Page 2 of 4 · complaints 51–100 of 198

2020 GMC Terrain complaints

Owner reports filed with NHTSA about this vehicle, newest first and reproduced as filed. They are unverified accounts: one proves nothing, and a pattern across many is the thing worth reading. Back to the full 2020 record →

Service Brakes, Hydraulic
Filed Dec 2, 2025198,000 milesNM

The contact owns a 2020 GMC Terrain. The contact stated that while driving up the driveway at approximately 10 MPH, the brake pedal was depressed but failed to function as intended. The contact used force to depress the brake pedal. When the vehicle came to a stop, there was an abnormal grinding sound coming from the front brakes. The contact stated that the message "Power Assist Brakes" was displayed on the instrument panel. The vehicle was not taken to the dealer or an independent mechanic. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 198,000.

Service Brakes
Filed Nov 30, 2025MI

While driving on a main road at around 45mph the vacuum pump that supplies brake fluid to the brakes failed. The car was unable to be stopped and had it not been late in the night I could have crashed into other vehicles on the road or hit someone walking. There was not indication prior to the malfunction and was very sudden. This issue has been observed by the dealer as well as multiple other individuals with the same problem for this make and model of car as well as others by the same manufacturer for similar years of manufacturing. This part has also been shown to break into the engine causing complete engine failure due to lack of a shear pin on the vacuum pump.

Back Over Prevention
Filed Nov 26, 202571,000 milesWI

The contact owns a 2020 GMC Terrain. The contact stated that upon shifting to reverse(R), the rear-view camera image was blue, and the parking sensor beeping sound was inoperable. The contact had taken the vehicle to a local dealer, where it was diagnosed and determined that the rear-view camera needed to be replaced. The vehicle was repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 71,000.

Unknown or Other
Filed Nov 22, 2025OH

The rear backup camera in my 2020 GMC Terrain failed. I first noticed and noted that the image was 'cloudy' on 5/3/2023, and it became very bad by 1/22/2024. On 7/1/2024, the image stopped working completely, replaced with a blue screen on the dashboard screen. I ordered a new camera and replaced it myself on 8/1/2024. Because the dealership did not mention any safety effects or recalls, and instead quoted me a very expensive repair estimate, and the vehicle was out of its 3 year warranty, I assumed it was my responsibility to repair this feature. However, I have seen recent news articles where other vehicles have been recalled by NHTSA for similar problems with backup cameras.

Electrical System
Filed Nov 21, 2025MI

My a/c went out within 2 years of having the car in 22’. In 2025 i have had nothing but problems, the radio will go out when im driving for about 2 hours and it resets, the screen goes black, music stops, navigation stops and then it turns on like nothing happened. It happens everytime I drive 2+ hours. Back in September of 2025, I was on my way to work when I was stopped at a red light, it turned green and then my brakes locked up and I couldn’t drive my car had shut off, and wouldn’t come back on. I was stuck in the middle of the road not knowing what happened as the car had driven fine up until i stopped at the red light. Then tonight November 21,2025 around 0315 I was leaving work, I started my car, my car threw up a message that said “Low fuel, 0 miles” I had half a tank of gas when I got to work. I turned my car off then back again and it did the same thing. I let my car sit for a second and then my Gas gauge started to slowly increase to the correct amount of gas. Then when I got home (3 mile drive from work) I turned my car off and then back on and this time when I turned the car on my brakes were locked and I couldn’t start my car. All of the Engine lights were on so I turned the car off and then let it sit for a minute before trying to start it. When I tried to start it this time, I couldn’t. It’s like the car had died and was getting no power. I couldn’t lock my car, no lights were working, I couldn’t turn it on or start it. Some time went by and my interior lights

Service Brakes
Filed Nov 13, 2025MI

Vacuum pump went out. It was a recall, previously on older models, but this model needs to

Service Brakes
Filed Nov 8, 2025MI

I filed a complaint with NHTSA on November 3, 2025, about my brake system. Here is another one adding more information. I had to have another brake system part replaced. This time it was the brake booster. Cost $1441.63 (covered by extended warranty actual cost to me $100.00.) So far, I have had the booster sensor replaced twice, the vacuum pump and now the brake booster. I asked the mechanic how many parts related to this system were left to replace? This vehicle has 66,000 miles on parts for the braking system started needed to be replaced at 37,000 miles. The total cost for parts, labor is about $500. That does not include the loss of use for this vehicle which is about 15 days. Taking days off of work about 6 days. This has been a problem for GMC Terrains since 2015; there is still a problem with 2020 model year. Please do something before there is a loss of life due to brake failure.

