Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

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Constant MAP Matching








Basic location finding (dead reckoning)
using direction and distance traveled






Map-supported location finding
(map matching)






GPS satellite location finding

Continuous location finding is the calculation of the current position of the vehicle. It is active when the ignition is switched on and is accomplished by the navigation processor integrated into the COMAND operating, display and control module (A40/3). During the switch-on phase (software loading phase) only the basic location finding feature is available. After switching off the ignition all important locating parameters are stored for a certain time (approx. 30 min.).

Three different methods are used for continuous location finding, which can be matched with one another and therefore ensure extremely precise and reliable location finding:
- Basic location finding (dead reckoning)
- Map-supported location finding (map matching)
- GPS location finding

NOTE: Manual entry of vehicle location
It is possible to enter the location manually on the operating and display unit. This may be useful in the following cases:
- After transport of the vehicle (e.g. train or ferry) or
- when GPS reception is not possible at the beginning of a trip.