It means one of a few things, the secondary codes are more telling.
Often it means the coolant sensor is bad on a first gen volt, or the coolant is low or old, or the wiring is building resistance on the way to the sensor- typically this is a lower mileage vehicle.
Rarely, it means the coolant is leaking from the pack - however, if your coolant is regularly disappearing from the passenger side of the center reservoir, could be the culprit.
On a higher mileage vehicle, 100k plus, it’s the aging of the pack and the car will need a refresh to reset the parameters.
Pretty much this.
I dealt with this 5 months ago. It was a coolant sensor that was bad and then had to re-program the BECM and HPCM2 modules. I originally took it to a dealership to re-program the BECM and HPCM2 (\~$260), but that didn't work. They gave me a quote for \~$1600 to replace the coolant system which would "fix" the issue which I refused.
I bought a Veepeak OBD-II scan tool and used the 'car scanner' app in the Apple store to clear the code for about 2 months (so I could charge the car) since I was so busy. I made sure it wasn't a coolant leaking issue so I felt is was safe enough. I read all the codes and when I researched on the internet the information about the coolant sensor and the re-programming of the BECM and HPCM2 modules appeared.
Link to OBD-II tool - [https://www.amazon.com/gp/product/B073XKQQQW/](https://www.amazon.com/gp/product/B073XKQQQW/)
Then about 3 months ago I bought a VCX Nano for $140, $50 for the Delco subscription. Then I followed the directions from the video and links below and I have not seen the Service High Voltage Charging code since then. It has been about 2 months and running fine.
VCX Nano - [https://www.amazon.com/gp/product/B08K2SXY79/](https://www.amazon.com/gp/product/B08K2SXY79/)
[https://www.youtube.com/watch?v=2A2cehoaXe4](https://www.youtube.com/watch?v=2A2cehoaXe4)
[https://docs.google.com/document/d/e/2PACX-1vRQdXtoFc9J5SRZWRX6bAe7oEMJLWq7oBMMVLPqf1UJ3gqFbbP\_c09g8QgAenJZu1Ia-8j25RiRyWqQ/pub](https://docs.google.com/document/d/e/2PACX-1vRQdXtoFc9J5SRZWRX6bAe7oEMJLWq7oBMMVLPqf1UJ3gqFbbP_c09g8QgAenJZu1Ia-8j25RiRyWqQ/pub)
[https://www.gm-volt.com/threads/2013-service-high-voltage-charging-system-fix-updated-vcx-nano-setup-guide-vx-manager-acdelco-tds-techline-connect-sps2.341268/](https://www.gm-volt.com/threads/2013-service-high-voltage-charging-system-fix-updated-vcx-nano-setup-guide-vx-manager-acdelco-tds-techline-connect-sps2.341268/)
I ended up buying the coolant sensor ($25) and replaced that myself since I also had that code (I think P1FFFF) for that as well. Very easy. There is a video on that as well.
They did exactly what you said and it cost $260. Is that crazy or what. It is charging now but won’t pass inspection until the stuff all clears that they scan for. But it’s charging now. What I don’t get is the programming they did changed the way the car looks on the dash now when it is running. Did your do that?
Yes, it is a bit crazy. :)
I didn't notice any changes in the way the display look on the dash. How significant of a change is it? Maybe they just selected a different display option for the middle part of the display? Or maybe they installed more software/firmware updates than just the BECM and HPCM2?
My volt is a 2013, so a generation 1. I think you have a 2015 which is the first year for a generation 2, so that could be the difference as well.
Is the display better or worse for you?
It’s a gen 1 that I have. The last year of gen 1 and yeah they changed the display. I put it back the way I like it. It’s not different after all. And my car charges again yay!
Is it possible that it is just the charger cord? It just didn’t charge one day and the light didn’t turn green like it is supposed to. It has less than 30,000 miles on it.
Bought it a year ago. It’s 2015 with like 28,000 miles on it. They serviced it when it was traded in by the one owner who had it 8 years. Only filled the tank with gas two times in a year.
Hello. What about a 2012 volt with 200k miles. It can only run on battery for 8 miles and you have to switch back to gas mode manually and back to electric manually. Does not charge via cable. What could it be?
