The ABS electronic control unit
M50 is
supplied (at pins 2 and 6) directly by the battery via a line protected
by ABS maxifuse B7.
The supply controlled by the ignition (15/54) reaches
pin 23 from the line protected by the specific fuse
B31.
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.
The brake pedal switch
I30 with the N.A.
contact sends an enablement signal to pin 32 of control unit M50;
this signal arrives from the line controlled by the ignition (INT) protected
by fuse
F1 of the junction unit (it involves the same signal
that lights up the brake lights
See
E2021
BRAKE LIGHTS
.
The switch for the brake pedal
I30 with
an N.C. contact, on the other hand, sends a go ahead signal to pin
20 of control unit M50;
this signal arrives via the line
controlled by the ignition (INT) protected by shunt fuse
B10.
Steering sensor
K58 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 management control unit M1 and
to the ABS control unit M50, pins 24 and 40.
Yaw sensor
K74
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 sensor
K72
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
.
The ABS control unit
M50 is connected,
via the special CAN line, from pin 22, to the instrument panel E50
to manage the ABS failure warning light, the EBD warning light and
the ASR/ESP warning light.
The ASR OFF button, located in the switch
unit
H90, connector C, sends a deactivation signal to pin 27
of M50, whilst the signal that switches on the LED when the system
is switched off is sent from pin 18;
; switch
H90C is supplied
by the line controlled by the ignition (INT) protected by shunt
fuse B10.The autodiagnostic data can be read by connecting
to connector R10: it receives signals from pin 11 of the control
unit M50 via the special diagnostic line.