10.0

really awful
Crashes / Fires:
0 / 0
Injuries / Deaths:
0 / 0
Average Mileage:
0 miles

About These NHTSA Complaints:

The NHTSA is the US gov't agency tasked with vehicle safety. Complaints can be spread across multiple & redundant categories, & are not organized by problem. See the Back button — blue bar at the very top of the page — to explore more.

Get notified about new defects, investigations, recalls & lawsuits for the 2021 GMC Sierra 1500:

Unsubscribe any time. We don't sell/share your email.

Get free help with your lemon!
close ad
problem #1

Nov 102022

Sierra 1500 6-cyl Diesel

  • miles
Within 100 miles after purchasing this truck from GMC (used with 74K miles)I got messages both on my phone and later through inspection at GMC service center that the DEF system had a problem. The check engine light came on then off as well.I was getting messages saying I only had so many miles before the DEF system needed more fluid even though the tank was full or near full. The dealer here in Tucson indicated there was a bulletin on this problem and ordered parts for the repair. I was informed it was not a recall and I would have to pay over $800 for this repair. To date the dealer has had my truck for 2 weeks. Additionally, another message said insufficient coolant flow so they are installing a new coolant pump to be paid for by an after market warranty which I purchased at the time I bought the truck. This repair is over $1000

- Tucson, AZ, USA