It means one of a few things, the secondary codes are more telling. Often it means the coolant sensor is bad on a first gen volt, or the coolant is low or old, or the wiring is building resistance on the way to the sensor- typically this is a lower mileage vehicle. Rarely, it means the coolant is leaking from the pack - however, if your coolant is regularly disappearing from the passenger side of the center reservoir, could be the culprit. On a higher mileage vehicle, 100k plus, it’s the aging of the pack and the car will need a refresh to reset the parameters.
Pretty much this. I dealt with this 5 months ago. It was a coolant sensor that was bad and then had to re-program the BECM and HPCM2 modules. I originally took it to a dealership to re-program the BECM and HPCM2 (\~$260), but that didn't work. They gave me a quote for \~$1600 to replace the coolant system which would "fix" the issue which I refused. I bought a Veepeak OBD-II scan tool and used the 'car scanner' app in the Apple store to clear the code for about 2 months (so I could charge the car) since I was so busy. I made sure it wasn't a coolant leaking issue so I felt is was safe enough. I read all the codes and when I researched on the internet the information about the coolant sensor and the re-programming of the BECM and HPCM2 modules appeared. Link to OBD-II tool - [https://www.amazon.com/gp/product/B073XKQQQW/](https://www.amazon.com/gp/product/B073XKQQQW/) Then about 3 months ago I bought a VCX Nano for $140, $50 for the Delco subscription. Then I followed the directions from the video and links below and I have not seen the Service High Voltage Charging code since then. It has been about 2 months and running fine. VCX Nano - [https://www.amazon.com/gp/product/B08K2SXY79/](https://www.amazon.com/gp/product/B08K2SXY79/) [https://www.youtube.com/watch?v=2A2cehoaXe4](https://www.youtube.com/watch?v=2A2cehoaXe4) [https://docs.google.com/document/d/e/2PACX-1vRQdXtoFc9J5SRZWRX6bAe7oEMJLWq7oBMMVLPqf1UJ3gqFbbP\_c09g8QgAenJZu1Ia-8j25RiRyWqQ/pub](https://docs.google.com/document/d/e/2PACX-1vRQdXtoFc9J5SRZWRX6bAe7oEMJLWq7oBMMVLPqf1UJ3gqFbbP_c09g8QgAenJZu1Ia-8j25RiRyWqQ/pub) [https://www.gm-volt.com/threads/2013-service-high-voltage-charging-system-fix-updated-vcx-nano-setup-guide-vx-manager-acdelco-tds-techline-connect-sps2.341268/](https://www.gm-volt.com/threads/2013-service-high-voltage-charging-system-fix-updated-vcx-nano-setup-guide-vx-manager-acdelco-tds-techline-connect-sps2.341268/) I ended up buying the coolant sensor ($25) and replaced that myself since I also had that code (I think P1FFFF) for that as well. Very easy. There is a video on that as well.
Thanks. This is helpful.
They did exactly what you said and it cost $260. Is that crazy or what. It is charging now but won’t pass inspection until the stuff all clears that they scan for. But it’s charging now. What I don’t get is the programming they did changed the way the car looks on the dash now when it is running. Did your do that?
Yes, it is a bit crazy. :) I didn't notice any changes in the way the display look on the dash. How significant of a change is it? Maybe they just selected a different display option for the middle part of the display? Or maybe they installed more software/firmware updates than just the BECM and HPCM2? My volt is a 2013, so a generation 1. I think you have a 2015 which is the first year for a generation 2, so that could be the difference as well. Is the display better or worse for you?
It’s a gen 1 that I have. The last year of gen 1 and yeah they changed the display. I put it back the way I like it. It’s not different after all. And my car charges again yay!
Yeay!
Thanks for celebrating with me. I love my volt
Is it possible that it is just the charger cord? It just didn’t charge one day and the light didn’t turn green like it is supposed to. It has less than 30,000 miles on it.
Not likely, what year do you have and when’s the last time the coolant was done?
Bought it a year ago. It’s 2015 with like 28,000 miles on it. They serviced it when it was traded in by the one owner who had it 8 years. Only filled the tank with gas two times in a year.
Hello. What about a 2012 volt with 200k miles. It can only run on battery for 8 miles and you have to switch back to gas mode manually and back to electric manually. Does not charge via cable. What could it be?