Operation

OPERATION

The Powertrain Control Module (PCM) recognizes the rate at which the Accelerator Pedal is being pressed and switches between a few characteristic curves. Eighty percent of the engine's power is achieved for a pedal travel of about 50% for an aggressive driver and about 40% for a conservative driver. There is no further difference felt above a pedal travel of about 90%.

The characteristic curve for a conservative driver is active after a long drive. Then the Accelerator Pedal must be pressed down unusually hard to obtain a higher acceleration level.

The Accelerator Pedal Position Sensor in the Accelerator Pedal determines the opening angle of the throttle valve in the throttle body. The data transfers over the CAN data bus.

Further functions are: Idle speed control, cruise control, engine torque for ESP operation and short performance limitation; for example, for a higher coolant temperature.

The opening angle of the throttle valve will only be determined by the Accelerator Pedal signal when no limiting functions are active.

The Accelerator Pedal Position Sensor is detected by the nominal value potentiometer or hall sensor in the pedal value sensor and information is released to the PCM. The PCM determines the position of the throttle valve and actuates the throttle valve motor.

The actual value potentiometer in the actuator signals the throttle valve position back to the PCM.

The second potentiometer in the actuator and the second signal from the pedal value sensor (potentiometer or hall sensor) supplies a reference value for the plausibility check. The system switches over to the second potentiometer or the hall sensor if the first potentiometer or hall sensor fails (emergency mode).

The Accelerator Pedal Position Sensor on the Accelerator Pedal works according to the hall principal. the sensor is integrated into the pedal lever axis. It consists of a shaft with a ring magnet. This rotates in a printed circuit board with a stator in the fixed hall elements. This produces a change in the voltage.

The Accelerator Pedal Position Sensor is supplied with 5 volts from the PCM. The information regarding accelerator position is supplied to the PCM by means of two voltages (pin 4: approximately 0 up to 2.25 volts and pin 5: approximately 0 up to 4.5 volts).

The kickdown simulator is not used as a "Kickdown Switch". Wide Open Throttle (WOT) recognition takes place over the signal from the Accelerator Pedal Position Sensors pressure point, which is located in the pedal assembly. WOT position is simulated before achieving the full load position.