Block Diagram
CAN abbreviations
| 15 | Ignition ON (terminal 15) | B52_L | Wheel speed sensor, front left |
|---|---|---|---|
| 30 | Battery positive (terminal 30) | B52_R | Wheel speed sensor, front right |
| 31 | Ground (terminal 31) | B76_L | Wheel speed sensor, rear left |
| A132 | Audio systems | B76_R | Wheel speed sensor, rear right |
| A155 | Navigation control unit | S216 | Brake light switch |
Function Table
| Terminal | Description | Source | Destination |
|---|---|---|---|
| X1-1 X1-2 X1-13 X1-14 HSCAN | Engine torque request | ABS | ECM |
| X1-1 X1-2 X1-13 X1-14 HSCAN | The ABS status is transmitted | ABS | ECM, TCM, CIM, YRS |
| X1-1 X1-2 X1-13 X1-14 HSCAN | Wheel speed is transmitted to the engine control unit for generation of the vehicle speed signal | ABS | ECM |
| X1-1 X1-2 X1-13 X1-14 HSCAN | The wheel speeds are transmitted to the engine control unit for calculating the odometer signal | ABS | ECM |
| X1-1 X1-2 X1-13 X1-14 HSCAN | Steering angle sensor information (ESP) | CIM | ABS |
| X1-1 X1-2 X1-13 X1-14 HSCAN | Network monitoring | CIM | ABS |
| X1-1 X1-2 X1-13 X1-14 HSCAN | Engine speed, accelerator pedal position, throttle valve position | ECM | ABS |
| X1-1 X1-2 X1-13 X1-14 HSCAN | Engine torque | ECM | ABS |
| X1-1 X1-2 X1-13 X1-14 HSCAN | The engine control unit status is communicated to the ABS (engine torque intervention, malfunctions and engine running status) | ECM | ABS |
| X1-1 X1-2 X1-13 X1-14 HSCAN | Information regarding transmission emergency operation, gear engaged and selected shift mode | TCM | ABS |
| X1-1 X1-2 X1-13 X1-14 HSCAN | Information regarding yaw rate and lateral acceleration (ESP) | YRS | ABS |
| X1-7 X1-8 | Registering speed signal for front right wheel | B52_R | ABS |
| X1-9 X1-10 | Registering speed signal for rear right wheel | B76_R | ABS |
| X1-11 X1-24 | Ground (terminal 31) for the valves (11), and for the pump motor (24) | Ground | ABS |
| X1-12 X1-25 | Battery positive (terminal 30) for the valves (12), and for the pump motor (25) | UEC | ABS |
| X1-17 | Detecting actuation of the brake pedal switch | S216 | ABS |
| X1-18 | Odometer signal for audio systems | ABS | A132, A155 |
| X1-19 X1-20 | Registering speed signal for front left wheel | B52_L | ABS |
| X1-21 X1-22 | Registering speed signal for rear right wheel | B76_L | ABS |
| X1-23 | Hard-wired line for ignition ON (terminal 15) | CIM | ABS |
Functional Description
Odometer Signal and Vehicle Speed Signal
The wheel speeds are transmitted from the ABS to the engine control unit via the HSCAN for generation of the odometer signal and the vehicle speed signal. Using this information and the wheel size, an odometer signal / vehicle speed signal is calculated in the ECM. The calculated information is then transmitted to the HSCAN bus. The engine control uses the left front wheel speed and in case of malfunction the right front wheel speed to calculate the vehicle speed. The distance travelled is calculated via the left rear wheel speed and in case of malfunction, the right front wheel speed.
Traction Control
Traction control is performed by means of a controlled brake intervention to the driven wheels and/or a torque control intervention calculated by the ABS/TC via CAN bus request via the engine control unit.
ESP (Electronic Stability Program)
The ABS/ESP intervenes by means of the controlled braking of individual wheels, e.g. the inside curve rear wheel during understeering or the outside curve front wheel during oversteering. This active intervention in cornering behaviour achieves a course-correcting effect in order to stabilise the vehicle. For this purpose, the yaw rate (rotation rate) data and the lateral acceleration registered by the YRS as well as the steering angle registered in the CIM are transmitted to the ABS/ESP via the CAN bus. If the lateral acceleration exceeds a specific value at which the ESP can no longer achieve a controlled braking of the vehicle, an intervention is requested in the engine control via CAN bus message, which initiates a reduction in torque.