RoadVitals

2020 GMC Terrain Problems

Owner-reported complaints filed with NHTSA, grouped by component

Data refreshed

Owner complaintsComplaints are reports submitted to NHTSA by owners and drivers. NHTSA does not verify most reports before publishing them, and a complaint does not establish that a defect exists. Volume is influenced by how many of a vehicle were sold, how long it has been on the road, and how much attention an issue has received.
196
Latest Sep 23, 2026
Components namedHow many of our component categories appear on at least one report for this model year. One report can name several.
16
Crash or fire reportedComplaints whose submitter recorded that a crash or a fire occurred. These are the reporter's own answers on the NHTSA form, not verified findings.
9

What this page shows

Everything below is an owner-reported complaint submitted to NHTSA about the 2020 GMC Terrain, grouped by the component NHTSA recorded on the report. These are not confirmed defects, and they are not recalls. NHTSA does not verify most reports before publishing them, and a category with more reports in it is not evidence that a part is defective.

Complaints are reports submitted by owners and drivers to NHTSA. They are not verified and do not establish that a defect exists.

Reports by component

Ranked by how many owner reports name each component category

Percentages are of component mentions. A single complaint can name more than one component, so these do not sum to the total complaint count.

Each component in detail

What the reports in each category say, in the owners' own words

Brakes

Reports naming service brakes, the antilock braking system, brake hoses, master cylinders or the parking brake.

71
reports

From owner reports, verbatim

While driving my 2020 GMC Terrain, I experienced a sudden loss of normal braking assistance. I had been traveling on the highway and exited onto a main road. As I approached a red traffic light at approximately 50 mph and attempted to brake, the vehicle would not stop normally. I was unable to stop for the red light and went through the intersection before I was able to safely get the vehicle off the roadway. Fortunately, there was no vehicle directly in front of me and I was able to make it through the intersection before any other cars, so no collision occurred. The vehicle was subsequently inspected and diagnosed by a GMC dealership. A diagnostic scan performed after the incident showed code P0556 for the brake booster pressure sensor circuit range/performance. The GMC dealership later diagnosed problems involving the vacuum pump, exhaust camshaft, and timing components and recommended replacement of the vacuum pump, exhaust camshaft, timing components, and related parts.” The sudden loss of braking assistance created a serious safety hazard and could have resulted in a collision, serious injury, or death. The vehicle is currently available for inspection.

NHTSA ID 11766529 · filed Sep 23, 2026

The contact owns a 2020 GMC Terrain. The contact stated that while driving at an undisclosed speed, the vehicle failed to stop as intended. The brake pedal was depressed to the floor, and the vehicle slowed down and eventually stopped. The vehicle was taken to an independent mechanic, where it was diagnosed with a failed vacuum pump. The mechanic informed the contact that the vacuum pump needed to be replaced. The vehicle was repaired. The contact stated that the failure was a known issue with the vehicle. The manufacturer was not notified of the failure. The failure mileage was approximately 92,000.

NHTSA ID 11760902 · filed Aug 31, 2026
All 71 reports naming brakes →

Engine

Reports naming the engine itself — including stalling, misfires, oil consumption, cooling and internal engine components.

61
reports

From owner reports, verbatim

While driving my 2020 GMC Terrain, I experienced a sudden loss of normal braking assistance. I had been traveling on the highway and exited onto a main road. As I approached a red traffic light at approximately 50 mph and attempted to brake, the vehicle would not stop normally. I was unable to stop for the red light and went through the intersection before I was able to safely get the vehicle off the roadway. Fortunately, there was no vehicle directly in front of me and I was able to make it through the intersection before any other cars, so no collision occurred. The vehicle was subsequently inspected and diagnosed by a GMC dealership. A diagnostic scan performed after the incident showed code P0556 for the brake booster pressure sensor circuit range/performance. The GMC dealership later diagnosed problems involving the vacuum pump, exhaust camshaft, and timing components and recommended replacement of the vacuum pump, exhaust camshaft, timing components, and related parts.” The sudden loss of braking assistance created a serious safety hazard and could have resulted in a collision, serious injury, or death. The vehicle is currently available for inspection.

