2020 GMC Terrain Problems

What owners report

Complaints about the 2020 GMC Terrain cluster around two things: a stiff, hard-to-press brake pedal traced to the vacuum pump or brake booster, and stalls or a no-start traced to the fuel pump and fuel pump control module. Both are reported across a wide mileage span, from a few thousand miles to well past 100,000. Owners also describe electrical glitches — a blue rear-view camera screen and intermittent blank displays — along with occasional transmission and engine concerns.

1. 1
   Brakes

   Stiff brake pedal / loss of power assist (vacuum pump)

   • 70 complaints (36%)
   • median 53,500 mi at 5.0 yrs old (14 state mileage)
   • 6 mention a crash, fire or injury
   • owner-quoted repair $1,400 (median of 9 quotes)
   • filed 2020–2026

   Owners describe the brake pedal becoming very hard and requiring heavy force, sometimes with no warning light, and in some cases stating that the vacuum pump or brake booster had to be replaced. Several say the pump was found fractured and that debris reached the engine. Complaints mention the repair being repeated because the symptom returned, and some reference an extended warranty for the pump that their vehicle was told not to qualify for. Reported from about 40,000 to roughly 160,000 miles, often during low-speed stopping or after extended driving.

   What to check: Ask whether the brake vacuum pump or booster has been replaced and whether any related extended coverage applies to this vehicle's build. On a test drive, press the pedal from a stop and note whether it feels firm or requires unusual effort.

   2 excerpts from owner complaints in NHTSA records

   “I am submitting this complaint regarding a serious and dangerous brake failure involving my 2020 GMC Terrain SLT with approximately 150,000 miles. While driving, the vehicle suddenly experienced a vacuum pump failure that caused a severe loss of braking ability with no warning beforehand. The brake pedal became extremely hard, and the vehicle would barely stop. This created a very dangerous situation and could have easily resulted in a serious accident. …”

   NHTSA complaint #11740175, filed 2026-05

   “On my 2020 GMC terrain the vacuum pump failed and caused my braking system to go out completely. I had to almost stand up on the brakes to get the car to stop and thankfully I got it come to a stop before smashing into another car. …”

   NHTSA complaint #11689847, filed 2025-09
2. 2
   Fuel system

   Stall, no-start or rough power loss (fuel pump)

   • 16 complaints (8%)
   • median 46,046 mi at 5.5 yrs old (6 state mileage, few)
   • filed 2023–2026

   Complaints describe the vehicle stalling while accelerating from a stop or shortly after refueling, sometimes refusing to restart and displaying low-battery or start-vehicle messages. Owners report being told the fuel pump or the fuel pump control module needed replacement. Some note that a related recall exists but their vehicle identification number was not included. Mostly between about 40,000 and 60,000 miles, with some reports at lower and higher mileage.

   What to check: Ask whether the fuel pump or fuel pump control module has been replaced, and check whether the vehicle's VIN was included in any fuel-system recall campaign.

   2 excerpts from owner complaints in NHTSA records

   “Vehicle stalled while stopped in middle lane during rush hour traffic. Vehicle would not start, and could not be put in neutral to be pushed to side of road. Vehicle was towed to repair shop where they needed to replace the fuel pump control module. The automotive repairmen stated they have seen this with multiple GMC vehicles and they do not understand how it has not been recalled yet because, as they stated, it is going to get someone killed one day.”

   NHTSA complaint #11647936, filed 2025-03

   “The contact owns a 2020 GMC Terrain. The contact stated that while attempting to restart the vehicle, the vehicle failed to start. The vehicle was towed to the local dealer who diagnosed that the fuel pump was faulty and needed to be replaced. The vehicle was not yet repaired. The manufacturer was not yet notified of the failure. The failure mileage was 42,000.”

   NHTSA complaint #11523793, filed 2023-05, 42,000 miles
3. 3
   Electrical system

   Rear camera shows blue screen or service message

   • 24 complaints (12%)
   • median 58,000 mi at 5.0 yrs old (9 state mileage, few)
   • filed 2020–2026

   Owners report that when shifting into reverse the rear-view image is replaced by a blue screen or a service camera message, sometimes with parking sensor beeping not working. Some say the camera was replaced under warranty and the problem later returned; others report the dealer charged for diagnosis without resolving it. Reported from roughly 50,000 to 105,000 miles, though some note it appeared within the first few years of ownership.

