What year is the most reliable GMC Sierra 1500?
For the most reliable GMC Sierra 1500, look for model years 2021, 2016 to 2018, 2011 to 2012, and 2004. As you can see, the GMC Sierra’s reliability goes back to 2004 due to its stout engine and good crash test results. GMC Sierra 1500 Problems by Model Year 1999 – 2002: High number of reported transmission issues, electrical problems, and brake issues. Reports of engine issues, transmission problems, climate control issues, and issues with the infotainment systems.