S Naqvi

My 2017 GLS 450's AC stopped working all of a sudden. The freon looks good, the local shop is saying the compressor isn't getting enough freon to kick in. So suggesting it be replaced. Before I pay $2200 I want to make sure this isn't a fuse/relay that is bad. Does anyone know which one controls the compressor? Thanks

Chefcct

Make sure they check the control unit in the car.
part number 1669009821
mine gave all of your symptoms and it was this control unit inside the car…

S Naqvi

How did you figure out that was the issue?

Chefcct

My mechanic changed it out.

S Naqvi

This morning I got the ac to work. I tried messing with the temp control console attempting to "reset" AC by pressing a combination of Air circulation and Defrost ... It didn't quite work the way it was supposed to .. but some how the combination of pressing buttons and starting/restarting the car ac started blowing cold air.

I thought I fixed it. But it was shortlived by the afternoon it was blowing hot air again. But I do see the compressor running when I have ac button on and when I turn the AC off the compressor shuts down.

So is this still a compressor issue? Or some other issue? Only recent work I had some was have the TCM replaced.

amusa

You sure you reset the A/C because I tried and found out they put in lock mode. The only way to do it through coding. It's not like the older Benz where you can reset it by holding 2 or 3 buttons.. By the way you should be posting in the X166 forums.

Check this thread out. I would go through all over it especially post #15 and so on.
https://mbworld.org/forums/mercedes-...edes-c300.html