2021 Tesla Model 3 acceleration problems

Filed Jun 12, 2026 · Acceleration, Brakes · TX

The forward-facing camera and Autopilot computer system on my 2021 Tesla Model 3 has failed. The dashboard first showed intermittent warnings that "Automatic Emergency Braking is currently unavailable" and "Adaptive headlight features are unavailable." Over several weeks the problem worsened from intermittent to constant, and the vehicle progressively lost its forward road visualization and all active safety features. Using the vehicle's Service Mode diagnostics, the Autopilot computer's Primary (A) processing node reports a "CRITICAL" status. The fault log records repeated alerts including dasMIA (driver-assistance system not responding), aebFault (automatic emergency braking fault), and fisheyeCamInitFault and fisheyeCameraStreamExit (forward camera initialization and stream failures). The cameras themselves are physically clean and unobstructed. Safety risk: the failure disables Automatic Emergency Braking and forward collision avoidance, lane-keeping/driver assistance, and the adaptive auto high-beam headlights. AEB is a critical crash-avoidance system; losing it leaves the vehicle unable to brake automatically for an imminent collision, and the loss of adaptive headlights reduces nighttime visibility. A Tesla service center inspected the vehicle, confirmed the diagnosis, and determined the Autopilot computer — a sealed, solid-state control unit — had failed and required full replacement at approximately $3,400. The vehicle is well under 50,000 miles. This failure appears consistent with the same car-computer power-component shorting failure for which Tesla issued a recall on its newer model-year vehicles. The vehicle and the failed component are available for inspection on request. The vehicle has not been inspected by police or insurance.

Filed May 11, 2026 · Acceleration, Driver assistance · UT

When using cruise control, there has been 4 times that the car has engaged in “phantom braking”. We were driving on highways going the posted speed limit of 70 mph, when the car suddenly slammed on the brakes and decelerated to less than 30 mph – all four times we were thankfully not being closely followed by another vehicle or we would’ve had a devastating crash. One time when we looked at the screen, it showed the outline of a person in the median but there was no person/ other obstacle at all. We have reported this to the Tesla service center and they said it is a known issue, and what we have to do is just click the scroll bar and report it so that the engineers can mark the timestamp and collect data so that some patches can be sent over the air/ uploaded at a future date. Nothing has been done to fix the issue and we feel dismissed about our concerns about our family’s safety, and the safety of drivers around us.

Filed Apr 17, 2026 · Acceleration, Driver assistance · CA

2 problems 1,Phantom braking when cruise control is activated. 2, There's no rear door mechanical release in the event of a electrical power failure in the event of R.T.A

Filed Jul 1, 2025 · Acceleration, Brakes · TX

Incident Details: • Date of Incident: [XXX] • Time: [XXX] • Location: San antonio, Tx • Weather/Road Conditions: Clear, dry highway; 90 F • Speed: 60 mph; • Description: while driving my 2021 Tesla Model 3 with Full Self-Driving (FSD) software version 12.6.4 engaged, the vehicle unexpectedly changed lanes without my input, likely due to the Auto Lane Change feature. Immediately after, it braked hard for and unrecognized slowing traffic ahead. This sudden jolt caused immediate pain in my upper back, neck, and chest, which persists. I believe FSD misjudged traffic patterns or road conditions, a known issue with v12.6.4 based on online reports. The incident occurred in heavy traffic and no crash occurred, but the abrupt braking posed a safety risk and caused injury. I’m unable to see a doctor today but plan to soon for a diagnosis. This is a serious safety concern, as FSD’s erratic behavior could cause collisions or further injuries. Injuries: Yes, back, neck, and chest pain caused by sudden braking. No medical diagnosis yet; planning to see a doctor soon. Crash: No Fire: No Police Report: No accident Attachments: i have video INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed May 28, 2025 · Acceleration, Electrical · NC · crash

Attempting to park. Slowly inching forward while turning left. Vehicle accelerated. (Sudden Unintended Acceleration: SUA) Vehicle jumped a curb, bounced off a tree, dropped off the curb before comping to a stop. Internet search shows other similar reports; attributed, by Tesla, as pedal misapplication. This was not "pedal misapplication". I am not looking for anything. But the federal safety agency should increment occurance counter by 1. Tesla has a problem. Electrical or Mechanical...do not know. They have also lost me as a customer. The car will be sold. I have video...mp4

Filed Dec 1, 2024 · Acceleration, Brakes · CO

vehicle constantly phantom brakes while driving. i have reported 100+ incidents thru my tesla "report bug" feature. It will read the speed limit sign on the off ramp and slow the vehicle down 20mps abruptly, it will see a car on an onramp and slam the brakes on thinking there is a collision coming. it is every single day using cruise control

Filed Oct 25, 2024 · Acceleration, Driver assistance · MD

My Tesla was operating in Full-Self-Driving Beta when it experienced a sudden uncontrolled accelration event. I was driving on [XXX] at approximatley [XXX] this morning. The road speed limit was 40 mph. The car display was correctly showing that the road speed limit was 40mph. The speed offset in the cars setting was limited to 5 mph max above the speed limit. While the car was driving it suddenly accelerated very hard from approximately 40 mph to over 60mph before I was able to stab the brake pedal and kick the car out of full self driving mode. There were no errors, warnings, or signs that anything was wrong with the car. I have also notified Tesla via the service request function in the Tesla App under the section for "software performance". INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Oct 18, 2024 · Acceleration, Electrical · 35,000 miles · UT

The contact owns a 2021 Tesla Model 3. The contact stated while driving approximately 65 MPH, the braking system erroneously activated, causing the vehicle to abruptly decelerate. The contact stated that the failure was due to a failure with the computer reading the speed limit as 45 MPH instead of 65 MPH. The cause of the failure was not yet determined. The manufacturer and local dealer were not notified of the failure. The failure mileage was 35,000.

Filed Jun 20, 2024 · Acceleration, Driver assistance · OH

Ever since Tesla rolled out an update for everyone to beta test FSD, the adaptive cruise control has been changing speeds when near interstate type exits and entrances. I've had it change from 75 down to 40 mph which is dangerous in traffic. This change in speed some times is just a drop to the next 5mph increment, such as from 73 to 70. Sometimes it is more from 73 to 65 at the same place/exit. It is not consistent. The only thing consistent is it's near exits even when not in an exit lane or nearest lane to the exit. This "Feature" needs to be removed as it is unpredictable which makes it dangerous. Owners manual [XXX] Cruising Near or On Exits INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Jun 6, 2024 · Acceleration, Electrical · TN · crash

The vehicle, a 2021 Tesla Model 3, had an episode of sudden unintended acceleration. I was almost stationary waiting to make a left when the car accelerated by itself, left the road, crossed a grass field at high speed and crashed into bushes. The vehicle was not on auto pilot, it resulted in damage of almost $ 20.000 as estimated by insurance. The vehicle is available for inspection, it will be checked by Tesla service after the damage is fixed. There were no previous warnings, this is the first incident of this kind. It is not clear what component malfunctioned, probably some electric/electronic device in charge of acceleration. It was obviously a very dangerous event that could have jeopardized my safety and/or some others.