The robotized gearbox control unit M54 controls and regulates the entire gearbox management systemThe direct power supply for the control unit arrives from the battery from the line for fuse F39 of the engine compartment junction unit B1, at pin 27 of connector A.The ignition-controlled power supply (INT) from the line for fuse F23 and relay T6: involves an ignition-controlled power supply controlled from pin 1 of connector A of M1 which reaches pin 28 of connector A of M54.Pins 1 and 2 of connector A of M54 are earthed.A group of sensors and potentiometers on the gearbox inform the control unit of the gear engaged.The potentiometers receive a power supply from pin 73 of connector B; pin 66 provides the reference earth: the gear selection potentiometer K68 returns a signal to pin 51 of connector A; the gear engagement potentiometer K69 returns a signal to pin 39 of connector A; the oil pressure sensor for the hydraulic unit K96 returns a signal to pin 40 of connector A.The clutch position potentiometer K95 is supplied by pin 79 of connector B, receives a reference earth from pin 59, returns a signal to pin 52 of connector A of M54Pins 38 and 50 of connector A M54 are connected to the vehicle speed sensor (gearbox input) K78 .Gear control unit H37 is connected to control unit M54 to indicate the gear engagement request: these signals are sent to pins 67, 74, 68 of connector B of M54 and to pin 26 of connector A; from pin 66 of conector B it receives a reference earth while a power supply is received from the ignition operated line (INT) protected by fuse F23 of engine compartment control unit B1.The button for selecting the "ECO" operating mode, located in unit H90, is connected to the control unit M54 at pin 77 of connector B.Pin 69 of connector B of M54 receives the signal coming from the brake lights switch I30 supplied by fuse F22 of the Body Computer M1.On the basis of the operating logic the control unit controls the electro-hydraulic unit located in the gearbox which produces the gear changes: the electric pump N47, which keeps the fluid in the hydraulic unit pressurized, is controlled from pin 31 of connector A. The pump N47 is controlled by a dedicated relay J87 supplied by the line for the specific maxi fuse F7 of B99.The control unit then controls the opening of the hydraulic unit solenoid valves:- the two gear engagement solenoid valves L51 and L52 are controlled from pins 32 and 44 of connector A of M54- the gear selector solenoid valve L53 is controlled by pin 29 3 of connector A of M54- the clutch control solenoid valve L56 is controlled by pin 43 of connector A of M54.Control unit M54 also manages the doors open signal: the driver''s front door - lock open signal N50 reaches pin 78 of connector B of M54 .Signals are sent, via the CAN - pins 33 and 45 and 7 and 19 of connector A of M54, for the gearbox failure warning light located in the instrument panel E50 and for the gear indication display for the actual equipment.