Which parts fail
Components named in complaints (battery, alternator, wiring, ignition, instrument cluster, infotainment).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2020 GMC Terrain owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2020 GMC Terrain. The contact stated that while driving in cold weather at various speeds; moisture accumulated and deactivated the charger, causing the vehicle to go into LIMP Mode and lose drive power. The vehicle was taken to the dealer, who diagnosed the vehicle and determined that the charger air cooler was defective and needed to be replaced. The dealer also wanted to place an air deflector on the vehicle. The contact was informed of a service update for the failure however, the VIN was not included. The vehicle was not repaired. The contact researched and learned that in Canada, the issue was being remedied with a bra apparatus and a thermal wrap for the engine to prevent the failure. The manufacturer was made aware of the issue and confirmed that the VIN was not covered. The contact was waiting to hear from a supervisor. …
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.
Infotainment system shuts off completely. Disables blinker. Bluetooth and USB ports continuously went in and out and wouldn't stay connected. Took to dealership on 02/07/2022 and was advised the system needed an update and the USB port needed to be replaced. USB port was replaced and software bulletin #20-NA-171 was applied. I picked up my vehicle on 02/08/2022 and the infotainment issue has not been corrected. It turned off again. USB ports seem to be working as they should for now. Also an issue with rear camera. Camera view sometimes shows a fisheye lens instead of normal camera view. Rear camera will sometimes stay on once car is in drive for a few seconds. I also notice a noise and vibration within my gas pedal randomly while driving. Clearly there are multiple issues that GM needs to acknowledge. It's not a coincidence that this is happening to multiple people.
Dash had gone black intermittently, did not know what speed I was going. OnStar called oor phone multiple to notify us that our airbags we're offline for ten days no warning light on dash until one to two days later . Took to service was informed that gear shift control, engine control module, passenger presence module and airbag sensor needed replaced. All within a month of purchase of said USED vehicle. Vixed under warranty. Then another monther later, got warning on dash saying "conditions not current for shifting", park break light came on, and a p in a yellow circle with a wrench under it came on. Serive did fix vehicle, but could not verify message on dash about conditions not favorable... Also recalibrated breaker. Complained numerous times to dealer about these issues and was told "live with it".
2020 GMC Terrain SLE Elevation Package 83,000 miles and needs complete engine rebuild @ cost of $10,700 per Dealership Service. Was told "I drove the vehicle with low oil" which Inturn is the cause of needing engine rebuilt. I have had this vehicle serviced, oil changed regularly etc NOT ONE TIME has the oil pressure/low engine oil nor anything related to oil illuminated on my dash. CEL yes after it apparently was too late and damage was done which showed code P06DD And P0324 through OnStar Diagnostics. There are also other complaints with same issue, and no notification of oil /oil pressure issues with relatively low mileage that have led to engine rebuild. I still owe on this vehicle through GM Financial, and a $10,200 engine rebuild on top of that... Not what I would expect out of GMC~
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.
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.
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.
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.
Radio goes from normal volume to as loud as possible while just driving.scares ya to death! Can't turn volume down with out 1st shutting off radio and turning it back on.dealship stayed there isn't a problem they could find.Blu tooth cuts in and out and locks the radio up untill you shut vehicle off and restart.shows you still on a call even though you have disconnected phone from radio.volume issue has happened several times
Electrical complaints in other Terrain years
Frequently asked questions
How common are electrical problems on the 2020 GMC Terrain?
NHTSA has 27 complaints about the electrical system of the 2020 GMC Terrain, 14% of the model year's 197 complaints. The component named most often is adas › hill descent assist › sensor (1 mentions).
Is there a recall for 2020 GMC Terrain electrical problems?
No. NHTSA lists no electrical system recall for the 2020 GMC Terrain, though it has 2 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2020 GMC Terrain electrical problems start?
Half of the complaints with a recorded mileage happened before about 6,000 miles, and 67% before 25,000 miles.
Is it dangerous?
Owners linked 0 crashes, 1 fire and 0 injuries to electrical system problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.