McLaren-Honda's struggle continued into the second week of testing on Tuesday after the team was forced to make an engine change on the first morning back at the Circuit de Catalunya.
An electrical issue saw Stoffel Vandoorne complete just 34 laps before the team suspended its morning run plan to change the engine. The power unit was the same specification as the one that suffered two problems last week, but Honda is expected to bring an updated spec ahead of the first race in Melbourne. The replacement power unit being fitted to the car for the afternoon session is also the same spec as last week's.
"We detected an electrical issue with the PU in Stoffel's car," a Honda spokesperson said. "In the interest of maximising track time, we opted to replace it and investigate the issue further once the PU is out of the car. The PU we are using today is the same spec as the PU run last week at test one."
McLaren completed 208 laps in the opening week of testing, which was 49 less than it managed in the first week of testing last year. Over the course of the week it suffered a problem with the oil tank, which was redesigned and manufactured in time for day three, and a mechanical issue, which was due to be investigated between tests.
Tuesday is Vandoorne's penultimate day in the car ahead of the first race in Australia at the end of the month.