Which parts fail
Components named in complaints (automatic emergency braking, adaptive cruise, lane keeping, backup camera).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2021 Subaru Forester owners, lightly cleaned up (personal details are redacted by NHTSA).
While driving on I-17 Southbound near mile marker 311 at approximately 75 mph, I experienced a sudden and dangerous malfunction of the Lane Keep Assist (Auto-Steer) system in a 2021 Subaru Forester. The feature was active at the time and unexpectedly veered the vehicle sharply toward the concrete wall on the left shoulder of the highway. I attempted to regain control, but due to the abrupt nature of the malfunction, I overcorrected and collided with the wall on the rear driver side. There were no vehicles in the immediate vicinity, or this could have resulted in a multi-vehicle collision at high speed. I hit my head during the impact but did not require emergency medical services at the scene. Road conditions were dry and clear, with no visible debris or extreme weather factors. There were no warning lights or error messages from the vehicle prior to or during the incident. …
After arriving home from a short drive to the grocery store I parked my car in the drive way and went inside. On the drive home I could hear a low humming coming from the speakers and the car was decelerating when the accelerator was not being pressed, no warning lights or sounds came on. About 10 minutes after I parked a neighbor knocked on the door letting me know my car was smoking from inside the hood. Within a minute or 2 the entire hood of the car was engulfed in flames. The entire front half of the car burned to a crisp, the fire also burned half a tree. The car was burning so hot that it melted the hood of the car, had I parked it with the hood facing my house my house would have caught fire. The problem has not been reduced or confirmed by dealer or independent service. The vehicle is being stored by the insurance and for the time being is accessible for investigation. …
The contact owns a 2021 Subaru Forester. The contact stated while driving 40 MPH, the automatic emergency braking system activated, bringing the vehicle to a complete stop. The vehicle returned to normal functionality, but the failure became a regular occurrence. No warning lights were illuminated. The vehicle was taken to the dealer, who was unable to duplicate the failure. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was 24,000.
While driving down a two-lane road at 50-55 mph, the car started beeping and said "obstacle detected" despite there being *no* cars in front of, to the side of, or to the rear of me. Also, there was *nothing* on the road (no roadkill, litter, or other debris). Immediately upon beeping, the speed abruptly dropped from 50 to below 15 in a matter of milliseconds. Had there been a car behind me, they would've either rear-ended me or had to swerve (possibly into oncoming traffic), and had the road been wet or slippery, I would've likely spun out, possibly into oncoming traffic. Had the incident occurred on the interstate, it is entirely possible that I could've been rear-ended by a driver traveling at full speed. Again, all of this over no physical obstacle and with nobody around. …
The RCTA system operates very poorly. When backing up and we see a car in the rear camera screen approaching from the back side of our car, we cannot hear or see any allert. My wife and I are both seniors in our seventies and I suffer from normal age-related hearing loss....my wife not so much. Her hearing is quite normal. But we cannot hear the alert alarm. Also, the visual alert is located in a place where you do not look when you are backing up. It wasn't until I owned the car for four months that I discovered that there is a visual RCTA alert in the side view mirrors (of all places)....an area one does not look at while backing up. With a car with a rear camera, your eyes are usually glued to the camera display screen when backing up; after all, it is a safety device. We have nearly had a collision a half dozen times already. …
On August 12, 2025, at approximately 10:16 AM, while driving at normal speed on CR-43 NW southbound just past Minnesota Ave in Big Lake, MN, my Subaru's EyeSight Driver Assist System, specifically the Automatic Emergency Braking (AEB) / Pre-Collision Braking System, suddenly activated without warning and with no obstacle present. The braking was abrupt and unnecessary, causing the vehicle behind me to nearly rear-end mine. Road conditions were clear, dry, and unobstructed, with no pedestrians, vehicles, or hazards in my lane. This appears to have been a "false positive" from the AEB system. This sudden stop placed both my safety and the safety of other drivers at serious risk, and in different circumstances could have caused a collision resulting in injury or death. The vehicle is available for inspection upon request. …
1. July 15, 2021 the brakes didn't fully engage three times. Twice within 30 minutes while driving to work and once on my drive home. 2. Unknown 3. Yes. Car was at dealership put through all kinds of tests and field engineer checked it out. They had me come out on Monday, 9 August and drive it with the head mechanic while hooked up to a computer trying to see if the problem replicated. 4. Yes. 5. Yes. Eyesight technology picked up there was a problem - light came on, a text and an email were sent to me. Subaru got the message too. A specific issue was not identified at that time. Vehicle was towed to dealership three days later. Subaru's field engineer was called into examine vehicle. Apparently, he saw something he didn't like on a reading - it had to do with the AEB-autonomous emergency braking system. …
Braking system sometimes is activated by a sign on the side of the road, by a tree if we are turning, or nothing at all. Nearly in 2 rear end collisions when the system activated incorrectly. We cannot drive into our garage with the system activated...brakes keep slamming on. The only safe way to operate this subaru is to manually turn it off every time we start the car. Subaru dealership states it cannot recalibrate the eyesight system as it does not have that ability. Dealership is in Corvallis oregon. Lane notification system also has issues in construction zones (it tries to steer the car into the water barriers marking the lane changes. At least the side warning system can be permanently disabled. We have filed many complaints with subaru to no avail. Promised return phone calls never happen, phone transfers to their technical department result in dropped calls. …
Purchased brand new from dealer. Less than 3 months later a tiny pebble came up and hit the center of the windshield, immediately you could see an indentation and a spider web. Now the whole windshield has multiple spider web cracks. The splits go from edge of driver's side all the way to edge of passenger side of the car. As well as 3 separate rings going around center indentation. Only had the car 3 months when this occured. Have had 3 instances that I could not start the car. Now the cigarette lighter charge port will not work. Moon roof malfunctioning and will not close sometimes when fully opened. Now I am having issues with the brakes sticking. It's 1 year old and this is way too many issues for a brand new car! Never again!
The first incident occurred when I drove into a parking space, applied the brakes, and the car suddenly sped forward, so I had to repeatedly jam on the brakes to make the car stop. Fortunately, no person or vehicle was directly in front of me. In the past week, we have experienced problems with the ADAS. We were backing into a parking space at night and made contact with a parked car. Our car made no warning sounds or lights to warn us. The following day, the blind spot detector light went on and off intermittently, sometimes with an exclamation point, and sometimes without an exclamation point. The lights on the mirror did not come on when cars were approaching from behind. We are making an appointment with the dealer ASAP.
Collision Avoidance complaints in other Forester years
Frequently asked questions
How common are collision avoidance problems on the 2021 Subaru Forester?
NHTSA has 20 complaints about the driver assistance of the 2021 Subaru Forester, 10% of the model year's 210 complaints. The component named most often is automatic emergency braking (13 mentions).
Is there a recall for 2021 Subaru Forester collision avoidance problems?
No. NHTSA lists no driver assistance recall for the 2021 Subaru Forester. 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 2021 Subaru Forester collision avoidance problems start?
Half of the complaints with a recorded mileage happened before about 24,000 miles, and 100% before 25,000 miles.
Is it dangerous?
Owners linked 1 crash, 1 fire and 1 injury to driver assistance 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.