This will cut the engine if it fails because the engine wont know when to fire or inject fuel correctly so for safety it kills it, can you start the engine now? Did you get the engine warning light when it cut? And will the fault clear?
Rust on the tracking wheel flange often creates this problem as it clogs up the sensor and gives an unbroken signal.
So if you go ahead and change the sensor then I'd recommend you do the belts, tensioners and variator whilst the engines apart, you shouldn't reuse the current belt anyway.