On my 2008 GL450, whenever I turn on the COMMAND unit, I hear a high pitch sound coming from the unit. It is not very loud but I can definitely hear it when the car is not moving. Once I turn off the COMMAND unit, the noise stops. It sounds like a motor or something in the COMMAND unit making the sound.

Is this normal or is there something wrong with the COMMAND unit? I even popped out the Nav DVD and the single CD and the sound is still there. So the sound is not coming from a spinning disk or something.

 

It's normal at least in my opinion. I have the same high pitched noise. if I put my ear closer, i can hear a fan too.

 

I can hear a low computer like buzz. Not noticeable unless I'm listening for it.

 

It is the cooling fan in the back of the head unit. Somewhat normal. Eventually they start to squeal and stop or just seize quietly.

 

It gives out a rather high pitch sound. Quite annoying. Not sure if it really is normal. Hard to imagine that it would do this while it was still new.

 

if you are still under warranty you can have the headunit replaced.

if not, you can have it pulled out and the fan lubricated.

 

It is still under warranty. let me go and have them take a look. thanks for all the feedback.

 

When to the dealer and they said it is normal sound from the head unit. But I am surprised that it can be called normal sound.
Again, when I turn on the COMMAND unit, I hear a high pitch sound right away, then it is followed by another sound that sounds like a cooling fan or something.
Can you guys confirm if your GL450 have the same sounds coming from the COMMAND unit? It is very noticeable when you turn the COMMAND unit on without turning on the engine.