2025 Chevrolet Trailblazer

Component Affected: POWER TRAIN: AUTOMATIC TRANSMISSION / TRANSMISSION CONTROL MODULEDescription of Safety Defect:The vehicle is experiencing a severe, intermittent, and violent mechanical "garage shift" engagement lurch. This occurs specifically when shifting the gear selector from Reverse to Drive during a cold-start cycle.When the gear is selected, there is a distinct hydraulic delay followed by a violent mechanical slam that causes the entire vehicle to violently lurch forward. This unintended vehicle movement occurs even though the engine has naturally idled down completely below 1,000 RPM, and while the brake pedal is fully and firmly depressed to the floor.Safety Hazard and Consequences:This defect poses an immediate and severe safety hazard. The mechanical force of the lurch is strong enough to potentially overcome the vehicle's braking system or cause a foot-slip off the pedal, resulting in sudden, unintended vehicle movement. This creates a high risk of a low-speed collision, vehicle damage, or striking a pedestrian or property during tight parking or garage maneuvers. General Motors' internal service bulletins (such as Bulletin 24-NA-009) indicate known issues with sticking clutch regulator valves or solenoid over-travel causing line pressure spikes in these modern transmissions, yet no safety recall has been issued to permanently address this dangerous powertrain defect.

On 4/14 with only 21 miles on the odometer in this newly purchased car the entire transmission failed, per the dealership because of a “leaking valve”. The check engine light came on after the car was jumpy and then the car refused to speed up on an extremely busy street and began locking up, putting us at serious risk of an accident. It was barely able to reach a parking lot and at that point all of the transmission fluid leaked out all over the parking lot.

The contact owns a 2025 Chevrolet Trailblazer. The contact stated that when he stopped the vehicle and had shut the vehicle off but had left the vehicle in drive (D) and had not engaged the parking brake, the vehicle rolled forward. The contact stated that this was also occurring when he had stopped the vehicle, turned the vehicle off and placed it in reverse (R) without engaging the parking brake the vehicle rolled backwards. The contact had not taken the vehicle to a local dealer or independent mechanic. The vehicle was not diagnosed and was not repaired. The manufacturer was not informed of the failure. The failure mileage was approximately 700.