Unknown or Other
Filed Nov 8, 2025WA

I was driving on the highway below the speed limit when I heard a pop that sounded like a balloon and instantly the sound of wind getting into the car. I pulled over and found that the sunroof was rapidly shattering. I did not see a rock that had hit it. Maybe the tempered glass just exploded. I was not driving very close by any other vehicles at the time, but was on the highway.

Service Brakes
Filed Nov 3, 2025MI

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. Last thing GM and dealership recommended was to replace the battery. Cost $104.00 Check engine light came on 10/25/2025 while returning home from Tennessee to Michigan, light came on in Louisville, KY. Had it scanned, booster sensor was the cause. Called AAA had them replace battery light went off. (as you know that if you do that it reset the computer not surprised light went off drove rest of the way home to Michigan) Cost of replacement battery $295.00 Check engine light came on again 11/2/2025 my best bet is that it is booster sensor again. NHTSA and GM need to fix this issue. I have not lost breaking ability yet but the horror story that I've read on this site scars me. WHAT ARE IS NHTSA AND GM GOING TO DO WAIT UNTIL SOMEONE IS KILLED BECAUSE OF THIS ISSUE !!!!!!!!

Service BrakesCrash
Filed Oct 30, 2025GA

SERVICE BRAKE ASSIST CAME ON, CHECK ENGINE LIGHT CAME ON AND VEHICLE WAS HARD TO STOP. Took to authorized service dealer and all parts were replaced. After driving it for a little while, SERVICE BRAKE ASSIST BACK ON, CHECK ENGINE LIGHT BACK ON AND VEHILCE IS HARD TO STOP.

Service Brakes
Filed Oct 24, 2025SC

Break assist light comes on and brakes stiffen suddenly with no warning. Happened 6 times now in a 3 year span. Gotten it "fixed" each time but it keeps happening

Unknown or Other
Filed Oct 23, 2025HI

The Vehicle Identification Number for this vehicle is not recognized in the NHTSA program. From Online vehicle registration Oahu Hawaii

Fuel/Propulsion System
Filed Oct 23, 2025AL

From a complete stop my car refused to accelerate no matter how much I pushed the gas pedal. I was pulling into traffic and was on a hill so my car rolled forward naturally into the road but would not respond to the gas pedal. The RPMs didn't move, the car had power, I tried putting it in reverse and then back into drive. Nothing worked for a solid 2 minutes at least. Then all of a sudden it registered and worked. I was almost t-boned from a car coming through the curve but luckily, they were able to go around me in time. This put me and my small daughter at risk of being severely injured from a malfunction that I can't recreate to show the technicians. Since this incident, it has happened several times randomly. Sometimes I'm at a red light, or backing out of a parking spot, or pulling out into traffic. When it happens, there are no codes thrown to show any engine malfunctions, but it WILL NOT MOVE! I've noticed more and more the lack of power when driving. Almost as if the transmission is slipping or losing power as well. I bought the car new, only have 38K miles on it, and service it every 5k miles at a GMC dealership. This is going to end up killing someone. The mechanic told me to trade it in, but I just paid it off and it's only 5 years old. There are multiple complaints about this same thing happening with tons of Terrains and there isn't a recall yet.

