The German had completed 40 laps in Barcelona when the mishap occurred and the car had to be towed back into the pits.
Vettel had the sixth-best time of the day at the time, some seven-tenths of a second behind leader max Verstappen of Red Bull.
He missed the opening day of testing Wednesday because he didn't feel well, and shared Thursday with team-mate Charles Leclerc.
Another three days of testing at the Circuit de Catalunya are scheduled for next week. The season starts on March 15 in Australia.
Vettel had the sixth-best time of the day at the time, some seven-tenths of a second behind leader max Verstappen of Red Bull.
He missed the opening day of testing Wednesday because he didn't feel well, and shared Thursday with team-mate Charles Leclerc.
Another three days of testing at the Circuit de Catalunya are scheduled for next week. The season starts on March 15 in Australia.