2024 GMC Terrain Problems

What owners report

Owners of this model year most often describe transmission faults such as gear drop-outs, delayed engagement, and gear selector problems, followed by sudden or reduced engine power, in some cases tied to a fuel pump failure. Other reports describe the rear camera image going black or distorting, and unexpected braking or throttle behavior from driver-assist and brake systems. Most reports are recent, filed from 2024 to 2026, and where mileage is given the cases are mostly at low mileage, up to about 55,000 miles, so the pattern is still developing.

1. 1
   Fuel system

   Sudden power loss or reduced engine power

   • 20 complaints (38%)
   • median 6,766 mi at 1.5 yrs old (3 state mileage, few)
   • filed 2024–2026

   Owners describe the engine suddenly losing power or going into a reduced-power mode while driving, sometimes with stalling, shaking, or a no-start afterward. In some cases the high-pressure fuel pump or fuel module was replaced, and some owners say the car smelled of gas before cutting out. Some owners describe repeated power reductions or warning messages after an update, with the same symptom returning after the dealer's repair, and others describe sensors, a battery, or a catalytic converter being replaced first. Where mileage is given it ranges from very low mileage up to about 57,000 miles, with failures noted near 25,000 and 30,000 miles.

   2 related service bulletins

   What to check: On a test drive, check for hesitation, surging, or a reduced-power message under acceleration, and ask whether the fuel pump and any turbo intake connections have been checked. Ask whether any bulletin on reduced power or surge has been reviewed, since complaints describe the symptom returning after repairs.

   2 excerpts from owner complaints in NHTSA records

   “Since purchase, this vehicle has consistently had an issue with the fuel system. When I call GMC they state only use no ethanol fuel. I wouldn’t have bought this car if that was the case. The dealership never said that when I was buying it. We replaced the entire engine for $11,000 because of a torn radiator hose, overheating and cracked a gasket. Now, the car is refusing to drive, giving engine power reduced”

   NHTSA complaint #11744779, filed 2026-06

   “On Febuary 14 2026 I was driving on the feeder of the freeway with speeds of 50 mph my car suddenly down shifted in the middle of driving started shaking real bad stalled wouldn’t start wouldn’t go in gear at all would just die and say engine power reduced. This is after it had just been at the dealership and they said all I needed was an update. It had to be towed and the dealership said it was my high pressure fuel pump had failed. They replaced it and gave me the car back. …”

   NHTSA complaint #11720325, filed 2026-02
2. 2
   Transmission and drivetrain

   Transmission drops out of gear, lags or fails

   • 25 complaints (47%)
   • median 6,766 mi at 2.5 yrs old (3 state mileage, few)
   • filed 2024–2026

   Owners describe the transmission suddenly dropping out of gear or shifting into neutral, locking out a gear, or slipping, with the car sometimes stopping in traffic. Some describe a delay of a few seconds before a gear engages from a stop, and accelerator lag while the transmission searches for the right gear. Some say the transmission was replaced and the new unit had erratic or hard shifts, or later leaked fluid. Others describe limp mode and warning messages, with the diagnosis pointing to a pressure solenoid or valve body fault. Where mileage appears in the reports it is about 3,800 to 14,800 miles, and the complaints were filed from 2024 to 2026.

   What to check: On a test drive, shift through every gear, including a slow start from a stop, and watch for hesitation, a pause before engagement, or a gear dropping out. Ask for the diagnostic records and whether any transmission software update has been installed, since some complaints say a software fix was not received.

   2 excerpts from owner complaints in NHTSA records

   “We purchased our 2024 GMC Terrain on April 13, 2024 and on June 12, 2024 my husband and I were headed out to go to dinner and when leaving our neighborhood I noticed a weird transmission shift or slip and then the vehicle rpms increased suddenly. I pulled off the road and put the vehicle in park then I attempted to put the vehicle in reverse. The reverse lit up and just began to blink in the dash but the transmission did not go into reverse. …”

   NHTSA complaint #11614243, filed 2024-09

   “Was driving along and transmission downshifted (?) wouldn't change gears. Tachometer was like a race car. Just went wild. Limped it along to a dealership. They informed us it was probably the transmission. It was determined it was indeed the transmission. They also stated that they had 7 more waiting in the service area waiting for parts to repair. Ours was to be #8. We called the dealer we bought it from, they sent a tow truck and towed it to their service area. …”

   NHTSA complaint #11600652, filed 2024-07
3. 3
   Transmission and drivetrain

   Gear selector moves to Park or sticks while driving

   • 10 complaints (19%)
   • median 8,908 mi at 2.5 yrs old (2 state mileage, few)
   • filed 2024–2026

   Owners describe the gear selector moving to Park while the car was moving or stopped, or failing to move out of Neutral, sometimes with a loss of power or a warning message. Some say restarting the engine or switching the ignition off and on temporarily restored normal operation. According to the complaints, a dealer found debris inside the transmission and flushed it, and fault codes pointed to the transmission in another report. Where mileage is given it is about 6,800 to 11,000 miles, and the complaints were filed from 2024 to 2026.

