Tesla began pushing FSD (Supervised) v14.3.9 to customer cars on Tuesday afternoon and withdrew the pending update from owners’ vehicles within about 20 minutes, according to owners who had been downloading it, for reasons the company has not given.
The release, software update 2026.27.6, carries the first new capability in the 14.3 branch since mid-summer: Automatic Collision Evasion.
The feature switches FSD on while the driver is driving manually if the car judges a frontal collision to be imminent or the driver to be inattentive.
Tesla has not commented on the withdrawal as of the time of writing.
“Tesla FSD V14.3.9 just officially started rolling out,” Sawyer Merritt, a Tesla investor, owner and content creator wrote on X at 5:35 p.m. Central time, posting the in-car release notes and adding, “Downloading it on my Model Y right now.”
About 15 minutes later he wrote: “Update: Looks like Tesla temporarily pulled the pending software update from everyone’s cars. Not sure why.” Another owner, posting as Zack with the handle @BLKMDL3, replied that the update had “disappeared from all my cars.”
“Mine too. Weird,” Merritt answered.
The Feature
Tesla AI teased the release on September 4, in a post that had 1.3 million views by Tuesday. “FSD Supervised v14.3.9 starting to roll out shortly,” it read.
“This release includes a new active safety feature set: FSD Supervised can now activate on your behalf when an imminent collision is detected and Automatic Emergency Braking (AEB) may not be enough. It may also engage if we detect you’re heavily distracted or have accidentally disengaged FSD.”
The employee build, 2026.27.5, was documented by September 6. The public build, 2026.27.6, reached AI4-equipped customer cars on Tuesday afternoon before being withdrawn.
In the in-car notes Merritt, Tesla says the”Automatic Collision Evasion activates Full Self-Driving (Supervised) to try to keep your vehicle safe and then continue driving.”
The company adds, “It can engage in the following situations while you are driving manually: Scenario 1: A frontal collision is imminent and braking alone may not avoid it. Scenario 2: Your vehicle detects that you are not sufficiently attentive to the road (for example, reaching toward the back seat), or that Full Self-Driving (Supervised) may have been unintentionally disengaged. See your Owner’s Manual for more details.”
Feature Details
Tesla’s owner’s manual details that, for the frontal-collision case, the conditions include when a collision with another vehicle is imminent and braking alone cannot prevent it, the car is on a controlled-access highway below 85 mph (137 km/h), no pedestrians, cyclists or other vulnerable road users are in the path, the steering system is functional, and the road is not wet or slippery.
The car may then change lanes or move onto the shoulder, braking or accelerating as needed. For the inattention case, the system operates between 22.5 and 85 mph on any road type.
During a manoeuvre the accelerator is muted and the brake slows the car without cancelling it. Firm steering force is the override. A chime prompts the driver to resume once the hazard clears.
The feature requires an FSD purchase and is enabled under Controls, then Self-Driving. Tesla describes it as a last resort, not a general obstacle-avoidance or lane-change function.
It is the first time Tesla has allowed its supervised driving policy to take control of a car that the driver, not the software, is driving.
Existing active-safety features, automatic emergency braking, obstacle-aware acceleration, blind-spot and lane-departure warnings, intervene without engaging FSD.
The feature is limited to AI4 (HW4) cars in North America. Europe’s FSD Supervised markets run a separate 14.2.2.x branch and are not included.
The 14.3 branch has had one rough patch this summer. Owners reported braking regressions on v14.3.6 in late July, and v14.3.7 in early August was received as the fix.
The v14.3.8 was a firmware merge with the Summer Update rather than a driving change.
