2026 GMC SIERRA EV Complaints

Component/system malfunctioned: Adaptive Cruise Control integrated with Traffic Sign Recognition/Speed Limit Assist (camera-based speed sign detection and automatic speed adjustment). Vehicle available for inspection upon request. While driving ~35 mph in 35 mph zones with Adaptive Cruise Control engaged, the system repeatedly misread speed signs (or GPS data) as much higher (e.g., 75 mph). The vehicle then automatically accelerated aggressively toward the incorrect higher speed without driver accelerator input. Acceleration is sudden and strong due to electric powertrain torque. This problem can be reproduced in multiple locations in low-speed zones. Safety risk: Vehicle sped up dangerously in restricted areas (residential, traffic, pedestrians), risking loss of control or collision before I could brake or disengage system. No crash/injury occurred, but risk was high. Problem not reproduced/confirmed by dealer or service center. Vehicle/component not inspected by manufacturer, police, insurance, or others. No warning lamps/messages/symptoms before acceleration; dashboard briefly showed incorrect higher limit. First occurrence UNKNOWN, but multiple incidents since ownership. Appears to be defect in software, camera recognition, or integration of Traffic Sign Recognition with Adaptive Cruise Control, causing unintended high-speed acceleration in low-speed areas.

Car rolls after parking brake is set. This happens on low hill grade and high hill grade parking location.

The contact owns a 2026 GMC Sierra EV. The contact received notification of NHTSA Campaign Number: 25V594000 (Electronic Stability Control (ESC); however, the part to do the recall repair was unavailable. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The contact stated that while driving over uneven pavement, there was an abnormal bumping sound coming from the front passenger's side suspension. Additionally, the contact stated while driving at various speeds, the contact noticed an abnormal rattling sound coming from nearby the pillars surrounding the infotainment system. There was no warning light illuminated. The dealer was contacted. The vehicle was taken to the dealer, where the contact was informed that the recall repair would take 30 minutes; however, the vehicle had been at the dealer for 15 days, and the recall repair had not yet been performed. The manufacturer was informed of the failure. The failure mileage was approximately 4,000.

Rear right clunk in rear suspension. Dealer kept truck for 2 days and can't figure it out. Worried it could be a suspension nut or bolt and could cause a crash.