2020 GMC Terrain

These are unverified consumer reports filed with NHTSA, shown as submitted.

• 12/31/2022· UNKNOWN OR OTHER,SERVICE BRAKES

  My service brake assist light came on and then within seconds my vehicle then said engine power has been lowered and my vehicle pretty much shut down no steering no brakes couldn't do anything. Took it into the repair shop and my vacuum pump has shattered and now damaged my camshaft. I am aware there's been many other vehicles recalled with GM's vacuum pumps and I'm not sure why my year and model has not been included when it's doing the same thing and not to mention I have seen countless other cases of people saying same things happen to them with their GMC terrains.

• 12/31/2021· ELECTRICAL SYSTEM,ENGINE

  This 2020 GMC Terrain has a "feature" called autostop. This is not a switch to turn this off. It would not be so bad if the engine would run for 5 minutes at a stoplight before stopping the engine but it immediately shuts down the engine after a stop. This is getting annoying and dangerous due to the delay in getting the car moving. I have only had the car for a month. I understand that later gmc cars have a disable switch. This car should be recalled and either disable the auto stop permanently or be able to disable the "feature" on demand. Problem: potential crash hazard due to car not starting and damage to battery and starter.

• 12/29/2025· ELECTRICAL SYSTEM

  Towards the tail end of a nearly 2.5 hour drive, the Automatic Theft Deterrent System was activated on the interstate. I lost every display on the dash panel including my speedometer, battery, coolant, gas, turn signals, and windshield wipers. I went into the nearest parking lot and was unable to restart the vehicle. It was towed to the dealership closest to our home and was repaired for $2200. The technicians at the dealership were not sure of what caused it and had never seen an issue like this so it was “elevated” to the GM engineers at their headquarters. They replaced the electrical control module and both key FOBs. We have not experienced any similar issues.

• 12/29/2024· SERVICE BRAKES

  No warning, the brake pedal went stiff as a board. No brakes could not stop doing 35 on a residential road. Had to coast to a stop in neutral.

• 12/26/2024· SERVICE BRAKES,FORWARD COLLISION AVOIDANCECrash

  The brake system failed. No warning. When the brakes failed, driver ran the car into a tree to stop instead of hitting pedestrians or other vehicles

• 12/23/2024· UNKNOWN OR OTHER

  Every time it rains, the floorboard of my car is soaking wet. I took it to the dealership, and they stated the leak is coming from inside the firewall. I have only had this vehicle for 2 years and just recently moved to a house without a garage. Now that I am just now noticing it, I am wondering if it was like this when I bought it, but I am only noticing it now that I do not have a garage. They want to charge me over $1,000 just to take apart the dashboard to find the leak and that is just insane. There is no telling how much mold, rust, etc. could be in my car from this leak.

• 12/22/2023· POWER TRAIN

  The contact owns a 2020 GMC Terrain. The contact stated that while at a stop, there was an abnormal burning odor coming from the vehicle, with the service brake assist message displayed. The brake pedal became firm, and the contact used excessive force to stop the vehicle. The contact pulled into a gas station and restarted the vehicle while the check engine light was illuminated. Despite the failure, the contact was able to drive the vehicle to the residence. The contact inspected underneath the hood and discovered an oil leak as well as black soot that had covered the entire engine. The dealer was notified of the failure and provided the contact with a diagnostic fee for an inspection. Upon investigation, the contact discovered NHTSA Campaign Number: 20V668000 (Power Train) which was linked to the failure. The manufacturer was not notified of the failure. The vehicle was not repaired. The failure mileage was approximately 57,000.

• 12/21/2020· AIR BAGS

  MY AIR BAG WARNING LIGHT/DASHBOARD MESSAGE HAS COME ON 7 TIMES IN THE LAST 3 WEEKS, ALONG WITH 4 OTHER TIMES IN THE 2 MONTHS PRIOR, BUT THE GMC DEALERSHIP WILL NOT INVESTIGATE SINCE IT DOES NOT STAY ON. AT THE MOST RECENT EVENT THIS WEEKEND, I PRESSED ONSTAR, AND THEY RAN DIAGNOSTICS AND EMAILED ME THE "B0085" DETECTED ERROR CODE, BUT MY DEALERSHIP WILL STILL NOT INVESTIGATE, SINCE THE LIGHT WENT OUT. THE LIGHT HAS COME ON AT STARTUP AND WHILE DRIVING. WARNINGS HAVE COME ON 8/27/20, 10/5, 10/8, 10/12, 111/28, 12/2, 12/8(X2), 12/11, 12/14, AND 12/19/20.

