2021 Tesla Model 3 Collision Avoidance Problems

Which parts fail

• Adaptive cruise control
  283
• Automatic emergency braking
  232
• Warnings
  81
• Assist
  22
• Warning
  15
• Blind spot detection
  5

Components named in complaints (automatic emergency braking, adaptive cruise, lane keeping, backup camera).

Mileage when the problem started

• Under 25k
  1381%
• 25k–50k
  213%
• 50k–75k
  16%
• 75k–100k
  00%
• 100k–150k
  00%
• 150k+
  00%

Owner reports

Selected complaints filed with NHTSA by 2021 Tesla Model 3 owners, lightly cleaned up (personal details are redacted by NHTSA).

The contact owns a 2021 Tesla Model 3. The contact stated while driving approximately 8 MPH, the vehicle inadvertently accelerated and jumped the curb. The contact depressed the brakes pedal to the floorboard; however, the vehicle continued to accelerate and crashed into a wall where the vehicle came to a stop. There was no warning light illuminated. The seat belt was on and the driver's air bag deployed, however, the contact head hit the windshield, and it shattered. The air bag was not covering the contacts face completely. The police arrived on the scene and filed a report. There were injuries to the contact's left wrist, neck, hip, and back, and a fracture to the right foot. The contact started receiving medical treatment the same day. The vehicle was towed to the contact's residence. The damage was to the front of the vehicle. …

The contact owns a 2021 Tesla Model 3. The contact stated while using a self-driving mode at 50 mph, it would not stay in the lane and drive slowly into the next lane. The contact stated on April 9, 2023, while using a self-driving mode at 15 mph, a pedestrian walked into the lane and the vehicle did not detect the person and hit the pedestrian. No air bags deployed. The contact did not sustain any injuries. The pedestrian sustained an unknown fractured leg and a fractured arm and sought medical attention for his injuries. A police report was filed. The vehicle was not drivable. The vehicle was towed to a Tesla collision shop and had the front windshield replaced. The contact took the vehicle to the local dealer but was informed no failure was detected. The vehicle was not repaired and continued to experience the failure. The manufacturer had been informed of the failure. …

On 1/3/21, approximately 2pm. Driving south on I-77 in the city of Broadview Heights. In center lane of highway with Autopilot (speed and steering only) on. A Hummer in my left lane drifts into my lane and hits my car (I have video). No alarms or alerts went off to warn me. No automatic steering occurred. My car continued in lane and at speed (about 64mph), until my driver mirror broke off and adjusted my position to the left. Broadview Height police report # [redacted]. I have a service request into Tesla. I am awaiting the at-fault party insurance to contact me to begin repair process. To above questions: -I am suspicious about the ultrasonic sensors and/or camera and it failure to warn me I was about to be hit. …

On [Wednesday, 07/09/2025], I was driving my Tesla Model 3 in rainy conditions when the vehicle suddenly swerved and crashed into a sidewall. The road was wet but not flooded, and I was traveling at a moderate speed. As I lifted my foot off the accelerator to slow down, the car's regenerative braking system engaged abruptly, which I believe shifted weight forward and caused the rear tires to lose traction. This led to hydroplaning and complete loss of control. There were no warning lights or alerts prior to the incident. The road surface did not have visible hazards or standing water that would typically explain a spinout. The tires were moderately worn but within usable limits. As a result of the crash, the car was declared a total loss. The insurance company now has possession of the vehicle. Thankfully, no one was injured, but the crash was severe. …

The components involved are the automatic emergency braking (AEB) system and the airbag system. During the collision, the AEB system did not activate, and the airbags did not deploy. The vehicle is available for inspection upon request. I was driving on a main roadway with no stop signs or traffic controls in my direction when another driver entered from a side street with a stop sign and pulled directly in front of me. I was unable to avoid the collision, and my vehicle was struck the other vehicle. The failure of the AEB system to engage and the airbags not deploying increased the risk of injury to myself and could have posed a risk to others involved. The issue has not been reproduced, and it has not yet been confirmed by a dealer or independent service center. The vehicle has been inspected by police and insurance representatives. The other driver was determined to be at fault. …

I am reporting a repeatable safety problem with FSD Lite's end-to-end parking behavior. On July 22, 2026, FSD Lite reversed the vehicle into a solid concrete garage wall while backing into a parking space. The vehicle did not stop before hitting the wall and sustained a scrape. On September 20, 21, and 22, 2026, FSD Lite selected parking spaces and began reversing toward parked cars. I had to intervene each time to prevent a collision. When I select the parking space myself, the maneuver works correctly. A previous software update briefly fixed the problem, but it returned after the vehicle updated to FSD Lite v14.1 Lite, software build 2026.26.6.5. This is a repeatable reverse-parking safety defect that can cause property damage and could injure someone. No one was injured, and no other property was damaged. The vehicle and its logs are available for inspection. …

The contact owns a 2021 Tesla Model 3. The contact stated while driving approximately 75 MPH, the vehicle decelerated inadvertently. The contact stated that the vehicle would detect a non-existent road hazard causing the vehicle to slow down dramatically, almost causing a rear-end crash. The contact stated that there were no warning lights illuminated. The contact stated that while researching online he became of similar failures. The dealer and the manufacturer were contacted; however, no assistance was offered. The approximate failure mileage was 10,000. On a recent trip up the same two-lane segment of US-95 where chronic incidence of my 2021 Tesla Model 3 suddenly removing acceleration causing a very dangerous unexpected drastic slowing from high speeds, recurrence of this problem indicated what might be causing the problem. …

Hello, Driving on a snowy road around 20 MPH. Attempted to slow down in a straight line, used the brakes to try and slow vehicle to go into a driveway. Vehicle would not respond to any inputs. The brake pedal seemed frozen, coming off and back on the brake pedal did not change anything. There sounded like an ABS pulsing but it was not working. Post accident pictures showed it looked like the car was dragging one axle like it was locked in the snow. Car ending up grazing a mailbox post and afterword said 'take control'. I believe the car tried to do an automated braking maneuver which did not work. The road was covered in 1-2" of snow and the mailbox would have been a reference point in the distance. When turning the steering wheel away from the object that was hit, the car continued to go straight like the wheels were not attached. …

The contact owns a 2021 Tesla Model 3. The contact stated while driving approximately 65 MPH with the self-driving feature activated, the vehicle experienced phantom braking. There was no warning light illuminated. The contact stated that there were no other vehicles nearby in the lane. Additionally, the contact was unaware of any shadows or anything else in the lane. The contact stated that the vehicle slowed down and then resumed a higher speed. The contact stated that he disengaged the self-driving feature and manually drove the vehicle. The vehicle was not taken to a dealer or independent mechanic to be diagnosed or repaired. The contact stated that he attempted to notify the manufacturer thru the vehicle App but was unable to leave a full detailed report. The approximate failure mileage was 10,445.

The contact owns a 2021 Tesla Model 3. The contact stated while driving at 55 MPH with the Forward Collision Adaptive cruise control engaged, the driver was approaching a railroad overpass and the vehicle stopped independently. The cruise control was disengaged and the vehicle operated as designed. The contact stated that the failure was intermittent. The contact stated that the Adaptive Cruise Control signal recognition was not functioning as designed. The contact reached out to the manufacturer and provided an online form describing the failure. The manufacturer confirmed that the issue was a known failure and that a fix was in the process. The vehicle was not diagnosed or repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 50.

Related recalls

NHTSA investigations

Collision Avoidance complaints in other Model 3 years