Adaptations and Equipment Variations

Adaptations
Adaptation makes it possible for the engine control module to learn certain values from components and equipment variants, thus making it possible to compensate for certain component tolerances.

These adaptation values can be reset to their original status with the "Reset adaptation values" service function and they must be relearned afterwards.

Example: Mixture adaptation
The fuel-air mixture formed in the intake tract requires a certain period of time until it reaches the oxygen sensor in the form of exhaust gas. This time decreases as load and engine speed increase. For this reason, the response time of the emission (Lambda) control system is also dependent on load and engine speed. Fuel-air mixture deviations detected by the oxygen sensor result in adaptation values (learned correction values) being stored. By way of the adaptations, the injection can be brought close to the nominal value in advance. A reduction in the response time is achieved in this way. For example, the Lambda control would have to constantly increase the injection time if the basic injection values of the control map for the engine control module are too low at idle speed in order to maintain the ideal fuel-air mixture. In this case, an adaptation value is learnt, which corrects the basic injection value. The emission (Lambda) control then only needs to undertake the fine adjustment.

Longer operation between idle speed and partial load is necessary in order to learn the mixture adaptation values.