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

[james92se]

I'm not finding much info online for this code. Hoping somebody here has some info or can point me to somewhere to troubleshoot this.

2015 X5 sDrive 35i - 128k miles

Air conditioning suddenly stopped blowing cold and I can see the compressor clutch is not engaging.

ISTA shows code "80436E compressor clutch: line disconnection or short circuit to B+"

It's definitely not unplugged and hasn't been jarred or touched or anything. Should I see 12V at the compressor with the dash AC switch "on" or is this system so fancy I can't rule in/out the clutch this way?

Of course I can't properly test the operating pressures as the system won't kick on.

Thanks for any tips.

[james92se]

Well, nobody replied here and couldn't find much information online about this. Being BMW, what little info I could find online from owners just resulted in tAkE iT tO tHe DeAlEr responses, but I'm not sure what the point of forums and communities are if that's the answer to everything.

I did find some threads/people with this same situation who all ended up replacing the entire compressor - which is par for the course with a shop. Magically, the entire compressor is always bad with any AC problem lol.

Anyway, despite not finding a whole bunch of info on this error message I took a chance on a new AC clutch and coil assembly. The only part I could find for this was an aftermarket on eBay from seller "coldfusionacparts" and brand name CoolTech MPN 574. The cost was $48.03 total shipped.

Long story short I did get this fixed and only cost me $48.03 but I do need a favor if somebody doesn't mind looking at their X5 for me? More on that later.

I could see space was tight and likely going to be a pretty annoying job so I did some testing with my multimeter before I started.

With the HVAC unit on but AC button OFF, the compressor power wire was getting 10-11 volts (little odd, but I'm not sure how complicated the BMW AC circuit is):



With the HVAC unit on and AC button ON, the compressor power wire was getting ~14 volts and no AC clutch engagement so this confirmed to me the clutch/coil was the culprit here:







Onto the very tight, very annoying work of replacing the clutch/coil ON the vehicle.

Fought the fan assembly out. Looks peaceful sitting here but this fan assembly was very annoying to get out:







Here's how much space we're left with after fan assembly and plastic duct removal:








I rented an AC clutch removal tool from O'Reilly's but not all that unsurprisingly it didn't fit. Thankfully I had a pully puller that fit. Look how little clearance there is between the radiator:






Had a helper:






Everything removed:










New coil installed:









I have to say, messing with these retainer clips blind was a huge headache. HUGE. I resorted to using my cell phone in my other hand on the video screen to try to line up the snap ring pliers with the clips and it still was a nightmare. Getting the new stuff on was much more difficult retainer clip wise than taking the OEM stuff off. I also ran into trouble with the pulley install. Thankfully the new pulley slid right on, but when fully seated did not leave enough room for the retaining clip to go in. I got to comparing the two pulleys and you can see the inner race of the bearing on the aftermarket pulley is significantly "taller" than the OEM. I ended up taking a Dremel and grinding down the inner race flush to the bearing seal and this just barely gave me enough room to get the clip in. This all caused it to align fairly goofy and the shims provided with the new kit weren't enough and practically locked the clutch to the pulley when I tightened the bolt down. So I pulled the clutch back off and used the old shims and got the clutch spaced to about what "feels" right.

Here's the pulley installed (prior to grinding) as well as a comparison picture of the race height:










After all that I was able to get it together. I also did a new serpentine belt, tensioner, and idler pulley while I was in there.






Air works again!






Now for the favor. After getting this back together the AC works perfectly again. HOWEVER, I have noticed that anytime the HVAC panel is "lit up" - even with the AC button OFF - that the clutch spins. My testing before this job showed 10-11 volts at the clutch with the HVAC unit on and AC button OFF but I'm not sure if this should be enough voltage to lock the clutch. The clutch on this appears to only be disengaging with the entire HVAC unit turned OFF (aka no lights or anything on). Can somebody confirm on their vehicle if this is normal? It very well may be, but I'm used to vehicles that when you turn off the AC button, it kills the compressor entirely. Thanks!

[turboawd]

Interesting. I thought the x5 didn't have an ac clutch. And that it has a variable solenoid or valve internally to adjust ac pressure.

[CatalinP]

The pin you are monitoring receives a PWM voltage, so you will not get 0V and 14V, but something in between.

