2003 Mercedes SLK-Class Owner's Manual - Page 76

Controls in detail Locking and unlocking ! If you can no longer lock or unlock the vehicle with the remote control, then either the batteries in the remote control are discharged, the remote control is malfunctioning, or the vehicle battery is drained. Check the batteries in the remote control and replace them if necessary ( page 212) or Synchronize the remote control ( page 213) or Use the folding key to unlock the doors ( page 210) and the trunk ( page 210) as required. Lock the vehicle using the folding key ( page 211). If the remote control is malfunctioning, contact an authorized Mercedes-Benz Center. Checking the batteries Press button ‹ or Œ longer than 1 second. The battery check lamp 4 lights up briefly to indicate that the key batteries are in order. Warning! G When leaving the vehicle, always remove the key from the steering lock and lock the vehicle. Do not leave children unattended in the vehicle, or with access to an unlocked vehicle. It is possible for children to open a locked door from the inside, which could result in an accident and/or serious injury. ! If battery check lamp 4 does not light up briefly during the check, then the remote control batteries are discharged. Replace the batteries ( page 212). You can obtain the required batteries at any authorized Mercedes-Benz Center. 76