2008 Mercedes C-Class Owner's Manual - Page 77

Controls in detail Locking and unlocking with the engine running, the message Key not recognized appears in the multifunction display while driving off Find the SmartKey with KEYLESS-GO or change its present location immediately (e.g. place it on the front passenger seat or insert it in shirt pocket). If you have started the engine with the KEYLESS-GO start/stop button, you can turn it off again with: the KEYLESS-GO start/stop button the SmartKey with KEYLESS-GO inserted in the starter switch, when the gear selector lever is in position P Remember that the engine can be started by anyone with a SmartKey with KEYLESS-GO that is left inside the vehicle. Possibility 1: (One SmartKey with KEYLESS-GO in the vehicle, one SmartKey with KEYLESS-GO outside the vehicle): If you leave the SmartKey with KEYLESS-GO behind when exiting and locking the vehicle, no message appears in the multifunction display. Possibility 2: (One SmartKey with KEYLESS-GO in the vehicle, no SmartKey with KEYLESS-GO outside the vehicle): When exiting and trying to lock the vehicle, the message Key still in vehicle appears in the multifunction display. The vehicle will not be locked. Factory setting i Your vehicle is equipped with an acoustic lock and unlock confirmation signal feature. An acoustic signal will sound when the vehicle is locked or unlocked using the SmartKey with KEYLESS-GO. If you wish to activate or deactivate the feature, or adjust its signal volume, contact an authorized Mercedes-Benz Center. 1 Outside door handle 76