2010 Mercedes C-Class Owner's Manual - Page 311

Unlocking/locking manually G Warning! Unlocking the driver's door 309 If the 45 indicator lamp does not illuminate or remains out with the weight of a typical 12-month-old child in a standard child restraint or less on the front passenger seat, do not transport a child on the front passenger seat until the system has been repaired. Unlocking/locking manually If you cannot unlock the vehicle with the SmartKey or with KEYLESS-GO, unlock the driver's door and the trunk using the mechanical key. The anti-theft alarm system will trigger when you Runlock the driver's door or the trunk with the mechanical key and the driver's door or the trunk Ropen Unlocking the trunk A minimum height clearance of 5.9 ft (1.8 m) is required to open the trunk lid. To cancel the alarm, insert the SmartKey into the starter switch. Removing the mechanical key X X Move locking tab : in the direction of arrow. X Slide mechanical key ; out of the housing. Insert mechanical key ; into the trunk lid lock. X Turn mechanical key ; counterclockwise to position 1. ! When you open the trunk, the trunk lid swings open upwards. Always make sure there is sufficient overhead clearance. Z Practical hints Unlocking the vehicle X Insert mechanical key ; into the driver's door lock. X Turn mechanical key ; counterclockwise to position 1. X Pull the door handle to open the driver's door. X Turn mechanical key ; back and remove it from the driver's door lock.