Tesla’s Brief FSD v14.3.9 Rollout and Its New Automatic Collision Evasion Feature

Tesla’s FSD (Supervised) v14.3.9, associated with the 2026.27 update branch, was briefly made available to North American AI4/HW4 vehicles before the pending rollout was removed. Reports described the withdrawal as occurring within minutes. Tesla had not publicly explained the decision at the time of reporting, so claims that a specific defect, regulatory issue, or the new feature itself caused the pull are unverified. 5

What v14.3.9 introduced

The consequential addition was Automatic Collision Evasion. Unlike conventional Automatic Emergency Braking (AEB), which primarily reduces speed through braking, this feature was intended to let FSD (Supervised) activate during manual driving and use steering, braking, and acceleration to attempt an evasive maneuver when AEB alone may not avoid an imminent collision. 34

Tesla also said the system could engage when it detected that the driver was heavily distracted or believed FSD had been disengaged unintentionally. The feature was described as an active-safety layer within FSD (Supervised), rather than a replacement for driver attention or responsibility. 34

When Automatic Collision Evasion could operate

Reporting on the feature described two broad triggers while the driver was manually operating the vehicle:

1. An imminent frontal collision: The vehicle determines that braking alone may not prevent impact and can engage FSD to try an evasive maneuver. 36
2. Loss of effective driver control or attention: The system detects serious inattention, or concludes that FSD may have been turned off unintentionally. This mode was reported to operate from 22.5 to 85 mph on any road type. 6

For the frontal-collision scenario, the initial operating envelope was notably narrow. It was reported to require:

• a controlled-access highway;
• a speed below 85 mph (137 km/h);
• an imminent frontal-collision risk for which AEB alone may not be sufficient;
• no detected pedestrian, cyclist, or other vulnerable road user in the intended path;
• functioning steering; and
• road conditions that are not wet or slippery. 67

Those constraints mean the feature was not presented as a general obstacle-avoidance system or a license for hands-off driving. FSD remains explicitly supervised: the driver must watch the road and stay prepared to take control. 6

Who was expected to receive it

Automatic Collision Evasion was reported as a North America-only capability for vehicles with FSD (Supervised), with availability tied to AI4/HW4 hardware in the v14.3.9 rollout. It was not described as a standard active-safety feature for owners without FSD. 568

Why Tesla’s withdrawal remains unexplained

The clearest conclusion is also the least dramatic: the rollout was removed, but no public explanation established why. Tesla’s published feature description explained what Automatic Collision Evasion was intended to do, not why v14.3.9 stopped appearing as a pending update. 15

That leaves several possibilities—such as ordinary staged-rollout caution, a packaging or compatibility issue, or a safety-related concern—but the available reporting does not establish any one of them. It is not supported to attribute the withdrawal specifically to Automatic Collision Evasion.

Why the timing drew attention to the FSD 14.3 branch

The pull occurred after the 14.3 branch had attracted scrutiny. In late August, a Tesla reported to be running FSD v14.3.7 failed to stop at an active railroad crossing and nearly entered the path of a passing train, according to the driver and dashcam footage reported by Electrek. That incident is important context, but it does not demonstrate a connection to v14.3.9 or its withdrawal. 29

There were also owner-community reports of parking and routing problems on v14.3.7, including a report that the vehicle attempted to cross double lines to park. These are anecdotal observations, not evidence of how widespread a behavior was or of a defect in v14.3.9. 35

Meanwhile, the FSD release-note text for v14.3.8 was reported to be unchanged from v14.3.6 and v14.3.7, despite a firmware change underneath. Against that backdrop, v14.3.9 stood out because it proposed a new type of intervention: autonomous steering and speed control while the human was otherwise driving manually. 1226

Bottom line

FSD v14.3.9 was a brief and unexplained rollout reversal, not a confirmed recall or a confirmed software failure. Its new Automatic Collision Evasion capability was designed to go beyond braking in tightly restricted emergency scenarios, including by steering around a hazard. The safety implications are significant precisely because the system could intervene during manual driving—yet the evidence provided does not show why Tesla withdrew the update or whether the decision was related to recent reports involving the broader 14.3 branch. 356