Adaptation of the increment wheel

Misfiring causes irregularities in the rotational speed of the crankshaft. These irregularities can be detected by way if changes in the segment time.

The crankshaft sensor continuously determines segment periods (time in which a certain number of teeth of the increment wheel run past the sensor). These segment periods are constantly checked during engine operation. In the event of a fault, a corresponding fault code is stored in the fault memory and the fuel injection is deactivated at the corresponding cylinder. Refer to misfiring detection.

After having replaced the Digital Motor Electronics control unit, the range extender digital motor electronics control unit or the crankshaft sensor control unit, carry out an increment wheel adaptation to prevent incorrect evaluations.

If the increment wheel is replaced, the increment wheel adaptation must be deleted before and after the exchange.

The increment wheel adaptation determines the irregularity of the increment wheel and takes it into consideration when evaluating the segment periods. The increment wheel adaptation is carried out automatically as soon as the engine is operated in coasting/overrun mode for a minimum of 10 seconds.