and
• exit the calibration mode and operate the spark ignition system on the basis of the stored ignition parameter.

A method of controlling a spark ignition system of an engine, the method comprising:

• operating the engine in a calibration mode, including:
• performing a stepwise reduction of spark ignition energy by changing a spark ignition parameter from an initial value to a current value;
• determining whether misfire is detected after each step-change to the spark ignition parameter;
• and
• storing the current value and exiting the calibration mode responsive to detecting misfire.