ABS OPERATIONAL DESCRIPTION

Operational Description

The ABS function is managed by ABS control unit M050.

Pins 2, 6 of connector A receive power from engine bay control unit B001 via a line protected by maxifuse MF02. Pin 23 connector A of control unit M050 is supplied by junction unit B001 via a line protected by fuse F03.

The control unit M050 converses, from pins 24 and 40 of connector A, via the CAN, with the body computer node M001, at pins 2 and 4 connector M.

Pins 19, 35 connector A of control unit M050 communicate via the CAN with engine control unit M010 at pins A3, A4 connector A.

Control unit M050 controls the speed of each individual wheel via wheel sensors K070 (pins 12, 28 connector A), K071 (pins 16, 16 connector A), K075 (pins 13, 14 connector A) and K076 (pins 30, 31 connector A).

Pin 32 connector A of control unit M050 receives a right and left front wheel brake pad wear earth signal from sensors K020 and K021.

An earth signal is received at pin 22 connector A coming from the sensor K025 signalling the brake fluid level; these signals are then sent, via the CAN, to the instrument panel and to the milometer warning lights node M140.

The lighting up of the ABS system warning lights (ABS failure, EBD function/minimum brake fluid level) is managed by the milometer warning lights node M140, which communicates, via the CAN, with the instrument panel E050 and the body computer node M001.

The instrument panel E050 and the milometer warning lights node M140 receive a supply via the CAN (pin 13 of E50 and pin 4 of M140) through the line protected by fuse F24 of the body computer M001.

A speedometer signal is available from pin 33 of the ABS control unit M050; this wire is not connected on the dashboard side of the coupling D001 and can be used for connecting the meter for the TAXI version or for any device that requires this signal.

The brake pedal pressed signal comes from the brake pedal switch I030, connected to the body computer node M001 at pin 2 of connector B and is supplied directly by the ignition switch H001.

Clutch pedal switch I031 and the safety switch on the brake pedal I035 supply a signal to indicate engagement has taken place to pins E3 and E4 of connector B of M010, respectively.

The two switches receive a supply from the ignition-controlled line protected by fuse F18 of the body computer M001.

The "redundant" switch I035 is the "normally closed" type (when the pedal is pressed, the switch contact opens): the system checks the consistency of the "pedal pressed" information in this way.

The information is sent, from the control unit M010, via the CAN, to the control unit M050.

Control unit M050 has an autodiagnostic function: the autodiagnostic data can be read by connecting to connector R010 - pin 12: it receives signals from pin 11 connector A of M050 via the special diagnostic line.