NHTSA Complaint #11680319 — 2019 GMC SIERRA 1500

Subject: Urgent Vehicle Safety Complaint – 2019 GMC Sierra Denali Escalating mechanical and electrical failures — many beginning before 100,000 miles, and continuing as of today, at approximately 110,000 miles. These issues have made the vehicle unreliable and unsafe to drive. Since purchasing the vehicle, I have had it serviced regularly and reported that it was driving rough, jerking into gear, and showing early signs of engine and transmission problems. These issues were noted during multiple multipoint inspection services, yet no lasting solutions were provided. Major issues have included: •Engine performance failures •Fuel injector malfunction •Serpentine belt and idler pulley damage •A/C compressor belt failure •Power steering malfunctions •Vehicle stalling at traffic lights •Loss of power on major highways •Rear window water leaks •Significant and ongoing electrical system problems •Shaking when brakes applied after having brakes and rotors replace in March •Screen monitor going out after paying over $ 900 dollars for updated software and repairs to the electronic component that cost over $2500. Despite continued maintenance, on Thursday, July 3, 2025, my truck began losing power and smoking heavily while driving on a busy highway in Georgia. My grandchild, who was riding with me, yelled, “Grandma, it’s smoking — please get out!” as we pulled off the road in fear of a fire. This terrifying incident left us stranded and emphasized just how dangerous this vehicle has become. I filed a formal complaint with the GMC Corporate Office, but no support provided or an investigation. Over the past six months, I have spent more than $5,000 trying to keep this vehicle operational. So many critical systems have failed, despite consistent maintenance, raises serious concerns. Finally, the fuel injector repaired 3 days later a message on dashboard displaying service Tire monitor system and steering wheel shaking when brakes are applied.