One problem related to car will not start has been reported for the 2020 GMC Sierra 3500. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2020 GMC Sierra 3500 based on all problems reported for the 2020 Sierra 3500.
Progressive pause starts when starting vehicle. After a few weeks of pause starting vehicle had no power at all. Towed it to dealer they replaced a bad battery. Pause start continued and after 4-5 weeks vehicle would not start. Couldn't turn park break off. There was power (lights in dash came one) but didn't start. Vehicle parked and only after sitting unused this happened both times. (1st time no start, hadn't driven for 3 days, end of summer weather) (2nd no start, sat overnight cool weather, but no freezing. Towed to dealer and they found nothing wrong.
| Electrical System problems | |
| Car Will Not Start problems |