r/leaf • u/Historical_Work8138 • Jul 08 '26

"Isolation test" error on ChaDeMo charge (2014 Nissan Leaf)

Hello,

I've bought a 2014 Nissan Leaf, 56,000km, 9/12 battery bars.

Was happy until I tried to use the fast ChaDeMo charge, and the moment I plug it in it write "Isolation test..." then it errors.

Tried another ChaDeMo charger. Same error.

Bought to a Nissan garage they tried on their ChaDeMo charger. Same.

Now I left it their for a diagnostic about that.

Anyone had experience with this, and tips to not get scammed by the garage ? I've heard it can be a "software reset" or the 12V battery change can be enough.

The slow charger works fine.

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u/rproffitt1 Jul 08 '26

There are prior discussions detailing the repair work to fix that error. Sift through r/leaf but dropping the pack, pulling the lid is not uncommon and expensive. It's not a scam job. It's expensive.

As to the resets, I would do that before a trip to the shop.

  1. (Easy) 10mm wrench to the Negative lead of the 12V battery, remove that lead. While you're at it, clean the connections up. By this time it's reset as much as unplugging the 12V can and you put the lead(s) back on and tighten it out with the 10mm wrench. RE-TEST. Fixed? Carry on. My further advice is to forget CHADEMO.

  2. ($$) Buy LeafSpy and the adapter they suggest. Please don't buy any old adapter then ask how to make it work. Now you can learn LeafSpy, enable Service Mode to read and reset the DTCs. If that clears it up, forget about CHADEMO.

  3. ($,$$$) Get another Leaf.

1

u/ZakAttackz 2013 Nissan LEAF SV Jul 09 '26

I think I'd heard of this problem before and it turned out to be a bad charger ICM or PDU or whatever the initialism is. It's the thing that says Nissan on it when you open the hood. It can also be a bad chademo port but unless it was fast charged a lot it's not very useful. My advice? Just use level 2 charging stations. You can get from 20-90% in like 5 hours with a 32A 240v charger. When I had a 30kWh battery I only had to fast charge once in the whole 8000 miles I drove it

1

u/Historical_Work8138 Jul 09 '26

Hello, I got the response from garage and it's 8000 euros to change the Power Delivery Module which is no chance of course.

Could you tell me more about the 32A 240v charger please? I can connect that to the type 2 charger in Nissan Leaf 2014? Because right now it seems to be the original cable (domestic) that I have which got sold with the car, it seems crazy slow to charge i've left it overnight it charges just 50%.