2021 Tesla Model Y acceleration problems

VEHICLE SPEED CONTROL

Separately, the system could not hold a consistent speed on open highway with no vehicle ahead. It would surge from a set 70 mph to roughly 72-73 mph and then drop back, repeatedly, producing a pulsing acceleration and deceleration. The system also hesitated frequently and issued repeated audible alerts without an identifiable hazard present. I previously filed a complaint regarding phantom braking on this same vehicle (ODI number 11450326, filed February 4, 2022), which described nearly identical behavior triggered by trucks on the same Georgia-to-New Jersey route. That complaint concerned FSD/Autopilot software from 2022. The behavior described here occurs on Tesla’s current v14 Lite software released to Hardware 3 vehicles in July 2026. The defect has persisted across more than four years and multiple software generations. Unexpected hard braking at highway speed with no hazard present creates a rear-end collision risk to my vehicle and to following traffic.

NHTSA complaint #11755578 — an unverified report by a vehicle owner.

VEHICLE SPEED CONTROL

I am submitting this complaint to request an investigation into a serious safety defect involving my Tesla vehicle. On multiple occasions, the vehicle has experienced a significant and unexpected loss of acceleration when I attempted to enter or cross intersections. Despite pressing the accelerator, the vehicle failed to respond as expected, leaving me unable to accelerate normally while entering active traffic. This is not a minor hesitation or inconvenience. It is a serious roadway safety hazard. Drivers rely on immediate acceleration when crossing intersections, turning across traffic, or merging. A vehicle that unexpectedly limits acceleration can place occupants directly in the path of oncoming vehicles, creating a substantial risk of a severe collision, serious injury, or death. I reported this issue to Tesla Service and provided multiple timestamps documenting the events. Tesla was unable to identify any fault codes or provide a diagnosis and indicated that because no fault was recorded, the issue could not be confirmed. Through independent research, I found numerous reports from other Tesla owners describing substantially similar acceleration limitation events. Many reports specifically reference Obstacle Aware Acceleration as a possible cause, and some owners report that disabling the feature resolved the issue. If a safety system can falsely detect an obstacle and reduce acceleration while a driver is actively entering an intersection, the system itself may create a greater danger than the one it is designed to prevent. I respectfully request that NHTSA investigate whether Tesla vehicles are experiencing unexpected acceleration limitation or torque reduction during intersection entry and traffic merging situations, evaluate the role of Obstacle Aware Acceleration and related software systems, determine whether a broader pattern exists, and assess whether corrective action or a recall is warranted. This could cause serious injury or fatal crash

NHTSA complaint #11743088 — an unverified report by a vehicle owner.

VEHICLE SPEED CONTROL

The vehicle began experiencing repeated Autopilot/FSD failures while driving. Symptoms included sudden Autopilot disengagements, cruise control becoming unavailable, and loss of road visualization/navigation display functionality. The issue progressively worsened over time. The vehicle was first brought to Tesla service in 2025 for the same overheating-related concern. At that time, Tesla identified a coolant-related issue, topped off the coolant system, and returned the vehicle to service. However, the problem continued and gradually became more frequent and severe afterward. During the most recent service visit, Tesla diagnosed the HW3 Autopilot computer as overheating due to a heat transfer failure between the Autopilot board and cooling cold plate. Tesla stated that heat generated by the board could no longer be efficiently transferred to the coolant system, causing the Autopilot computer to overheat. Tesla further advised that continued operation without repair could eventually impact additional vehicle functions, including the center display screen shutting off due to overheating-related failures. Given the loss of driver-assistance functionality and potential impact to core vehicle systems, I am submitting this report so the issue is documented as a potential thermal management or hardware reliability concern involving the HW3 Autopilot computer system.

NHTSA complaint #11736263 — an unverified report by a vehicle owner.

VEHICLE SPEED CONTROL

Incident Date: April 11, 2026 Approximate Time: 6:30 PM Component(s): Unknown (Suspected: Electronic Stability Control, Steering, ADAS) Description of Incident: On April 11, 2026, at approximately 6:30 PM, I was operating my Tesla Model Y on a highway with a self-driving mode engaged. I experienced what appeared to be a sudden, unintended acceleration combined with an erratic "zig-zag" steering pattern across multiple lanes. I am not certain of the technical cause, but the vehicle’s behavior felt like a loss of system control that was not initiated by me or the road conditions. I had to intervene immediately to prevent an accident. Post-Incident Actions and Manufacturer Contact: I have since contacted Tesla Service, and while they confirmed that data for that date exists, my formal "Privacy Data" requests for those specific logs have come back empty or missing the relevant timeframe. Summary of Concern: I am reporting this because I suspect a serious software or hardware malfunction occurred, though I do not have the technical diagnostic to confirm which system failed. The combination of the vehicle’s erratic movement and the subsequent difficulty in obtaining the data logs for this specific window of time leads me to believe there is a potential safety defect that requires investigation.

