[hybridpadawan]

Hello all. I'm a relatively new volt owner. I purchased a used chevy volt this past june. around the middle of november i got the service high voltage charging system message on my car, and i took it to the chevy dealer. I had read some forum posts saying that it could just need an update to the software, and that's what the service tech did. It charged again and I brought it home.

A month later in december it did it again. I had read about the defeat plug for the coolant sensor so I purchased that and was going to install it after taking it into the dealer once again to update the software and clear the code. due to winter weather i wasn't able to get my car into the dealer until mid January. When i did get it there (about an hours drive from home) they said that they needed to keep it overnight, and they ended up keeping it 7 days. I finally got a call saying that the high voltage battery needed to be replaced. I've attached photos of the notes that the service tech did. the first from november when he fixed it and the second from january when I was told that the battery needed replacing for $10,200.
I declined the battery replacement, as thats about $100 less than what i paid for the car.

I was in despair for a while. I made a post on the reddit volt sub asking what to do.
A few users mentioned that if the battery were truly bad that I wouldn't have been able to drive it on gasoline, and that many times thats the response when either they don't know what to do,or its a go away tactic.
I had spoken with the service tech both times and he seemed pretty forthcoming on all of the steps that he had to do and what the step by step process was that gm had him follow. It also sounded like he had to call or be in contact with someone at GM in order to do the steps for troubleshooting some of the times.
Some redditors advised me to check with an obd2 scanner some things. I didn't have one so I ordered one online. I purchased the OBDLink MX+ OBD2 Bluetooth Scanner for iPhone, Android, and Windows after looking on this forum for recommended scanners.
It will arrive later today. I don't know what apps I need exactly. I've been reading some posts and I have seen some like my green volt app.
What other apps do I need to get in order to help diagnose my 2012 volt battery problems?

I hope that I can get this all sorted out so I can charge the battery again as I very much like the car and have not had it very long.

 

[Jim Fallston Md.]

The battery is warranted for 8 years & 100,000 miles in case you are not aware.

 

[hybridpadawan]

The battery is warranted for 8 years & 100,000 miles in case you are not aware.

Yeah, unfortunately my 2012 has 140,446 miles on it, both times I took it into the dealer they stated, "this vehicle is out of warranty" so I paid for the repair and diagnosis.

 

[hybridpadawan]

So I got home plugged my new obd2 mx scan tool into the car. It's got the P1E00 code, P1FFF code in the confirmed section, both of those again in the pending section. In the permanent section there's the P0AA6 code and the P1FFF code.
I tried clearing them not expecting much. And the dash indicator flashed green for a second, the car honked once and the codes still remained.

I got the my green volt app and bought the battery monitor thing, I couldn't export anything, so I snapped a couple of screen shots. I don't really know how to interpret the data. I also got the my volt hold app which allowed me to force the engine to run, and I put it into mountain mode.
The soc I assume means state of charge. At first it showed 44.71%, it slowly kept creeping upward, so I left it run for 10 minutes.
It seemed to stop getting a higher percentage after it reached 49.80%.

Any idea on what I should try next?

 

[ElectricCow15]

It seemed to stop getting a higher percentage after it reached 49.80%.

That's about right for MM.

At a glance the cells look ok (12 and 8 mV), but its best to look at them at full and empty. Mine is usually around 8mV when full and 15mV when empty.

 

[obermd]

After you charge the car this way, turn it off for a couple of minutes and then turn it back on. Does the car operate normally? If so the battery is most likely good and the issue is the on-board charger.

 

[Off Oil]

Reading through all the tech notes, the fault is from a loss of isolation beyond the threshold, not a cell voltage DTC. It looks like the tech did everything correct including involving GM TAC. The coolant was also replaced, which if that was never done may have resulted in an isolation issue. I'd say the battery pack is EOL, which isn't unheard of for a 10-11 year old pack.

 

[hybridpadawan]

After you charge the car this way, turn it off for a couple of minutes and then turn it back on. Does the car operate normally? If so the battery is most likely good and the issue is the on-board charger.

It had operated normally the whole time minus the ability to charge it with the evse.

I guess there isn't anything different after charging it this way last night

 

[Bill Step]

look closely at the charge port plug on the car,,my guess is its cracked and corrosion has started to form.thats what happened to my ELR

 

[obermd]

It had operated normally the whole time minus the ability to charge it with the evse.

I guess there isn't anything different after charging it this way last night

I don't think you need a new battery. As Bill Step said, check the charge port on the car for hairline cracks. Also, try some public chargers. If you find cracks in the charge port replace it. If any public charger works, replace the EVSE with one from Amazon.

 

[hybridpadawan]

Reading through all the tech notes, the fault is from a loss of isolation beyond the threshold, not a cell voltage DTC. It looks like the tech did everything correct including involving GM TAC. The coolant was also replaced, which if that was never done may have resulted in an isolation issue. I'd say the battery pack is EOL, which isn't unheard of for a 10-11 year old pack.

Does that mean that the only way forward is to replace the high voltage battery As Chevy told me? Or is there anything else I should look into?

