Unable to Restart after using AC (was AC causes failure)

[Coffee_Slurry]

And unless someone advises otherwise....if you get "the little yellow car with the exclamation point" warning showing up while driving after turning on your A/C, I recommend NOT stopping right away. Instead, turn off your A/C, and drive it to the Nissan dealership before shutting down, so they can fix what needs fixing.

I agree. With a normal ICE car, we're taught to stop when the problem appears, for fear of doing increased damage by driving.

For the LEAF, my advice would be the opposite. Drive as close to a dealer or home as you can, since it probably won't turn on again.

 

[IBELEAF]

(2) Turn on the AC for at least 15 minutes while not moving, then try to go somewhere. This seems to trigger the issue fairly consistently.

Does the speed matter or for how long should I be driving?

 

[palmermd]

(2) Turn on the AC for at least 15 minutes while not moving, then try to go somewhere. This seems to trigger the issue fairly consistently.

Does the speed matter or for how long should I be driving?

Nope, mine did it while sitting parked in the dealership garage. But all future deliveries are going to have the refrigerant level checked and should not exhibit this problem. And I sincerely hope Nissan is working on fixing the software so that if the A/C is overcharged in the future it only shuts down the A/C system and not the entire car. I'm not sure if they are working on this or when it would be available to install in our cars.

http://www.mynissanleaf.com/viewtopic.php?f=30&t=3139&start=71
http://www.mynissanleaf.com/viewtopic.php?f=30&t=3139&start=78
http://www.mynissanleaf.com/viewtopic.php?f=30&t=3139&start=123

 

[TomT]

They want the levels adjusted by region?! More indication of a much more serious problem than refrigerant level! What's next, adjust them for each season???

Nissan better get a REAL handle on this before the press catchs wind of it...

BTW. system pressure in a vehicle AC system will always increase when the vehicle is not moving due to less air flowing trough the condenser... It also increases with higher ambient temperature,

(1) Just make doubly-sure that they check the refrigerant levels against the latest recommended value for your region.

 

[abasile]

Adjusting for "region" won't cut it for me. In terms of weather, my home in the San Bernardino Mountains might as well be considered a totally different "region" compared to the dealer down below in Fontana. It helps that we only rarely use car air conditioning up here (our home doesn't even have AC). But we sure as heck need AC when we go down the hill!

We need some assurance that this problem is going to be completely fixed, not just minimally patched.

 

[BrendanDolan]

I've also dealt with this in airplanes, BrendanDolan; but I've never had my airplane engine go into "failsafe" mode and shut down. That might be a little dicey if you're in flight.

Yeah, something like that would ruin a day quickly. An old teacher of mine had an upset in an Airbus A320, rolled past 60 degrees of bank, and that's the time Fifi said "Nope, we don't roll past 60 degrees of bank, so if all three computers said we did, something is wrong, as we should reset." Supposedly they don't do that anymore.

I'm used to small planes that blow breakers and avionics that randomly reset.

 

[palmermd]

My dealer said in their conversation with Nissan engineers that the proper setting was 0.9 and it was not for a region. If you look at what azdre wrote, it looks like their dealer was trying to see if they could add more for some reason.

My post: http://www.mynissanleaf.com/viewtopic.php?f=30&t=3139&start=123

azdre : http://www.mynissanleaf.com/viewtopic.php?f=30&t=3139&start=141
and http://www.mynissanleaf.com/viewtopic.php?f=30&t=3139&start=137

It almost looks like they were guessing as they worked their way down to 0.91.

 

[TomT]

Again, this is all simply nonsense! Nissan needs to get to the root cause asap.

My dealer said in their conversation with Nissan engineers that the proper setting was 0.9 and it was not for a region. If you look at what azdre wrote, it looks like their dealer was trying to see if they could add more for some reason.

 

[LakeLeaf]

And unless someone advises otherwise....if you get "the little yellow car with the exclamation point" warning showing up while driving after turning on your A/C, I recommend NOT stopping right away. Instead, turn off your A/C, and drive it to the Nissan dealership before shutting down, so they can fix what needs fixing.

I agree. With a normal ICE car, we're taught to stop when the problem appears, for fear of doing increased damage by driving.

For the LEAF, my advice would be the opposite. Drive as close to a dealer or home as you can, since it probably won't turn on again.

Sounds like for this particular issue, continuing to drive to a dealer before shutting down isn't going to hurt the car. From what Brendan posted, there is a slight overdraw of current by the compressor which doesn't sound like it is hurting anything.

