13-Pin« Trailer Socket
The backup lamps, »continuous current«
and charging cable can be used on the trailer with the
»13-pin« trailer socket. A
»13-pin« trailer socket is
recommended if a bicycle rack will be installed or a camper will
be towed.
  ...
Warning lamp
First read and observe the introductory information
and safety warnings
Lit up
Possible cause
Solution
Fault in the alternator.
Go to a qualified workshop. The electrical system should
be checked.
Switch off all electrical ...
Legal Requirements
The manufacturer is granted general type approval for the
whole vehicle including all parts and for specific retrofitting
(general type approval according to § 20 StVZO (Motor Vehicle
Construction and Use Regulations or EU type approval).
...