The ABS electronic control unitM50 is supplied (at pins 2 and 6) directly by the battery via a line protected by maxifuse F4, housed in the engine compartment junction unit B1. The ignition-operated supply (INT/A) reaches pin 23 from the line protected by the fuse F42 of under facia control unitB2. The control unit is earthed via pins 1 and 5.The four sensorsK70, K71, K75, K76 send wheel speed signals to pins 28-12, 15-16, 13-14 and 30-31 of M50 respectively. When the brake pedal is pressed, the brake pedal switchI30 sends an enablement signal (N.O contact) to pin 32 of control unit M50: the ABS cannot intervene unless the brake pedal is pressed. The switchI30 is supplied when the ignition is switched on (INT) from fuse F37 of junction unit B2. When the pedal is released, the N.C. contact is sent to pin 20 of the control unitM50;this contact of switchI30 is supplied when the ignition is switched on (INT) from fuse F35 of junction unit B2.The ''ASR OFF'' control button on panelH35 sends a deactivation signal to pin 27 of M50, while pin 18 relays a signal that turns on a led on panel H35 when the system is off. Pin 37 ofM50 emits a discrete speed signal that is sent to Body Computer M1; the same signal is also copied via the CAN network.Steering sensorK58 is supplied by ABS control unit M50 at pin 39 and receives a reference earth from pin 21: the signal that detects sudden changes in steering direction is sent via the CAN line to engine control unit M1 and ABS control unit M50. Yaw sensorK74 is supplied from ABS control unit M50 at pin 39, while it receives a reference earth from pin 21: control and command signals are exchanged with ABS control unit M50, at pins 8, 9, 10 and 41. Pressure sensorK72 is supplied from ABS control unit M50 at pin 42, while it receives a reference earth from pin 25: the pressure detection signal is sent to pin 26 of ABS control unit M50. Via the CAN line, pins 24 and 40 of ABS control unitM50 connect to Body Computer M1 and and instrument panel E50 to control the ABS warning light and - if the problem lies in the EBD function - the low brake fluid level and handbrake warning lights. The VDC and ASR functions manage the relevant warning light as described previously.Self-diagnostic data can be read by connecting to connector G of Body ComputerM1 - pin 1: it receives signals from pin 11 of control unit M50 via a special diagnostic line.