2026 TESLA MODEL Y Vehicle Speed Control Problems

Tesla self driving detects and sets a speed limit and displays it as a speed limit icon. I used self driving to exit my driveway, which turns onto a dirt road with a speed limit of 15 MPH. Near the bottom of the driveway self driving suddenly reset the speed limit from 10 MPH to 55 MPH. The car then accelerated abruptly shortly before the turn onto the dirt road. There is no mechanism for overriding the speed limit the Tesla self driving automatically selects. It is clear that the speed of the vehicle is adjusted according to the speed limit that Tesla self driving selects. Before I could regain control of the vehicle I was almost into the field opposite the driveway. The inability to re-set the automatically selected speed limit is dangerous. The speed limit has spontaneously reset to 55 MPH on two other occasions, and the vehicle spontaneously speeded up.

The contact is a police officer from the Simi police department, who called on behalf of the owner of a 2026 Tesla Model Y. The contact stated the owner was driving at 30 MPH with full autopilot mode with direction destination set, the vehicle increased in speed to make a U-turn on the opposite side of a driveway; therefore, the driver attempted to disengage the autopilot and depressed the brake pedal. The vehicle failed to stop and instead increased in speed, causing the driver to crash into a curb, a Dodge Ram truck, a light pole, and an occupied Nissan Maxima vehicle, where the vehicle came to a stop. Both vehicles that were crashed into were occupied by 1 occupant each. The contact stated the owner's air bags did not deploy. The contact stated that the owner did not sustain any injuries. No medical attention was required. The vehicle was towed to an auto collision center; however, the vehicle looked drivable. A police report was filed. The manufacturer was not notified of the failure. The approximate failure mileage was 5,000.

Mileage: 5,000

Incident date 11/27/25 Incident Location: CA State highway 101between San Luis Obispo and Los Angeles. Driving Conditions: Daylight/dry roadway. Description of Safety Defect / Complaint: During a single approximately 400-mile highway road trip, while using Tesla’s Traffic-Aware Cruise Control (TACC) feature enabled, the vehicle abruptly and forcefully applied the brakes on at least six (6) separate occasions without any apparent cause. On each occurrence: • No vehicle ahead was braking or decelerating, • No vehicle was merging or cutting in front of my vehicle, • No stationary or moving obstacles (including overpasses, road signs, or debris) were present in or near the travel lane, • The forward roadway was clear and unobstructed for a considerable distance. These sudden, un-commanded braking events were severe enough to cause significant deceleration, requiring me to immediately intervene by pressing the accelerator pedal to override the system. Due to the frequency and unpredictability of these phantom braking events, I no longer feel safe using Traffic-Aware Cruise Control or any Tesla advanced driver-assistance features that rely on the same sensor suite and software. I am filing this report because repeated uncommanded braking in highway traffic constitutes a serious safety hazard that could lead to rear-end collisions, particularly when closely followed by other vehicles or commercial trucks. Additional Information (if applicable): • Software version at time of incident: v12 (2025.38.9 fe 714a33a545) • Full Self-Driving Capability package: No. Enhanced Autopilot: No. • Any dashcam or Sentry Mode footage available: No I request that NHTSA investigate this recurring phantom braking issue in Tesla vehicles equipped with Traffic-Aware Cruise Control and Autopilot systems.

My car installed update v12 (2025.38.8.7) last night. This morning I was driving to work using autopilot when alarms sounded, the hazard lights turned on, and the screen flashed a warning that I had to take over immediately. The message included a note that autopilot had failed due to a "systems error." The navigation and visualization screen froze, went blank, and took 10 minutes to come back on. I asked Tesla to roll back the update and they have told me that they cannot do that. I came very close to crashing into a concrete guard rail as the car was going around a turn when the system failed.

When using cruise control (traffic aware cruise control and autosteer) the car acts dangerously and stops for no reason. I've been driving on open roads with no traffic in front of me on regular roads, the car will slam on the brakes and it causes the people behind me to need to slam on their brakes as well. I feel like I'm going to get into an accident constantly... I was on the freeway and no one around in front of me and the car slammed on the brakes to almost a stop on a 70 mph speed limit road. Today the same thing occurred in high traffic on a 55mph road, luckily the driver behind me wasn't to close and was able to stop in time ... There is no option to use regular cruise control or disable enough features to prevent this from occurring... It's incredibly terrifying. If they can't do traffic aware cruise, there should be the option to do regular cruise... And it shouldn't require passing Tesla $8000 for full self driving to be able to drive your car at a speed without the that of being rear ended. This feels like extortion... I've submitted feature requests to Tesla, talked to their bot about fixing this and I've currently been on hold for almost an hour without any response. This dangerous tech is unacceptable!