 

[Off Oil]

Does that mean that the only way forward is to replace the high voltage battery As Chevy told me? Or is there anything else I should look into?

The only potentially fixable loss of isolation issue that I can think of would be if the wrong battery loop coolant was used, or it was bad. The tech drained the coolant when the battery was dropped and the housing opened. If they used new coolant when they refilled it, that would rule out that fix.

 

[hybridpadawan]

look closely at the charge port plug on the car,,my guess is its cracked and corrosion has started to form.thats what happened to my ELR

I don't think you need a new battery. As Bill Step said, check the charge port on the car for hairline cracks. Also, try some public chargers. If you find cracks in the charge port replace it. If any public charger works, replace the EVSE with one from Amazon.

The charge port on the car is in good condition, justa little dust on it.
I have the original voltec charger, and also the (Schumacher Electric Vehicle - EV Charger 16 A 28 ft from Napa) that I bought this summer which I've been using primarily.

I live in a rural area and there are not any public chargers.

I wouldn't think that would fix the problem with the car since it has the service high voltage charging system, and is throwing codes?

 

[leppard3]

The cracks on the charge port are always (ok, nearly always) on the back, you would have to remove it to check. Even then they are VERY tiny. I know, I had to replace the charge port on my 2011, it is VERY EASY. Reading through this thread, I would try replacing the port before even considering a new battery. But I hear they are quite hard to find. Just an idea.

 

[BarryD]

The only potentially fixable loss of isolation issue that I can think of would be if the wrong battery loop coolant was used, or it was bad. The tech drained the coolant when the battery was dropped and the housing opened. If they used new coolant when they refilled it, that would rule out that fix.

That is never a fix. Coolant is always an electrical conductor. Bad/old/wrong coolant will be slightly corrosive and will corrode the metal that is separating it from the HV circuits. Changing coolant won’t fix what’s corroded.

They have verified that the battery heater (a common failure point) has high enough isolation. Isolation loss in the charging system would normally set a different code. The only fix for this is to replace the HV battery. Sorry. It’s nearly 12 years old at this point. Time to move on.
Barry

 

[Btravelen]

The battery is warranted for 8 years & 100,000 miles in case you are not aware.

A 2012 has been out of warranty for a couple years regardless of mileage

 

[Brock_WI]

It is a pain to do, but you can "reset" the system yourself if your handy enough. We muttled through it. I just ran across this video which is exactly what happened to us. You do need to subscribe to techline connect, which is tied to your vin and valid for 2 years. The re-program the module to clear the code. The more it happens the more I think the battery is just getting old and getting out of range and throwing the code, I think being cold makes this happen more likely. If you know a dealer that can do this without charging $250 it should work.

 

[n75885]

A 2012 has been out of warranty for a couple years regardless of mileage

I had a similar situation to you and was also stressed for awhile, but after reading lots of post on this forum, I was able to find a solution that didn't involve battery replacement, although that would be the best fix if the battery prices ever came down.

Here's what I experienced and learned:
-During the drive home on the highway, I got population reduced message. Luckily, it switched itself to gas mode and I made it home, but upon parking it ran really rough and after turning it off, I was not able to get it restarted and drivable or chargeable.
-After reading lots of posts here, I learned that the voltage dropped too low on one of the many cells (probably due to the highway speeds/high load on battery) which created a fault and the car disconnected the battery from the propulsion system as a protection/safety mechanism and once that happens, the car is basically a paperweight. I bought the code reader you mentioned above and the app, but that didn't really help me with getting it fixed.
-One the car has this fault, the battery is not chargeable and the only fix is to reset the codes. This particular fault is not resettable by which the average code reader. It is called a permanent code and has to be reset by someone who has a specialized computer to access our car. I took mine to a friend who has a workshop and has the computer for this.
-After I had the car towed to the workshop, he reset all codes. Per Forum instruction, immediately put the car into Mountain Mode so it charges the battery back up to an acceptable voltage. Once that is done, it's drivable. Drive it home in Mountain Mode.
I did this several months ago and it's still my daily driver. Every time I go for a drive now, I put it in Mountain mode so the battery range and voltage is not allowed to drop too low and trigger this fault again.

Hope that helps, Andy

 

[BarryD]

After reading lots of posts here, I learned that the voltage dropped too low on one of the many cells (probably due to the highway speeds/high load on battery) which created a fault and the car disconnected the battery from the propulsion system as a protection/safety mechanism and once that happens, the car is basically a paperweight.

That’s a different problem. This is a verified loss-of-isolation problem which is very different. Follow the codes. GM invested a lot in the Volt’s excellent diagnostic system.
Barry

 

[imanjunk1963]

So I got home plugged my new obd2 mx scan tool into the car. It's got the P1E00 code, P1FFF code in the confirmed section, both of those again in the pending section. In the permanent section there's the P0AA6 code and the P1FFF code.

Find out of the GM software fix for the SENSOR RECALIBRATION patch has been applied. Mine started not charging back in 2022 and that patch fixed the problem on my 2014 for those simlar codes as I recall.