Why your FOB goes to sleep.
Thread Starter
MBWorld Fanatic!
Joined: Oct 2014
Posts: 4,524
Likes: 1,181
From: WI
17 E43; 21 GLS580
Why your FOB goes to sleep.
Might be old story, but it was news to me. I thought it went to sleep to save battery, but its an antitheft device to prevent the key from being cloned. I know that is an issue in Europe but hacent heard about it in the US.
Out Of Control!!
Joined: Nov 2018
Posts: 11,398
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From: San Francisco Bay Area
2019 C63CS
Not cloned, but used in a relay attack. Fob has a motion sensor built-in and if no motion is detected for 2 minutes, it stops sending out a signal, so thieves can't use a relay device to extend the range of the signal and trick the car into thinking the fob is nearby. The newest fobs for select 2024 models, those that support Apple Car Key, now use UWB (Ultra Wideband), which has time of flight security. ToF measures how long it takes for the signal to travel from the fob to the car, so if a relay attack is attempted, UWB can detect that the fob is in fact farther away.
