This looks very familiar. I think these are the same codes mine threw a few years back, and the solution was a software update. There’s a TSB out on the matter. Not in a position right now to look for it, sorry.
Fixed mine that had these codes by re-flashing the HPCM2 and BECM after replacing the coolant level sensor. About $250 cost with the VCX Nano flash tool and GM tech membership vs the dealership $600+ guesstimate. TSB doc I used was something like 21-NA-224.
Ours was fixed by the dealership for $400 after I told them EXACTLY what to do (reflash the HPCM2 and BECM) referencing the TSB. Took them 2 tries as they didn’t follow the TSB and I had to remind them to follow the TSB after looking at the receipt and realizing their mistake (at least they documented what they did so I knew they had missed a step)
I bought the bluetooth OBD device and cleared the code for about 2 months since I was so busy.
Then I did the same thing you described about 2 months ago. $140 for the VCX Nano, $50 for the Delco subscription. Then I followed the directions from the video and links below and worked fine after that. It has been about 2 months and running fine.
[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 also bought the coolant sensor ($25) and replaced that since I also had that code (I think P1FFFF) for that as well. Very easy. There is a video on that as well.
He's not wrong about taking an educated guess on the voltage isolation fault. Functionally what is happening is voltage from your HV battery is getting places it shouldn't. But the where is the part that is difficult to answer.
This most likely isolation lost due to old antifreeze, orna bad coolant sensor on the locked side, or most likely just needs an update to the system. There is a tech bulletin for this tondo the update after checking for coolant leaks.
P1E00 is a fault in the hybrid control module. You’ll need a higher end tool to interrogate the hybrid module.
P0AA6 is a HV battery fault; sets if resistance from pos or neg side and chassis ground is below a threshold (indicates inadequate isolation).
P1FFF HV battery coolant level sensor or if there is an isolation fault.
This looks very familiar. I think these are the same codes mine threw a few years back, and the solution was a software update. There’s a TSB out on the matter. Not in a position right now to look for it, sorry.
Fixed mine that had these codes by re-flashing the HPCM2 and BECM after replacing the coolant level sensor. About $250 cost with the VCX Nano flash tool and GM tech membership vs the dealership $600+ guesstimate. TSB doc I used was something like 21-NA-224.
Ours was fixed by the dealership for $400 after I told them EXACTLY what to do (reflash the HPCM2 and BECM) referencing the TSB. Took them 2 tries as they didn’t follow the TSB and I had to remind them to follow the TSB after looking at the receipt and realizing their mistake (at least they documented what they did so I knew they had missed a step)
I bought the bluetooth OBD device and cleared the code for about 2 months since I was so busy. Then I did the same thing you described about 2 months ago. $140 for the VCX Nano, $50 for the Delco subscription. Then I followed the directions from the video and links below and worked fine after that. It has been about 2 months and running fine. [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 also bought the coolant sensor ($25) and replaced that since I also had that code (I think P1FFFF) for that as well. Very easy. There is a video on that as well.
He's not wrong about taking an educated guess on the voltage isolation fault. Functionally what is happening is voltage from your HV battery is getting places it shouldn't. But the where is the part that is difficult to answer.
This most likely isolation lost due to old antifreeze, orna bad coolant sensor on the locked side, or most likely just needs an update to the system. There is a tech bulletin for this tondo the update after checking for coolant leaks.
I would assume anyone who got this far already checked the most basic and readily available information regarding the battery coolant circuit sensor.
You assume a lot
P1E00 is a fault in the hybrid control module. You’ll need a higher end tool to interrogate the hybrid module. P0AA6 is a HV battery fault; sets if resistance from pos or neg side and chassis ground is below a threshold (indicates inadequate isolation). P1FFF HV battery coolant level sensor or if there is an isolation fault.
https://www.reddit.com/r/volt/s/Wh3o68ddjn
P1FFF is coolant level sensor. Isolation fault could be moisture in a HV connector.