Service High Voltage Warning Messsage

[super8]

Well, 2 months and 2 payments in, I got the dreaded "Service High Voltage " warning message pop up. It seems to drive find, but won't charge. So looks like another trip to the dealer next week.

 

[super8]

This was meant to be GM’s solution, but unfortunately, it didn’t work in my case

Check if you see a red icon in your instrument cluster that looks like a vehicle with an exclamation mark on it and/or one of these messages:
1. “Service Vehicle Soon”
2. “Unable to Charge”
3. “Service High Voltage System”

These messages can mean there is a problem with your battery cooling system and that your vehicle needs service.
However, they can also occur when the battery cooling system encounters an error. If the red light appeared while you were driving, you can troubleshoot it yourself.

IMPORTANT: Before trying to troubleshoot, make sure your vehicle is parked in a safe location. Depending on the error, you may not be able to restart your vehicle after turning it off.

Here’s how to check if there’s a problem with the system or if it’s an error you can fix:
1. Turn your vehicle off.
2. Open and shut the driver door.
3. Wait 30 seconds. During this 30 seconds, your vehicle’s software will attempt to fix the problem.
4. After 30 seconds, turn the vehicle back on. You may still see the red warning light in your instrument cluster, but your heat/air conditioning should turn back on and your vehicle should start charging again.
5. Turn the vehicle off and back on again. The red warning light should disappear. If it does, your vehicle is safe to charge and drive.
You might see the red warning light and your heat/air conditioning might not work after turning your vehicle on after not driving it for a few hours. In that case, try the following steps to determine if there’s an issue:
1. Turn the vehicle on and off five times, waiting 30 seconds between turning it off and turning it back on again.
2. After five on/off cycles, the light should go away and your heat/air conditioning should turn back on.
3. If not, contact your Dealer to schedule service.

 

[Dragoon]

That's a buzzkill! Hopefully, it's a quick fix for the dealer, and they don't have to have it for long.

 

[Helipilot]

They left out…Do the Hokey Pokey and turn yourself around

 

[Georgiy]

Every time after washing the truck, it does not charge the truck. Returns an error . Then after some time, 5-6 hours, the error disappears. Who have you had this situation with? Please tell me who solved the problem.

 

[Georgiy]

I have the same mistake, every time after washing the truck, I began to put the bag in the charging slot, before washing, so that no water would get in.

 

[Georgiy]

I really look forward to your information from the dealer on this issue.

 

[super8]

Great news, the Hummer seems to have fixed itself! After a 15-minute drive and a quick 10-minute park, the error message disappeared when I restarted. Everything’s working fine now, and it even charged without any issues last night.

 

[Georgiy]

Great news, the Hummer seems to have fixed itself! After a 15-minute drive and a quick 10-minute park, the error message disappeared when I restarted. Everything’s working fine now, and it even charged without any issues last night.

And how did you reboot it?

 

[super8]

And how did you reboot it?

I didn't have to, but if you disconnect the battery in the frunk, that should reboot/reset everything.