Possible causes of fault

Implausible terminal 15 signal (plug B, pin 2) or implausible data from KESSY control module via CAN comfort
Fuse F41, fuse carrier at right of dashboard

NOTE: The trailer hitch control module receives the terminal 15 signal in two ways: as an analog signal via the signal wire (plug B, pin 2) and also via the CAN comfort bus from KESSY. A cyclical check and comparison of both sets of information takes place in the trailer hitch control module (redundancy). If different comparison values are detected, a fault is stored in the fault memory.