Stoffel Vandoorne stopped his Renault-powered McLaren on the main straight about an hour into the session. Picture: Jose Jordan / AFP

Montmelo, Spain - The final week of Formula One pre-season testing began on Tuesday with McLaren facing early problems at the Circuit de Catalunya.

Stoffel Vandoorne stopped his Renault-powered McLaren on the main straight about an hour into the session, prompting the first red flag of the day. The car had to be pushed back into the garage for repairs.

"We suffered a power shutdown during Stoff's last run, meaning we lost data," McLaren said. "The team are investigating, but we'll be back out as soon as we can."

McLaren is debuting the Renault engine this season after three dismal seasons with Honda. The team got off to a good start in last week's tests, with Vandoorne finishing with the third-fastest time overall.

Vandoorne's team-mate, former double world champion Fernando Alonso, ran a few laps on Monday on a "filming day." Practice is restricted in F1 but teams are allowed to take their cars to the track for a few brief periods for marketing and commercial purposes.

McLaren also struggled in the first week of testing last week as Alonso lost a rear wheel and was forced off the track. The first four days of testing were hampered by bad weather and cold temperatures in Barcelona, keeping teams from making quality runs on a track that lacked enough grip and didn't reproduce the conditions expected during the season.

Defending champion Lewis Hamilton had the fastest time last week with Mercedes. Team-mate Valtteri Bottas and Ferrari driver Sebastian Vettel were among the fastest early in Tuesday's session.

Teams will test until Friday, before the season proper begins with the Australian Grand Prix in Melbourne on 25 March.

AP