Power Train
Filed Oct 8, 202594,000 milesCA

The contact owns a 2020 GMC Terrain. The contact stated that while making a turn, the transmission shifted into neutral and briefly lost motive power and stalled. No warning lights were illuminated. The contact was able to restart the vehicle; however, the vehicle failed to function while shifting to drive(D) or reverse(R). The contact opened and closed the door to see if the vehicle would reboot. After several attempts, the vehicle returned to normal functionality. The contact stated that on a separate occasion, the transmission was leaking transmission fluid. The transmission was constantly slipping. The check engine warning light was intermittently illuminated. The vehicle was taken to the dealer, where it was diagnosed that the START/STOP accumulator in the cap was missing bolts, which caused the transmission to fail. An unknown code was provided to the contact. The vehicle was not repaired due to the cost. The vehicle was taken to various independent mechanics who confirmed that the transmission had failed. The manufacturer was made aware of the failure. The failure mileage was approximately 94,000.

Electrical System
Filed Oct 5, 2025MA

Backup camera not working and has a blue screen. The camera was replaced. The fuses & wires were inspected and the screen remains blue.

Service Brakes
Filed Sep 26, 2025KY

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. I contacted gmc and while they know this is a ongoing problem and there is a warranty out for this particular problem (150,000 miles or 10 year warranty) I was told it is part/ factory specific and that if it was manufactured in certain facilities or had certain parts that they would cover the cost to fix it but however my vehicle was not covered. This poses a dangerous problem for GMC owners. As soon as the check engine light came on I had absolutely no control over the brakes and it was a miracle it stopped. There was no warning prior to this incident and upon looking up information this seems to be a recurrent problem that GMC needs to address seeing as they say they value their customers.

Service BrakesCrash
Filed Sep 18, 2025GA

My 2020 GMC Terrain brakes pump failed causing me to hit the median wall on the highway.

Service Brakes
Filed Sep 15, 2025NY

While driving my 2020 GMC Terrain (VIN: [XXX] ) with approximately 110,501 miles, I experienced a sudden and complete loss of brake assist. After about 2 hours of highway driving, I exited and the brake pedal became extremely hard to press, making it very difficult to stop. No warning lights or messages appeared before the failure. The dealer diagnosed the cause as the brake booster vacuum pipe exploding internally, which immediately eliminated vacuum to the booster. This created a serious safety hazard and nearly caused a crash. I have since had the part replaced, but the fact that this component can fail without warning at highway speed is alarming. GM has issued TSB 21-NA-107 describing this exact failure mode, which indicates it is a known issue. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Engine
Filed Sep 13, 2025CA

First problem was when the ac went out which affected the starter 2 weeks after that while I was driving something popped underneath the vehicle the vehicle completely stopped working when I checked underneath the vehicle there was leak ish a broken crankshaft car would not turn back on….

Fuel System, Gasoline › Delivery › Fuel Pump
Filed Sep 10, 202558,000 milesWI

The contact owns a 2022 GMC Terrain. The contact stated while depressing the accelerator pedal from a complete stop, the vehicle lost motive power and started shaking and then shut off. Several unknown warning lights were illuminated. The contact attempted to restart the vehicle; however, the vehicle failed to respond. A dealer was contacted. The vehicle was towed to the residence first and was then towed to a dealer to be diagnosed. The contact was informed that the fuel pump module needed to be replaced. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was 58,000.

Service Brakes
Filed Sep 10, 2025OR

Driving down the road and an engine power reduced light came on and then the driver was not able to apply the breaks to stop the car. Almost ran into a car at a 4 way stop before getting the car to stop.

Unknown or Other
Filed Sep 9, 2025MI

Back up camera does not work. It shows a blue screen and says service repair needed.

Service Brakes
Filed Sep 9, 2025MN

Driving down busy highway and suddenly had no brakes!!! No lights came on dashboard as a warning. Found out it was a braking pump that broke and shot metal pieces into the engine. Now im facing a new engine for a 2020 terrain!!

Engine
Filed Sep 2, 2025OH

I have been having intermittent problems for well over 1 year with my vehicle not accelerating. I try to accelerate from a stop, the vehicle does not respond. I have the accelerator pedal pressed to the floor nothing happens for 10-15 seconds, then vehicle will lurch forward and start responding. This has happened several times as I am pulling into traffic. Major safety concern that could cause severe injury or fatality. I also have other issues with vehicle not shifting gears, engine feels as though it is skipping while driving. I have taken this to the dealership and was told that they could not recreate the issue. No engine code or service lights have ever displayed. Dealership told me is can't be anything major since there are no codes or service lights. Currently have 72,000 miles, did purchase an extended warranty. I have seen many complaints of this same problem from other Terrain owners. GMC needs to fix this problem before someone is killed in a collision because their product won't accelerate.