• 12/20/2024· UNKNOWN OR OTHER

  My car sunroof drainage system is not draining properly and GMC won’t see me for a month. There’s an excessive amount of water that’s pooling in the rear passenger floorboards buckets of water.

• 12/19/2025· POWER TRAIN

  The contact owns a 2020 GMC Terrain. The contact stated that while driving 35 MPH and depressing the accelerator pedal while driving uphill or making a left or right turn, the tires were skipping, and there was a clicking and whining sound coming from the front of the vehicle. There was no warning light illuminated. The contact stated that a friend test-drove the vehicle and informed that the vehicle had experienced transmission failure. Neither the independent mechanic nor the dealer was contacted. The vehicle was not taken to the dealer or an independent mechanic to be diagnosed or repaired. The contact related the failure to NHTSA Campaign Number: 20V668000 (POWER TRAIN); however, the VIN was not included in the recall. The manufacturer was notified of the failure and informed the contact that the VIN was not included in the recall. The failure mileage was 104,000.

• 12/19/2024· VISIBILITY,STRUCTURE

  The contact owns a 2020 GMC Terrain. The contact stated that rain water had leaked from the sunroof drainage into the vehicle causing the floor carpets to become saturated with water and mold had developed inside the vehicle. The contact also discovered a pool of water inside the spare tire well. The vehicle was taken to the local dealer who replaced the sunroof motor and sunroof liner, unclogged the sunroof drainage assembly and replaced the carpets. The contact indicated that later the failure had reoccurred although the sunroof drainage assembly was consistently unclogged each time the vehicle was in for service. The contact had also experienced respiratory illness due to the mold present inside the vehicle. The manufacturer was notified of the failure but no assistance was offered. The failure mileage was 12,300.

• 12/18/2025· ENGINE

  This message concerns a persistent engine light that activates and generates engine code P0299, indicating an engine underboost issue. There have been several occasions where I am driving over 55mph on the highway and my 2020 Terrain SLT fails to pick up speed over 60mph in traffic. I took it to my GMC dealer earlier this year for them to diagnose, and they discovered that the charge air cooler tube had collected moisture. Once that was fixed, the vehicle was fine for about a month when the same thing happened. I took it to another GMC dealer and found that the turbocharger wastegate actuator had to be replaced. Once replaced, I had no problems until it began to get cold where I live. Now the vehicle is doing the same thing. Now what happens is the engine light will come on and give the engine underboost message but goes away after a week of driving. I have taken it to 2 dealers for diagnosis, only for the engine light to disappear before they can figure out what the problem is now. This continues to be an issue, as I frequently drive on the highway over 55mph for work, errands, etc., and presents a potential hazard if I have to pick up speed and can't on a major highway.

• 12/17/2025· POWER TRAIN,ENGINE

  The intercooler has been a document problem on GMC Terrains for awhile now. I had my intercooler replaced and now less than 10 months it is having the same problem. The vehicle will go into reduced power mode which would be a safety hazard because it will also stall sometimes when it is having performance issues. That could lead to someone colliding into me if it suddenly stops when someone is behind me. I believe this part should be recalled and fixed for free.

• 12/17/2024· ELECTRICAL SYSTEM

  Vehicle has not recently been inspected, backup camera has recently gone out leaving only a blue screen with "service rear vision system" to my knowledge nothing has happened to the unit that would cause this. Regular day to day driving, there was nothing that would have given me any notice that this would be happening.

• 12/16/2025· SERVICE BRAKES

  Since August 2024, my brake booster has gone a total of five times each time with the notification on the dash service brake assist. And it just went again as of two days ago. I’ve brought it to Firestone where they have replaced it each time with a warranty on the part. I called them yesterday to tell them that it went again and they refused to fix it telling me that they got the part from the dealership and that I would have to take it there so the dealership would have to figure out what’s wrong with it as to why the car is “chewing up” the part. I have young kids and this part has gone five times.