NHTSA complaint #11731428 — an unverified report by a vehicle owner.

VEHICLE SPEED CONTROL

Vehicle will suddenly apply brakes while using standard cruise control for no apparent reason. This is extremely dangerous as it has almost caused several accidents on the highway. I have almost been rear-ended several times. This is a very common problem and well documented problem referred to as "phantom braking" on Teslas and something needs to be done immediately.

NHTSA complaint #11720876 — an unverified report by a vehicle owner.

VEHICLE SPEED CONTROL

Detailed Description of the Defect: Friday Incident: While picking up my son from school, the vehicle abruptly disabled multiple safety and driver-assist features. The car rolled backward on a slight incline, failed to display any surrounding vehicles on the FSD visualization, and retained accelerator input even after I removed my foot from the pedal. The vehicle continued to speed up slightly in Drive and Reverse without my input. Soft resets did not resolve the issue. Monday Incident (Collision Caused by Malfunction): On Monday morning, the same malfunction occurred. As I reversed into my garage with the door opening, the car again held the accelerator input after I lifted my foot, causing the vehicle to continue moving backward unexpectedly. The vehicle struck my garage door, causing property damage and a dent to the trunk. This was not driver error. It was unexpected propulsion after pedal release — an extremely dangerous condition.

NHTSA complaint #11700358 — an unverified report by a vehicle owner.

VEHICLE SPEED CONTROL

The contact owns a 2021 Tesla Model Y. The contact stated that while coasting into the garage, the vehicle independently accelerated. No warning light was illuminated. An independent mechanic or dealer was not contacted. The vehicle was not taken to a dealer or independent mechanic to be diagnosed or repaired. However, the contact was in the process of repairing the vehicle. The manufacturer was not notified of the failure. The approximate failure mileage was 38,727.

NHTSA complaint #11695849 — an unverified report by a vehicle owner.

VEHICLE SPEED CONTROL

The Adaptive cruse control would stop working off an on. also it would give false land departure warnings causing driver to swerve thinking they were going to run into another care

NHTSA complaint #11655447 — an unverified report by a vehicle owner.

VEHICLE SPEED CONTROL

Several times on residential speed control the system does not recognize yellow flashing school speed reduction signs. Never slows or breaks. The speed of 25 mph does not register on the screed (other speed signs do). I told tesla service center when other services were being done. They said they were aware. I have seen no improvement over the last several months

NHTSA complaint #11641759 — an unverified report by a vehicle owner.

VEHICLE SPEED CONTROL

My Tesla still has the phantom braking problem. It is repeatable and consistent. I can tell when it will occur on a route that I drive regularly. Day or night does not seem to alter the occurrence. There is no indication on the touch screen when this occurs. Traffic volume does not matter. It always occurs at the same places so it should be relatively easy to fix if someone would just monitor my computer when it occurs. I regard this as a dangerous problem on the freeway because my car suddenly slows and if the person behind me is not paying attention, I am going to be rear ended. Such a serious fault for a vehicle that performs so well otherwise. Since Tesla does not have a service center in my town no one has offered to look at the problem but since it has been reported so often, I'm not sure they would. I would be happy to demonstrate the problem to a technical person who might be able to diagnose it.

NHTSA complaint #11619769 — an unverified report by a vehicle owner.

VEHICLE SPEED CONTROL

Tesla removed the ability to use only cruise control, with adaptive following distance, and have forced the only option to now use full self driving instead (with a recent soft-ware update). I do NOT feel safe using full self driving (even supervised) and believe Tesla is being unsafe forcing full self driving use. We used to be able to just use cruise control-with adaptive following distance-a driving option in all other recent cars!!! , but cannot do that now in Tesla? Why would a company take away what I consider to be a safer option?? This is not an improvement (but a forced help-Tesla-improve-it’s-unsafe-full self-driving-software!)

NHTSA complaint #11589166 — an unverified report by a vehicle owner.

VEHICLE SPEED CONTROL

Please look up my Facebook post for public safety awareness. All the details are explained [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA complaint #11587038 — an unverified report by a vehicle owner.