Electrical System
Filed Aug 26, 2025NY

Sunroof/moonroof/sunshade and frame leaking for 2nd time.

Service Brakes
Filed Aug 26, 2025OH

As I was driving down the Ohio Turnpike on my way to work on Tuesday, August 5, 2025, my check engine light came on. Almost immediately I got a notification that the car was operating at reduced power. I had no previous issues with the vehicle. As I got off the turnpike my braking system failed. I was able to come to a stop partially in the grass before entering into oncoming traffic. The entire car shut down. I was unable to restart the car. We were also unable to put the car into neutral to push it off of the road the remainder of the way because the wheels were completely locked up at this point. The parking brake was engaged on its own. We also could not get the car into neutral. I had the car towed to a local repair shop, not knowing at all what the issue was. The vacuum pump had failed and broke apart in the engine. This caused my braking system to fail completely also. The vacuum pump on my 2020 GMC terrain has been noted as faulty or defective. However, an official recall has not been issued for my vehicle. Had the pump failed a moment sooner I could have been in a crash trying to exit the turnpike. I took my vehicle to a repair shop and spent $1400 out-of-pocket. The car still does not run correctly now as there are pieces in the engine of my vehicle that were unable to be retrieved.

Unknown or Other
Filed Aug 19, 2025PA

The bolts fell out and the bracket that holds the drive shaft in place fractured while driving.

Service Brakes
Filed Aug 15, 2025IL

I was driving on the expressway, attempted to brake and the brakes were stiff and would not go down to stop the vehicle. . Thankfully, I was able to glide over three lanes of traffic and exit the expressway and glide into a parking lot and drove around until the car came to a stop. No lights. No warning. The car had to be towed to my mechanic. This could have been catastrophic. I could have killed someone else or myself. This is the second time that this has happened with this vehicle!!! By the grace of God I am still here writing this complaint. I am traumatized and do not feel safe driving this car. They MUST RECALL this vehicle before somebody gets killed. The issue is with the vacuum pump and I have seen other complaints about the same issue.

Service Brakes
Filed Aug 14, 2025CA

GMC techs have already documented this issue could not be caused by wear and tear or lack of service - of which there is none the car has been serviced every10k miles as advised. GMC coperate has been contacted case # 71853883 The vacuum pump has failed due to MECHANICAL FAILURE causing it to explode and send pieces into the camshaft. The lack of vacuum caused complete brake failure rendering the car unsafe. GMC is aware of the issue as others habe reported it (I have proof of this) and refuses to recall the cars. The cars loose breaking in the middle of driving with no indicator lights or any other indications. The breaks had just been replaced in may - the incident occurred in October. Has not been driven since.

Service Brakes
Filed Aug 12, 2025PA

I was driving on the highway & my brakes failed. My brake pedal was completely hard & could not be used. i had to steer onto an exit ramp & be towed to the dealership. There was absolutely no warning of this happening. Once at the dealership, they confirmed it was my vacuum pump that blew up, which damaged the camshaft & caused pieces of metal to be floating around in my engine. The greater portion of the repair was covered under warranty, however, I had to pay $350 out of pocket. This could have been catastrophic. I or others on the road could have been injure for worse. This system failure should be fixed immediately and owners be compensated. I do not feel safe driving myself or my family in this vehicle after experiencing this occurrence.

Carry Handle, Shell, BaseCrash2 injured
Filed Jul 22, 2025KY

During a vehicle accident, my 2.5 year old daughter's car seat detached from the base and landed in the back part of my part. We were t-boned on the passenger side back seat. We spun and the car seat detached and she was flung around the car. She had severe whiplash, a contusion and possible fabric burn on her head. She was buckled in properly and the car seat was properly installed. Yes, all parties (other than manufacturer) saw and inspected the car seat.