NHTSA ID 11766529 · filed Sep 23, 2026

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 ID 11762749 · filed Sep 8, 2026
All 61 reports naming engine →

Fuel system

Reports naming fuel storage or delivery — tanks, pumps, lines, injectors and fuel leaks.

31
reports

From owner reports, verbatim

Fuel pump control module and or the in tank fuel pump failed and or isn’t making proper connection for car to run correctly. Safety was put at risk as car came to abrupt halt while driving. Driver was outside of vehicle at busy intersection for vehicle diagnostics and battery jump. Battery was removed and new battery installed yet problem persists. Not confirmed by dealer but code is as follows (p129F). Maintenance performed by owner;Code reader used for diagnostics, new battery installed. Problem persists. Car started, drove and stumbled to then die. Check engine now displays.

NHTSA ID 11761691 · filed Sep 2, 2026

COMPONENT OR SYSTEM FAILED - GMC Dealership replacing fuel pump. SAFETY OR SAFETY OF OTHERS AT RISK - stalled in remote area with no internet/cell service. In order to get to safety we travelled 13 miles of narrow 2 lane roads with no shoulder or escape areas. Road included 3 miles of a steep downhill grade. HAS THE PROBLEM BEEN REPRODUCED OR CONFIRMED BY A DEALER - Yes, Walser GMC [XXX] WERE THERE ANY WARNING LAMPS, MESSAGES OR OTHER SYMPTOMS OF THE PROBLEM PRIOR TO THE FAILURE - No, drove 400 miles w/2 stops, rest stop and lunch/gas. Got to our destination, shut off the car. Needed to move the vehicle to designated parking spot and at first the vehicle would not start, got it started but lurched forward, engine chugged, no acceleration and then stalled. Waited 10 minutes vehicle started with same symptoms but became drivable so we headed to safety 13 mile to nearest town, [XXX]. The area has recently been battling forest fires and in our area, although "safe", there was still HIGH fire danger. We did not feel safe w/o a vehicle for (possible) rapid escape. The city has limited services, no rental car company, no Uber/Lift, closest car dealership 90 miles away. Vacation cancelled. Hired North [XXX] Towing to transport vehicle and people 300 miles to Walser [XXX], [XXX]. Family member drove us to our home in [XXX]. To date vehicle mileage - 30,000 miles! INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID 11759075 · filed Aug 24, 2026
All 31 reports naming fuel system →

Powertrain (other)

Powertrain reports that are not specifically the engine or transmission — driveshafts, axles, transfer cases and differentials.

27
reports

From owner reports, verbatim

While driving my 2020 GMC Terrain, I experienced a sudden loss of normal braking assistance. I had been traveling on the highway and exited onto a main road. As I approached a red traffic light at approximately 50 mph and attempted to brake, the vehicle would not stop normally. I was unable to stop for the red light and went through the intersection before I was able to safely get the vehicle off the roadway. Fortunately, there was no vehicle directly in front of me and I was able to make it through the intersection before any other cars, so no collision occurred. The vehicle was subsequently inspected and diagnosed by a GMC dealership. A diagnostic scan performed after the incident showed code P0556 for the brake booster pressure sensor circuit range/performance. The GMC dealership later diagnosed problems involving the vacuum pump, exhaust camshaft, and timing components and recommended replacement of the vacuum pump, exhaust camshaft, timing components, and related parts.” The sudden loss of braking assistance created a serious safety hazard and could have resulted in a collision, serious injury, or death. The vehicle is currently available for inspection.

NHTSA ID 11766529 · filed Sep 23, 2026

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 ID 11762749 · filed Sep 8, 2026
All 27 reports naming powertrain (other) →

Electrical

Reports naming the electrical system — wiring, battery, charging, control modules, infotainment and electrical accessories.

