2004 Mercedes C-Class Owner's Manual - Page 84

Controls in detail Locking and unlocking ! If you can no longer lock or unlock the vehicle with the SmartKey, then either the batteries in the SmartKey are discharged, the SmartKey is malfunctioning or the vehicle battery is drained. Check the batteries in the SmartKey ( page 84) and replace them if necessary ( page 307). or Use the mechanical key to unlock the doors ( page 305) and the trunk lid ( page 306) as required. or Use the mechanical key to lock the doors ( page 306) and the trunk lid ( page 306) as required. or Have the vehicle battery and the battery connections checked. The trunk can also be opened from its inside in an emergency, see "Trunk lid emergency release" ( page 88). If the SmartKey is malfunctioning, contact an authorized Mercedes-Benz Center. Checking the batteries Press button ‹ or Œ. Battery check lamp 5 comes on briefly to indicate that the SmartKey batteries are in order. Unlocking and opening the trunk lid You can unlock and open the trunk separately. A minimum height clearance of 5.71 ft (1.74 m) is required to open the trunk lid. Press button Š until trunk unlocks and begins to open. i If the batteries are checked within signal range of the vehicle, pressing the ‹ or Œ button will lock or unlock the vehicle accordingly. ! If battery check lamp 5 does not come on briefly during check, then the SmartKey batteries are discharged. Replace the batteries ( page 307). You can obtain the required batteries at any authorized Mercedes-Benz Center. ! The trunk lid swings open upwards automatically. Always make sure there is sufficient overhead clearance. 84