According to several media outlets, Frenchman Isack Hadjar of Red Bull, who had set the fastest time on Monday, was involved in a minor off-track incident at the end of the day, slightly damaging the rear of his car.
Ferrari took to the track for the first time this week with Monegasque driver Charles Leclerc, who racked up 64 laps in the morning despite the rain, before handing over the wheel to seven-time world champion Lewis Hamilton, who put in a sturdy 57-lap stint.
"For now, it's all about trying to understand if everything is working properly, which it kind of did," Leclerc said.
"It's not the best conditions because it has been a little bit raining this morning, but actually we did our programme anyway because we are not focused on performance whatsoever."
Four-time Dutch world champion Max Verstappen also drove for Red Bull and set the fastest time of the day in dry conditions, more than a second ahead of Leclerc.
McLaren, the two-time defending constructors' champion, preferred to fine-tune their settings on Tuesday and confirmed that their car would take to the track on Wednesday and is also expected to run on Thursday and Friday.
Aston Martin announced on Monday that they would not be running until Thursday, losing one of their three authorised days of testing, while Williams decided not to take part in this session in Spain due to delays in the development of their car.
On Monday, seven of the 11 Formula 1 teams took to the Circuit de Barcelona-Catalunya for the first day of private testing, held behind closed doors without spectators or journalists - they were Alpine, Audi, the new American team Cadillac, Haas, Mercedes, Racing Bulls and Red Bull.
With the upheaval in technical regulations set to take effect for the upcoming season, teams are focusing this week on the reliability of their cars rather than performance.