27
reports

From owner reports, verbatim

The back passenger seat exploded and caught fire, burning the back of the seat in front and burning the ceilings. Inside the whole vehicle is black from smoke damage. Incident assessed by fire marshal who has ruled as electrical issue. No warning lights or systems displayed anything.

NHTSA ID 11751287 · filed Jul 18, 2026

Transmission wouldnt shift. Sensor in car is causing issue, code is N 202321840

NHTSA ID 11741315 · filed Jun 1, 2026
All 27 reports naming electrical →

Driver assistance

Reports naming forward-collision avoidance, lane keeping, back-over prevention, cruise control and related electronic driver-assistance systems.

25
reports

From owner reports, verbatim

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. Vehicle owners should not be responsible to fix faulty parts from the manufacturer.

NHTSA ID 11745463 · filed Jun 21, 2026

Random problems accelerating. Like I can be pulling out of my parking spot in revese then switch it to drive an try to move and it won’t move at all or very slowly then out of nowhere it accelerates fast

NHTSA ID 11731643 · filed Apr 16, 2026
All 25 reports naming driver assistance →

Body & structure

Reports naming the vehicle structure, frame, body panels, doors, hood and trim.

5
reports

From owner reports, verbatim

The contact owns a 2020 GMC Terrain. The contact stated while the vehicle was parked, the contact noticed that the tire well was filled with water. The contact stated that the unknown box on the side was filled with water. In addition, the contact stated that the water dripped onto the ground underneath the rear tire. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The manufacturer was not made aware of the failure. The failure mileage was approximately 70,000.

NHTSA ID 11737045 · filed May 11, 2026

I noticed a sticker in driver door stating recall however no evidence. The vehicle will not pull hills, back up on a hill and will not accelerate over 25 miles per minute. Dangerous to drive on roads. Took vehicle to a GMC dealer for diagnostic test, received the report for what the report found. Took the report to auto shop to get repaired however the vehicle still continues with same issue. Took the vehicle to another auto shop. I was informed of some differences added issues. I had those issues fixed. The vehicle still running the exact way after all of the repairs. The top hood on the vehicle paint starts peeling after a year of owning it. I purchased the vehicle at Kia of Gardendale 2020. No one had any answer regarding the situation. Very disappointed with a GMC vehicle. I just want to know the mystery.

NHTSA ID 11713540 · filed Jan 27, 2026

Too few reports in this category for a page of its own — they appear in the full complaint list.

Visibility

Reports naming windshields, glass, wipers, defrosters and mirrors.

4
reports

From owner reports, verbatim

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.

NHTSA ID 11644884 · filed Feb 25, 2025

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.

NHTSA ID 11631628 · filed Dec 19, 2024

Too few reports in this category for a page of its own — they appear in the full complaint list.

Other / unspecified

Reports whose component NHTSA recorded as unknown, or that do not map to one of the categories above.

4
reports

From owner reports, verbatim

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.

NHTSA ID 11675295 · filed Jul 22, 2025

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.

NHTSA ID 11669512 · filed Jun 26, 2025

Too few reports in this category for a page of its own — they appear in the full complaint list.

Airbags

Reports naming the air-bag system — deployment behaviour, inflators, sensors and warning lights.

3
reports

From owner reports, verbatim

The airbag system on my 2020 GMC Terrain has an intermittent malfunction. The airbag warning light turns on and off and the diagnostic code B0014 has been identified by a dealership. When the warning light is on, the airbag system may not deploy properly in a crash, creating a safety risk. The vehicle has approximately 49,000 miles. The problem has occurred for about three years. The dealership repaired the issue when the vehicle was first purchased and the light went off temporarily, but it returned a few months later. A second dealership attempted a repair and again the light went off temporarily before returning. The issue continues to occur intermittently. The warning lamp for the airbag system appears on the dashboard. The vehicle has been inspected by dealerships but the problem has not been permanently fixed.

