Greetings Hgpatta, a sensor as such of RPM does not exist, it bases its synchronization calculations using the CKP and the CMP, if some of them did not fail or there would be power problems and firecrackers, based on those sensors the ECU sends an RPM signal in some vehicles to the board (such as the Corsa) in others directly controls the position of the RPM needle What link did you download the manual to see if I can帮助您解决问题?