US Tesla driver stranded in the desert after smartphone app failure

Smartphone car control is still a fairly new concept. Photo / Instagram / Ryan Negri

A Tesla driver was stranded in Red Rock Canyon near Las Vegas after the car's keyless control app suddenly stopped working.

Interested in testing a feature that lets Tesla owners unlock and power their car using their smartphone, Ryan Negri decided to leave his keys at home when he went for a drive around the canyon yesterday.

The keyless smartphone feature, which is available through Tesla's iPhone and Android apps, lets users remotely monitor and control their Tesla Model S without their key. One of the main features of the app is the ability to "unlock and drive Model S without your key".

Negri was able to do just this - but only to begin with. After getting out of the vehicle to adjust something when he was six miles from home he found himself locked out of the car unable to get back in let alone start it.

"Six miles down the road we decided to turn back, but before that, had to adjust Mozy & Millie's car bed, so I exited the vehicle...bad idea," Negri said on Instagram. "Need to restart the car now, but, with no cell service, my phone can't connect to the car to unlock it."

What Negri didn't know before leaving the house without his keys was that the feature requires the owner's phone to have signal.

Without signal it is unable to connect to Tesla's servers to unlock or start the car.

While wireless key technology is fairly common, smartphone car control is still a fairly new concept. Negri said he should have taken his keys as a precaution but also criticised Tesla for not having a contingency plan in such cases.

To save the family from being stranded in the desert all night, Negri's wife had to run two miles to find signal and call a friend to bring the key fob. Had they driven further into the canyon when the problem arose it could have been more difficult for them to get home.