Tesla has begun rolling out version 14.3.9 of its Full Self-Driving (FSD) Supervised software, adding a safety mode that activates the system without driver input when a collision is imminent and automatic emergency braking (AEB) may be insufficient. The update also enables automatic engagement when a driver is detected as heavily distracted or has accidentally disengaged the system.

The collision feature activates when the system assesses AEB alone as insufficient. FSD Supervised has until now required active driver oversight; this version adds a mode in which the system can initiate without driver input under defined safety conditions.

The distraction and accidental-disengagement triggers extend the same principle: FSD Supervised can now re-engage on a driver’s behalf when inattention or an unintended deactivation is detected. Together, the three scenarios form what Tesla describes as a new active safety feature set.

In a post on X, Tesla said: “FSD Supervised v14.3.9 starting to roll out shortly. 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.”

Why this matters:

• Manual driving is no longer a firewall.By allowing FSD to take control even when the driver has not engaged the system, Tesla is narrowing the line between assisted and autonomous driving, which could complicate how liability is assigned when the system intervenes uninvited.
• Undisclosed intervention rates raise a validation question.Tesla has not published how often the feature is expected to activate or how it handles false positives, leaving the system’s real-world reliability and the risk of unwanted takeovers largely untested in public data.
• Coordinated evasion pushes past emergency braking’s limits.Steering and accelerating around a hazard, rather than simply braking in a straight line, suggests Tesla is testing capabilities that overlap with automated driving functions regulators typically scrutinise more closely than standard AEB.