Apparent Air Conditioning Failure

[Nubo]

Since the ambient sensor is near the nose of the car, it might susceptible to damage and would seem to be easy to check. It's one of the things that will cause the VCM to not activate the compressor.

 

[nlspace]

Lots of error codes for the a/c system according to alldata.com.
P31EE references the pressure sensor.
Dealer scan tool may be the only way to read these.

Good catch to find that code, it's not in the HAC but rather the EVC section.

P31EE:
Signal voltage from refrigerant pressure sensor remains Approx. 0 V for 2.5 seconds or more
Signal voltage from refrigerant pressure sensor remains Approx. 4.7 V or more for 2.5 seconds or more

 

[bobkart]

Since the ambient sensor is near the nose of the car, it might susceptible to damage and would seem to be easy to check. It's one of the things that will cause the VCM to not activate the compressor.

Is that the same sensor that feeds to the outside air temperature readout on the 'eyebrow' dash? If yes, mine seems to be working.

Then there's the 'sun load' sensor under the front right of the windshield. I think that also feeds into the control logic for the AC. But don't have any feedback on whether it's working.

 

[bobkart]

If the heater works, then the SSOFF relay is probably okay by that diagram, but not sure if it is the same for your year. The AC relay should click with a heater command. And the blower fan motor would likely work with the heater but not the AC.

The VCM commands the AC relay, and the pressure sensor is the main input to the VCM related to AC. You mentioned earlier that there may have been a leak in refrigerant near one of the service fittings, so maybe there is no pressure in the system. i would find and check/clean the connector to the pressure sensor; and maybe try the AC with the connector off to see if a code gets thrown. Then any AC shop with AC gages could check the system pressure, but if it takes special freon then hopefully the dealer has the right tools and materials to check and recharge the system. Maybe there is no DTC for low or no freon--the system just quits with no warning or code?

I couldn't get the AC relay to click when turning on the heater, although the heater does work (hot air plus load shown in LeafSpy).

On the potential signs of a refrigerant leak, another member here pointed out that the discoloration around the service fitting is likely due to where they brazed the fitting onto the pipe. Seems reasonable.

I really want this to be as simple as being out of refrigerant, but when I stopped by the local shop, they used a UV light that's for detecting leaked refrigerant, and found none. But maybe the leak happened long enough ago that it's no longer detectable that way.

On the P31EE code, I see someone reporting it in this post:

https://mynissanleaf.com/viewtopic.php?t=19040#p411453

AND they mention using the Consult tool to see it, so that's consistent with the theory that LeafSpy won't reveal that code. So hopes of this just being low refrigerant pressure are still alive. Although that probably means there's a leak somewhere, but it could be very slow or (hopefully) easy to repair.

Thanks again for everyone's help.

 

[bobkart]

At this point I'm just getting the car ready for taking it into the dealer tomorrow morning.

I reconnected the VSP Speaker and the VSP DTC was able to be cleared. Rather than mount the speaker in that difficult-to-reach original location, I just attached it just above that space. Will likely remove it again once the AC problem has been addressed. This is all just to have as few DTCs for the dealer to be distracted by when they look at it.

So I'm down to just the Air Bag DTC now. No change in AC symptoms.

BUT: something odd happened during one of the power up/down cycles. Shortly after powering off, I heard a beep/whine from under the hood (seemed like the right side). Lasted about 30 seconds. During this time the dash was completely blank, not even the blinking red security icon as is usually present. The Start button was not illuminated and pressing it had no effect. Once the beep stopped I was able to power back up, and things looked normal on the dash. LeafSpy showed a new DTC though:

C1A90 0108 BRAKE

I was able to clear it. Oh and my dash memory had been reset as if the 12V battery had been disconnected.

The results of a brief search suggest that this is related to the very odd brake problem I had late last year:

https://mynissanleaf.com/viewtopic.php?f=30&t=18283&start=90#p595739

It's gone now but leaves big questions as to what's going on with that. Seems unrelated to the AC problem, and not due to the 12V battery being low as many report (had been on and off several times before that happened, thus 12V battery was relatively topped up).

 

[bobkart]

Looks like the bill is climbing . . . calling now to understand what that verbiage means.

 

[bobkart]

The service advisor is saying they found a leaking high-pressure AC line. He says the part itself (in stock) costs $300-something. Then a fair bit of labor to swap it out. A bit over $1K when it's all said and done (end of day). Ugh.

 

[nlspace]

The good news is they found the problem, it's not a complicated repair, and it's not the compre$$or.

The bad news is the price of replacing a piece of metal tubing. Valves leak; seals leak; fittings leak; but metal pipe or tubing leaking...maybe a wreck or an accident?

The ugly news is hard to believe that no DTC gets thrown for low freon pressure and that the HAC section of the FSM doesn't even have a description or diagnostic procedure for checking the pressure. Not really a surprise i guess since there is no DTC--can't troubleshoot without one in the FSM...

Hope they get you squared away soon and under budget (like that ever happens :lol: )

 

[bobkart]

Yeah that is ugly . . . arguably the most common failure mode is not reported? Yet the system knows that the condition is present (to save itself).

All in all this went reasonably well. About $950 out the door . . . apparently they needed less labor than expected. Of course I would have preferred a smaller bill. Other than refrigerant there were just two parts:

92490-3NK0A HOSE FLEXIBLE, HIGH
92472-M823A SEAL-O RING

What's odd is that the pictures I'm seeing of the 'hose' with that part number don't line up with the part I got back from them. And of course it's not a hose, it's a tube, and it's not flexible. Here's the part I got back from them:

Mostly I'm trying to understand how such a part develops a leak, and if there are any steps I can take to reduce the possibility of that happening again. It seems well supported, so failures due to repeated flexing stress seem unlikely. Maybe this is just a case of the part being bad out of the gate. But the fact that they had this part in stock suggests that failures of this part are not rare. Possibly longevity wasn't high on the list of design goals. Not that I have any HVAC expertise, but I might have considered breaking it up into two parts. Certainly servicing would be less involved. Of course the connection between the two pieces becomes an additional potential point of failure. I suspect slightly more tubing wall thickness would cut the failure rate way down, but could push manufacturing costs up.