Power Train
Filed Jul 12, 2025PA

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. This behavior is unpredictable and has occurred at stop signs, traffic lights, and when attempting to turn onto main roads. It has nearly caused accidents due to my inability to safely accelerate in time when merging or crossing traffic. I’ve read that GMC recalled certain 2021 and 2022 Terrain models for a fuel pump defect causing similar symptoms. My 2020 model is not currently included in that recall, yet it displays the same dangerous loss-of-power issue. I believe this is a serious safety defect that should be investigated and potentially included in the existing recall. I respectfully request that NHTSA investigate this issue further. I would also appreciate confirmation that this report has been logged. Vehicle Info: 2020 GMC Terrain VIN: [XXX] Engine: 1.5L Turbo Mileage: 62,142 Thank you for your time and your work in ensuring vehicle safety. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Service Brakes, Hydraulic
Filed Jul 7, 2025162,000 milesCT

The contact owns a 2020 GMC Terrain. The contact stated while driving 40 MPH the "Brake Assist" warning light illuminated. The contact attempted to depress the brake pedal, but the pedal was stiff. The contact was unable to depress the pedal. The vehicle was taken to a local dealer and unknown repairs were performed. The vehicle was repaired; however, recently the failure reoccurred. The contact stated that the "Brake Assist" warning light illuminated, and the brake pedal was difficult to depress. The vehicle was not taken to a dealer or an independent mechanic to be diagnosed or repaired. The manufacturer was not informed of the failure. The failure mileage was approximately 162,000.

Fuel System, Gasoline
Filed Jun 30, 202588,000 milesOH

The contact owns a 2020 GMC Terrain. The contact stated while driving at an undisclosed speed, the vehicle lost motive power with the check engine warning light illuminated. The vehicle was towed to an independent mechanic, where it was diagnosed that the fuel pump control module had failed and needed to be replaced. The vehicle was not repaired. The dealer was contacted. The vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure and referred the contact to the NHTSA Hotline for assistance. The approximate failure mileage was 88,000. The VIN was not available.

Engine
Filed Jun 26, 202537,000 milesMA

The contact owns a 2020 GMC Terrain. The contact stated that the vehicle was taken to a dealer for an oil change. The contact stated that approximately 5 weeks after returning the oil change, while driving at approximately 65 MPH, the vehicle and steering wheel started shaking abnormally and the vehicle lost motive power. The contact stated that the traction control, check engine, and stabili-trak control warning lights were illuminated. The vehicle was taken to a dealer where it was diagnosed that there was no oil in the engine and the spark plugs and ignition coils needed to be replaced. The vehicle was repaired; however, the failure reoccurred three weeks later. The manufacturer was not notified of the failure. The failure mileage was approximately 37,000.

Engine
Filed Jun 26, 2025PA

On 6/22/2025, brakes stopped working while trying to make a turn. Next multiple engines light came and car went into reduced speed mode. As I tried to find a safe place to stop, the vehicle went into limp mode and shut down in the middle of the road. The dealership said the issue was the vacuum pump which caused the timing chains to break. There have multiple recalls for this exact issue but my car is not on the list. My manufacture warranty ended on 5/21/2025. When I spoke to a GM representative I was told there was nothing they can do because there is not a recall for my vehicle. They explained even though I had the same problem the recall is for other vehicles. GM also issued a warranty extention on the vacuum pump to 10 years 150,000 miles. However my vehicle is not on the list for the extention. this issue is a safety hazard regardless of the vehicle type. I was lucky that no one was behind me or they would have hit me.

Engine
Filed Jun 18, 2025MI

While my wife was driving on [XXX] speed (60 –70 mph), the engine suddenly seized without warning. This created a dangerous situation, especially at that speed. Upon inspection, it was confirmed that a camshaft end cap detached, causing catastrophic internal engine damage. I believe this may be due to a manufacturing defect or insufficient part durability, and poses a serious safety risk to myself and other drivers. Please investigate this issue for broader safety concerns and potential recalls, especially if other owners report similar failures. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Service Brakes
Filed Jun 12, 2025MO

I got off a highway exit ramp and with no warning my brakes were hard to press. There was no warning lights on my dash. The brakes take a lot of force to push for a stop. The warning light finally came on a day later with codes p0556 and u040171.

