2019 GMC Terrain transmission problems

Filed Oct 23, 2026 · Transmission · IL

Transmission leak caused but start and stop accumulator

Filed Oct 13, 2026 · Brakes, Engine · CA

VIN: [XXX] Mileage: Approximately 103,576 Incident location: [XXX] Safety Complaint: While my wife was driving our 2019 GMC Terrain into a shopping center parking lot, the vehicle suddenly experienced a severe loss of braking assistance. The brake pedal became extremely stiff and difficult to depress, and she was barely able to slow the vehicle. This occurred unexpectedly while the engine continued running, creating a serious risk of a collision. Following the incident, I inspected the vehicle using an OBD-II diagnostic scanner, which identified diagnostic trouble code P0016 (crankshaft/camshaft position correlation). The vehicle also displayed an oil-pressure warning. We subsequently had the vehicle inspected by John's Automotive Care in [XXX] on XXX. During the inspection, the technician discovered a significant amount of metallic debris in the engine oil. The repair facility suspects a mechanical failure of the engine-driven brake vacuum pump, potentially resulting in damage to the engine and lubrication system. The repair facility recommended replacing the mechanical vacuum pump and engine oil-pressure switch and performing an oil change. However, the service representative explained that these repairs would not guarantee the engine's continued reliability because the engine was compromised and could fail at any time. We are extremely concerned that a failure involving the brake vacuum pump could cause sudden loss of braking assistance without adequate warning, potentially resulting in a serious accident. We request that the federal safety agency investigate whether this failure represents a safety-related defect affecting the 2019 GMC Terrain and other vehicles equipped with similar engine-driven brake vacuum pump systems. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Sep 23, 2026 · Transmission · 60,000 miles · MI

The contact owns a 2019 GMC Terrain. The contact stated that after pulling into a parking lot, the vehicle failed to shift into park. The vehicle was towed to a dealer where the contact was informed that three fault codes were found. The dealer informed the contact that the transmission needed to be disassembled for a full diagnostic test. The vehicle was not repaired. The vehicle was scheduled for the transmission to be disassembled for the diagnostic test. The failure mileage was approximately 60,000.

Filed Jul 3, 2026 · Transmission · IL

No engine lights are on. When at stops it starts chugging and when I accelerate sometimes it does not go like it should. It idles high and feels like it is slipping. I have almost been hit in the rear several times when this happens. One lady did rear end me but the damage was so little that I did not call the cops. This vehicle has not been inspected and it is available for inspection at any time.

Filed Jun 10, 2026 · Engine, Transmission · TN

The turbo went completely out at around 105k miles while I was driving to work. I had to coast into a repair shop because it was smoking and wouldn’t go over 20mph and then have it towed to the place that repaired it. Since then, the transmission is having trouble shifting gears. The car struggles to accelerate and I have to go abnormally slow after coming to a complete stop in order for the car to get into gear. The onstar diagnostic says everything is fine but it is clearly not fine.

Filed Mar 17, 2026 · Transmission · 180,400 miles · TX

The contact owns a 2019 GMC Terrain. The contact stated while driving at an undisclosed speed, the transmission unexpectedly shifted into neutral(N). There was transmission fluid on the ground, and the vehicle became disabled. The vehicle was towed to the dealer, where it was diagnosed with a transmission accumulator leak. The vehicle was not repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 180,400.

Filed Jan 13, 2026 · Brakes, Engine · IN

Vehicle was started for the second time that day on 1/5/26 and the engine light was on. I drove the vehicle to an auto parts store to have them check it with an OBD-II scanner. It had code P050F. I had no idea how serious this issue could be at the time. I made an appt with the GMC dealership and dropped it off the evening of 1/6/26. They said there was a software anomaly in the engine control module and needed to be reprogrammed. I paid the $200 diagnostic fee for them to reprogram it. I learned that this anomaly could have caused my brakes to not work while driving it. I had been driving the vehicle back and forth to work until I dropped it off. This issue could have caused serious harm or death to myself and others. While researching online, I've seen that other vehicles have had safety recalls and additional warranties added for these issues, but my vehicle isn't included in this.

Filed Jan 10, 2026 · Engine, Fuel system · GA

Drove car approximately 15 miles. Parked car. Car would not turn off. Message- Transmission/Park. Wouldn't Car stayed neutral. Had to call wecker to take dealership. ... Diagnostic Solenoid Valve Body faulty.... 2019 Terrain Miles 91669. Is there recall. Have more reports of issue. Should this happen with a well maintained vehicle All maintenance updated to date.

Filed Dec 5, 2025 · Electrical, Engine · MI

I bought this Terrain brand new from Betten Baker Chevrolet in Muskegon Mi in 2019 with 500 miles. That same year we had transmission Slippage causing it to slip out of gear then slam back into gear while driving. I took it to the dealer to have it looked at. They did nothing and informed me it was known by the manufacturer that this was an issue. I then had to bring it back for electrical issues as the lights would all start going off in the cab including dome lights and shift buttons. All key fob would not be recognized by the car and would have to be reprogrammed counting 5 times now. Now I am sitting at just oflver 100,000 miles and what I thought was going to be a simple spark plug change gas turned into a complete motor failure. did an oil change and there was no oil in it. The turbo was replaced and now the engine started making a lot of rattling noises and just stopped. the dash says service transmission, ECS, Extremely low battery voltage and has jost die after oil started pouring out the bottom of the car. It is now sitting at the dealership service department where I was told by am employee there that they have been seeing them come in at 150,000 miles for complete rebuilds and mine was early. let me tell you that this car isn't even paid off yet. And the 2006 Ram 1500 is more reliable.

Filed Sep 22, 2025 · Acceleration, Fuel system · MI

Vehicle struggles to shift from low gears; seems to completely miss 3rd gear. Codes from maintenance indicate TCC slip