McLaren will revise Honda's MGU-K system with its own components for this week's final pre-season Formula 1 test, while Honda works on solving the problems that ruined its previous outing.
A faulty seal on the MGU-K component of Honda's ERS system compromised all four days of the McLaren-Honda F1 squad's running at Barcelona last week.
The problem restricted Jenson Button to just 21 laps on day one at the Catalunya circuit, while Fernando Alonso had to drive the car at reduced power to prevent a recurrence of the problem on day two.
This prompted McLaren racing director Eric Boullier to declare the team was "50 per cent behind" with its test programme at the midway stage of pre-season.
Honda produced a redesigned seal from its UK base in Milton Keynes in time for the third day of running, but this also failed, meaning Button completed just 24 laps before having to stop the car.
McLaren installed an old MGU-K unit in order to allow Alonso to recover some lost mileage on the final day of the test, but that too came to a premature end when the double world champion crashed at high speed exiting Turn 3 on his 21st lap of the morning.
The seal problem is understood to be a key difficulty that affected other manufacturers when they first designed engines for F1's current V6 hybrid turbo formula, one for which AUTOSPORT sources say there is no 'quick fix'.
McLaren intends to use the internal expertise it gained from developing its own Kinetic Energy Recovery Systems when KERS was introduced into F1 in 2009, in the short term, to allow Honda more time to find a proper solution to the problem.
AUTOSPORT understands the team will revert to using Honda's MGU-K unit in the MP4-30 for this week's final pre-season test, but with a McLaren seal fitted.
The test gets under way at Barcelona on February 26.
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