BMW F33 - no sound output

With the above-mentioned vehicle type, it can happen that the entire sound output in the car fails. And sloshing noises can also be heard in the vehicle interior while the car is being driven. 

If one of the above-mentioned complaints is present, the first step in troubleshooting should be to check the audio amplifier for moisture ingress. If traces of water are visible during the visual inspection of the amplifier, special attention should be paid to the water drainage in the area of the rear window lifters. 

If the water cannot drain away properly here, large quantities will collect in the water drainage system, which can in time overflow into the luggage compartment. Accumulations of dirt in the water drainage system and between the sill and the outlet can be the cause of this problem. 

Water can be poured onto the rear side windows in order to carry out a test. This gets into the water drains via the side windows and should be drained from there to the outside. During the test, water discharge in the area in front of the rear wheels must be recognisable. 

If the drains are blocked, cleaning and removing the lower plugs from the water drains can help. In order to carry out such cleaning, the sill panelling and the side underbody panelling must be removed in accordance with the manufacturer's instructions. After cleaning the components, the plugs in both water outlets must be removed. The water should then drain correctly again after these measures have been completed. 

If other components have been damaged by the water ingress, these are to be repaired in accordance with the manufacturer's instructions. The problem has been identified by the vehicle manufacturer and rectified during the course of a service campaign.  

This fault profile may also occur in other vehicle models with comparable equipment variants.