Naturally, with my extended warranty recently expired, drove down to daughter's house and the truck would not shut off. I could get the dash lights to go dark but the engine was still running and transmission stuck in park. Unhooked the negative battery post, searched without luck for the fuel pump fuse. Found the ECM fuse and pulled it and engine stopped running. Hooked battery back up and drove it back home. Same thing when I pulled into my parking spot. Wouldn't shut off and had to pull the ECM fuse again. My indy shop is closed this week for vacation. Anybody have an idea of what's going on? Thanks!
Chevy specialists, need help. 2020 Silverado won't shut off
- Thread starter rainman49
- Start date
I've heard it can be an ignition related relay issue. Swap the run/crank relay with another like the parking lamp relay. If that doesn't do it then swap the starter pinion with something else. It could also be a bad fuse so if you have a test light try the little ones. Also heard that pulling the afm fuses work on them so they don't actuate but may or may not cause some software triggered issue but putting them back in and clearing codes will make it go away.
https://www.startmycar.com/us/chevrolet/silverado/info/fusebox/2020
https://www.startmycar.com/us/chevrolet/silverado/info/fusebox/2020
AZjeff
$50 Site Donor 2023
Make sure it's the exact same relay. In a recent South Main Auto video Eric O said all relays aren't the same and you can fry components switching them around.
Makes me think of the unintended acceleration issues, and how everyone would say turn it off. 
After more reading, I think it’s stuck in remote start mode. I started it while I was inside the house to get the AC running before we went to my daughter’s house. I tried unhooking both batteries cables and touching them together to clear it to no avail. I’ll let my Indy shop with the big scan tools sort it out next week.
Is your remote start aftermarket? If so, perhaps it can be disabled by pulling its inline fuse
It could be ignition switch related or the computer doesn't recognize that the transmission is in park. Have you tried holding the shifter up in park and seeing if it turns off?
UPDATE! My indy shop couldn't fix the problem after spending several hours on it, resetting the ECM and several modules. Finally took it to Pete Moore Chevrolet in Pensacola, and a DC to DC converter was the issue. It had killed my battery, so I had to have a replacement battery, new converter and a fuel relay module that popped up during a test run. After they replaced the battery, it didn't take long to diagnose the bad converter. Total $1,260. I've had it for a week and all seems perfectly fine.
Rainman49, is your truck still shutting off ok? My 2020 Silverado Z71 is doing the same thing. Several months ago they charged me $400 and said my truck only needed updates. So I replaced the battery for a total of $700. Now 3,000 miles later it’s doing the same thing. The truck only has 21,400 miles total on it. The truck won’t shut off, the dash goes dark and it keeps running. I have to pull the ECM fuse to shut it off. If I don’t unhook the battery something in the transmission hums and runs down the battery. I read in a different forum a guy replaced his fuel pump module and that fixed it. My trouble codes mention low voltage on a few. I’m tempted to get a new converter and fuel pump control module since I have to pay the first $200 of my extended warranty that they will probably try to beat me out of. My question is, if I replace the DC to DC converter and the fuel pump control module, does the truck need to be recalibrated by the dealership? Or are the parts plug and play? I feel like I need to help solve this problem or it’s going to cost me big money, that’s why I’m doing my homework. I pulled out my DC converter and it has the exact same part number as yours. It sounded like your truck was doing exactly what my truck is doing, my service writer and their mechanic said they have never heard of a truck not shutting off when you push the button. Of course that is my luck. This truck is a pampered low mileage truck that has never been off road or in the snow or deep water. Any advice from you or anybody on this forum is appreciated. I am a former dealership mechanic from the 80s and I used to be ASE certified. But that doesn’t help me much with modern vehicles, thanks!
