3315758 - E7022 VDC - Functional description

Functional description

The ABS electronic control unit M50 is supplied (at pin 2 and 6) directly by the battery via a line protected by fuses F2 and F4 housed in the engine compartment junction unit B1. The supply controlled by the ignition (15/54) reaches pin 23 from the line protected by fuse F9 of junction unit B2.The control unit is earthed via pins 1 and 5. The ABS control unit M50 is connected through a CAN line from pins 24 and 40 to the engine management control unit M10 allowing the exchange of information between the two control units. This CAN line also connects the steering sensor K58 and the slewing sensor K74 from pins 21 and 39 of M50. Pins 8, 9, 10, 21, 39 and 41 are connected to the slew sensor K74 , which informs the control unit M50 on the rotation of the vehicle around the vertical axis. Pins 25, 26 and 42 of M50 are connected to the pressure sensor K72 . The four sensors K70, K71, K75, K76 send wheel speed signals to pins 28-12, 15-16, 13-14 and 30-31 of M50 respectively. The control unit M50 also controls the ASR functions: it is connected from pin 27 to the special on/off button located in the control panel on the tunnel H36 (pin 14). When the ASR function is deactivated, the control unit turns on the LED next to the button from pin 18 - pin 5 of H36. Both the button and LED for H36 receive an ignition-controlled supply (15/54) from the line protected by fuse F5 of junction unit B2. The switch I30 N.A. contact is supplied when the ignition is turned on (15/54) from fuse line F1 of junction unit B2:when the brake pedal is pressed, the switch closes and sends the enablement signal to pin 32 of control unit M50. The ABS is deactivated entirely unless the brake pedal is pressed. The same signal for the brake pedal I30 is also used for operating the brake lights See E2021 BRAKE LIGHTS .

the second contact for the brake pedal I30, N.C. contact, receives an ignition-controlled supply (15/54) from the line protected by fuse F9 of the junction unit B2; when the brake pedal is released, the switch sends a signal to pin 20 of control unit M50.

Pin 37 of M50 produces a speedometer signal (average speed of all four wheels) which is directed to instrument panel E50 - pin 2 of connector B See E4010 INSTRUMENT PANEL . The ABS includes a self-diagnostic system: when the control unit detects problems with the ABS function, it sends a signal from pin 38 of M50 to instrument E50 - pin 19 of connector C - which turns on the ABS fault warning light.If the problems involve the EBD function, the control unit also sends a signal on the same serial line to the 'insufficient brake fluid level' and 'handbrake applied' warning light.pin 22 of M50 E50 if the ASR system intervenes the warning light flashes; if there is a failure, the warning light remains on constantly. The autodiagnostic data can be read by connecting to connector R10 - pin 1: it receives signals from pin 11 of the control unit M50 via the special diagnostic line See E8010 DIAGNOSTIC MULTIPLE CONNECTOR .