   What to check: Shift into reverse during the test drive and confirm the camera image appears promptly. Ask whether the camera or display module has been replaced previously.

   2 excerpts from owner complaints in NHTSA records

   “Twice within the last two months my entire radio shut off, my screen went black and so did my gauges for at least 20 seconds. Then they just came back on and picked up where it left off.”

   NHTSA complaint #11374234, filed 2020-11, 5,600 miles

   “Backup camera stopped working and displays a blue screen stating “service backup camera.” This was an issue when the vehicle was under 3 year manufacturer bumper to bumper warranty and was fixed by dealer at no cost. Now this same issue has occurred again approximately 3-4 years later. I thought at first this was an issue specific to my vehicle but now after doing research I see this is an issue across several GMC Terrian vehicles and other GM vehicles. This issue should be fixed by the manufacturer for all vehicles affected. …”

   NHTSA complaint #11745463, filed 2026-06
4. 4
   Engine

   Engine stalls with oil loss and warning lights

   Mentioned in 6 of 60 sampled complaints

   Some owners report the engine shutting off or losing motive power with the check engine light on, and in a few cases the engine was found low on oil or requiring replacement. Complaints also describe turbo underboost codes with reduced power in cold, damp weather that eased once conditions changed. Reported from a few thousand to about 70,000 miles, including some vehicles still under warranty.

   1 related service bulletin

   What to check: Check the oil level and look for leaks, and ask for service records showing oil changes and any engine repairs. A service bulletin addresses intake manifold replacement after severe internal engine damage, so ask whether that work was done.

   2 excerpts from owner complaints in NHTSA records

   “Having the start stop issue on my terrain and recently over the last few months, it has been using oil everything that sounds exactly like the recall but mine is not included. My start stop is not working and I have to get him since it had only 60,000 miles on it years ago, but nothing was done.”

   NHTSA complaint #11762749, filed 2026-09

   “I just purchased this vehicle about 2 weeks ago, and was driving through the fog/cold weather and my check engine light came on. Went to O'Reillys and had them check the code. Came up as P0299 (My car was telling me that the engine power was decreased) I had a loss of power I could feel while driving as well. The code said turbo under boost. After I got back into town and the weather was warmer and no fog was present, the turbo started working again. …”

   NHTSA complaint #11500119, filed 2023-01
5. 5
   Transmission and drivetrain

   Hesitation or brief loss of power from a stop

   Mentioned in 5 of 60 sampled complaints

   Complaints describe a delay of several seconds when accelerating from a stop sign or light, after which power returns, and in some cases the transmission slipping into neutral or failing to engage drive or reverse. Owners report tire skipping and clicking or whining sounds from the front while accelerating uphill or turning. Described across a broad range, from around 50,000 to about 105,000 miles.

   Recall 20V668000

   What to check: During a test drive, accelerate from a dead stop and note any delay before the vehicle moves. Ask whether transmission software updates or repairs have been performed.

   2 excerpts from owner complaints in NHTSA records

   “I have been experiencing loss of power when going from a full stop to acceleration. I purchased my 2020 Terrain. I almost got in a car accident for the 3rd time today due to this loss of power issue. Stopped at a stop sign, I accelerate but the vehicle will barely move no matter how far down you push the peddle down. The loss of power is anywhere from 4 to 6 seconds then all of the sudden power will return. I've looked for recalls but there are none for my vin. …”

   NHTSA complaint #11673104, filed 2025-07

   “Check engine light is on took vehicle to dealership 10/13/2023 vacuum booster sensor replaced (37,435 miles) $0 GM Covered cost 12/9/2024 brake vacuum pump replaced (56,456 miles) $0 extended warranty 1/8/2025 vacuum booster sensor replaced (57,087 miles) $252.48 not covered by warranty Check engine light is on 10/11/2025 took to dealership. They were unable to find issue light was off, was told that GM had recommended several things that could be the cause of light coming on still could not find issue. …”

   NHTSA complaint #11697102, filed 2025-11

Buying note. Have any 2020 Terrain inspected for brake pedal firmness, fuel pump service history and stored engine or transmission codes before purchase, and confirm which warranty or extended coverage applies to the specific vehicle. Service records showing prior repairs to the vacuum pump, fuel pump or camera system are worth reviewing.

Summary written with AI from a sample of 60 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.