Table 1 shows one common vehicle speed control related problems of the 2026 GMC Sierra 1500.
| Problem Category | Number of Problems |
|---|---|
| Vehicle Speed Control problems |
Vehicle: 2026 GMC Sierra 1500 at4 (3. 0l lz0 duramax diesel) current mileage: ~16,500 miles check engine light status: no check engine light active description of incident & symptoms: •interstate incident: while driving at highway speeds, a severe drivetrain vibration occurred (felt like a rear wheel weight flew off). •dashboard warnings: within 5 minutes, intermittent "traction control" and "forward collision warning" alerts appeared on the dash, accompanied by a sudden drop in engine power. •engine noise & idle: once safely pulled over, the engine exhibited a loud mechanical knock and a very rough, unstable idle. •extended crank: after shutting the engine off and waiting a few minutes, restarting the truck took roughly twice as long as normal (long crank/delayed start).
6 month old, 9,000 miles 2026 Sierra 1500 with duramax 3 liter suffered an engine control module failure 4 hours into a 12. 5 hour drive home from family vacation. First a transmission service warning flashed, then an emissions system failure with a forced speed reduction warning. This happened with two children and a dog in the vehicle. Onstar did diagnotics and said I had to see a dealer. Fortunately one was nearby and they determined the engine control module needed to be replaced--but I was 8. 5 hours' drive from home with kids and dog and would have had to stay for 2-4 days awaiting parts and repair. I traded the truck at the dealer for a new vehicle and drove that home. This was a major safety concern traveling with children and a dog on a nearly 100 degree day. And it was a brand new vehicle.
My engine seized up on me on the highway. I was stranded and couldn’t start the vehicle and it was freezing outside.