VEHICLE SPEED CONTROL

The main screen on my Tesla Model Y flickers while driving, as well as charging. I have a video of it happening, if you slow the video down it completely shuts the screen down for a millisecond and then turns back on. I have sent this video to Tesla, as well as Tesla technicians has confirmed the issue happening when they had the vehicle. I have had the vehicle into Tesla 3 separate times for service, they don't know how to fix the issue and keep telling me to wait. I have been dealing with this issue since January 2024 and am tired of waiting and putting my safety at risk. I feel that I have been more than patient with them and now I feel that they are now blowing me off. They don't feel that it is a safety concern even considering that the display screen went out while driving 70 mph, for 13 miles and I couldn't get it to turn back on. Aditionally the side cameras on the vehicle intermittently go out. There is no warnings or symptoms prior to it happening it just happens. I have 29 times documented of it happening to me. I have requested a buyback which was denied as well as a loaner from Tesla until they can fix the issue, yet they denied that as well. It seems that Tesla does not care about the safety of me and I want this issue to be investigated. I have the video of the Screen flickering reach out to me to get it since I cant post it in the place below.

NHTSA complaint #11586653 — an unverified report by a vehicle owner.

VEHICLE SPEED CONTROL

The vehicle's primary Autopilot processor randomly and completely failed while in active use on February 10th, causing the vehicle to immediately change course towards a highway barrier at high speed. Since that moment, every time the Autopilot DAS computer is reset, the primary processor refuses to transition from the INIT state to the NOMINAL state and instead transitions to CRITICAL state. The vehicle had software update 2023.44.30.8 for recall campaign #23V-838, recall number SB-23-00-008 applied 1 month ago, which was supposed to decrease the probable misuse of the DAS system. However, many individuals reported that the recall immediately and irreversibly damaged their DAS computer, so Tesla offered them a free replacement without hassle. However, I have been struggling to work with Tesla's Carlsbad, California service center for over a week to get the DAS computer replaced at no cost, since the computer was damaged after an update caused the computer to become irreversibly damaged after their software update was installed -- a software update which was supposed to have made the Autopilot system safer, but which has instead unfortunately irreversibly damaged the Autopilot computer, and caused my vehicle to randomly and immediately weave towards a highway barrier at high speed. I am wrongfully being asked to pay in excess of $2500 for a replacement computer as a result of the update damaging the DAS computer. They claim the catch-all diagnosis of a "short circuit" internal to the DAS computer caused the damage which would be out of warranty, except the computer has never been opened by myself. They confirmed to me that they chose that diagnosis after a process of elimination without actually probing the electrical system within the computer. The Carlsbad service center refuses to give me an accurate estimate for any further engineering analysis, claiming it could take multiple hrs/days at $245/hr. This is extremely unreasonable and presents unlimited risk.

NHTSA complaint #11572616 — an unverified report by a vehicle owner.

VEHICLE SPEED CONTROL

When driving the car abruptly slows down. This also happened on the freeway. I get an error message that says “power limited” and a turtle symbol. This is the second time this issue has happened. Tesla service center has not been able to confidently diagnose this issue. They say it’s resolved and once I leave the service center and the problem comes back.

NHTSA complaint #11571568 — an unverified report by a vehicle owner.

VEHICLE SPEED CONTROL

I was driving to work this morning, February 7th, 2024 driving at freeway speeds. My Tesla touchscreen dropped out and went completely dark. The reset process is to press and hold for about 30 seconds and another 30 seconds for the full restart. I attempted this twice and proceeded to pull off the highway. During this period, I could not see how fast I was driving, whether my brake lights, turn signals, or headlights worked at this time to safely transit through traffic to get off the road. I put my hazard lights on, but again did not know if these worked or not. The screen finally came back online and seemed fine until I could get to work, this was an extremely scary experience and a perfect example as to why all cars should have a cluster driver screen mandatory, I will be getting rid of this car as soon as possible.

NHTSA complaint #11570487 — an unverified report by a vehicle owner.

VEHICLE SPEED CONTROL

While driving on highways using adaptive cruise control, the vehicle will slow down quickly from highway speeds of 60 to 75 mph, down to 40 or 45 mph without the presence of an obstruction in front, such as a vehicle, or even a shadow, that could fool the vehicle’s camera. This puts us at risk of being rear-ended on the highway. The problem happens randomly. I have reported the issue to Tesla twice. It happened once while on the phone with a Tesla representative that had called me back regarding my reported complaint. The Tesla rep said they were aware of the issue and were working on correcting the issue via a software issue. Tesla has cancelled my requests for service appointments regarding this issue. In September of 2023 we attempted to use the cruise control to see if it had been repaired but it happened again. There were no prior warnings. The issue first appeared in September of 2021. It has happened many times since then. I first reported around Sep of 2022.

NHTSA complaint #11564006 — an unverified report by a vehicle owner.

VEHICLE SPEED CONTROL

My car has had a problem with TACC since the day I bought it. Brakes aggressively in what should be a normal driving situation. For instance, when I pass a semi truck on the interstate with my own lane in front of me, the car will slam on the brakes when it is beside the truck. Highly likely to cause a rear end collision.

