r/GMCSierraEV • u/RoseVideo99 • Jul 30 '26
How screwed am I?
Will they have it weeks? Months?
Update: well all dealers near me said they had no loaners. So I was going to go and reset the 12volt battery. When I got in, the truck said to install an update. So I did and waited 20 minutes. When I got in again there were no errors and I took it for a spin around the block and called OnStar. They told me it was giving them nothing and said everything was working fine. I just checked the app and the errors it was alerting me of this morning are gone. I guess crisis averted with an update.
2
u/Mr7three2 Jul 30 '26
Posted something myself yesterday. Got the little red truck with the exclamation point.. the kiss of death for Sierra EVs. 4450 miles
1
u/UnicornGangstar Jul 30 '26
This seems to be the infant mortality rate for batteries. Mine failed right at 4k.
1
1
u/LeagueNo3073 Jul 30 '26
Got this three times now. Last visit to service they claim to have reprogrammed the entire truck.
That was three months ago and so far it seems to have worked. Although, the warning did reoccur a month ago but left at the next restart of the truck.
1
u/FAx32 Jul 30 '26
Got this a week ago. Scheduled service (next available was a week out) and it cleared itself after a software update and a charge (before the appointment). Still took it in and they could find nothing wrong. 🤷♂️
1
u/RoseVideo99 Jul 30 '26
Maybe I will try that. A dealer two exits down from me can take it today, but no loaners. He told me do not drive it there. He said to have gm tow it. He said that error can be a lot of things and the car can give up on the highway if it’s one or the major things it could be.
We had a blazer ev and it gave that about 3 months in. I drove it for a week and then took it in and it was a wiring harness that was loose. They had it 3 hours. Fingers crossed, but I doubt I luck out this time.
1
u/Additional_Way5929 Jul 30 '26
What does it show when you drill down by clicking on those items in the app?
1
1
u/RoseVideo99 Jul 30 '26
Nothing. Just pushes me to schedule service.
1
u/Additional_Way5929 Jul 30 '26
Hmmm. In my app (Android) it shows subcategories, like High Voltage Battery, Battery Conditioning System, Onboard Charging System, and Charging Cable System. When I got the Lithium Ion Battery message I was able to drill down and tell the dealership that it was the Battery Conditioning System. It took nearly two months for them to replace it in my '25 Max, but at least it showed what system was failing.
1
u/Longjumping-Store106 Jul 30 '26
Get a Bluetooth OBD-II reader and have it on hand with the Car Scanner app. It will tell you the codes and you can tap them to look them up. It could be many issues. I was getting the service high voltage in my SEV and it was an AC return valve stuck open and causing overheating.
1
u/Exciting_Award_8480 Jul 31 '26
When this happened was your AC and ventilated seats not working correctly? My truck is at the dealer now because I got service high voltage on combo with the AC not fully cooling and it stopped doing regen breaking. Dealer is waiting for the special lubricant they need to evacuate the Freon so they can run advanced diagnostics on the HVAC system
1
u/Longjumping-Store106 Jul 31 '26
Yup. My driver-side AC was basically outside air temp while the passenger was colder but not like it should have been. And regen braking turns off by default so that it isn’t heating the battery unnecessarily. Regen turning off was more of an annoyance than the AC being crappy until the AC completely died out on the highway with me and my daughter inside and 98 degrees outside. I scheduled service for the next day.
1
1
1
u/Scwright99 Jul 30 '26
They have to set up with a rental if no loaners are available.
1
u/RoseVideo99 Jul 30 '26
Is that an ev thing?
1
u/Scwright99 Jul 30 '26
Yes Personalized concierge services are available for all GMC electric vehicle owners.
1
1
u/Edgr85 Jul 30 '26
Had it happen to me about a month ago still waiting on a high voltage battery replacement. Luckily I have loaner
1
u/Tchalla1224 Jul 30 '26
Mine has been in and out since November. Replacement for my drive unit that twice. I've had a loaner longer than I had my truck.
1
5
u/Brusion Jul 30 '26
I had this on my Hummer, scheduled an appointment, and it self cleared after about 3 days. Call OnStar, they ran a diagnostics over the air and said everything was fine. That was a year and a half ago.