Curiosity got the better of me. I searched the forum, Google, Owner's Manual but couldn't find the answer. What's the small round hole (~.75") on the dash just to the left of the center vents? Microphone for cell phone?

yes, that's the microphone for the hands free phone function.

I read somewhere that it's the temperature sensor for the cabin, and that the microphones are in the rear view mirror.

+1^

+1

pretty sure it's the microphone, as when people can't hear me well I get closer and they hear much better.

LOL! I found a thread where agreement couldn't be found either. I'm sure there are more. I'll just ask the SA at the next visit.

https://mbworld.org/forums/c-class-w...icrophone.html

P31 in my manual shows microphone at rear of mirror.

It sure ain't in the dash.

My Pontiac has the same little grill in the same place dash and it doesn't have a microphone.

HTH

Thanks. It's p.38 in my manual. Maybe the one I was asking about is some temp sensor. I'll find out eventually.

In my Saab a similar screen in a different location was a glass breakage sensor.

... and yet another idea. I'm beginning to think it performs all the above-mentioned functions.

It's actually a microphone that only records only when you say "watch this" or "check this out" so the dealership can listen as you do stupid crap in your car so they can void your warranty... It's connected to the automatic wallet scanner in the driver's seat that runs your credit cards so the dealership knows just how much more you REALLY CAN pay for an oil change.

Everyone should do what I did: Use a large concrete drill bit and drill at least 18" into the dash through the mysterious grate to destroy the microphone. Multiple warning lights must flash on the dash to ensure you really found the heart of this system.

The wallet scanner is disrupted by methane... Ensure you eat plenty of Taco Bell and/or binge drink beer every night to ensure you're safe.

How has CNN not covered this already? Doesn't anyone believe me?!?

Who said folks living in Germany did not have a sense of humour ? !!.

Haha, I'm an American... Just living here for a while!

Anyone find this out?

Anyone? How many should find it to make you happy? The question is how should forum members answer this question to make everyone believe instead of posting speculative thoughts.

See the attached document showing HVAC component locations and make up your mind.

Awesome post

Diesel Benz knows his stuff

The best part of this post is thinking of all the people who talk into their temp sensor so people on the phone can hear them better

Cabin air temp sensor.

All MBs with climate control have had this going back as far as you want to. There is usually a small fan that draws in air past the sensor which is at the inner end of a soft duct.

When in fact they are just getting closer to the mike which is near the mirror.

If it was an air temperature sensor, wouldn't there be one on the passenger side as well? Dual-zone climate control...

What do you mean "if it was"? It has been proven that it's the temp sensor.

Dual Zone means you can turn the temp up or down separately each side.

Sorry, I didn't know it was proven.

I'm under the impression that the dual-climate zones are thermostatically-controlled -- each side of the cabin reports temperature and the HVAC system responds accordingly, adjusting air temperature up or down to meet the setting. If the temperature of the cabin as a whole is known, and not each side, then each side "fights" to lower or raise the temperature relative to the set temperature. Seems inefficient, but I guess that's the way they do it.

Well I would assume that the temperature sensor is only used for the AUTO function of the A/C to maintain a cabin temperature. When the two thermostats do not match, I would guess that it tries to match the average (net cabin temperature) of the two thermostats?