NHTSA complaint #11555805 — an unverified report by a vehicle owner.

VEHICLE SPEED CONTROL

Car will, without warning brake aggressively while in cruise control, without pressure applied to brake. No other factors on road, except cars behind. This occurs frequently when car is driven in autopilot. Car will, without warning accelerate to a high speed without pressure applied to the accelerator. This acceleration is stopped with pressure being immediately applied to brake.

NHTSA complaint #11554312 — an unverified report by a vehicle owner.

VEHICLE SPEED CONTROL

While in cruise control, car will randomly suddenly brake without warning or visible obstacle. This has been an ongoing problem ever since buying the vehicle in 2021. Very dangerous as it has happened on the highway. Is startling and causes seat belt locking. I have reported the issue to Tesla and it's apparently a "limitation of software". We usually do not use cruise control in the Tesla because of the dangerous of this, but I decided to try again recently in hopes they had fixed it but to no avail.

NHTSA complaint #11553954 — an unverified report by a vehicle owner.

VEHICLE SPEED CONTROL

driving from Albuquerque NM to Farmington NM, in approximately 1 1/2 hours of driving on hwy 550, 4 lane divided highway, encountered no less than 12 hard shadow breaking events. in all instances there were no vehicles, animals or debris in front of the vehicle. It was a cloudless day, starting around 9am, clear no fog, temperature in the 40's. high risk of being hit if a car was following close behind, incident has been reported to tesla, no inspection. there was no waring prior to all hard shadow breaking events.

NHTSA complaint #11553785 — an unverified report by a vehicle owner.

VEHICLE SPEED CONTROL

When travelling with adaptive speed control enabled the car will suddenly and violently decelerate 30 to 50 MPH below the set speed. This happens frequently and does not appear to correlate with anything specific. Sometimes it happens when passing a large white truck. Sometimes there is no other traffic anywhere near me. At the very least I would like Tesla to give me the option of disabling the "safety" features so the car operates like every other car with adaptive cruse control. This is not just me. Search the internet for Tesla phantom braking and you will find many instances going back years. It seems to be getting worse with each software update.

NHTSA complaint #11553698 — an unverified report by a vehicle owner.

VEHICLE SPEED CONTROL

Phantom Braking. When there are refractions on the road seen in my lane in bright sunshine. Also in a 2-lane highway with oncoming vehicles that have lots of chrome also in bright sunshine. Never happens at night or when cruise control not enabled.

NHTSA complaint #11535910 — an unverified report by a vehicle owner.

VEHICLE SPEED CONTROL

I was on the highway with cruise set to 80. With no vehicles anywhere near in front of me, the car brakes hard and the cruise was set to 50. I was able to gain control by hitting the accelerator but slowed down quickly from the phantom breaking.

NHTSA complaint #11535924 — an unverified report by a vehicle owner.

VEHICLE SPEED CONTROL

The contact owns a 2021 Tesla Model Y. The contact stated while driving 65 MPH, the vehicle independently accelerated at high speed. There was no warning light illuminated. The contact desperately depressed the brake pedal, and the vehicle came to a to stop. The dealer was contact, but the vehicle was not diagnosed or repaired. The manufacturer was contacted, and a case was filed. The failure mileage was approximately 42,000.

NHTSA complaint #11532811 — an unverified report by a vehicle owner.

VEHICLE SPEED CONTROL

We have recently experienced a significant and concerning increase in incidents of phantom braking and have thus far been unable to receive an adequate response from Tesla. We have had at least six instances of this occurring today, 16-Jun-2023 in the first 6-7 hours of our cross-country drive, and I’ve shared these time stamps with Tesla service. This is because we experienced this same thing 2-3 times on another long drive in November of 2022, and Tesla service told us at the time they couldn’t do anything about it unless we had time stamps because otherwise, it’s too many pages of code to sort through and beyond that, you have to notify them within 12 days of the incident or they can’t look into it at all (which is what happened with me- although I had to chase them to even get a response). They also said it was a “known issue” but were unsure about a planned remedy. I took screenshots of that conversation with Tesla service and have attached to this submission in the event that’s helpful. We are still pending a response from Tesla service for the multiple incidents today. Interestingly, we had taken this car on multiple lengthy drives in all types of conditions prior to Nov 2022, but never experienced this issue previously. It certainly seems to be increasing in frequency and intensity (I know my n=1 for my sample size here makes this somewhat anecdotal, but it’s terrifying regardless) and it seems like only a matter of time until tragedy strikes.

NHTSA complaint #11527418 — an unverified report by a vehicle owner.