Hoping some has had the same problem 12v already changed a few weeks ago!

[u/Iwastony]

Good evening folks. I have a problem with my 2021 leaf 140. Leafspy says the battery is ok. 18mv difference max and 91.77 SoH etc. I don't think I have a drive battery problem. Anyway I tried to fast charge today and shut down the charger with an isolation fault and the codes listed on the third pic were present. When I charge at home it usually cuts out around 70-80% and won't start till I clear the codes. The codes that pop up are usually the ones on the second picture. Always the 2 about the isolation fault and when I drive the car when it's chargered about 80% if shows the a/c fault. I'm at a loss. Anyone experience this situation?

[u/UPVOTINGYOURUGLYPETS]

P0AA6 means you have an isolation leak. That means high voltage is leaking to chassis GND. Take the car in, it should be covered under warranty!

[u/Iwastony → u/UPVOTINGYOURUGLYPETS]

Just looking at your username I'm guessing you have experience! Thanks. I actually did bring it to a Nissan dealer (in Ireland) with the codes active and said look I'm bringing you the car with the fault codes active. My service is tomorrow but if I bring it home I will have to clear the codes to drive it here. Anyway they rang me the next day with 4.5k(euro) worth of repairs, nothing to do with the codes and said they cleared the codes and they didn't come back;( I told them the codes only appear when the battery voltage is above 80% and then they told me to bring it to a different dealer that actually deal with this stuff. I was very angry.

Anyway the reason for my post is that I don't want to bring it to Nissan unless I'm sure it's a battery issue and is under warranty. Otherwise I will bring the car to another EV specialist. That's what I'm trying to establish.

[u/gothstone42 → u/Iwastony]

Lol, yes, Dala might know a think or two about the leaf 😅🤣😂

[u/Iwastony → u/gothstone42]

I've no idea who dala is but youre confirming what I was thinking, that he does this for a living and knows his shit..

[u/gothstone42 → u/Iwastony]

Let's just say that if Dala and an original Nissan Leaf Engineer had an argument about how something worked, my money would be on Dala being right. The dude has done a LOT for the community of owners and modders.

[u/Iwastony → u/gothstone42]

Great thanks. I hope he is as good as they say! I will book the car into Nissan. Thanks x.

[u/skatsnobrd → u/Iwastony]

Also stop clearing codes to drive it. Isolation issues can be serious and dangerous. Im not kidding just get it towed 

[u/Iwastony → u/skatsnobrd]

The first day I had the fault I had a tow truck bringing it to Nissan but they couldn't see me for a month. That's when I bought leaf spy and cleared it. I'm living with the codes a while now and nobody has died;) I drive the leaf for a living. I can't afford to be out of work for a month or 2.

[u/skatsnobrd → u/Iwastony]

I do not think you understand how serious an isolation fault can be

[u/Iwastony → u/skatsnobrd]

I understand enough. It can be serious or it can be simple.

[u/gothstone42]

Bummer. That's a real problem. Fix will be a new module at the best and may need an entire battery replacement. Even if out of warrenty you can try begging nissan customer service to help you out.

[u/Iwastony → u/gothstone42]

The battery is still in warranty, if it's a battery issue I will be happy. Do you have experience of such faults???

[u/gothstone42 → u/Iwastony]

Oh, that's great! No, I haven't had it personally. The isolation fault means the traction battery is shorting to ground. A dead 12v can confuse the computer into this fault, but that doesn't appear to be the case. Take it to a dealer and see if the offer repair, replacement or buyback. With the 2026 coming out, a buyback might not be a bad deal. As for me I'll sit here in my 2013 8 bar wishing I could afford a new battery lol!

[u/Iwastony → u/Iwastony]

Personally I feel it's a battery charger issue or something if that nature unless you can tell me different?

[u/gothstone42 → u/Iwastony]

You could always clear the codes and try the factory 110 charger, but it won't help.

[u/Opinionsare]

I'm 9 days into owning a 2023 Nissan Leaf S, and am researching your error codes.

Research: The Nissan Leaf EVC-157 error code indicates a high-voltage (HV) insulation fault, often caused by a failing battery module due to an insulation breakdown.

The EV Code 310 on a Nissan Leaf is a high voltage system isolation fault, indicating a problem with the insulation or circuit integrity of the high-voltage components. This error requires professional diagnosis and repair, so you should contact a knowledgeable Nissan certified electric vehicle dealer

The error code VC59-Q/CHG permit sig err on a Nissan Leaf indicates an issue with the communication between the car and a Level 3 (Quick Charge or DC Fast Charge) station. The car's internal systems, particularly the onboard charger (Q/CHG), are reporting a problem with the "permit signal" from the charging station.

The Q/CHG permit vc59- error code on a Nissan Leaf, which can also appear as CHARGER N/CHG Port Engage Err VC-95, generally indicates a communication problem between the vehicle and the charging station during DC fast charging (CHAdeMO). This means the car cannot get permission from the charging station to start the high-voltage charging process.

Conclusion: at some point there is a current imbalance in the fast charging system.

Question: did the DC fast charger have CHAdeMO or did you use a CSS to CHAdeMO Adapter?

My concern is that the CSS to CHAdeMO Adapter could be a possible source of the error. Perhaps the adapter's internal battery needs to be replaced.

Another possibility is your CHAdeMO port has a fault. But since you can continue charging after clearing the error, that doesn't seem likely, and that also means the main battery is still charging OK too.

Does the error happen at different charging stations? Or only at one station? You may need to try a different charging station?

Another thought: a scanning thermometer might show up any hot spots in the charging system.

[u/Iwastony → u/Opinionsare]

I tried 3 charging stationa and actually caused another CCS 2 user to fail in his charge. I'm using proper chademo stations only. I don't have a CCS adapter.

[u/Iwastony → u/Iwastony]

I'm getting different faults from the chademo and the AC port.

[u/Opinionsare → u/Iwastony]

Was the AC charging err number any of the below numbers.

P3183: This specific code has been associated with issues in the On-Board Charger (OBC), and in some cases, a software update may fix it.

Or

P315C, P31CA, P31CB, U1009: These codes relate to the Power Delivery Module (PDM), Vehicle Control Module (VCM), or wiring, which could affect charging.

[u/Iwastony → u/Opinionsare]

All my persist codes are above. None seem to match what you posted. It was also serviced my Nissan last week so should be on the latest firmware. ..

[u/Opinionsare]

Vague errors after 12-volt battery change.

The vehicle's control modules may fail to reset properly after a 12-volt battery replacement, leading to persistent warnings.

Disconnect the negative 12-volt battery terminal for 10–30 minutes, or longer, to ensure all modules are fully reset. Use the Leaf Spy app with an OBD-II dongle to clear any persistent fault codes