doubled1

Hi,pull the ecm off truck and remove cover to check to see if board is corroded.

I have a 2015 with 6.2 and 8 speed .Have always been a gm consumer but find there are too many reliability issues with the truck.The 8 speed doesn't seem to operate properly even though all flushes have been done.Check the headliner for water stains as this is common for 3rd brake light to leak or antenna.Why is a truck with low mileage for sale is why I would need to find out.I always buy new just for reliability but have more trips to dealer for issues that shouldn't happen.I would suggest you investigate further also headlights are terrible and I could go on.This is the last gm truck for me until they start to build more reliable trucks.Son has a Toyota truck bought new and has not been to dealer for any issues

I have a @015 Sierra 6.2 8 sp and it is a piece of junk compared to a 2000 I owned.Lately th 3rd brake light leaked staining the headliner out of warranty.Replaced light as it has a new revised gasket but stuck with a stained headliner.Recalls constanly on poor engineering and crap parts.Also the 8 speed trans issues and the vacuum pump for the brakes,crappy paint,onstar antennae that is just a matter of time before it leaks,rear window defogger that has fuse removed to prevent possible explosion or fire etc.I could go on but you should get the drift that the GM trucks are problems