The official notice
Defect
On certain vehicles, the DISTRONIC driver assistance system might not detect when the driver removes their hands from the steering wheel. If the driver has a medical emergency (and is unable to drive or loses consciousness), the active emergency stop assist and emergency call functions would not activate. Note: This recall only affects vehicles equipped with a heated leather steering wheel.
Safety Risk
If the active emergency stop and emergency call features do not work in an emergency situation, there could be an increased risk of a crash, and there could be a delay in response from emergency services.
Remedy
Mercedes-Benz will notify owners by mail and instruct you to take your vehicle to a dealership to update the software for the hand detection system.