3026245 - E7021 ASR / TCS - Functional description
Functional description
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
.
The 'ASR OFF' control button on panel
H35
sends a deactivation signal to pin 27 of
M50
, while pin
18 viene relays a signal that turns on a led on panel
H35
when the system is off.
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.
The CAN line that connects
M50
to
M10
allows the ASR function to notify the engine management
control unit of excessive engine power.
Pins 24 and 40 of ABS control unit
M50
connect to Body Computer
M1
and instrument panel
E50
to control the ABS warning light and - if the problem lies in the
EBD function - the low brake fluid level and handbrake warning lights.
The ASR function manages the relevant warning light as described
previously.
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.