Mercedes has been forced to bring an early end to its programme on the opening day of F1 testing at Jerez following an electrical issue with the new F1 W04.
Nico Rosberg had completed only a handful of laps on Tuesday morning and hadn't set a time when his car ground to a halt on track before the German had been able to set a time.
It brought the session to a halt for the second time after Jenson Button's McLaren had stopped earlier and having spent time investigating the issue, Mercedes has now confirmed that Rosberg's day has come to an early end.
“After identifying the cause of the problem, we will not be running again today whilst parts are modified ready for tomorrow,” the team revealed on its Twitter
“The part which requires modification is the wiring loom where the electrical fault originated this morning.”
Rosberg is due to hand the car over to Lewis Hamilton for his debut in Mercedes colours on Wednesday.