The latest version of Tesla FSD software does not let me fully control my speed. You can switch profiles or stop using Full Self-Driving, but you cannot set the speed to what you want. In the last version, you could use the right scroll wheel to increase or decrease the speed. Now that shifts profiles but even that does not give you control over what exact speed you are driving

Full self driving disengage with no warning and won’t start up again. Unsafe.

The newest FSD update v14 as of 10/23/25 took away the ability to manually limit the speed limit. Full Self Driving profiles are fixed, and the limits are invisible to me as the driver. The all except the Sloth fixed profiles can cause the speed to go 15 miles an hour over the limit unexpectedly which can cause arrest. There is also some very concerning random breaking now in the middle of empty roads where there might be a slight bump during the dark morning hours. The lack of manual speed control also is an issue when the expected speed limit is wrong in the system. In a 20 mile an hour neighborhood the car thinks it is 25 and can never drive compliant to the speed limit even with the Sloth profile. This is a dangerous oversight.

Upon purchase of the vehicle, unlike previous models and versions of the software - the vehicle’s speed limit control was incapable of being set - instead, using FSD, you had to select from percentage based offsets - which were frequently ignored and would still go much higher or much lower than the percentage value set. The owner of the vehicle was unable to say limit to only 10 over the speed limit; instead it was percent based and not reliable. In addition, more than a third of the time - the speed limits in the infotainment system did not match the posted speed limits. Sometimes, in the middle of a highway - it would randomly go from 55 to 25, posing a significant threat hazard when using the FSD or cruise control system (which is something Tesla charges extra for access to) causing the vehicle to immediately decrease speed when other vehicles behind are getting up to speed and not expecting a vehicle to randomly slow down excessively. Additionally, when you manually override the speed limit control, or the system does, the user interface hides this limit so the driver is unaware of what limit of speed it is set to. These issues were already bad enough, but just yesterday my vehicle was pushed a software update that dramatically reduced the performance of FSD, and now I am unable to manually control the speed limit at all in FSD. This was a regression from purchase, when a scroll wheel at least allowed me to manually set the speed limit or correct it when it was wrong. Now, that feature has been removed and instead there’s a duplication of FSD profiles (left/right on the right scroll wheel does the same as scrolling up/down). And continuing this trend, the driver is incapable of seeing what the speed limit is set to because it’s hidden from the user interface. In addition, the driving behavior for FSD has significantly regressed from before the update. Cruise control’s most basic functionality should be to set a speed limit. Now this feature has been removed.

The contact owned a 2026 Tesla Model Y. The contact stated that while depressing the brake pedal to attempt to stop at a stop sign, the vehicle failed to respond as intended. The contact mentioned that when attempting to make a left turn, the steering wheel seized and became difficult to maneuver, and the vehicle crashed into a curb and merged into a landscaping facility. The contact was able to shift the vehicle into neutral, then reverse. The vehicle began to work as intended, and he looked out of his rearview mirror. He could see smoke coming from the rear passenger side, and he heard an abnormal noise coming from the rear passenger tire. No warning lights illuminated. A dealer was contacted. The vehicle was towed to a dealer to be diagnosed; however, the diagnosis was unknown. The contact mentioned the dealer, and insurance deemed the vehicle a total loss. The vehicle was not repaired. The manufacturer was notified of the failure and offered no assistance. The approximate failure mileage was 4,900.

Mileage: 4,900

The Curvature Assist function activates and applies the brakes automatically on straight and level sections of freeways with no observable obstacles or curves, requiring driver to resume acceleration to override the brakes.

While driving along a few roads using Traffic Aware Cruise Control (TACC) or AutoPilot (AP), the car will suddenly brake for no reason at all. Speeds reduced from 75 to 50 in 2 seconds. Had there been a car close behind me, we may have collided. I am able to reproduce this on several other roads as well. I have not yet reported this to the manufacturer, but a review of internet forums shows this to be a relatively common occurrence among owners. They refer to this as Phantom Braking.