Variable Valve Gear / Valvetronic (Help Texts)

Variable valve timing gear / Valvetronic:

Learning the stop positions
In order to achieve the correct valve opening height, all the tolerances in the valve gear must be balanced by an adaptation. In this learning procedure, there is a slow approach to the mechanical adjustment limits of the eccentric shaft. The positions thus reached are stored and used in each operating point as the basis for calculating the current valve stroke.

The learning procedure runs automatically if, for example after a repair, a difference between the last stop position and the new starting position (with terminal 15 ON) is detected. The adaptation can also be requested via the DIS-plus Tester.

After the learning procedure has been initiated via the DIS-plus Tester, a brief adjustment sound can be heard in the engine compartment. The DME reports whether the adaptation has run correctly or not.

For learning the stop position, faults can also appear in the fault memory of the DME; there is a test module for this.