C8 owners I could use some guidance on my new electrical problem, any help will be greatly appreciated! My 2020 C8 stingray started showing electric/ computer /fob issues two weeks ago. The symptoms are the rear trunk popping open while the car is completely off. Also the lights flash on / off every minute or so. Initially this wasn’t constant. Then two weeks ago the original battery was dead so I had it replaced. Drove it for a week, the trunk popped open once I think no lights flashing. The next Monday the new battery was dead. I figured I had an electrical issue had the car towed to my main Chevy dealer in SLC. On day two the service rep said the new battery was defective and put a second new one in. They said they tested it for signals to the computer found none. They said they put an amp meter on it for 24 hours and found no parasite drainage! Your car is ready. I drove to my storage place. Three days later my storage MGR. called and told me the symptom’s had returned. Service dealer said to disconnect the FOB battery to see if FOB is the problem and hours later the issue is back.
I will be bringing it to the dealer in a day or so to start all over. Is this familiar to anyone, anything specific to look for they may have overlooked, relays, manual trunk button. I know the C8 has electric /computor issues like all complicated cars,
just hoping to speed up the fix process, Thank you Gary

 

In a way, it does sound like the car is behaving as if it is responding to a remote command from a FOB (or via its "On-Star Connection"), although that's only one possibility. You mentioned FOB, but there are two of them supplied from the factory. Where are your FOBs when this happens? Are they near the car? Did you disable both FOBs? Have you ever used the remote App on the phone (I never had a subscription and never used it).

Of course its more likely an internal issue with the car - the dealer will likely need to contact GM for assistance unless you have DTC to guide them. Are there any codes?

One more thing - where is it stored? Any chance rodents got in and chewed some wires?

 

@garygorga were you able nail down what the issue is?

 

Mr' Jonathan; thanks for the follow up. No I haven't, After my original post we disconnected the battery in both FOBs. The car sat for three days or so. Then the battery started to take a charge on the Chevy battery tender. Next day battery was charged the car started up and I drove it. Every thing was normal for a week or so then I put the car back in my storage facility for 10 days or so. When I called them to pick it up they said the problem had returned, the battery was dead They jump started the car and left it running. I got in the car and pulled onto the road and the car came out of drive. I pulled over, the car would not go into drive . I turned it off for 10 minutes, started it up and it went into drive, I pulled back into the storage facility. The symtoms returned, the trunk would pop open on its own. The next day the battery was dead again. We disconnected the FOB battery and are charging the battery while not connected to the cables. So I am back to square one, the dealer can look at the car again next week. I wish I could give the dealer more input from others who had a similar problem. If there is a short I would think the dealers tech would be able to find it? Any thoughts would be greatly appreciated, thanks Gary Gorga

 

Common denominator - does this only happen at the storage facility after the car has been there for a while?

 

MKC8; Thanks for the follow up. The car has had these symtoms both at the storage facility where it is most of the time and also at home. The storage facility stores all FOBs in a metal key lock box that is suppose to block any FOB signals.
Yesterday we charged the battery, the car started up fine they moved it outside for me to pick up. When I got to the car the rear trunk was open to the first unlocked position. I closed it and drove the car for 2.5 hours with no issues. The battery gauge 14.5 Volts charging. When returned the car restarted fine. The car is now at storage unit and I will monitor any symptoms. Thanks Gary Gorga

 

Is the storage facility sitting on a large iron ore deposit?
I recall about 15 years ago visiting the controversial "grave site of Buffalo Bill" near Denver CO, on Lookout Mountain.
We noticed the remote fobs for our camper van wouldn't work while we were there, and had to use the keys to lock/unlock.
Once we resumed our trip, away from the mountain, the fobs worked fine.
Seems there's a lot of metal ores in the mountain that may have affected our fobs.

 

MKC8; I will check for Iron ore next time I am there. Apparently the symptoms came back while it sat idle outside the storage facility. I will have the car towed to the dealership Monday to have them start a search again.
I would appreciate any guidance from anyone who has had a similar situation!! The closest big city to me is Salt Lake City Utah. I have been using Larry H.Miller Chevy in Murray. Rik Noring is my service rep who is corvette certified or something. Does anyone recommend a different dealership in Salt Lake City?
Thanks for your time, Gary Gorga

 

Did you get that radio software update? It would download too often and kill the battery…

I still have to do mine.

 

How old is your battery?

 

C8 owners who followed my post on electrical / computer issue. The car is now ar a second Chevy dealership to try and solve the problem. Yesterday, they reconnected the battery checked all connections, the tie down bar. They charged the battery up and the car would start. This morning the battery was dead again, the FOB was away from the car. The tech is now checking the car again.
Can Chevy be sending updates to the car, such as a radio update that would drain the battery? M mentioned a radio update on this thread.
Is it possible the computor system has commands stuck in it like"open the rear trunk" (which is what is happening) that just keep going to the car when it is off?
Any thoughts on this continuing issue would be helpful, please see my original post, thanks Gary Gorga

 

There are procedures for measuring parasitic draw - are they checking that? They should see it drop to 10 ma or so after 15 minutes.

 

Follow up to my 2020 electrical issue!!

The solution; The second dealer technican kept following input from Chevy home office support. In the end After at least $1,600 in labor charges the answer was :there is a seperate electrical module in the rear trunk that controls the rear trunk opening and closing and the license plate light. This module had a short , a new $300 or so module part solved the problem. My issue is the amount of labor charges I had to pay to find the problem. Especially since the symptoms clearly pointed to the rear trunk opening by itself. Two different dealership technicans apparently failed to immediately follow the symptoms even though they got help from Chevy home office techs!
My advice to other C8 owners is have the techs " follow the symptoms". I hope this helps some other owners with their cars!
PS; I love the car and I am thinking about trading up to a ZO6!!

 

Happy to hear the issue was found! Sad to hear the cost was outrageous! I appreciate you posting the information regarding the rear trunk module. I know there are folks who have had similar issues with battery drain, and erratic frunk/truck issues. Hopefully this info helps folks in the future.

 

Glad he was able to find it. Easy once found to look back and say the should have.... But with so many microprocessors controlling everything and all working on a common buss can understand.

As I read thru your issues sounded like Christine!

 

I have same issue with my 23 z06. Trunk was open and the battery was dead today. Going to take it to the dealership this week, hopefully they figure it out.

 

$1600! Wow. One more reason to buy the extended warranty. This warranty would have paid for itself with this one is. My local dealer charges $200/hr for labor. All it takes is one day to cover the warranty cost.

 

-
Yep, reminded of my favorite comment since my C6, 4 Vettes ago. When you go to the Corvette Service Writer and discribe the issue, their comment is, “Yep, sounds like one of the many computer operated systems. It will be $2000, now we can plug into the OBD port and see which one needs replacement.”

 

If You park in a storage facility, maybe mice or other rodents