Leaf won't operate. Warning - Service EV System, Warning - Service EV System Unable to restart after power off

[knightmb]

If testing the isolation at the center disconnect on the HV battery shows no issue, can there still be another possible isolation problem? My 2022 leaf keeps throwing the same start inhibition and HV battery isolation codes (P31E7 and P0AA6 EVC157) every time I charge my car and it reaches 86%. The EV Service warning message only comes on at that point, otherwise I can drive and charge my car normally once I clear the codes with my leafspy. I won't get the errors until I charge my car again and it hits 86%. My husband tested the voltage at that back seat access point and found no isolation issue, the voltage reading dropped steadily as normal. Any advice would be greatly appreciated as we live in The Bahamas and there is no Nissan EV service available.

That would suggest that you do indeed have a real issue. Somewhere in the battery pack, thermal expansion during charging is touching the outside of the shell. The best way to test this and be certain; have everything ready to measure the isolation voltage the moment it charges to 86% and the error occurs. Then you will be about to see if a voltage is remaining after the capacitance is slowly leached away by the measuring equipment while the battery is still warm.

 

[Bombastinator2]

*imagines the ending of the movie “Nosfreratu” The silent one. Then imagines the movie “Cars”*

You’ve got to set a trap and catch it in the light.

 

[aant]

Yay, this is happening to our 2018 Leaf now. Just over 100k miles, too (around 100,200). The message came up this morning right after leaving the house and we turned around and went home, tried to restart it and it's not really starting. I did replace the 12v battery in January (several months ago), so that should be good. That was around the same time the charging cable that came with the car stopped working and I replaced it with another one (could the new cable be doing something?). I'm in socal and have generally only charged to 80-90%, although last night I did let it charge to 100% because we were going to drive more today. Haven't pulled codes yet. I don't have a Bluetooth reader so can't use leafspy. Will any dtc reader work? (We're out for the day so haven't gotten back home to try more yet, but thought I'd post here for any other ideas while I'm waiting)

I made an appointment with the dealer already and assuming I'll need to tow it in Tuesday morning. Bummed, we were just talking about how reliable our Leaf has been!

 

[Jerrymander]

My Leaf displayed Warning Service EV System, Warning Service EV System Unable to restart after power off. tonight. Battery is 100% charged according to the dash display but the Battery symbol at the top right side of the dash is illuminated as are the warning lights for front and rear hazards.
The vehicle is a 2021 Leaf S Plus. I have 88K on the odometer and have never had anything other than tires installed. My battery pack does seem to be degraded and only shows 180-190 miles range when fully charged. (New was 230 Miles). Any advice on what to do here?

I've heard tell that your 12V "car" battery may be bad. The car needs it to run the systems and won't start if its low. Try getting a jump. Good luck.

 

[Bombastinator2]

I've heard tell that your 12V "car" battery may be bad. The car needs it to run the systems and won't start if it’s low. Try getting a jump. Good luck.

That is the first answer with that kind of warning. If you’ve got a trickle charger you can probably throw it on the thing and make it work. Whether it will do it NEXT time of course is an open question. The problem is batteries are a bit like balloons. They start at a voltage higher than 12v, and are empty at a voltage lower than 12. The leaf requires 12v or more all the time or it gives that reading. This is why some people put LiFepo4 batteries in them. Those are 12.8 till the bitter end. Theyre really expensive though.

Might make sure it actually is the battery. Put a multimeter on it and if it’s less than 12v, well there’s your problem.

 

[isaakson64]

Any updates on this issue? Was it resolved by the dealer? I'm having similar issues with my 2018 40kWh. Same codes, replaced the 12V but the codes continued after they were cleared. Dealer wants $2000 to pull the motor and the PDM to continue to search for the isolation fault. Doesn't seem like they know what they're doing either. Didn't even have a multi-meter that would work on voltages involved. Any help is appreciated. Thanks

 

[cornbinder89]

1st thing I'd do is an isolation check, watch Dala's video on how to do it. Be careful you are dealing with high voltage, and if there is in fact an isolation problem in the battery, then the chassie is "hot".
I would find another dealer, as it doesn't sound like they have much of a clue.
If you not comfortable working with the voltages involved, I would look to an independent EV shop, they are going to be better versed in EV's and can isolate the components without pulling the PDM and motor to look for a HV leak.

 

[cornbinder89]

This brings up (once again) a peeve of mine. Isaakson, understandably, balked at paying a $200 "diagnostic fee" but willingly paid about that to replace a 12 volt that didn't cure the problem! Now that diagnostic fee, has doubled due to the battery cost.
Too many here start with "replace the 12 volt"! NO, do not replace the 12 volt unless and until, it has been recharged and tested and proved to be faulty!
I am not blaming him, I am blaming those that advocate replacing the 12 volt as a solution to every problem, without stressing the need to confirm the battery is the problem.
Most have some sort of 12 volt battery charger around the house. Pull the battery and recharge, if you don't have the means to test it, many autoparts stores will do so for free (Autozone Orielly's Napa etc)
In the norther hemisphere we are heading into the colder weather. So we are likely to see more discharged battery problems, whether they are faulty or just discharged will be the question that needs to be answered!

 

[oxothuk]

This happened to me when my 2021 SL+ was about six months old. First time, I had it towed to dealer and the could not reproduce the problem (after clearing DRCs). 3 months later it happened again and I drove it directly to the dealer; this time they were able to reproduce the issue and located a bad module in the battery. It’s been almost 3 years now since they replaced the bad module and I have had no further problems.

 

[EZiLife]

I've heard tell that your 12V "car" battery may be bad. The car needs it to run the systems and won't start if its low. Try getting a jump. Good luck.

My 2021 Nissan Leaf stalled when I was trying to move away with the 'Service EV System' fault screen. It turned out a battery module (module 4 to be exact) had failed in the main battery pack. Fortunately for me I was still under warranty but the vehicle had to go back to the main depot up in Sunderland (UK) for a replacement module.

 

[isaakson64]

Thanks for the help everyone! Thoughts on what to look for if I scan the system with Leafspy? Module voltages etc? New to leafspy but have watched plenty of Dala's vids which are very helpful.

On another note, looking to tow the stricken leaf onto a flatbed and need to get the tow bolt but not sure what the thread pitch is on them. Found a forum thread saying it's M22 diamter but what thread pitch?? Standard metric thread? Is "standard" really a thing?

Thanks!

 

[cornbinder89]

1st clear the codes with leafspy, this should allow the vehicle to be driven one time before the code sets again and locks you out. I think you can re-set as many times as you want, but it will lock out after each time.
Leafspy battery readings aren't really a help here, the issue is that somewhere there is a leak of HV to car chassie.

The above video I think is the one where Dala checks his battery for an internal HV leak.

 

[chk]

Happened with our ZE1 of 2018. Took 5 month to repair it, module 24.

 

[cornbinder89]

Sorry, wrong video above, but still worth the watch.
This is the one where he diagnoses it.