Barcelona: Kimi Raikkonen`s Lotus team pulled out of the second pre-season Formula One test in Barcelona on Tuesday after a problem with their new car.
The former Renault team had earlier called a halt to the first day of the session at the Circuit de Catalunya after Frenchman Romain Grosjean had completed just seven laps in the second chassis.
Lotus had said they would return the car to the factory in Britain and replace it with the first chassis used in Jerez last month, where returning 2007 champion Raikkonen was fastest on the first day, but that plan was later abandoned.
Technical director James Allison said in a statement that the team had run simulations at the factory based on data provided from Tuesday`s few laps and had identified what needed fixing.
"It will be more productive for us to carry out these modifications to both chassis at Enstone rather than send (car) E20-01 out to this week`s test," he said. "We`ll put the right measures in place and we will be able to fix the problem before next week."
The second pre-season test runs until Friday with the third and final test starting next week at the same circuit. The season starts in Australia on March 18.
Team principal Eric Boullier said it had been a tough decision to take.
"We draw faith from the fact that the E20 was quick out of the box in Jerez and showed its reliability there," he added. "We have a lot of work ahead of us over the next week but everyone at Enstone is ready for this challenge."
Red Bull`s double world champion Sebastian Vettel was fastest overall on Tuesday, with fellow-German Nico Hulkenberg second on the timing screens for Force India and McLaren`s Lewis Hamilton third.
"It`s difficult to judge where we are compared with the others right now. It`s all based on feeling and the feeling I have inside the car at the moment is fine," said Vettel.
Australian Daniel Ricciardo was fourth for Toro Rosso, ahead of Ferrari`s Fernando Alonso and seven-times champion Michael Schumacher in the new Mercedes that was presented to the world in the morning.
"My initial feelings with our new car are certainly good," said 43-year-old Schumacher, whose session was ended by an hydraulics problem. "It`s certainly an improvement and we have worked hard on the areas we had defined last year."
French rookie Charles Pic completed the most laps, 121, in the 2011 Virgin for what is now the Marussia team.
The team missed the Jerez test and plan to launch their new car at the final test on March 1.