[SwissXC90]

And here's the technical description from VIDA:


For 5-cylinder engines the charging regulator (also called Alternator control module (ACM)) is connected to Engine control module (ECM) and communicates via LIN-communication. Engine control module (ECM) then communicates with Central electronic module (CEM) via the CAN-net when it comes to control of the alternator.

The central electronic module (CEM) has internal functions to regulate the voltage level and the power consumption in the vehicle. The central electronic module (CEM) controls the charge regulator via the engine control module (ECM) and therefore the current/voltage generated by the generator (GEN).

The generator does not initially charge when the engine is started. The charge increases successively when the engine has been started, controlled by Engine control module (ECM). When there is an increase in load at the generator, the increase from 0 – 100% takes place over the course of a few seconds (this time varies slightly depending on the operating mode the engine management system is in). This is to gradually increase the load on the engine during the start-up phase and to ensure the engine starts.
If the engine speed (RPM) exceeds idle speed (the exact engine speed varies depending on the mode the engine management system is in) during this delay, or if the progressive increase is interrupted, full charge is obtained immediately.

If there is no communication with the charge regulator, the charge regulator will not start charging on start-up. The charge regulator can however self magnetize the rotor and start charging. This occurs at engine speeds greater than approximately 2100 rpm. There is no charge engagement by stages with self magnetization, the generator operates at full charge immediately.
When self magnetizing has begun, the generator (GEN) also charges at engine speeds below 2100 rpm.