The ABS electronic control unit receives a power supply (at pins 2 and 3) directly from the battery from the line protected by fuses F1 and F23 of the engine compartment junction unit B1.The ignition-controlled power supply (INT) arrives at pin 18 from the line protected by fuse F42 of the junction unit under the dashboard B2.The control unit is earthed at pins 1 and 4.The four sensors K70, K71, K75, K76 send wheel speed signals respectively to pins 5-16, 10-9, 17-6, 19-8 of control unit M50.The brake pedal switch I30 sends an enablement signal to pin 20 of the control unit M50: all intervention of the ABS is excluded unless the brake pedal is pressed (signal from N.A. contact); switch I30 receives an ignition-controlled power supply (INT) from fuse F37 of junction unit B2.The discrete speedometer signal sent to certain systems requiring this information leaves from pin 23 of M50; the same signal is replicated via the CAN.Via the CAN line, ABS control unit M50 is connected - from pins 14 and 25 - to the engine management control unit M10 and, from pins 15 and 26, to the Body Computer M1 and the instrument panel E50, to manage the ABS warning light and, if the problems concern the EBD function, the low brake fluid level/handbrake applied warning light.The autodiagnostic data can be read by connecting to connector C of the Body Computer M1 - pin 1: it receives signals from pin 11 of control unit M50 via the special diagnostic line.On right hand drive versions there is also diagnostic connector R10 separate from the Body Computer.