A/C compressor not engaging and code 80436E - testing procedures?

[lakefishing2000]

Hi james, thanks for the update. My update is that my new clutch coil and pulley was blowing cold for about 24 hours. Then it stopped working. I am still pulling code 80436E, Compressor clutch: line interruption or short circuit to positive.

I put the multimeter on the old clutch and the new denso compressor I bought. Both show the same numbers. I don't think my issue is the clutch. My line from compressor is showing zero volts. I am almost at the point of putting in a new compressor, but I am not sure that will fix it. I do know when the clutch was engaged, it blew cold, was recharged 8 months ago.

I did replace the valve cover about a month ago, did not notice air condition issues as it was still pretty cold outside. Have no idea when the ac went.

re: coolant, years ago I had a honda civic that would eat coolant, had a hairline fracture on cylinder 3. coolant would come out of exhaust pretty quickly, and the tank would empty. We are talking in a matter of minutes, the whole reservoir would empty. Had to get remanu head to fix it.
If you are planning to tear it down to that level, might as well pull out engine and get all the seals and lower gaskets, basically a rebuild. good luck.

[lakefishing2000]

Update: So i've spent a few weeks on and off without air conditioning, only thing to show for it, is a lot of new tools and the code 80436E. So I gave up and paid a local indy shop to diagnose it. $130 later, I was told more than likely needed a new compressor. So I had them vacuum out the freon and replaced the compressor.

Follow my instructions for accessing compressor. If you can remove the clutch, compressor a lot easier. Compressor was out in about 30 minutes, on the reinstall I attempted to reuse o-rings out of laziness, don't do it, you can't. New o-rings are smaller and fit just right, over time the O-ring expands. So off to the dealer I went for two o-rings. I have the part number if someone needs it for a 2016 f16, you need one for high and one for low. It's better you talk to the parts guy at the dealer, they will pull the part based on your VIN. I took it back to the shop, they pulled a vacuum and charged the freon. No luck, so they kept it for a day, did some more diagnostic, and nothing. The owner charged me $85 for the freon, and suggested I go to the dealer for computer help. I offered to pay more, as they did take the time to diagnose. The owner earned my business for life, said he charged me for the cost of freon, and since he didn't fix it, wouldn't be right.

So today went to the dealer, $265 an hour plus tax and shop fees. All they told me was I needed another new compressor, when they install the new compressor for $3600, they will do a bunch of other diagnostics. At first it felt like a rip off, but it did make sense, they have no idea what a DIY did, so they need to start from 0, so they can offer a warranty. Anyways I was pretty much out of luck, so I took the car home.
I then watched a video on youtube, from the bmw doctor.

I then remembered this sensor, the AUC sensor hanging loose outside of the cabin air filter housing. So, I got to it, found that it was meant to be held right between the two cabin filters, under the housing. I also disconnected the sensor and plugged it back in. And the air conditioner started working, the new compressor and clutch engaged. I drove it for about 30 minutes, all good. Let's see how long this lasts...

Cost wise, I returned the two defective clutch assemblies, and bought a bunch of new tools. So cost looks like this, compressor $460, Tools $200, Shop 1 (with freon) $210, Dealer $300. All the while, probably don't need the compressor yet. Just a sensor out of place and needed to be reseated. I am also spending some money upgrading my old laptop to support ISTA.

So my lesson learned is to put back everything disassembled, the AUC probably came lose from the valve cover replacement. I will reporting back if any other issues, I encourage everyone who posts to close the loop and talk about resolution.