The US National Highway Traffic Safety Administration (NHTSA) on Wednesday announced an investigation into a second crash of a Tesla Motors vehicle that may have been using the company's pioneering self-drive "Autopilot" technology.

The accident, involving Tesla's latest Model X, took place on July 1 in the US state of Pennsylvania, nearly two months after a fatal crash in Florida in which the "Autopilot" function may have been in use.

The NHSTA told the AFP news agency it is investigating "to determine whether automated functions were in use at the time of the crash."

Tesla said it attempted to contact the driver to no avail upon receiving an electronic data message from the car "indicating a crash event."

"As we do with all crash events, we immediately reached out to the customer to confirm they were OK and offer support, but were unable to reach him," Tesla said.

"It is not possible to learn more without access to the vehicle's onboard logs," the company added.

The US highway safety agency has already launched a probe into the May crash, in which the Tesla vehicle failed to stop as a semi-trailer truck turned, resulting in the hatchback car running under the trailer. The driver died in the crash.

"It is important to note that Tesla disables Autopilot by default and requires explicit acknowledgement that the system is new technology and still in a public beta phase before it can be enabled," the company said in June after the NHSTA launched its first probe.

Tesla added that the self-drive technology "requires you to keep your hands on the steering wheel at all times," and serves as an "assist feature" to reduce driver workload.

ls/sms (AFP, Reuters)