[james92se]

Originally Posted by turboawd

Interesting. I thought the x5 didn't have an ac clutch. And that it has a variable solenoid or valve internally to adjust ac pressure.

Variable displacement compressors WITH a traditional clutch are not that uncommon. For example, the late 90's/early 00's LS1 Fbodys had a variable compressor and still had a clutch.

It did not even occur to me though that this might be variable given the clutch/coil and single power wire. You might have just inadvertently answered my question. With a variable displacement compressor, it makes sense that this clutch would be engaged all the time and why even with the AC button "off" it's still engaged. That said, I would still like a community member if possible to verify that this is the case on their F15 X5.

CatalinP Good info, thanks. I've used Newtis some but didn't see this part of it, though maybe I don't know how to properly navigate. Do you know if it shows anywhere in there what recommended clutch gap is? Again, I just had to do this by "feel" but would like to make it textbook correct. I believe the general rule of thumb is anywhere between .3 to .6mm clutch gap but if we had an exact number that I could shim this to that would be awesome.

[drummajorc]

Has this fix held up pretty well? Have a f82 M4 with the same exact code, same exact compressor, and no cold air. I already have the pulley and coil off, and ordered the kit from the same place. For what it is worth, the clutch was always engaged, even with the AC button off, when I was first trying to troubleshoot this. This thread for your x5 is the only place I saw anything remotely helpful.

[james92se]

Originally Posted by drummajorc

Has this fix held up pretty well? Have a f82 M4 with the same exact code, same exact compressor, and no cold air. I already have the pulley and coil off, and ordered the kit from the same place. For what it is worth, the clutch was always engaged, even with the AC button off, when I was first trying to troubleshoot this. This thread for your x5 is the only place I saw anything remotely helpful.

Yep - blowing ice cold still in the middle of the Texas summer. 10k miles on the repair now. She really racks up the mileage on this car.

I'm glad I helped somebody. Newer BMW's are incredibly frustrating for anybody who doesn't want to just blindly turn over their cars to the dealership and pay their outrageous prices. It's been pretty frustrating for me not being to find much DIY info online for this generation since there just aren't many of us doing our own work on these (yet).

Good luck with it!

[heysushant]

Thank you for detailed post.
I ran the diagnostics, same trouble code - 80436E compressor clutch: Break in wiring or short circuit to B+.
The problem now is, I dont have the tools, and I cant find a mechanic who would replace the compressor clutch in Toronto, the ones I called wanted to replace the entire compressor for $2k.
I have reached out the ebay seller for help in identifying the correct clutch, will continue to find a mechanic who would be willing to replace it.
Thanks again!

[james92se]

Originally Posted by heysushant

Thank you for detailed post.
I ran the diagnostics, same trouble code - 80436E compressor clutch: Break in wiring or short circuit to B+.
The problem now is, I dont have the tools, and I cant find a mechanic who would replace the compressor clutch in Toronto, the ones I called wanted to replace the entire compressor for $2k.
I have reached out the ebay seller for help in identifying the correct clutch, will continue to find a mechanic who would be willing to replace it.
Thanks again!

Good luck with it man. I'm amazed these days how actual shops/mechanics don't want to actually just fix what's broken. I guess they gotta get their flag hours in.

[mikeson]

Wow, thank you for the detail info.

[Ajgatz]

Thank you as well. I am getting that same code (Glad there is a relevant discussion on here)

I have run pretty much every diagnostic check to determine that it is either the AC compressor or just the clutch. (also getting 12v at the electrical line)

Was there something specific about taking a chance that made you decide to just go for the clutch rather than whole compressor?
For me its the Freon recharge, I don't want to go through all of that if I don't have to. So I also have been trying to find what the fault code that would register for a bad AC compressor.

Also was this random that this occurred for you or were you messing around with some other stuff in the car prior to this happening?

[james92se]

Originally Posted by Ajgatz

Was there something specific about taking a chance that made you decide to just go for the clutch rather than whole compressor?

Well, I do have a lot of automotive experience - 20 years worth dating back to my teenage years, just not any BMW experience prior to this vehicle. I have done a lot of AC work over the years on other vehicles and so I know that contrary to what the typical shop will tell you when they're trying to charge you $2k for a new system, AC compressors almost never just "go bad" randomly. Plus, since this was only a 5-6 year old car, let alone a very expensive one, made me fairly confident the actual compressor was not suddenly bad.