NHTSA ID 11723564 · filed Mar 11, 2026

Brakes hard to press. Almost cause an accident on interstate. Was able to contain vehicle. Took to autozone to assessed and it said Powertrain System. Brake Booster Senor Circuit.

NHTSA ID 11452898 · filed Feb 18, 2022

Too few reports in this category for a page of its own — they appear in the full complaint list.

Steering

Reports naming the steering system — racks, columns, power-steering assist and steering linkage.

3
reports

From owner reports, verbatim

I was driving 55 miles an hour on an Expressway. And suddenly my truck just shut off.The brake became very hard unable to break very scary situation for me and my children. Engine power was reduced and would not start, many errors came up. The vacuum pump failed, which also caused the cam shafts to fail.The vacuum pump exploded into pieces and sent metal into my engine.

NHTSA ID 11722686 · filed Mar 7, 2026

Service brake assists light flashes on dashboard . Steering wheel locks up and jerk’s loose suddenly when making a right turn, in these moments when the steering wheel jerks loose ;hands are off taken off the steering wheel otherwise injury can occur. Battery life 2 -yrs old is not performing optimally. Can not hold a sufficient charge and ESC light flashes. Vdnt valve leaks discovered.

NHTSA ID 11506056 · filed Feb 7, 2023

Too few reports in this category for a page of its own — they appear in the full complaint list.

Suspension

Reports naming suspension components — springs, struts, shocks, control arms and related hardware.

2
reports

From owner reports, verbatim

THIS VEHICLE IS UNSAFE DUE TO A VIOLENT SIDE TO SIDE WOBBLE IN THE FRONT END MUCH LIKE THE JEEP DEATH WOBBLE. THIS HAPPENS CONSTANTLY ANYWHERE FROM 30MPH - 70MPH USUALLY AFTER HITTING A SMALL BUMP OR WHEN TURNING HARD. THE TURNING ASPECT IS WHERE IT HAS BECOME VERY DANGEROUS ON SLIPPERY SURFACES AS THE CAR THEN SLIDES OUT. I LIVE IN THE MOUNTAINS WHERE THIS IS A NORMAL OCCURANCE. I AM ACTUALLY AFRAID TO DRIVE THIS VEHICLE ANY LONGER. THE DEALERS HAVE CONFIRMED THE ISSUE, BUT STATES THAT GM DOES NOT HAVE A FIX FOR THIS AS OF NOW. I HAVE HEARD THIS IS AFFECTING ONLY THE AWD TERRAINS AND EQUINOX PLATFORMS. GM HAS BEEN UNRESPONSIVE TRYING TO GET AN ANSWER OR GETTING THIS FIXED. THE CAR HAS BEEN INTO MULTIPLE DEALERSHIPS SEVERAL TIMES FOR THIS SAME ISSUE AND HAS BEEN HAPPENING SINCE THE CAR TURNED ABOUT 2400 MILES AND HAS BEEN HAPPENING MORE FREQUENTLY SINCE THEN FOR THE PAST 6000 MILES.