• 12/12/2024· FUEL SYSTEM, GASOLINE

  The contact owns a 2020 GMC Terrain. The contact stated that while his wife was driving 5 MPH and exiting a parking lot, the vehicle inadvertently stalled. There was no warning light illuminated. The vehicle failed to restart. The messages "Low Battery" and "Start the Vehicle" were displayed. The contact stated that the brakes had seized. The vehicle was towed to the dealer, where it was diagnosed and determined that the fuel pump and the fuel pump driver control module needed to be replaced. The vehicle was being repaired. The manufacturer was notified of the failure and informed the contact that the vehicle was not covered under warranty. The failure mileage was 45,175.

• 12/11/2025· FUEL/PROPULSION SYSTEM

  Re: 2020 GMC Terrain. Our fuel pump control module (FPCM) unexpectedly failed after driving a short distance. Vehicle stalled without warning on the street and was unable to be started again. This could have resulted in a crash and/or injury to other people in the area. An independent service center suspected an issue with the module but was unable to make an official diagnosis. The vehicle was towed to the local GMC dealer who confirmed the FPCM failure and needed to be replaced at a cost of $850. There were no warning indicators prior to the incident and the vehicle's display only showed "battery saver mode" after stalling on the street.

• 12/03/2025· SERVICE BRAKES

  While driving my brakes failed. I was unable to stop my car, my brake pedal became very stiff and I could not stop my car. There were no warning signs or lights on indicating there were any issues with my car prior to this happening. I had to have my car towed to the dealer. The current estimate is for a vacuum pump failure resulting in camshaft damage. Both need to be replaced. I see other GMC cars were recalled for what appears to be a similar issue. I am lucky no one was injured as this could have very easily resulted in a fatal event. I have never heard of such a thing happening before and am beyond belief that this has occurred. This is the third repair I've had done this year. I have also replaced a booter pipe and valve gasket due to leaking oil. The amount of repairs required in such a short a time seems excessive.

• 12/02/2025· SERVICE BRAKES, HYDRAULIC

  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.

• 11/30/2025· SERVICE BRAKES

  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.

• 11/30/2024· ELECTRICAL SYSTEM,SERVICE BRAKES,FORWARD COLLISION AVOIDANCE

  My Terrain has a light that has been coming on for a couple months. Service Brake Assist. I took it to the dealer after my brakes locked up and about $800 after getting it fixed the light continues to come on. The forward collision light comes on every time I start the car. More the check engine light came on and says engine electrical system. What the heck is going on? I love this car and take very good care of it but I feel like the $800 that I just spent was a waste. I fear that I will get in a wreck like when the brakes totally locked up and I couldn't press on them.

• 11/26/2025· BACK OVER PREVENTION

  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.

• 11/22/2025· UNKNOWN OR OTHER

  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.

• 11/21/2025· ELECTRICAL SYSTEM,UNKNOWN OR OTHER,ENGINE

  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 were on so then I started the car and it’s almost like my car reset. I can’t see my tires PSI, the clock went to midnight (it was about 0330) it was all just very weird!!

• 11/18/2020· FUEL/PROPULSION SYSTEM

  VEHICLE WAS ON 1/8 OF A TANK,I TRIED TO FILL, IT WOULD ONLY TAKE ON 5 GALLONS OF FUEL, GAS GAUGE READ FULL. REPORTED TO DEALER, THERE IS A 'BULLETIN' ON THE VEHICLE, FUEL TANK WAS REPLACED. AFTER SUCCESSFULLY FILLING TANK 3 TIMES, IT HAPPENED AGAIN, RETURNED VEHICLE TO DEALER, THEY COULD NOT REPLICATE, BROUGHT VEHICLE HOME, DEALER WAS ABLE TO FILL TANK WITH APPROX 13 GALLONS, I RAN IT TO 1/8 OF A TANK TRIED TO FILL AND IT CONTINUES TO ONLY FILL WITH 2-6 GALLONS, AND RECORD ON THE GAUGE A FULL TANK. VERY DIFFICULT TO TELL HOW MUCH FUEL IS ON BOARD. MEETING WITH GMC DISTRICT REP 11/19/2020. THEY SUGGESTED I DRIVE IT TILL IT RUNS OUT OF FUEL AS TO SEE WHAT THE GAUGE READS! REALLY? HELP PLEASE! I HAVE PHOTOS OF THE PUMPS AND DASHBOARD TO RECORD AND TIME STAMP. I NEED HELP PLEASE! THE FIRST OCCURRENCE WAS SEPTEMBER 28, 2020 , SECOND OCCURRENCE OCTOBER 16,2020 AND THIRD WAS NOVEMBER 15,2020. THE VEHICLE WAS RETURNED TO THE DEALER ON OCTOBER 16, THEY TRIED TO REPLICATE WITH NO LUCK, VEHICLE WAS RETURNED TO ME NOVEMBER 11,2020! 26 DAYS LATER. HELP!

