Carlos Sainz took over from Dany Kvyat at Toro Rosso this afternoon but suffered the same drivetrain issue which limited the Russian's running in the morning.
Sainz was forced to stop out on the track at Turn 4, ending his session with two hours to spare. A state of affairs which naturally frustrated the Spaniard.
"Doing only half a day today, we were looking to maximize it, get into a good rhythm and add plenty of mileage to the car," explained Sainz.
"Unfortunately, we suffered a drivetrain failure half way through the afternoon, which meant we had to stop and not run any more today.
“It’s frustrating, but this is what happens sometimes during testing."
Toro Rosso's Jody Egginton, Head of Vehicle Performance, admitted the issue was a setback but one which the team vowed to resolve as early as possible.
"The issues today, combined with not having had a perfect day one and day two, leaves us with a lot of ground to cover between now and the end of the next test.
"However, we are up for the challenge and feel confident that there is a lot of potential in the STR12; we just have to remain focused in the remaining test we have and we will unlock it."
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