Madys55

Light on the "AC Off" button just stays on, and wont blow out any cold air. any ideas on how to fix? im hoping its a fuse or just needs to be recharged??

awiner

I had this same problem early on and it was fixed under warranty. In my case it was the EVAP temp sensor that went bad. Part # 2208300772.

Malones Perf.

When the A/C off button is illuminated and won't turn off it means your AAC module is sensing either a temp sensor malfunction but 90% of the time its due to the refrigerant sensors to low of a charge meaning a leak somewhere. Even if you charge for A/C back to specs it needs to be reset with a scan tool in the AAC module before you can switch it back on!! Hope this helps

Madys55

thanks bud. that was my exact problem.

rsflynn

I had similar issues with the AC. It can be a variety of things. First off, a code has been thrown to shut down the AC. This is primarily because when the codes get thrown, the computer usually reads this as a loss of refrigerant pressure. The compressor uses the refrigerant to lubricate itself and if it were to run without refrigerant or a low pressure of refrigerant it would harm the compressor. First time that this happened my dealership (Atlanta Classic Cars) recharged the system. They added a tracer chemical to the refrigerant to see if there was a leak. There was none. The second time (about a week later) they found a leak when running the trace. Parts and labor about 1200. The third time, I now take my Benz to Blue Ridge Mercedes in Atlanta, it was only because codes were thrown and the computer needed a reset (I had run the system for a while with the doors open prior to this). So the net of this is, it could be a lot of things within the A/C system that have caused this.

AWOL

How do you reset the codes? Or is that dealer only? If so, how much $$ we looking at?

Sher Judge

Do a search for "AC Control Reset"

In the W220 section, try it, it works.

Get your system re-gassed, you should be good.