First, the MB alarm in your car will not keep the car from starting, except maybe by running the battery down. Th ealarm is set and disarmed via a switch in the door handle. There are switch of equal command in the front doors and the trunk. Verify proper control by trying all of them first as the drivers door logically is the first to fail as it is used 99+ % of the time.

The door handle imparts an action to the door lock which is connected to the lock actuator linkage which has the control of the lock system. Again each front door and trunk has the ability to operate this separate system. Try looking and unlocking at each before deciding what is and isn't working.

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Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician