Fixed - 2015 Pathfinder No Air from Vents

Intermittent issue where with the fan on any speed, air will stop blowing out of vents. I pull the cabin filter door off and there are gale force winds in there, so I'm thinking there is blockage. I drive the car home last night and watch the evaporator temp sensor hit -6 degrees so I'm thinking it's freezing up. It was only like 27* this morning in my way in, so I shut the intake door and turned off the AC. Got the evaporator up to like 50* and air was flowing from vents nicely. The lowest I could get the evap temp was 32*. Pulled it right into the shop and noticed the AC compressor wasn't on while being commanded. Shop was 67*. Ancient temp sensor wasa reading 22*, so I figured that was preventing it from working. Unplugged. the sensor, it dropped to -30, good. Plugged in, 22*, but compressor kicked right on. Maybe a key cycle is needed to reset the temp? Not sure, but after a while it did read correctly. I recovered 1.1lb of refrigerant and it holds 1.9lbs. Could a low charge cause freezing? I can't get it to act up again and I'm missing some key data from when it was acting up. I don't know if the ECM was commanding the compressor on, which it should have. It's suppose to cut the relay if the evap is under 40*. I also thought the thermal expansion valve might be stuck open but I see that, the AC auto amp, and compressor were recently changed. It is a budget compressor if that matters.

Currently with proper refrigerant, in the shop (67* and 50% humid) the high is at 175psi and low is 35psi. I'm not great with the gauges but the lines all feel about right to me. Cold low, hot pre condenser, warm post condenser.

The customer is a monster so I'm being pressured to get it figured out fast, but our foreman is out this week, so I'm taking a bearing on all of the challenges. I like them, but don't like all of them at once, all needing to be done right now! I've got a new hire to my right and one to my left just getting into diag, so it's a cluster. Breathe...

Nissan Technician

If evaporator is freezing up your txv valve would be the possible issue. (Sticking partially shut) How long after you shut ac off do the pressures equalize? Also check to see if the heater core is leaking which would contribute to the freezing up of the evaporator. The last thing i would do is look for a fur critter nest or debris on either side of evaporator

I'll check the stabilization time tomorrow. All good suggestions, thanks.

Nissan Technician

I drove it this morning and saw that the compressor was being commanded on with the evaporator down to 15*. I also found in SI that when you push the auto temp control button, the AC button should also illuminate. I was about to source a 2014 that was going to wholesale and took it to lunch to monitor the activity. Auto button made the AC button light up and compressor was cycling to prevent EVAP freezing. With all of the other inputs seemingly working properly based on data, I decided to swap the AC auto amp. Bam, it worked. Here's what's odd. It's a different part number that's made for 2013-2014. I googled the problem last night and found a lot of 2015s with this issue, unresolved with numerous dealer trips and nearly the whole system replaced. Weird.

Nissan Technician

Awesome nice find congrats

Thanks, I kept the old part and at some point will put it in a other car to see if I just got a bad part or if there was something to using the other part number.

Nissan Technician

I got another AC auto apt that is supposed to be for this vehicle bqs d on vin, and it doesn't work, only the one from the 2014 is working. Something must be wrong with the part #/catalog.

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Tutti57 wrote: It is a budget compressor if that matters.

It may. There's mention of an incorrect, 2014 MY, compressor causing the issue in this thread. Might explain why the truck worked with a 2014 auto amp...

Another guy also says compressor replacement was the fix but doesn't give details on that one.

www.pathfindertalk.com/threads/erratic-b...hfinder.35895/page-3

Good info, thanks. I'll share it with my parts manager and let him look into it.

Some of the Nissans have a variable rate compressor that stays on but changes piston stroke length rather than cycling on and off. I wondered if that was the case here, but those have two connectors on them, one for the clutch, and the other for the PWM action. The one installed was your standard set up and I couldn't find an extra unplugged connector anywhere. Wire diagram confirmed this too.

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According to HA-50 in SI these compressors are variable displacement. I guess they're internally "self regulating" for want of a better description. So it's possible they have different pressure/flow curves and the auto amps are programmed to work with those specific curves.

Just had another one of these in yesterday on a 2016 Pathfinder. Same exact symptoms. Already been somewhere and got a new AC auto amp, compressor, heater box, rear ac lines, and a blow motor resister, ha. I ordered that "old part" and it fixed it today.

I did a little research in a Nissan hvac training manual on the compressors Nissan uses when this first came up and from what I can recall of the top of my head now, there is a fixed stroke compressor and a variable stroke squash plate compressor. The fixed is your standard on off clutch and the squash plate varies piston stroke to change compression as needed. I saw in the manual that it is calling the one for these variable, but I don't have much confidence in the accuracy of the manual. I know for a fact that some of the compressors have two connectors on them, maybe newer rogues, one for the clutch and the other I thought was to control variance. It also said that when the variable strokes fail in the long stroke position, you can get evap icing, but I'd expect there to be high pressure readings too, which I didn't have in either case.

Definitely an odd one.



Nissan Tech

Hey Tutti,

I have a 2015 Nissan Pathfinder that is doing the same thing. The air sometimes blows but generally nothing is coming out but we can hear lots of air moving behind the glove box. The Nissan tech wants to replace the blower but after reading this thread I really don't want to waste my money... A little bit of history: It was overheating and the AC wasn't working during the summer so we took it into Nissan and they said it needed a new compressor. So I bought one online and swapped it out. The old one didn't seem broken so I thought I could get away with only replacing the compressor. I went to another mechanic to make sure that would be ok and I explained the initial problem and he said it was most likely not the compressor but the radiator fan. He looked at it and sure enough it was. So the compressor didn't need to be replaced.... Anyway, now we are here with the no air blowing situation and I'm wondering if it is because I swapped the compressor and now maybe I have a variable one? Any help would be appreciated!

Ben

It might be tough convincing a tech that you read something online that might fix it. Maybe someone else has recommendations on how to approach it. It's also possible that something else is causing the icing up. The compressor is supposed to shut off if the evaporator core gets near freezing. Scantool data for that sensor is called intake temp, which can throw you off. I'd want to make sure that's reading right. Proper evac and vacuum before recharge. Are you seeing any icing on the lines under the hood when this is happening? I was confident when I replaced the auto amp becuse it made sense that it was busted, but I didnt expect to find that out using an old older version.

I'm not totally sure about that info on the variable vs fixed stroke compressors unless it has to do with auto vs manual climate control when it comes to parts?

Maybe you could ask them what the plan is, if that doesn't fix it? Can they apply the money from that toward the next thing? We know already that if you hear the fan blowing,then it's not broken.

Hi there. I know this thread is a bit old, but I have a 2016 Pathfinder with the exact same issue and am looking to replace the ac auto amp with the 2014 version. Do you have a part number for that unit by any chance?

The part number is 27760-3KA3A.

Did you confirm that the compressor is not turning off when the intake PID approaches freezing temps? You just want to make sure that it's not some else like moisture in the system or incorrect refrigerant amount.

Thank you. Yes, I believe I’ve eliminated other issues, although I’m going to confirm the right compressor is installed before replacing the ac auto amp as I’ve seen some other posts that this may be the root cause and often times the compressor gets replaced with the wrong model on these vehicles.