Bus messages, ESP
For a further description of the car's bus system, see BUS AND DIAGNOSTICS COMMUNICATION .
ESP uses the following information:
VALUE/UNIT DESCRIPTION
| Information | Value/Unit | From | Description |
|---|---|---|---|
| Engine RPM | RPM | ECM | ESP uses current engine speed and vehicle speed to calculate the current gear ratio. |
| Engine torque | Nm | ECM | ESP uses current engine torque and current gear ratio to calculate the current wheel torque. |
| Pedal position | % | ECM | Displays accelerator position, i.e. the driver's intentions, to determine how much wheel spin to permit. |
| Current gear ratio automatic transmission | 1-5 and R | TCM | ESP uses current gear ratio and current engine torque to calculate the current wheel torque. The value is compared to the control module's calculated value. |
| Current gear ratio manual gearbox | 1-5 and R | ECM | ESP uses the current gear ratio and current engine torque to calculate the current drive wheel torque. The value is calculated and transmitted by the ECM. |
| Steering wheel angle | +/-530° | SAS | The steering wheel angle sensor sends information on steering wheel position. 0° = straight ahead position. |
ESP sends the following information:
VALUE/UNIT DESCRIPTION
| Information | Value/Unit | Used by | Description |
|---|---|---|---|
| Wheel speed, front right | km/h | ECM | The wheel speed sensor has a voltage output, the frequency of which increases with increased wheel speed. The ESP transmits the current speed of the front right wheel. |
| Wheel speed, front left | km/h | not used | The wheel speed sensor has a voltage output, the frequency of which increases with increased wheel speed. The ESP transmits the current speed of the front left wheel. |
| Wheel speed, rear left | km/h | ECM, MIU, DICE, AUDIO, TWICE, SPA | The wheel speed sensor has a voltage output, the frequency of which increases with increased wheel speed. The ESP transmits the current speed of the rear left wheel. |
| Wheel speed, rear right | km/h | MIU | The wheel speed sensor has a voltage output, the frequency of which increases with increased wheel speed. The ESP transmits the current speed of the rear right wheel. |
| ABS lamp | ON/OFF | MIU | Internal diagnosis. In the event of system fault, the ABS lamp comes on. |
| ESP OFF | ON/OFF | MIU | Switch and internal diagnosis. The lamp indicates that the ESP function is off. |
| ESP indicator lamp | ON/OFF | MIU | Indication of ESP regulation. |
| Request for engine torque | Nm | ECM | The ECM controls the engine torque as requested by the ESP control module. |
| Calibrated steering wheel angle sensor | yes / no | SAS | The ESP control module sends a message that the steering wheel angle sensor is calibrated, once calibrated by Tech 2. The steering wheel angle sensor adjusts the offset (zero position) to this calibration. |