It was another disappointing day for the McLaren-Honda team in Spain on Friday when their progress on the final day of pre-season testing was hampered by a series of intermittent electrical issues.

The problem caused the car to shut down, stopping Fernando out on track twice within a few short laps in the morning session and at this stage, it's unclear if it's the same issue that Stoffel encountered on Thursday.

Overnight, the team changed a number of electrical components on both the PU and chassis, but the problem persisted.

With every run in the morning session, the team changed further parts in an effort to eliminate as many variables as possible and identify the source. Over lunch, the team elected to undertake more significant and time-consuming changes in order to get the car back out on track in the afternoon.

Fernando returned to the track at 15:40 for a more productive stint until the track closed at 18:00. Despite an interrupted day of running, he still completed 43 laps consisting of aero, set-up and tyre tests.

“Today was a disappointing way to end the test, as we weren't able to make the most of the final day of running. The morning started positively and we were working well through our programme, until the car lost power in the corner and shut off, so I had to park it.

“We managed to fire up again without any problems, and everything ran smoothly for a few laps until it happened again, so we realised we needed to investigate deeper over the lunch break and make more changes. I'm pleased we were able to get going again in the afternoon – we wanted to use all the track time we could – as every single lap we do is useful for our learning,” Fernando said.

“It's clear we have a lot of preparation ahead of us to be ready in time for Melbourne. I know the team is working hard and we'll be able to find more answers once we get the car back to the factory. I'm hopeful we'll be able to make the next step we need to be ready for Australia.”

The team will now return to base to analyse the information gleaned from the test in order to push forward in preparation for Melbourne.