Leaf 2019 - AC compressor problem

[Boudou]

Hello !

My 2019 Leaf refuses to start. The following message appears "Service EV System Unable to restart after power off". The mechanic at the dealership says it's a problem with the A/C compressor, that it needs to be changed, including wiring for $3700 CAD. Your opinion please.

 

[cornbinder89]

Hard to advise without DTC's. Something could be shorted, and not sure how the HV inverter would respond to a problem like this.
Trouble code are the key.
Why the need for wiring change?

 

[Boudou]

Thank you for your reply.
We didn't get a clear answer. The mechanic explained that they'd had the same problem with another Leaf, that they'd only changed the compressor, but that it was the wiring that was faulty. Since then, they've been changing the 2 at the same time!!!! It seems that access is difficult and that, as long as you have access, it doesn't cost much more to change both. That would be Nissan Canada's recommendation.
I haven't found any comments from other users about this problem, although I have consulted several forums about Leaf.

 

[cornbinder89]

I would be skeptical unless Nissan Canada is picking up the tab. Replacing one thing then saying we had a bad experience and now replace both as a matter of course, isn't diagnoising, it is throwing parts at the problem and hoping one of them fixes it.
If Nissan Canada will pay for that, then fine, If I was expected to pay for that, No WAY!

 

[GerryAZ]

DTC's would be helpful for offering insight. A high-voltage system ground fault could be the cause--if so, the ground fault could be in any of the high-voltage systems and wiring so the problem on the previous LEAF that the shop worked on could have been a fault in the A/C compressor wiring harness and/or compressor. Faults on your car could be anywhere in the HV system. Unless there are specific DTC's related to the A/C compressor, they are just guessing. This could get expensive if not under warranty.

 

[addyionut]

I have the same issue, since last year. The dealership said it's an internal High Voltage battery, an isolation problem, after they had checked A/C compresor, which looked ok.
There's a lot of Leaf with this issue. Check other topics, or search for error message " Ev system error. Unable to restart after power off"
Or use the error code from the picture attached.

 

[cornbinder89]

Any high voltage leak to chassie will give that message. Causes can be different, can be internal the the battery pack or external from the same.
DTC are essential to help find the problem.
You can end up chasing your tail if you try and diagnose using DTC from someone else, the problem may be similar but have a different root cause.
Without DTC everybody is just guessing. With DTC you can look in one area, much better chance of being correct, and often a way to pinpont the source of the problem.

 

[w7gz]

I'm agreeing with the other posters, that diagnosing this problem can be a lot of tail chasing. Be certain of the cause before changing parts, and only the parts at fault. This can be expensive.

I had this problem in my 2012 - the system detected a HV ground fault somewhere and the car refused to start. I used LeafSpy and its dongle to clear the codes, after which the car would start. I carried the dongle with me at all times in case the error popped up again so I wouldn't be stranded. Eventually the fault corrected itself with me having done nothing other than clear the codes numerous times.

Now a HV fault can be a safety concern so that is why the computer disables the car. If the problem immediately reappears after clearing the codes, it's not intermittent and must be diagnosed correctly and fixed. Otherwise, you will at least be able to use your car while gathering more information about the fault through LeafSpy. If it's truly a problem with the air conditioner module, it should reappear with its DTC.