Electrical System
Filed Jun 3, 2025FL

[XXX] once again while diving down the road 45mph Terrain once again goes in to park ,I was lucky the lady behind me wasn't to close .Also I contacted onstar when I was able to get vehicle moving at the store ..I told her what happen she ran diagnostics while parked at store said there was no codes I let onstar know this has happened several times..I had no warning, no indication, no lights came on.And I also let her know that this same vehicle was still stalling I was at intersection and the auto/stop is always on it will not let you bypass or default took it to dealership who I bought CPO back when it first would not let me turn it off cause its stalls at stop signs ,red lights etc crazy thing is if you turn the ac on it cranks up , if you hit the door unlock it starts... Thats not normal GMC knows that the dealership whom sold me CPO that wasn't the misleading is beyond crazy..GSM cussed me out It comes with life time warranty but when I had it towed right after I bought it 2 months ..I was talking about what the mechanics had said that this vehicle was in prior flood and accident GMC onstar has a different Vin then the one that on the vehicle..The doors are not original I can see the inside of steering wheel and on dash where they said air bags were deployed and they did a [XXX] job hiding it ... I paid over 32k for this 2020 Terrain that was advertised as CPO with 1 owner in Florida they showed me a fraudulent carfax, I pulled up my own and it came from New York ..This v

Service Brakes
Filed May 29, 2025TN

On Monday 5/26/2025 I was on the way home from work, coming down my street to turn in my drive (at approximately 2130) I pushed on the brake getting ready to make my turn, my car would not stop. It traveled maybe 100 -200 feet before coming to a stop. The brake pedal would not push in. (As I live on a cul-de-sac, if this happened during the daylight, there would have been children playing in the street and I could have killed someone's child). I managed very slowly to reverse the car and finally get it in the driveway. I thought it was going to hit my house!! Upon reading a lot of issues and complaints on my vehicle make/model I pretty much figured it was the brake vacuum pump. I called GM, however my car has 74,000 miles, is out of warranty and no recalls for my VIN so I'm told I have to have it fixed. My neighbor is a certified mechanic and has a shop. He looked at it and confirmed it is the vac pump. Not only that but the end that goes into the motor has sheared off and not there is metal pieces and fragments in my motor. I had to have it towed to his shop. (this morning) As of right now I am waiting to see if the motor can be flushed or if I am going to end up having to replace motor. I have missed several days of work due to transportation and now have to rent a car, and pay who knows how much for repairs which could easily cost thousands. I live week to week and still make payments on this car!! This is a faulty part and should have been a recall as I have read on many

Electrical System
Filed May 28, 2025NY

5.25.2025 - Car shut down while at a busy intersection. Called Amherst Police due to location and how dangerous the intersection was. Family member needed to jump start the vehicle. Vehicle started before police arrived. Drove home. Called police to let them know we were no longer at the busy intersection. 5.26.2025 Took out battery to check charge at Auto store - tested Good - 82%. Re-installed battery went to get gas thinking that may be the issue, low on gas, not the case the car wouldn't start at the gas station. Family member needed to jump start the vehicle again. Drove home, called dealer, taking to dealer next week 6.4.2025 due to availability of service. There were no warning lights prior to stalling out both times. This is very dangerous. We are afraid to drive this GMC 2020 Terrain.

Back Over Prevention › Warnings
Filed May 2, 2025VT

My backup camera in my 2020 vehicle has failed twice. Once was covered under manufacturer's warranty, and it then failed again 14 months later, which is not covered under warranty. As explained by the dealer, a parts warranty is 12 months if covered under manufacturer warranty and 24 months if paid for by the owner. Different warranties for the same part? Additionally, there is a service bulletin out about this issue as MANY other owners are reporting the same issue. The camera parts are being damaged by "water intrusion". There is NO rust or damage that would be contributing to this, thus it appears to be a manufacturing defect. There is no way I should have had to replace this part twice with only 40,000 miles on the vehicle. (first time at 24,000 miles, second time at 38,500 miles). I feel that the manufacturer should be fixing these as they know it is a widespread problem.

