Tesla updates software

DETROIT — Tesla Motors says a software update to its Autopilot system will disable automatic steering if drivers don’t keep their hands on the wheel.

The update also adds multiple features, including improved radar, better voice commands and an industry-first temperature control system that helps prevent kids and pets from overheating.

Tesla started moving the update to Model X SUV and Model S sedan owners Wednesday night over the internet.

Tesla’s Autopilot system, which was unveiled last fall, uses cameras and radar to maintain a set speed, brake automatically and change lanes without the driver’s input. Drivers can keep their hands off the wheel for minutes at a time, depending on road conditions. Critics questioned whether the system was ready to be on the road this summer after a driver using Autopilot was killed when his Model S sedan struck a tractor-trailer in Florida.

Tesla says the software update should help avoid crashes, since it will enhance the radar system and make Tesla’s vehicles rely more on radar signals — which can see through snow, bright sun and other weather conditions — than cameras. The new radar can detect braking in cars up to two lengths ahead and has a clearer picture of the road than the previous version. The company also redesigned its indicator lights to more clearly show when Autopilot is engaged.

If drivers ignore three warnings to place their hands on the wheel, the automatic steering will be disabled and won’t resume until the car is parked. As in earlier versions, the car will slow to a stop if the warnings are ignored.