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2012 Service High Voltage Charging System

1097 Views 15 Replies 7 Participants Last post by  Rhepler
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I’m posting as a last ditch effort to help before I have the dealership drop the battery in my poor Volt. I have a 2012 with the Service High Voltage System message for about 1 month now. The car drives fine, battery doesn’t charge (it does regenerate a little just from normal regen braking — not sure if that makes a difference). I had the same message last year in December which was resolved by updating the BECM. I took it to the dealer and basically he said he needs to drop the battery in order to diagnose. He said this after all of his initial diagnostic tests didn’t show the root cause of the problem. The biggest thing according to the mechanic is that the “insulation resistance test” is showing 0.0 kohm.

I had him replace the coolant level sensor and that did nothing. The cost for just the labor to drop the battery is over $1k so I’m hoping someone else has an answer that doesn’t involve that.

I’ve attached some reports from the dealership. Thanks so much for all the input!

P.S. I had a Volt tech from another group tell me that if the insulation test was actually 0.0 kohm, the car wouldn’t even start. The mechanic ran the test twice and came back 0 both times.
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Discussion Starter · #5 ·
I've not seen many cases on here where there was a solid short like you are reporting. Non-approved coolant (Dex-Cool concentrate and deionized water) could potentially cause that error. No isolation would be a serious safety risk.

Given that the high-voltage battery appears to have about 10 years of life in it and there are no new cells available to repair them, you may need to decide if it might be time to let this one go based on the news you get.
Safety risk? How so?
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