2025 GMC Acadia Powertrain & Transmission Problems

The vehicle has a serious transmission/drivetrain defect that repeatedly occurs when accelerating from a complete stop, especially onto an incline. The vehicle sometimes does not respond at all when the accelerator is pressed and fails to move, even though acceleration is being requested. In one recent incident, it remained stopped for about one minute before finally responding. During these events, the vehicle jerks and shakes severely and fails to gain speed as expected. This creates a major safety risk at stop signs, intersections, and uphill starts because the vehicle may not move when needed and cannot keep up with traffic. The problem has worsened, and during one of these incidents the check engine light came on. I have video evidence showing the loss of response to accelerator input, severe jerking/shaking, and the check engine light illuminating during the same event. The issue has been reported to dealers and GM customer service but has not been properly resolved.

I purchased my 2025 GMC Acadia on March 26, 2025. // My vehicle began to have electrical/communication/system issues in August 2025. // I took my vehicle to the dealer to address these issues at this time. When I got to the dealership, a representative performed diagnostics, and said "I can't even get a read on this. There is no signal coming from your module. You need to contact OnStar about this." // I called OnStar, and they ran a test, and stated that it is a manufacturing defect that needed to be handled with GMC. //No one informed me of the severity of the safety implications involved. // In March 2026, my vehicle was inoperable. The module controls everything, and was draining the battery at a severely high rate. I had my vehicle towed to the dealership. They tried to deny all liability and said that they weren't the dealership that sold me the vehicle. // I had my battery jumped so I could take it from the dealership have a new battery installed. My vehicle stalled and shut off while I arrived at the Auto Parts store. *** Answer to Questions: Q1: Yes. My vehicle is available for inspection. It is at the dealership. // Q2: My safety and others were put at risk because the brand new batteries were constantly draining and making me stall out in mid-traffic without having any control. // Q3: Yes. The problem has been confirmed by the dealer. They tried (and still are trying) to avoid responsibility. Other reports show that this is a significant safety issue with many GMC vehicles. // Q4: Yes. The vehicle was inspected by the GMC dealership. This is day-16 with no solution. // Q5: Yes, there were issues with the car, as stated above. But absolutely no indication that it would be safety issue. My engine was running normal the night before. No signs that the battery was low or dead and prohibit me from driving safely or that it would shut off.

The vehicle experiences a transmission/drivetrain defect involving delayed gear engagement, hesitation, and apparent slipping. When accelerating from a complete stop (especially onto an incline) the engine RPM increases but the vehicle fails to accelerate as expected. The vehicle jerks and shakes violently and is unable to gain speed. This issue is intermittent but highly repeatable and occurs almost every time when there is a slope immediately after a stop sign. It results in loss of acceleration, violent shaking, and inability to maintain or build speed, creating a serious safety risk in traffic. It first happened around 1 year (early 2026) after the new car purchase (Nov 2025). There are no warning lights or messages. The dealer claimed they were unable to reproduce the issue during a brief test drive without me present and incorrectly attributed it to a bulletin without performing a detailed diagnosis or repair or looking at the video we recorded on the issue. The issue persists and affects safe operation of the vehicle. No inspection has been done by police or insurance. In one instance, this occurred while other vehicles were approaching from behind, creating a dangerous situation where I could not accelerate to match traffic flow. This resulted in a high risk of being rear-ended due to the unexpected loss of acceleration. I am aware of other consumer reports describing similar transmission-related symptoms such as slipping, hard shifting, and hesitation in this model. Some complaints describe transmission issues occurring at low mileage without warning lights.

Transmission went out at 4,150 miles vehicle was having hard shifts and slipping