Beyond that, one can always immediately rule in/out some general AC trouble causes by eyeballing the compressor clutch. That's literally the first thing I always ask people when I get these vague questions from family or coworkers wondering why their AC isn't blowing cold - "is the compressor clutch engaging?".

If the clutch is not engaging, you know that you've got an electrical problem of some sort - it's normally low charge, the compressor isn't being fed power for some reason, or maybe the compressor isn't "receiving" the power being fed its way (aka clutch problem).

To rule in or out the clutch, in most cases, you can simply take the compressor supply lead and test it with a multimeter to see if it's receiving 12V+ when it "should" be. This is what I did on the BMW with the multimeter and testing when the compressor should be cycled on vs when it should be off. You can do this yourself too, you just need a multimeter. Even a cheap HF one will do. *edit* I see you already did this.

Traditionally, you won't see any voltage at the compressor when the system should be "off", so this was the only complication for me here as far as diagnosing it because I simply hadn't messed with any BMW AC stuff previously.

And no I was not messing around with the vehicle at all, it was totally random. Although, for the last year or so she had been complaining of just a handful of bouts of non-cold air from the AC but I could never replicate it myself. In hindsight, these were instances of the clutch not engaging temporarily then eventually it refused to engaged at all.

[mcortes187]

Thanks for writing this up I'm going to attempt to fix my girlfriend's car who having the same issue where the compressor gets 12v but no clutch engagement. I 100% agree with you I've searched all over and can't find a DIY for what you shared or replacing the compressor overall. Another issue is I can't seem to find a repair shop manual. I honestly don't have time or specific tools to do the pull so I'm going to just replace the compressor overall.

Can someone share where I can either purchase the repair manual or get one for free? I Would truly appreciate it. I'll most likely do a youtube video for a DIY.

[fixingstill]

There is a control valve on the compressor (for my denso 7SBU17A at least) and I do see them for sale on ebay. What is the chance is it going bad? Or the error 80436E points straight to the clutch coil? To those who had compressor failed and changing the control valve fixed your problem, was there any code associated?

[tylertyler]

Originally Posted by heysushant

Thank you for detailed post.
I ran the diagnostics, same trouble code - 80436E compressor clutch: Break in wiring or short circuit to B+.
The problem now is, I dont have the tools, and I cant find a mechanic who would replace the compressor clutch in Toronto, the ones I called wanted to replace the entire compressor for $2k.
I have reached out the ebay seller for help in identifying the correct clutch, will continue to find a mechanic who would be willing to replace it.
Thanks again!

Hi, I'm in Toronto too, and the same issue is on my f30. Did you fix it in the end?

[tylertyler]

the same issue happened on my F30, ac compressor clutch was not engaging. I spent $90 asking a mechanic to check for me. not ac refrigerant level issue. He uses ISTA to read the code 80436e. He checked the volt on the compressor, it seems like some wire is shorted/disconnected, I was told to replace ac compressor in the end.

But luckily, hot summer is gone, and winter is coming lol.

[tylertyler]

Originally Posted by mcortes187

Thanks for writing this up I'm going to attempt to fix my girlfriend's car who having the same issue where the compressor gets 12v but no clutch engagement. I 100% agree with you I've searched all over and can't find a DIY for what you shared or replacing the compressor overall. Another issue is I can't seem to find a repair shop manual. I honestly don't have time or specific tools to do the pull so I'm going to just replace the compressor overall.

Can someone share where I can either purchase the repair manual or get one for free? I Would truly appreciate it. I'll most likely do a youtube video for a DIY.

tbh, I don't think we can DIY to replace the compressor. The hardest thing is we need to refrigerant before replacing it.

[Shuasha]

For those that have had this code, was your A/C intermittent for a while or was it just lights out? I'm trying to see if this is a loose wire problem or a situation where the coil was just failing since mine would work, then stop for a while then kick back on.
I really can't see how it would fail intermittently if the fail safe in the coil had triggered.

[lakefishing2000]

james92se thank you for putting this together, saved me some time and probably at least $2000. I did a write up on how I tackled this job on a 2016 f15, will post that below.

