Description and diagnosis of this module

If a malfunction of one of the valvetronic components is detected, the management tries to drive both actuators to their end positions (limp-home = full valve lift). In this case, the charge control will be managed by the throttle. If one actuator cannot reach its end position, the valvetronic tries to ensure, that the load on both banks reaches a common level. Any reduction of valve lift will lead to a reduction of the engine power.

A DTC is stored, if one of both actuators was not able to reach its end position.

There will be a distinction, whether this error was detected directly by a comparison with the actuator angle or indirectly by checking the engine roughness or comparison of load or comparison of air mass flow.

This balance test is carried out for thermal protection of the catalyst. If the air charge distribution on both cylinder-banks is unequal, the fuel system runs a danger of delivering an incombustible mixture.

Valvetronic malfunction was detected and limp home mode is set. There is no information about the actuator's end position and the engine roughness is detected as too high.