Ferrari have revealed that their unique electronic pitstop light system was switched to manual before the pitstop blounder which cost Felipe Massa victory in Sunday's Singapore grand prix.
Massa was given the green light prematurely when he roared off before the refuelling hose had been disconnected from his car.
Team boss Stefano Domenicali explained after the race the overhead light signals are normally connected to the release handle on the fuel nozzle, indicating to the driver that he can leave when the hose is uncoupled.
But with so many cars coming into the pits at the time, the electronic system had been switched to manual, and it was a case of human error.
All the other teams use the conventional stop/go 'lollipops' held by mechanics in front of the car.