Jenson Button might not receive Honda’s upgraded power unit at this weekend’s Mexican Grand Prix as McLaren continue to investigate what caused team-mate Fernando Alonso’s to lose power.
The Spaniard had been running in fifth when he reported a loss of power, dropping him back to 11th and outside the points.
It’s not known whether the engine can be used again, or whether they will need to replace parts and thus take further grid penalties for the Mexican weekend.
“Fernando lost power, but we don’t know exactly why yet,” Boullier is quoted by Motorsport.
“We understand that there was an issue with some sensors maybe, so we had to tell him to reprogram differently the car, but the damage was done.”
The upgrade, which is believed to deliver around 20bhp over its predecessor, may not make a return this season unless a solution is found to the problem, therefore Alonso could revert back to the previous spec whilst Button continues to use his current unit.
“We need the investigation on the engine before we decide [to use it],” added Boullier. “Because we need the engine to last longer than this.”