W220 Aux+TV Tuner Issue

[JamesRan]

Hi All

Sometimes when I get in the car, and switch the Command unit to Aux, which my iPhone and freeview box are plugged into, nothing comes on.

The radio (FM/AM) however seems to be absolutely fine.

My suspicion is the TV tuner in the boot (where the 2 aux points are) for some reason isn't activating when I turn the ignition on. The only way I can fix it is to turn the car off, lock the car, wait until all lights are off, and then get back in.

Any ideas?

 

[lexman8]

Is it like mine in that you select TV as the input on the COMAND head unit then select AUX? When you select TV, do you get anything on the screen, on any input, including the original analogue TV (which will be just 'snow')?

The TV tuner is connected to a permanently 'on' live power feed and is woken up via a signal on the CAN bus. So the possibilities are:

1. Power supply issue to TV tuner
2. CAN bus/wiring/signalling problem
3. TV tuner fault
4. Head unit fault

Not much help but these systems are quite complex and it may need to go on STAR for a proper diagnostic.