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

Interesting... I just got off of a chat with CS. Their position now is that only the dealers have the correct info on the problem and one should only believe what they tell you... He said that "information on internet Leaf forums is more often wrong that right and you should talk to your dealer." He further claimed that "no one knows what VINs are affected."

Nissan is NOT handling this incident well, in my opinion. Throwing up firewalls like Toyota did will not help the matter! Every Leaf owner should have ALREADY received an email from Nissan with all the specifics as they currently know them, updated as they learn more.

I am less than impressed at this juncture...

Despite being told by a local dealer (NOT my PD!) that my car was not subject to the A/C issue and software flash, it did it for the second time about an hour ago. It was parked outside in the sun and I left for a lunch meeting. Since it was hot, I turned on the AC once the car was on and moving. About 10 minutes later I get the dreaded triangle, etc. I pulled in to the restaurant parking lot (this was an important meeting and I didn't have time to play the dealership game), shut it down, and, yes, it wouldn't restart. I disconnected the 12V battery and headed inside (glad I had my 10mm wrench).
When I came back out about an hour later, I reconnected it and all was well again. I'm now back at the office and used the A/C without incident on the way back.

Nissan really needs to let us know what the heck is going on with this! I'm not going to take it to a dealer until we have a more definitive cause and fix.

Ingineer said:

bowthom said:

Phil,
Excellent sleuthing, I suspect Nissan hesitates to lower the resistance / leakage test parameters due to safety concerns. I've been preheating in the AM (heater is on the "list" of offenders) without incident. The heater can draw 6 kWh and seems to me the A/C would be less so it has to be something other than just current draw. It is circuit sensitive, maybe noise, fly back, heat or current on that particular circuit that's knocking the IR detection out of range. Maybe all that circulating fluid through the pump and metal lines creates a static charge, add condensation and it finds it's way to the chassis then "POP" goes the P0AA6. Sounds like fun detective work doesn't it, I love a good challenge.

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They typically use a weak AC signal connected from the body alternately to HV+/HV- through a known resistance and read it's voltage. If the voltage is lower than a certain value the leak detection is triggered. The signal is read with an ADC input on a microcontroller, so the trip threshold is adjustable. This is how it's done in the Prius as well.

380k ohms seems awfully sensitive to me! That's only 1ma of leakage, worst-case! If it was me, I'd engineer it so it trips instantly at 100k or only if the fault exists for more than 10 seconds at 380k.

Because of this sensitivity, it may just be nuisance-tripping inside the A/C compressor.

-Phil

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From what I have learned I think Phil nailed this one, it is an issue with the resistance setting and a Nissan engineer must log into the dealer system remotely and change the setting to a more acceptable level closer to 100K, this solves the issue as it was too sensitive. There will be a fix likely in the future but it is done manually now as described. I will be taking my car in perhaps tomorrow and up date everyone on this but from what I have heard this is the actual issue.

I doubt there is a way for them to "change the setting" without doing a firmware update...

EVDRIVER said:

From what I have learned I think Phil nailed this one, it is an issue with the resistance setting and a Nissan engineer must log into the dealer system remotely and change the setting to a more acceptable level closer to 100K, this solves the issue as it was too sensitive.

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EVDRIVER said:

From what I have learned I think Phil nailed this one, it is an issue with the resistance setting and a Nissan engineer must log into the dealer system remotely and change the setting to a more acceptable level closer to 100K, this solves the issue as it was too sensitive. There will be a fix likely in the future but it is done manually now as described. I will be taking my car in perhaps tomorrow and up date everyone on this but from what I have heard this is the actual issue.

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That can't be it. Didn't you see mogur's post? :lol:

mogur said:

He said that "information on internet Leaf forums is more often wrong that right and you should talk to your dealer."

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mogur said:

I doubt there is a way for them to "change the setting" without doing a firmware update...

EVDRIVER said:

From what I have learned I think Phil nailed this one, it is an issue with the resistance setting and a Nissan engineer must log into the dealer system remotely and change the setting to a more acceptable level closer to 100K, this solves the issue as it was too sensitive.

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It's quite possible that there's a parameter area are that can be updated without actually changing any code. That would be safer than changing the actual code all the time, and also allows for fixes to be applied to vehicles individually instead of necessitating a complete update that might hold fixes for problems which the vehicle in question doesn't exhibit. We all know about fixing stuff that isn't broken... I have no doubt that after a proper testing regimen, this fix (or one like it) will find itself loaded automatically on all vehicles, but for now, piecemeal parameter changes sounds very plausible to me.

It's certainly possible but they usually like to use something less volatile and acessable in an automotive environment. It's conceivable that they could have an eeprom to hold such parameters separate from the actual firmware code but automotive designers are notoriously conservative as well as cheap...

Again, too bad that they didn't allow for such updates over the telemetrics, particularly for a vehicle that is not likely to see the dealer too often except for the yearly battery check but which is likely to see frequent code updates...

davewill said:

It's quite possible that there's a parameter area are that can be updated without actually changing any code. That would be safer than changing the actual code all the time, and also allows for fixes to be applied to vehicles individually instead of necessitating a complete update that might hold fixes for problems which the vehicle in question doesn't exhibit. We all know about fixing stuff that isn't broken... I have no doubt that after a proper testing regimen, this fix (or one like it) will find itself loaded automatically on all vehicles, but for now, piecemeal parameter changes sounds very plausible to me.

