New yaris stops dead while cruising

[wildgirl]

My dad purchased this Saturday an 18 month old Yaris 1.0 with just under 10,000 miles on the clock.
He took it out today for it's first distance drive and while cruising on the motorway it came to a dead stop - the engine was still running. He turned off the ignition and it took a couple of mins before he could start it again.
A few miles down the road and it did it again.
Is this a common fault?
Any ideas what it could be?

[jambo101]

I have an 08 Yaris sedan and it too stops running,the motor never dies its like it doesnt have any throttle response,got the dealer to check it out and he read the codes (P0121 and P2121)and found the problem to be a faulty
throttle position sensor