   What to check: During a test drive, move the selector through each position from a stop and watch the gear indicator. Ask whether the transmission was checked for debris and fluid condition, since a complaint reported debris inside the transmission.

   2 excerpts from owner complaints in NHTSA records

   “Bought new car August 16th 2024. Few days later, I was turning left at a light and the car lost power as I was turning and error messages came up on the dash screen saying service transmission. I also observed that the cars gear indicator went to Park by itself even though the car was still moving. Pushed the engine start button and car came back on and I switched the gear to Drive. Took car in on the 19th to get looked at. …”

   NHTSA complaint #11612288, filed 2024-09

   “When accelerating, the engine revved up, switched itself from drive to park, resulting in complete loss of control and the vehicle coming to a sudden stop. The car behind narrowly avoided a rear-end collision by swerving around me. The malfunction indicator light came on for the first time, and the vehicle would not switch out of park. After turning the ignition off and on again, the vehicle would switch out of park. …”

   NHTSA complaint #11652793, filed 2025-04
4. 4
   Other or unknown

   Rear camera image goes black or distorts

   Mentioned in 4 of 48 sampled complaints

   Owners describe the rear camera image going black when the car is put in reverse, showing distortion that appears from time to time and seems to be getting worse, or showing the top of the license plate. Some report the rear camera staying on after shifting out of reverse, with the sound and steering-wheel controls of the infotainment system also malfunctioning. Some say the dealer considered the image normal, and that the problem began after purchase. Mileage is not listed in these complaints, which were filed from 2025 to 2026.

   What to check: Shift into reverse and drive on a test drive and check that the rear camera image is steady and not distorted. Ask the dealer for the diagnostic results and whether any camera or display software procedure has been applied, since some complaints say the dealer considered the image normal.

   2 excerpts from owner complaints in NHTSA records

   “I am reporting a recurring backup camera malfunction in my 2024 GMC Terrain AT4. Since purchasing the vehicle, I have experienced repeated instances in which the rearview camera display goes completely black when the vehicle is shifted into reverse. This prevents me from seeing the camera image while backing up. The malfunction presents a safety concern because the rearview camera is an important aid in identifying pedestrians, children, objects, and other vehicles behind the vehicle. …”

   NHTSA complaint #11768559, filed 2026-10

   “The rear camera is displaying the top of the license plate! It wasn’t doing it when I first purchased the car. Dealer states it is normal. I do not agree.”

   NHTSA complaint #11686436, filed 2025-09
5. 5
   Forward collision avoidance

   Unexpected braking, cruise or throttle behavior

   Mentioned in 4 of 48 sampled complaints

   Owners describe adaptive cruise control failing to slow for a slower car ahead in rain, and automatic braking coming on unexpectedly at highway speed. Others describe the throttle holding for a short time after the pedal is released, causing unintended acceleration in forward and reverse, and a brake system warning at highway speed with a vibrating pedal and a long stopping distance. Some owners say they had to brake hard to avoid a collision. Where mileage is given it is roughly 3,800 miles, and the complaints were filed from 2025 to 2026.

   What to check: On a test drive, check that adaptive cruise and automatic braking respond as expected when a slower vehicle is ahead, and check throttle response after the pedal is released. Ask for brake system and throttle diagnostic records, since complaints describe brake warnings at highway speed and a pedal that vibrated.

   2 excerpts from owner complaints in NHTSA records

   “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.”

   NHTSA complaint #11750466, filed 2026-07

   “Vehicle was running but transmission was in PARK. Suddenly on screen in front of driver this message appeared: BRAKE SYSTEM FAILURE 43MPH TOP SPEED WARNING SERVICE ESC. Vehicle was not moving. Engine was running but vehicle was in PARK. I had to drive it home. Very difficult to stop. Brake pedal vibrated violently. Very long stopping distance even at 20MPH. I had the vehicle towed to the dealership from which I had purchased it. I bought this vehicle on 25 Nov 2024. Right now its mileage is 3757. …”

   NHTSA complaint #11653803, filed 2025-04

Buying note. For this model year, the most useful checks are a full test drive through every gear, including a slow start, and a check for reduced-power messages and fuel system service history. Ask for records of transmission and fuel pump work, and whether any bulletin on reduced power or surge has been reviewed, before buying.

Summary written with AI from a sample of 48 NHTSA complaints for this model year (picked at random, with complaints that state a mileage and recent ones taken first), then checked automatically against the source records. Where a problem shows a complaint count, every complaint for this model year was matched with fixed keyword rules (written with AI and tested against the sample), and the mileage, age and repair figures are calculated from those complaints; owners' figures are as stated, not verified. Other counts refer to the sample. The excerpts come from NHTSA's public complaint records and are unverified; capitalisation is normalised, NHTSA staff notes are removed, and shortened text ends with “…”. Something wrong? Request a correction.