My f15 is around 80k, and I just did he valve cover replacement because it was leaking. A few days later, noticed it was unseasonably hot inside the car and realized the ac was pumping outside air. Bimmerlink showed the 80436e code.

Followed these instructions, took about 2 weeks between trial and error of tools and parts. The job was done tonight. Hey james92se, how much longer did your compress last after changing out the clutch?

and to answer your question james92se, the factory clutch will engage and disengage. the after market one for me is engaged at all times, it's always spinning if the hvac is on now. it's ok since I keep the car between 68 to 70 all year round and the air conditioning helps dehumidify.

[lakefishing2000]

Shuasha, my ac had been having issues last year. I took it to dealer, and they put dye in and tested it, no leaks. So they charged it, $450 last august, then winter came. So I guess it wasn't used much. I found out about mid march air conditioner was not working.

Here is the kit I got, it says it doesn't fit, but working right now for me.
https://www.amazon.com/dp/B084ZVX5XC...roduct_details

I started on this kit, the pulley included was not 8 teeth and too thin for the belt on F15, I returned it
https://www.amazon.com/dp/B0CKGDZH5N...roduct_details

good luck

[lakefishing2000]

Tools:
TORX and E sockets
Rachets ¼, ½. ¾ and lots of different extensions
Electric rachet for removing cloth board under car
Jack and Jack stands
Real long screw drivers
https://www.amazon.com/dp/B07Q9Q7ZVV...roduct_details

long pliers - watched FCP euro video on removing radiator fan
https://www.amazon.com/dp/B08W5FRXKT...roduct_details

Pulley Puller
https://www.autozone.com/test-scan-a...B&gclsrc=aw.ds

Squeeze ring tool
https://www.amazon.com/dp/B07YS12VY5...roduct_details

Nice bright lights
https://www.amazon.com/dp/B0C8SVQXZ7...t_details&th=1

Screw drivers, shorter than 5 inches

Metric wrench
https://www.amazon.com/dp/B07YS12VY5...t_details&th=1

Angled needle nose
Pick tool set
https://www.amazon.com/dp/B082X6D5QY...roduct_details

telescope magnet and mirror tools
https://www.amazon.com/dp/B0BVM48LPQ...t_details&th=1

Parts:
Pulley kit - says it doesn't fit, but working for me
https://www.amazon.com/dp/B084ZVX5XC...roduct_details