 

[cwerdna]

I kept thinking you had an '11 but I wonder if that's the same part (maybe with a different part number) as what I pointed to at the bottom of https://www.mynissanleaf.com/viewtopic.php?p=587653#p587653. Since you have a '16 S, I'd have figured that was already a revised part less likely to fail.

A quick Google search for 92490-3NK0A turned up https://www.amazon.com/Nissan-Genuine-Discharge-Hose-92490-3NK0A/dp/B01FV6XDVK

Parts Included: ONLY PART REFERENCE #8 ON THE DIAGRAM IS INCLUDED, Year: 2013 2014 2015 2016 2017, Make: Nissan
Product Name: Genuine Nissan Discharge Hose 92490-3NK0A, Sku: 92490-3NK0A, Model: Leaf
Replaces Part Number: 92490-3NF0A, 92490-4NP0A, Genuine Oem: Yes
Manufacturer Part Number: 92490-3NK0A, Warranty: 1 Year
Fitment Type: Direct Replacement, Brand: Nissan

The '13 to '15 bulletin I pointed to on page 4 has 92490-4NP0A. And, that bulletin at the end mentions 3.1 hours of labor.

 

[LeftieBiker]

Corrosion is a common cause. They may have swapped in a universal fit hose for that steel line. I can't help thinking that they committed what used to be called "highway robbery" on the job.

 

[bobkart]

I kept thinking you had an '11 but I wonder if that's the same part (maybe with a different part number) as what I pointed to at the bottom of https://www.mynissanleaf.com/viewtopic.php?p=587653#p587653. Since you have a '16 S, I'd have figured that was already a revised part less likely to fail.

A quick Google search for 92490-3NK0A turned up https://www.amazon.com/Nissan-Genuine-Discharge-Hose-92490-3NK0A/dp/B01FV6XDVK

Parts Included: ONLY PART REFERENCE #8 ON THE DIAGRAM IS INCLUDED, Year: 2013 2014 2015 2016 2017, Make: Nissan
Product Name: Genuine Nissan Discharge Hose 92490-3NK0A, Sku: 92490-3NK0A, Model: Leaf
Replaces Part Number: 92490-3NF0A, 92490-4NP0A, Genuine Oem: Yes
Manufacturer Part Number: 92490-3NK0A, Warranty: 1 Year
Fitment Type: Direct Replacement, Brand: Nissan

The '13 to '15 bulletin I pointed to on page 4 has 92490-4NP0A. And, that bulletin at the end mentions 3.1 hours of labor.

Too bad that Amazon listing has no picture of the part. I found the 'P' version of the part at NissanPartsDeal, and there's the same wrong picture as with the 'K' version.

The cost of the Amazon part and the 3.1 hours you refer to tracks with what I had done today.

 

[bobkart]

Corrosion is a common cause. They may have swapped in a universal fit hose for that steel line. I can't help thinking that they committed what used to be called "highway robbery" on the job.

I checked under the hood as I was leaving the shop and the replacement part matches the original.

By corrosion do you mean on the inside, due to exposure to pressurized refrigerant? Seems like another reason to go with more wall thickness.

 

[nlspace]

It would be interesting to find out if the leak was in the aluminum tube or if it was at an end seal or fitting joint. If you could seal 2 of the openings (putty and tape) and then add some air pressure at the third opening. With a paintbrush and a soap solution--should see some leak bubbles.

 

[LeftieBiker]

By corrosion do you mean on the inside, due to exposure to pressurized refrigerant? Seems like another reason to go with more wall thickness.

I meant on the outside. The refrigerant contains oil, so I doubt that it corrodes.

 

[bobkart]

Yeah I heard about the oil, to lubricate the compressor.

On the outside I would expect some oxidation, but aluminum is pretty good at limiting that to just a thin layer (unlike ferrous metals).

I'm looking closely at the removed piece of tubing, and not seeing anything suggesting a leak. I'm considering trying to expose the leak as suggested above by nlspace. Just need to figure out how to seal the ends and add air pressure. Although sealing all three openings and submerging might work. But might not be enough pressure.

 

[leafamiga]

Update: local shop called back to say they would not have the right refrigerant for a recharge, suggesting the dealer instead.

I made an appointment for next Tuesday with the dealer where I purchased the Leaf. I heard $170 to diagnose and $270 if that leads to a recharge.

We're hitting triple digits here over the weekend, rendering this Leaf unusable.

Man - I am part reptile. I am fine with driving in 100 degree weather without AC. (I'm here because AC on my 2015 just went out and trying to troubleshoot at bit, as dealer says they think it's the AC High Pressure line and want $700 (Down from initial $845). Why (do I need to get it fixed, you ask ? The wife does not share my tolerance and almost 'like' of the heat)

 

[leafamiga]

not as easy as a 99c can or two of R12 Freon we used to be able to add in the old days

A pound of the refrigerant in the LEAF leaked to the air is about equivalent to 1,400 pounds of CO2

I cry for the earth when I think of how many tens (hundreds?) of millions of auto AC units have been irresponsibly dealt with over the years.

(No sarcasm intended, only a bit of exaggeration; I'm a proud tree-hugger)