The ABS electronic control unit
M50
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
unit
B2
.
The control unit is earthed via pins 1 and
5.
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.
Brake pedal switch
I30
sends an
enablement signal to pin 32 of control unit
M50
: the ABS
cannot intervene unless the brake pedal is pressed. The switch
I30
is supplied when the ignition is switched on (INT) from fuse F37
of junction unit
B2
.
Pin 37 di
M50
emits a discrete speed
signal that is sent tol Body Computer
M1
; the same signal
is also copied via the CAN network.
Pins 24 and 40 of ABS control unit
M50
connect to Body Computer
M1
and instrument panel
E50
via the CAN line to manage the ABS failure warning light and - if
the problems affect the EBD function - the low brake fluid and handbrake
warning lights.
Self-diagnostic data can be read by connecting
to connector G of Body Computer
M1
- pin 1: it receives
signals from pin 11 of control unit
M50
via a special diagnostic
line.