GMC Terrain adaptive cruise problems

Filed Nov 7, 2026 · Driver assistance, Electrical · TN

Lasted infotainment system update caused cruise control and lane assist to not function (car reports it is temporarily unavailable). And the internal temperature, AC, air circulation, fan speed buttons all are no none functioning (screen touch only) and the vehicle resets to high heat and defrost mode every time you start it, instead of your last setting.

Filed Aug 5, 2026 · Driver assistance, Engine · MA

adaptive cruise disengaging alert on dash- no cars or weather conditions to induce this. loss of power and bucking on highway( near accident caused) catostostrophic sudden loss of power engine/transmission failure while mechanic driving resulting in car towed back to dealer. loss of power multiple times causing near accidents. sudden jolting at stop light causing car to propel forward requiered both feet on brake pedal to stop. 4 episodes of near collision 1st altert started 04/4/2024 adaptive cruise light on dash 14,700 miles on vehicle 5 episodes continued and now car is still at dealership for emissions failure, loss of power x 4 weeks. ALL PHOTOS OF DASH LIGHTS, REPAIR INVOICES AND VIDEO OF DASH AVAILABLE BUT I AM NOT ABLE TO UPLOAD ALL.

Filed Jul 14, 2026 · Driver assistance · CO

I was driving about 55 mph with adaptive cruise control set to maintain a three-car-length following distance. It was raining, and when the vehicle in front of me slowed down, my vehicle did not detect it or slow down as expected. Instead, it continued accelerating, and I had to brake to avoid rear-ending the vehicle ahead.

Filed May 26, 2026 · Acceleration, Fuel system · TX

I was driving the vehicle on the highway the cruise control was on. All of a sudden I got a warning on vehicle info panel that stated vehicle power is reduced. The vehicle decelerated on its own and I could not accelerate past 55. The check engine light came on. I pulled off the road and turned the vehicle off. After about 10 minutes, I started the car back up and proceeded down the highway at normal speed. The check engine light remained on. I stopped at a Chevrolet dealer service center in Ft Stockton, TX, to have the vehicle looked at. They could find no error codes and could not duplicate the problem. I was sent on my way. This has happened multiple times while driving on roads in my area. Mostly while on the highway.

Filed Jul 1, 2025 · Driver assistance, Electrical · MI

Driving my vehicle with no warnings, messages, or symptoms on adaptive cruise control Sunday [XXX] on [XXX] in Michigan. I changed lanes into the right lane when the vehicle abruptly, without notification, and with force, caused braking that unexpectedly and dangerously slowed the vehicle then released braking before doing the same a moment later. Vehicle was pulled off the road onto the shoulder without an accident, thankfully nobody was behind because they would not have been able to stop in time before hitting my vehicle and I assume the brake lights weren't activated since I did not press the brake pedal either time the vehicle was abruptly slowed causing audible noise of traction loss due to skidding. Vehicle engine would function but parking brake remained active leaving vehicle unable to change gears and transmission warning showed on instrument panel. Vehicle towed to a Chevrolet dealer in Grayling, Michigan where it remains and would be available for inspection. Dealer shows transmission as the cause and in need of replacement. Vehicle has been maintained at GM shops since original ownership. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Apr 15, 2025 · Engine · 148,000 miles · MO

The contact owns a 2015 GMC Terrain. The contact stated while driving 70 MPH with cruise control activated, the RPM suddenly increased to redline, after which the vehicle lost motive power. The contact was able to coast to the shoulder of the roadway, where the vehicle failed to restart. No warning lights were illuminated. The vehicle was towed to the dealer, who diagnosed a failure with the positive crankcase ventilation (PCV) valve, which then caused a failure with the front crank seal, resulting in damage to the engine. The contact was informed that the engine needed to be replaced. The vehicle was repaired. After investigating the failure, the contact related the failure to the federal safety agency Action Number: PE25001 (Engine, Engine and Engine Cooling). The manufacturer was notified of the failure but provided no assistance. The failure mileage was 148,000.

Filed Mar 4, 2024 · Brakes · FL

This Saturday morning driving my family to Bradenton as I was coming off the hwy to my exit when I experienced a brake fail I thought, brakes got real hard and I couldn't stop the car on time like I wanted to, so I had to press the brakes pedal harder to come to a complete stop, three different places no one knew what could be the problem until I took it to GMC dealership they can only give a code P0556 / U0401 SERVICE BRAKE ASSIST, seems it was too late to checked out they where about to close , something to do with the busters not sure yet but it's getting checked out tomorrow morning, I was driving on cruise control at a speed limit when this happened, will let you know what's the result of my situation.

Filed Jan 17, 2023 · Transmission · NJ

Was driving on a highway on cruise control When it automatically disengaged by itself When I stepped on the gas the car began to shake violently, And it was not shifting years correctly. I was able to pull over and realize that the transmission Was a problem so I was able to drive manually to local dealer who diagnosed the problem as needing a new transmission. The vehicle is 2017 and has less than 63000 miles.

Filed Sep 8, 2021 · Acceleration, Driver assistance · TX

Not long after I bought my 2020 GMC Terrain my adaptive cruise started disengaging. There are never any warning lights, except the noise and vibration of the seat before it shuts off then tells you it's disengaging. I didn't think anything of it until it's became a regular occurrence in the last month or two. I tell my dealership about it and they drive it but it never disengages on them, so they say nothing is wrong with my vehicle. I have a picture of the "adaptive cruise disengaging" and video of where I can't reset it until after about 15 or so minutes or letting my car set for a while or turning off the engine then it works again. I also have noticed that my auto start/stop hasn't been turning on & off anymore.

Filed Nov 2, 2019 · Acceleration · 1,000 miles · IL

When cruise control is engaged at 71mph, holding +res button to increase speed and releasing it at 77mph sets cruise speed too high. Car continues to accelerate. Cruise gets set at 100mph and accelerates more then desired. See link with video of event https://photos.app.goo.gl/o7zgeqwcsu7kycv58 see attached picture of owners manual