Possible causes, elimination, notes: Elimination:

Examine battery and generator voltages.

Select Control module supply voltage  and Sensor supply voltage  under the menu item Actual values, and check the values with reverse gear engaged and the engine running.

Control module supply voltage display approx. 12 V

Sensor supply voltage display approx. 8 V

Delete fault memory, disengage reverse gear and switch off ignition.

Then switch on ignition, engage reverse gear again and read out fault memory.