But we don't know if there is a protection mode of the car that *will* shut it down if there is a current draw that is significantly out of spec - so much so that it could cause damage. Something to speculate on, I suppose. If there was a serious issue (e.g. enough current draw to melt something) would the car react any differently? Clearly in that case if the warning light comes on it would be in the cars best interest to shut it down a soon as it is safe for you to do so.

I know car manufactures don't want to make their documentation overly complicated, but I'd sure like to understand the fault/trouble paths the logic picks up.

 

[palmermd]

Again, this is all simply nonsense! Nissan needs to get to the root cause asap.

What do you suggest? What can we do to help them? Do you believe that they just adjusted the refrigerant in my car and are now on to bigger and better things? My belief is that they are working on finding out why the software is shutting down the car and in the mean time if you keep the A/C charge at 0.9 there does not appear to be any issues.

 

[TomT]

I'm an engineer. I design things. That has included large HVAC systems in the distant past. If I were to have designed something this fragile, I would have been fired.

Automotive AC systems see large changes in refrigerant pressures due to the widely varying operational and ambient conditions. This is considered normal and is a standard design parameter and consideration. The difference in charge level between .9 and 1.06 is statistically insignificant in such a system and typically considered a normal tolerance. Thus, the fact that it is causing a problem leads me to conclude that the real issue lies elsewhere and that simply adjusting the charge level is no guarantee that it will not reoccur on a much hotter day - or when you are stuck in traffic with reduced condenser AF - and the pressure, and thus compressor load, again increases...

Again, this is all simply nonsense! Nissan needs to get to the root cause asap.

What do you suggest? What can we do to help them? Do you believe that they just adjusted the refrigerant in my car and are now on to bigger and better things? My belief is that they are working on finding out why the software is shutting down the car and in the mean time if you keep the A/C charge at 0.9 there does not appear to be any issues.

 

[palmermd]

I understand and I completely agree. So for now all we can do is have the dealership set the refrigerant at 0.9 and we wait for a service bulletin to be announced for the "real" solution.

 

[davewill]

What can we do to help them? Do you believe that they just adjusted the refrigerant in my car and are now on to bigger and better things? My belief is that they are working on finding out why the software is shutting down the car and in the mean time if you keep the A/C charge at 0.9 there does not appear to be any issues.

Probably the best thing we could do to help them would be to see that the A/C gets used regularly, so that they have the best chance of seeing cars fail...but that might be difficult for some.

 

[evnow]

I'm an engineer. I design things. That has included large HVAC systems in the distant past. If I were to have designed something this fragile, I would have been fired.

I don't think it has been designed this fragile - since they would have tested the car in hot places with A/C. Something has changed in this particular batch of cars causing the problem - may be a sub-system they got from their supplier or a firmware update.

 

[TomT]

Perhaps, but my car was a January build and an early March delivery, and I've been able to replicate it in my car as well...

I don't think it has been designed this fragile - since they would have tested the car in hot places with A/C. Something has changed in this particular batch of cars causing the problem - may be a sub-system they got from their supplier or a firmware update.

 

[Gonewild]

My car was built the same time as Skywagan's I have used the AC and have had no problems. I have VIN#229 anyone near my number having problems?

I used the web site to test the remote turning on of AC but that was a month ago and it was not hot yet. Is it failing as you drive or only if you are using the pre cool option? Thanks

 

[evnow]

I wonder whether there will be a recall or they will call individuals and ask them to get their Leaf checked ...

 

[derkraut]

I wonder whether there will be a recall or they will call individuals and ask them to get their Leaf checked ...

IMHO, it would be prudent (and easy to do) for Nissan to contact all Leaf dealers and owners ASAP; explain in simple terms what the problem really is, and what steps are being taken to correct it. All this speculation just makes things worse, and will result in a significant loss of confidence regarding this car. I'm just happy I don't have mine yet. My Prius keeps humming like the finely tuned machine it is. :? :? :?

 

[davewill]

I wonder whether there will be a recall or they will call individuals and ask them to get their Leaf checked ...

Is there a difference? A recall is when you contact owners of cars that may have an problem and ask them to bring them in for service. The REAL question is whether they will call people in, or just wait for the cars to fail.

 

[TomT]

Unless they learned nothing from the Toyota fiasco, they'll call people in... Of course, if they just had the ability to push a firmware fix (I did check the service manual and find no references to this being possible, by the way), it would be easy...

The REAL question is whether they will call people in, or just wait for the cars to fail.