• 11/17/2020· POWER TRAIN,WHEELS

  ONLY A MONTH AFTER PURCHASING MY VEHICLE I STARTED TO FEEL A WOBBLE IN THE FRONT END WHEN ACCELERATING UP HILLS AND TURNING WHILE ON THE GAS. I TOOK IT TO THE DEALER AND THEY CHANGED OUT THE FRONT TIRES STATING THAT THE PROBLEM HAD BEEN FIXED. ONCE AGAIN WHILE DRIVING THE PROBLEM PERSISTED. I TOOK THE CAR BACK TO THE DEALER AGAIN AND THEY SAID THAT THEY COULD NOT FIND ANYTHING WRONG AND SUGGESTED THAT I MAKE AN APPOINTMENT TO GO FOR A DRIVE WITH THE MECHANIC TO SHOW THEM WHAT IS HAPPENING. I MADE AN APPOINTMENT. A DAY BEFORE THE APPOINTMENT I RECEIVED A CALL FROM THE DEALERSHIP STATING THAT AN EMPLOYEE RECENTLY PURCHASED THE SAME CAR AND THEY ARE HAVING SIMILAR DIFFICULTIES. THEY FOUND ONLINE THAT GMC WAS REQUESTING INFORMATION FROM DEALERS ABOUT THE PROBLEM AND WAS TOLD THAT I NOW NEED TO WAIT FOR GMC TO COME UP WITH A SOLUTION. MY CAR SHAKES EVERY TIME THAT I DRIVE IT, IT'S AWFUL, AND IT ONLY HAS AROUND 6,000 MILES ON IT. I'M NOT SURE WHAT TO DO BECAUSE THE DEALERSHIP TOLD ME THAT I HAVE TO WAIT FOR A SOLUTION. THEY ARE NOT EVEN TRYING TO FIX ANYTHING AT THIS TIME. PLEASE HELP.

• 11/13/2025· SERVICE BRAKES

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

• 11/12/2020· ELECTRICAL SYSTEM

  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.

• 11/09/2021· ENGINE

  loss of oil due to engine defect and need new engine. engine and car at dealership. engine has not been torn apart to find cause. occupants could have died because of engine stoppage... GM wants owner to pay over 15,000 for new engine and instillation. car under new car warranty has 24211 miles. no early warning lights of low oil.... Owner took car in immediately when warning lights appeared 9-27-21 and GMC dealership improperly serviced . on 10-14-21 same warning lights reappeared and taken immediately to same close dealership. Now told new engine needed.

• 11/09/2020· VEHICLE SPEED CONTROL,UNKNOWN OR OTHER

  PURCHASED NEW 2020 GMC TERRAIN W/7MILES. LEFT DEALERSHIP ON MY WAY HOME, AND WITHIN 20 MILES, RECEIVED A MESSAGE ON DASH-> SERVICE - ESC - DISMISS. CHECK ENGINE LIGHT FLASHED SEVERAL TIMES, AND THE SUV SLOWED DOWN AT LEAST 10 MILES FROM 65MILES PER HOUR. AFTER ENGINE LIGHT STOPPED BLINKING, I CONTINUES HOME AROUND 30 MILES MORE WITH NO MORE PROBLEMS. CALLED MY SALES PERSON THE NEXT DAY, AND HE DID NOT KNOW WHAT ESC WAS. (ELECTRONIC STABILITY CONTROL) HE CALLED ME BACK AND INDICTED THE VEHICLE MAY NEED A SOFTWARE UPDATE. I TOLD MY WIFE, WHY WOULD A DEALERSHIP NOT CHECK ON VEHICLE SOFTWARE UPDATES BEFORE RELEASING VEHICLES TO THE NEW OWNERS, PRIOR TO LEAVING THE DEALERSHIP. THIS IS CALLED, "BEING PROACTIVE." WE WERE ON THE HIGHWAY LEAVING THE DEALERSHIP AFTER PURCHASING THIS NEW SUV.

