Tesla Rolls Out FSD V14.3.9 and V14.2 Lite, 'Automatic Collision Evasi

Tesla has begun a dual-branch software rollout covering current hardware and legacy platforms. According to release notes for software update 2026.27.6, the company is deploying Full Self-Driving (Supervised) v14.3.9 and a new v14.2 Lite build for Hardware 3 (HW3/AI3) vehicles.

The update introduces Automatic Collision Evasion and formalizes a hardware split: newer vehicles gain active safety interventions during manual driving, while older models remain on a separate branch aligned with hardware limits.

FSD v14.3.9: Automatic Collision Evasion for HW4

The headline change in v14.3.9 is Automatic Collision Evasion. The capability was first noted in the owner’s manual and later confirmed to roll out with FSD v14.3.9.

When you are driving manually and the system detects an imminent crash that would be difficult to avoid, Automatic Collision Evasion hands control to FSD. The release notes state the feature is exclusive to vehicles with Hardware 4 (HW4/AI4) FSD computers. It also requires an active FSD purchase or subscription, plus Automatic Emergency Braking and FSD (Supervised) enabled in the vehicle’s settings.

Automatic Collision Evasion can engage in two scenarios while the driver is operating the vehicle manually:

Imminent frontal collisions: If the vehicle determines that braking alone will not prevent a crash with another vehicle on a controlled-access highway under 85 mph, it can steer around the hazard onto the shoulder or into an open lane. During this maneuver, the accelerator is muted, and the system resists inadvertent cancellation, requiring firm steering torque to override.
Inattentive drivers: Between 22.5 mph and 85 mph on any road type, the car can take control if the cabin camera detects inattention or if it infers that FSD (Supervised) was unintentionally turned off.

After the emergency maneuver, the vehicle shifts to a degraded autonomous state, plays a chime, and prompts the driver to take over. Beyond this safety feature, v14.3.9 also includes general FSD improvements, with release notes unchanged from earlier v14.3 builds.

FSD v14.2 Lite: Improvements and UI Tweaks for HW3

In parallel, v14.2 Lite is rolling out to vehicles with Hardware 3 computers. This is the second update to the Lite branch after an updated build in July that added new features and expanded availability.

The release contains FSD improvements, though the notes do not specify underlying model changes. Early users report UI refinements: the on-screen Park and navigation destination pins now have a white border, and the destination icon adjusts based on the selected Arrival Option.

This update may also broaden vehicle eligibility. Tesla AI lead Ashok Elluswamy said FSD v14 Lite is coming to Model S and Model X, and while early access sightings currently focus on Model 3 and Model Y, wider phases could include the older flagship models. The appearance of v14.2 Lite also hints that a v14.3 Lite may follow. However, v14 Lite will likely be the end of the line for HW3 until hardware upgrades to newer FSD computers are offered.