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 2020 Honda Civic owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2020 Honda Civic. The contact stated while driving at various speeds, the Forward Collision-Avoidance Automatic Emergency Braking erroneously activated causing the vehicle to abruptly stop. The contact indicated that the failure had occurred on eight separate occasions while driving between 5 and 65 MPH. The vehicle was taken to the local dealer however, the mechanic was unable to duplicate the failure. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 7,000.
The contact owns a 2020 Honda Civic. The contact stated while driving at various speeds, the lane departure assist steered the vehicle into traffic or over the lines randomly due to a possible object being in the roadway. The beeping sound, visual detection, and lane departure message were displayed. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was not notified of the failure. The failure mileage was 120. The VIN was not available.
Was T bones September 3rd 2023 exiting the freeway by a Ford F-350. Injury to left side of vehicle mainly . Airbags not side airbags deployed. Went through insurance and was told to report it to the manufacturer. Due to this I now need double knee surgery as I have tears and fluid and now have spinal injury .
The collision mitigation braking system consistently detects objects in the road and forcibly brakes when the road ahead of me is completely empty. This has happened 4 or 5 times just in the last year. The first time it happened I was driving on a completely empty road when the CMBS activated and kept slamming on the brakes until I pulled over and restarted the entire car. I don't always have to restart the car every time, but if it ever happens on a busy road it will cause an accident. The dealership refuses to inspect the system or try to recreate the problem despite the fact that there was a class-action suit against Honda for this exact CMBS malfunction in several other models. They just tell me to manually turn it off every time I get in the car. I am human and sometimes I forget, so this is not a solution. …
On multiple occasions, the collision mitigation braking system has had false-positive detections. There is one section of road where this occurs extremely frequently (maybe 20% of the time I drive through). On this section of road, it will not activate the brakes, it only beeps and displays "BRAKE" on the instrument cluster, but is extremely disconcerting and distracting. On another occasion on a different road, there was clear road ahead of me when the collision mitigation braking system had a false detection, and did activate the brakes and was incredibly close to causing a collision with a car driving behind me. On this same stretch of road, Ive had this occur two other times (out of hundreds I've driven on it), but no one was behind me and would not have caused an accident. In both of these spots, the road is fairly straight and the speed limit is 40 MPH. …
When driving at highway speeds with adaptive cruise control, vehicle will slow down or brake without any object/vehicle ahead. This usually occurs at curves, with no vehicles in current lane. I would then need to immediately step on the acceleration in order to continue highway speeds. This may cause unnecessary stress on the vehicle due to constant issue occurrence. At times, a blinking warning message from the emergency braking system will appear on the dashboard during these conditions. This causes a safety issue because cars in the back will not expect braking/slowing down when there isn't any obstruction from all perspectives. This is dangerous on the highway due to the increased driving speeds of surrounding vehicles. I have not taken it to the dealer due to the vehicle being out of warranty, however it has always had this issue. Vehicle was bought new at dealership.
on 7-28-26 After filling my vehicle with gas at the next red light, all lights on dashboard went on flickering warning (Christmas tree effect). on 7-29-26 After researching online Roadside came out and did Battery and alternator test that passed. I did hard reboot from instructions I found online and after several attempts the lights cleared twice, the morning of 7-30-26 when leaving for work the flickering lights came back on. Vehicle had a slight tremble but cleared after a few seconds while vehicle warmed up. I went to get the battery checked at the shop and it passed also had air filter changed. Lights still on, car is running fine, but I feel unsafe to drive and have an appt at the dealer for a diagnosis check on 7-31-26.
The automated emergency braking system activated bringing me to a sudden and complete stop. I was traveling at a lower speed (<20mph) with sufficient space both in front and behind my vehicle which prevented this incident from becoming an accident. This occurred at night. The braking system automatically engaged as I was releasing my foot from the gas pedal to coast. Should this happen at higher speeds or with traffic closer behind me, an accident could have happened. The system has not been inspected as of now and has not been reproduced or occurred a second time. There have not been any warning lights, messages, or other issues with the car since I bought it brand new.
The contact owns a 2020 Honda Civic. The contact stated that while driving at 60 MPH, the vehicle ahead of him attempted to make a right turn. Although his vehicle was at a safe distance from the vehicle ahead, the Forward Collision-Avoidance feature independently engaged, and the warning light illuminated on the instrument panel. The contact stated that the feature did not recognize that the vehicle was making a turn and that the abrupt stoppage could have caused a rear-end collision with the vehicle behind him. The dealer nor the manufacturer had yet to be notified of the failure. The vehicle had yet to be repaired. The failure mileage was approximately 12,300.
At least a half dozen times the car would brake automatically when nothing was in front of the car. The BRAKE warning light would appear on the dashboard as the car abruptly slowed down. The car slowed down but never came to a complete stop. This happened at various speeds. Once on the freeway at high speeds, 3 times just before an intersection where I had a green light and other various times. I brought the car to 2 different dealers. They could not replicate the problem so they said there was nothing they could do. The courtesy car driver who gave me a ride said they occasionally experience the same thing in the courtesy car.
Collision Avoidance complaints in other Civic years
Frequently asked questions
How common are collision avoidance problems on the 2020 Honda Civic?
NHTSA has 26 complaints about the driver assistance of the 2020 Honda Civic, 11% of the model year's 232 complaints. The component named most often is automatic emergency braking (17 mentions).
Is there a recall for 2020 Honda Civic collision avoidance problems?
No. NHTSA lists no driver assistance recall for the 2020 Honda Civic, though it has 5 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 Honda Civic collision avoidance problems start?
Half of the complaints with a recorded mileage happened before about 7,000 miles, and 67% before 25,000 miles.
Is it dangerous?
Owners linked 1 crash, 0 fires and 3 injuries 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.