• 11/08/2025· SERVICE BRAKES

  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.

• 11/08/2025· UNKNOWN OR OTHER

  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.

• 11/05/2021· ELECTRICAL SYSTEM,UNKNOWN OR OTHER

  While driving instrumental panel and infotainment panel completely blacked out for no reason at all. This is the second time in two days this has happened.

• 11/04/2024· BACK OVER PREVENTION

  The contact owns a 2020 GMC Terrain. The contact stated while in reverse(R), the back over prevention camera displayed a blue image on the screen. The dealer was notified of the failure but offered no assistance. The manufacturer was also notified of the failure and referred the contact to the NHTSA Hotline to report the failure. The vehicle was not repaired. The failure mileage was approximately 58,000.

• 11/04/2021· ELECTRICAL SYSTEM,UNKNOWN OR OTHER

  Instrument panel and infotainment system panel completely blacked out while driving vehicle

• 11/04/2021· SERVICE BRAKES

  The contact owns a 2020 GMC Terrain. The contact stated while driving at various speeds, the vehicle lost brake functionality while depressing the brake pedal. The contact stated no warning light was illuminated. The vehicle was towed to a local dealer where it was diagnosed with needing the vacuum pump replaced. The vehicle was repaired however, the failure persisted. The manufacturer was not informed of the failure. The failure mileage was approximately 40,000. The VIN was unavailable.

• 11/03/2025· SERVICE BRAKES

  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 !!!!!!!!

• 11/02/2019· VEHICLE SPEED CONTROL

  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

• 10/30/2025· SERVICE BRAKESCrash

  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.

• 10/24/2025· ELECTRICAL SYSTEM,SERVICE BRAKES

  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

• 10/23/2025· UNKNOWN OR OTHER

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

• 10/23/2025· ENGINE,FUEL/PROPULSION SYSTEM

  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.

• 10/21/2024· SERVICE BRAKES

  Slowed down from coming off of the highway to turn into the gas station and couldn't slow down. The brakes FAILED. Was trying to pump them and was able to come to a forecful stop, nearly colliding with the car in front of me and then again at the gas pump. Car had a failed vacuum pump at 65,000 miles. If this happened during normal rush our, my kids and I would have been sandwiched between two cars. Fatal flaw that clearly GMC already knows about. The Terrain should be included in the recall.

• 10/14/2023· VEHICLE SPEED CONTROL,UNKNOWN OR OTHER,ENGINE

  On 4/10/2023, I took my vehicle to a local GMC dealership because it was stalling and didn't have any power. Upon accelerating the vehicle it would stall and take off at a high speed. The dealership has had my vehicle periodically from April 2023 and it presently sets at the dealership because they ain't getting a code, But after the dealership drove the truck for over 200 miles, they were finally able to duplicate the stalling yet are not able to diagnose the problem!! This vehicle is very dangerous to be on the road and I have almost gotten hit twice and I'm not driving the vehicle anymore at this time. I have previously reached out to you all and I would be most thankful if you could get in touch with me. Thank you

• 10/08/2025· POWER TRAIN

  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.

• 10/08/2021· UNKNOWN OR OTHER

  I had an incident this morning when I put my car in park position it remained in reverse. I took it out of park and put in drive then I put forward but the vehicle still remained in reverse. I turned the vehicle off and it still remained in reverse. Ali controls on infotainment panel was inoperable. ( example: I couldn’t turned off or turned radio).

• 10/05/2025· ELECTRICAL SYSTEM

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

• 10/05/2023· ELECTRICAL SYSTEM

  Driving down the road at 40mph when the car shifts to park, the brake and steering wheel lock up and the car won’t accelerate. I had to pull over because I almost crashed due to the abrupt shift. Once pulled over I tried to restart the car but once off and back on it wouldn’t allow me to shift or drive it. The steering wheel and brake remained locked. It has happened several times over the past week.

• 09/28/2022· POWER TRAIN,ENGINE,FUEL/PROPULSION SYSTEM

  Turbo failed. Car ran fine with no warning lights. Stopped at red light entering interstate and then could not accelerate which left us stuck in traffic. When it did move it would not shift and took over a mile to get above 20mph in a 65mph zone.

• 09/26/2025· SERVICE BRAKES

  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.