Mercedes believes a failure within the Control Electronics of Valtteri Bottas’ power unit caused his exit at the Nürburgring and says further damage has been avoided.
Bottas was on course for a podium, having slipped from pole position to a net third after a mistake and early pit stop, when he reported a loss of power.
Mercedes opted to retire him from the race as it feared that remaining on track would result in further damage to the power unit.
Formula 1 drivers are restricted on the number of components that can use each year before having to incur grid penalties.
Mercedes initially suspected that a problem within the MGU-H caused the failure but has now narrowed it down to an issue from the Control Electronics.
Bottas’ retirement, allied with Lewis Hamilton’s victory, means there is now a 69-point gap between the Mercedes drivers in the championship.
“It was undoubtedly a tough blow at this stage of the season,” said Mercedes team boss Toto Wolff.
“We have identified a failed electrical component in the Control Electronics as the cause of the problem and the evidence suggests that swift action in retiring the car prevented mechanical damage to his Power Unit.
“A DNF is always tough for a driver, but one of Valtteri’s biggest strengths is his resilience and his ability to bounce back, so I’m sure he’ll be eager to hit the track in Portugal.”
It marked the first in-race mechanical failure for a Mercedes driver since last November’s Brazilian Grand Prix.