General information
If the trailer socket is occupied, some driver assistance
systems are unavailable, or available to a
limited extent. A Check Control message is displayed
where applicable.
When driving with a trailer or load carrier and the
trailer socket not occupied, some driver assistance
sys
REPLACING ALL SPARK PLUGS (N42, N40, N46, N45, N52, N52K, N51)
Special tools required:
12 1 171
12 1 200.
Necessary preliminary tasks:
Switch off ignition
Remove ignition coils.
Unscrew spark plugs with special tool 12 1 171.
Installation:
Tighten down spark plugs with special tool 12 1 171a