ABS control unit M050 receives a power supply directly from the battery - pins 17 and 18 - and an ignition-operated supply - pin 15 -. The direct battery power supply is protected by fuse F04 located in engine bay junction unit B001. The ignition-operated supply is protected by fuse F42, located in the under-facia junction unit B002.When the brake pedal is pressed, switch I030 supplies control unit M070 - pin 14 - with an ignition-operated supply protected by fuse F26, located in control unit B002.ABS control unit M050 activates wheel sensors K070, K071, K075 and K076 via pins 1, 2, 3, 4, 6, 7, 8, 9. If the system malfunctions, the control unit turns on the warning lights on instrument panel E050.Control unit M070 receives an activation/deactivation commandfrom control panel H090 - pin 4 connector C - from pin 31.Sensor K025 monitors brake fluid level. When this level is too low, the sensor closes the earth circuit by turning on the warning light on instrument panel E050 - pin 2 connector B -.Sensor K020 monitors brake pad wear and controls activation of a warning light on instrument panel E050 - pn 3 connector B - if the pads malfunction or are replaced.