VDC - Functional description
- Make
- Alfa Romeo
- Model
- 147 Factory Service Manual
- Year
- 2000–2004
- Section
- Vehicle electronic systems › VDC - Functional description
VDC - 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.
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 control unit M1 and ABS control unit M50.
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.
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 VDC and ASR functions manage 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.
Functional description
The ABS electronic control unit M50 is supplied (at pins 2 and 6) directly by the battery via the line protected by ABS maxifuse B5.
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.
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 control unit M1 and ABS control unit M50.
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.
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 VDC and ASR functions manage 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.
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