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mogur said:

He said that "information on internet Leaf forums is more often wrong that right and you should talk to your dealer." He further claimed that "no one knows what VINs are affected."

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It really disturbs me when people get lied to. When I called CS on Saturday, they specifically told me my VIN was impacted when I asked.

So, either they lied to you - or they lied to me. Either way, this particular forum is factual in stating that they lied (as long as we're not lying ). And for the record, the dealer hasn't responded to my latest query on the issue nor have I received the follow-up I was promised (though the day is not over yet)

After the discussion here over the last couple of days, I've decided that this is our number one concern right now (I was actually leaning that way all along). And so today I sent my contact the following email:

I'm compiling the list of questions as we speak. But I probably shouldn't let any more time go before asking you the most important question of all right now...the vehicle disabling air conditioning issue that seems to have popped up with the most recently delivered batch of cars. We are seeking information as to:

a) the number of cars affected
b) the VIN number range of the cars affected
c) what the actual cause of the problem is
d) what is being done to properly rectify it
e) how we should expect Nissan to communicate with us about the issue

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Hopefully that will bring the answers you (we) are all seeking.

mogur said:

Again, too bad that they didn't allow for such updates over the telemetrics, particularly for a vehicle that is not likely to see the dealer too often except for the yearly battery check but which is likely to see frequent code updates...

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Thanks, but no thanks. That's all I need is for Nissan to upload fixes without my knowledge or consent that end up causing me problems. I might not even know why my car started acting up.

Not to worry. If it was like Carwings, you'd have to say yes 12 times in advance anyway! :lol:

davewill said:

mogur said:

Again, too bad that they didn't allow for such updates over the telemetrics, particularly for a vehicle that is not likely to see the dealer too often except for the yearly battery check but which is likely to see frequent code updates...

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Thanks, but no thanks. That's all I need is for Nissan to upload fixes without my knowledge or consent that end up causing me problems. I might not even know why my car started acting up.

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Do it like DVD/Blu-ray players do and make us download a .bin file and stick it on a thumb drive or CD and pop it in... :lol:

My vehicle (#753, delivered 3/29) exhibited similar behavior twice today.

It's a warm day here in San Diego and I was demonstrating some charging equipment at one of our facilities and after disconnecting the J plug from the car (Columb Chargepoint EVSE) after starting I had the two yellow warning lights. I believe the AC was on at startup - I haven't been using it in the past few days thanks to forum advice, but had guests in the car so rolled the dice. The car drove fine at that point.

I drove at slow speeds to my next stop, about 1/4 mile down the hill. I was slightly nervous about powering down the car, but had a wrench with me to do the 12v reset trick. Fortunately, no wrench was required. After powering down the car (I made sure AC was off) it started again without the warning lights.

About an hour later, same sequence of events (which I didn't take careful notes on, so please don't consider these good test conditions), same results. Same lights, that cleared after shutdown and startup.

I did sit there for a couple minutes after that, turning the car off and on, AC off and on, etc. No lights, all good! Hopefully my luck will continue. If not, I have the wrench.

I know this is very disconcerting to many, but in my opinion shouldn't be cause for serious alarm. Easy for me to say, I know, not having to have the car towed (knock wood!). But this will get fixed, then we'll be on to the next thing

It sounds like there could be two issues here, once my car gets the error there is no way to start the car as the codes never clear unless the battery is disconnected. It is not a temporary issue with cycling the car on and off, once it happens a person without tech experience would need to be towed.

JoshSD said:

.... (Columb Chargepoint EVSE) ...

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To clarify - I should have mentioned this particular EVSE is a non-public station used for research & demonstration purposes.

I got a call from Paul at Leaf customer service a few minutes ago.

I had called on Saturday because the red master alert symbol was on. He had me take it to our dealer, and between customer service and our dealer, they decided I would need to have the A/C refrigerant level evaluated.

However since the alert light went out, we decided to wait until the 'real' fix was determined.

When Paul called back, he told me that they are no longer recommending that the refrigerant be replaced. They determined that the sensor was reading incorrectly, and that a software update would resolve that.

He had the dealership contact me to schedule the software update. It apparently is not too difficult, but since the dealer has never done one on a Leaf they want to have a Nissan tech on the phone to hold their hand while they do it.

Paul says that 26 cars were updated today, and that none of the cars with firmware updates have had the issue recur.

I'm planning on getting the update Wednesday.

Sounds like a quick fix and shouldn't delay orders by "weeks" as someone stated in another thread.

So my car was towed on Friday to the dealer, today I got the car back and the dealer confirmed a software update was needed. I have not had any issues so far including using the AC. I'll let everyone know if I have another problem.

GeekEV said:

Do it like DVD/Blu-ray players do and make us download a .bin file and stick it on a thumb drive or CD and pop it in... :lol:

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And if you don't, it won't play ... err. start.

This error makes me start to worry about something I was told when I was a boy.

There will never be electric cars because they require little maintanence.

I have a feeling that building in the ability to have this error took a great deal of effort and it makes me worry that Nissan is attempting to make an EV that requires maintenance because of bogus problems. I can see no reasonable explanation that the drivetrain would be tied into any system other than the drivetrain which includes, batteries, motor and the actual drivetrain.

Even more troubling would be if as others said a few years ago these cars will barely get on the market and then end up with some sort of recall to explain why EV's aren't viable..

To drive my EV, after it is charged I enter, turn on the key, select F or R, then depress the footfeed and I go. Nissan apparently felt they could improve upon this.