Principle
HDC Hill Descent Control is a downhill control
feature that controls the vehicle speed on steep
downhill grades, for instance when driving on unpaved
roads.
General information
When the system is active, the vehicle moves at
the speed set by the driver, without the driver
having to depress
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