Aluminum flange amazon
https://www.amazon.com/dp/B07DW5C85D...roduct_details

Idle pulley and tensioner kit from FCP euro
1 gallon of BMW coolant, 50/50 mix

Tear down:
1. Aluminum bar in front, 4 x screws
a. 3 plastic clips in the bar facing engine, holding in wires remove
b. Remove bar
2. Remove radiator fan
a. Remove bracket for ac lines, attached to top of radiator fan
b. Two brackets
c. Unplug on passenger side
d. Use real long screw driver, driver side, loosen clip, by pressing top in towards radiator, pull up a little, take your time.
e. Use long flathead on other side, radiator fan will lift, ac lines holding it down, take your time
3. Remove charge pipe and lower intercooler pipe.
a. Charge pipe pick tool, two attachments. I didn’t want to break clips, so I loosened screws on sensor, two of them.
b. Lower pipe, didn’t know how to remove, so lifted car and got it from underneath.
i. Lots of 8 mm bolts holding cloth shield in
c. Now I know I can get from the top and curved needle nose pliers, saves time.
4. Optional projects:
5. Aluminum coolant flange, from amazon
a. Thank god I did it, when I took it out, it was already in pieces
b. Lost a bit more than 1 gallon of coolant
6. Idle pulley, was really tight on, needed breaker bar, also used to jack up car
a. Needed to be replaced, was loose
7. Tensioner seemed ok, again needed breaker bar to move
a. Replaced anyways
8. Considered a front seal guard behind harmonic balancer, want to do more research before removing harmonic balancer, future project.
9. Topped off coolant tank and bleed
a. Turned on car, no starting just button
b. Set heat to high, and fan to low
c. Hold down gas pedal for about 10 seconds
d. You can hear it bleed, just wait about 10 min
e. When it was done, my full tank went to about half tank so I topped off again.
f. I repeated a bleed once more after everything was put back together, that got me to maybe an inch below reservoir
10. Time for the clutch assembly
a. Outer screw, 10 mm total pain, because clutch moves freely and independent of pulley
b. I used plumbing pliers to hold outer ring and then loosed with other hand
c. There are two spacers in there, grab them or use telescope magnet
d. Be careful and not damage radiator when working in there.
e. Was not much room to work with, so I put a piece of 2x2 across engine bay behind hood suspension and used cable ties to pull back lines in front of engine, very helpful to me.
f. First ring, use curved tool to remove, small screw driver helped
g. About a week and half wasted here between wrong pulley sent, and different pulley pullers that failed to clear radiator
h. Pulley was not coming out, need pulley puller, or specifically universal ribbed pulley puller, went through a week of amazon tools before finding it on a youtube video. rented rom auto zone, advanced auto parts did not have it
i. Once pulley was out, one more squeeze ring, use straight openers this time.
j. Came out with angled pic tool
k. Magnet was loose
l. Ground screw was stripped on top, used 8 mm wrench to get out
m. Use telescope magnet here, that screw is small and would be painful if it fell
n. Loosen clip to compressor and magnet coil comes out
11. New coil did not look like old coil, there is a bump out on he old coil, new one was flat.
a. Installed new coil, seemed loose even after clip went in, gave it a chance
b. Installed new pulley, easy on, and needed puller to remove, wanted to check the squeeze ring one more time
c. Put squeeze ring 2 on the pulley, again seemed kind of loose maybe perception. The pulley is a bit thinner than the one that came off
d. Clutch plate was same sized and depth
e. New spacer in the kit, 3 of them and hair thin. All 3 was thinner than each of the two that came off compressor.
f. Mistake #1, wanted some clearance between plate and pulley, I used stock spacers
i. Put 90% back together, started car and clutch was not engaging.
ii. So disassembled fan and charge pipe, got the clutch pate off and use the 3 spacers that came with kit.
iii. This time clutch would engage from time to time, no air conditioning
iv. About to give up when I thought about this post
g. Mistake #2 assuming aftermarket clutch kit worked like OEM
i. After market clutch doesn’t seem to allow clutch to disengage
ii. So I removed 2 out of 3 spacers and really tightened down the 10 mm
iii. Put everything back together and magically there was air conditioning.
h. And yes the clutch is engaged all the time, let’s see how long that lasts
i. Sure beats changing out a perfectly functioning compressor that was recharged last august at dealer for $450.
12. Drove car about 25 miles and bought some groceries
13. On the way back home, Drive Train Malfunction light comes on, car was driving fine
14. I slowed down and made it home, did some more reading and it could’ve been anything.
15. So I opened the hood, looked around and sure enough, forgot to clip back on the hose on the charge pipe, error went away.

If you got this far, this job can easily be done in under an hour if you know what you are doing. I have no idea how long this stop gap is meant to last, that clutch is not a BMW supported serviceable part, you will need to buy the whole compressor to do it right. Which means vacuuming out anything inside, change compressor, add the right type and amount of oil, then have it recharged or do it yourself. I do have air conditioning now, so that is nice.

[james92se]

Originally Posted by lakefishing2000

james92se thank you for putting this together, saved me some time and probably at least $2000. I did a write up on how I tackled this job on a 2016 f15, will post that below.

My f15 is around 80k, and I just did he valve cover replacement because it was leaking. A few days later, noticed it was unseasonably hot inside the car and realized the ac was pumping outside air. Bimmerlink showed the 80436e code.

Followed these instructions, took about 2 weeks between trial and error of tools and parts. The job was done tonight. Hey james92se, how much longer did your compress last after changing out the clutch?

and to answer your question james92se, the factory clutch will engage and disengage. the after market one for me is engaged at all times, it's always spinning if the hvac is on now. it's ok since I keep the car between 68 to 70 all year round and the air conditioning helps dehumidify.

The air conditioner and the compressor are still working properly on the car to this day.

Unfortunately, it's got much bigger issues now - blown head gasket (or cracked head or something). Couldn't quite make it to 200k miles. She had been having vague and inconsistent coolant pressurization issues for a year or so now. Finally got so bad I told her to park it for good. Not sure how much if any permanent damage has been done and I haven't quite gotten the head pulled off.