NHTSA ID 11396428 · filed Feb 16, 2021

THE COMPLAINT I HAVE IS THE INSIDE FRONT OF THE CAR IS TOO SMALL AND I CANT REACH THE GAS PEDAL EXCEPT WITH MY TOE. MY FOOT KEEPS SLIPPING OFF AS I AM DRIVING. I HAVE TO HAVE THE SEAT WAY UP OR I CANT REACH. I AM 5 FOOT TALL WOMAN. THIS IS A RIDICULOUS THING THAT I HAVE TO PUT UP. I DROVE IT FOR 10 MINUTES AND DIDN'T REALIZE IT. I ASKED FOR A PEDAL THAT IS LONGER AND CLOSER TO THE FLOOR AFTER I HAD BOUGHT IT AND SERVICE PEOPLE TOLD ME THEY DON'T HAVE ANYTHING TO DO TO FIX IT. THEY ASKED IF I HAD A BUTTON TO ADJUST IT AND I DON'T. ITS ON THE EXPENSIVE ONE. THIS SHOULD BE ON ALL VEHICLES FOR SAFETY. I WANTED TO GIVE IT BACK BUT THEY NEVER HELPED ME. I HAVE 1100 MILES ON IT .IT NEW STILL. THE OTHER THING THIS CREATES IS I AM UP SO CLOSE TO THE STEERING WHEEL THAT ITS ALMOST ON MY CHEST IN ORDER TO REACH PEDAL WITHOUT HAVING TO STRAIN AND LATER HAVING PAIN IN MY LEG FROM DOING THAT. I AM SO DISAPPOINTED WITH CHUCK NASH GMC IN SAN MARCOS , TEXAS. IS THERE ANYTHING TO BE DONE BY THE GMC COMPANY. I ALSO TOLD THE SALESMAN I WANTED A CANYON PICKUP LIKE I HAD BEFORE. I TRADED THAT ONE IN DUE TO THE FACT THAT THE 2017 CANYON WAS ALWAYS IN THE SHOP. ONLY HAD IT FOR 2 YRS AND 1 MONTH. THEY WERE NO HELP! THANK YOU, [XXX] PLEASE HELP ME INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6). *TR

NHTSA ID 11316405 · filed Mar 5, 2020

Too few reports in this category for a page of its own — they appear in the full complaint list.

Seat belts

Reports naming seat belts, buckles, retractors and pretensioners.

1
report

From owner reports, verbatim

Driver seat belt exhibits signs of fraying in area of belt hidden from view when not in use. When extended, hair-like fibers extend out, primarily from the car-forward side of the belt in the area coming out of the B-pillar and from behind the trim. It is available for inspection. Concerned that this may continue to degrade the integrity of the seat belt over time. There could be something sharp in the retractor, or flash on a piece of plastic trim hidden from view causing this. My understanding is that if there is a small nick on the edge of a safety belt it can tear across, and concerned that this condition could lead to a similar outcome over time and if the vehicle were involved in an accident. Upon taking to local dealership, was advised that this is a normal condition and not a concern. Advisor said technician told him that it is not fraying, it is a normal condition that can be exhibited by the belt fibers, especially towards the edges. They said the central portion of the belt is not exhibiting a similar condition and therefore not a concern. The fibers seem to have grown in quantity since vehicle purchase. I first recall seeing them during the pandemic, although became more concerned over time and finally took in prior to warranty expiration for review.

NHTSA ID 11501427 · filed Jan 12, 2023

Too few reports in this category for a page of its own — they appear in the full complaint list.

Interior & seats

Reports naming seats, latches, locks, linkages and interior fittings.

1
report

From owner reports, verbatim

The back passenger seat exploded and caught fire, burning the back of the seat in front and burning the ceilings. Inside the whole vehicle is black from smoke damage. Incident assessed by fire marshal who has ruled as electrical issue. No warning lights or systems displayed anything.

NHTSA ID 11751287 · filed Jul 18, 2026

Too few reports in this category for a page of its own — they appear in the full complaint list.

Transmission

Reports naming the automatic or manual transmission, including shifting behaviour, shudder, slipping and transmission control modules.

1
report

From owner reports, verbatim

2020 GMC TERRAIN. CONSUMER STATED THAT THEIR VEHICLE STARTED PULLING AND DRAGGING WHILE DRIVING.

NHTSA ID 11506197 · filed Feb 8, 2023

Too few reports in this category for a page of its own — they appear in the full complaint list.

Exterior lighting

Reports naming headlights, tail lights, turn signals and other exterior lighting.

1
report

From owner reports, verbatim

Interior lights stays on at night while driving and when parked. Tried turning it off but it won’t turn off

NHTSA ID 11448895 · filed Jan 25, 2022

Too few reports in this category for a page of its own — they appear in the full complaint list.

Higher-selling and older vehicles accumulate more reports. Counts are not failure rates and are not directly comparable between vehicles that sold in very different numbers.

Elsewhere on this vehicle

Data sources

Data on this page last refreshed .