Engine and Engine Cooling
Filed May 2, 2025WV

The contact owns a 2020 GMC Terrain. The contact stated while driving 45 MPH, the vehicle inadvertently lost motive power. The contact was able to pull over to the shoulder of the roadway, where the vehicle failed to restart. The check engine warning light was illuminated. The vehicle was towed to the dealer, who determined that the engine had seized. The contact was informed that the engine needed to be replaced. The vehicle was repaired, but the failure reoccurred. The vehicle was again towed to the dealer, who again diagnosed a failure with the engine. The vehicle was not repaired. After investigating the failure, the contact related the failure to NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling); but the VIN was not included. The manufacturer was notified of the failure, a case was opened, and the contact was referred to the NHTSA Hotline for assistance. The failure mileage was unknown.

Fuel/Propulsion System
Filed Apr 10, 2025LA

Having problems with fuel system

Fuel/Propulsion System
Filed Mar 12, 2025FL

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.

Engine
Filed Mar 10, 2025101,700 milesNY

The contact owns a 2020 GMC Terrain. The contact stated that the vehicle failed to stop while driving 55 MPH while depressing the brake pedal. The contact pressed the button that immediately shifted the transmission to park, and the vehicle came to a stop. The contact drove the vehicle to a safe parking space. After safely parking the vehicle off-road, the check engine and brake assist warning lights illuminated. The vehicle was towed to the dealer who diagnosed that the brake booster pump and camshaft had fractured and detached from the vehicle. The contact was informed that the brake booster, vacuum pump, and camshaft needed to be replaced. The vehicle was not repaired because the dealer was awaiting the parts to repair the vehicle. The manufacturer was not informed of the failure. The failure mileage was 101,700.

Service Brakes
Filed Mar 8, 2025WA

My 2020 GMC Terrain (under 100K miles) was running great until one day, after starting the vehicle, I shifted into reverse and felt soft brakes before the engine suddenly shut off. A licensed mechanic diagnosed the issue, pointing to Technical Service Bulletin #PIP5835, which identifies a defective brake vacuum pump. This failure caused damage to the exhaust camshaft and timing belt, ultimately leading to the recommendation of a full engine replacement. GMC’s response? They advised me to pay for their diagnostics and repairs, then file for a "Goodwill Repair," which they admitted was unlikely to be approved. Meanwhile, GM has since replaced this defective vacuum pump with an electric version, acknowledging the flaw—yet leaving owners like me to cover the cost. I believe GM should stand behind their product and take responsibility for this engineering failure, instead of forcing customers to absorb the expense.

Service Brakes, Hydraulic
Filed Mar 4, 2025108,000 milesMO

The contact owns a 2020 GMC Terrain. The contact stated that while driving at slow speeds in a parking area and attempting to stop, the brake pedal failed to depress all the way to the floorboard and was firm, requiring an increased effort; however, the vehicle failed to stop as intended. The contact was able to bring the vehicle to a complete stop by turning the vehicle off. No warning lights were illuminated. The vehicle was taken to the dealer, who diagnosed a failure with the brake vacuum pump, observing that the pump had sent metal fragments into the engine, resulting in damages to the engine. The vehicle was not repaired. After investigating the failure, the contact related the failure to Special Coverage Adjustment: N182202780. The manufacturer was notified of the failure, and a case was opened. The failure mileage was 108,000. The VIN was not available.

Visibility › Rearview Mirrors/Devices › Interior
Filed Feb 25, 202553,500 milesOH

The contact owns a 2020 GMC Terrain. The contact stated that after starting the vehicle and shifting into reverse(R); the rear-view camera screen was not functioning as needed. There was no warning light illuminated. The message "Service Rear Camera System" was displayed. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 53,500.

Power Train
Filed Feb 21, 2025IL

Gear selector

Reading these

NHTSA publishes every complaint as the owner wrote it and investigates only a fraction. Spelling, capitalisation and judgement are the filer’s own. What carries weight is repetition: the same component failing the same way across many filings, and whether the manufacturer eventually opened a recall for it.

Full record for the 2020 GMC Terrain → · Every Terrain year → · How the figures are calculated →