The official notice
Defect
On certain vehicles, the air conditioning drain hose might be installed incorrectly. This could allow water to leak inside the vehicle. If this happens, electrical components could short circuit. This could affect different parts, such as the door locks and emergency call (eCall) system. It could also result in reduced engine power or cause the vehicle not to start. Note: If this issue is present in your vehicle, you might notice wet carpets in the driver or passenger footwell and fogged windows.
Safety Risk
A loss of engine power could increase the risk of a crash. If the doors cannot be unlocked in an emergency situation, it may be difficult to exit the vehicle.
Remedy
Mercedes-Benz will notify owners by mail and instruct you to take your vehicle to a dealer to inspect how the air conditioning hose is installed and correct it, if necessary. Mercedes-Benz recommends that you should not use the air conditioning until the vehicle is inspected.