J'ai lu ce post #21 sur le forum AF1, ils préconisent le changement d'un capteur de vitesse de rotation moteur plus sensible :
It's TECHNICAL BULLETIN No. 009-2010 (29-03-2010) and says that the cause may be the ENGINE SPEED SENSOR, p/n 6389915. The sensor may bereplaced with the alternative part, p/n 897577, which has a different degree of sensitivity to the signal received from the tone wheel.