GF30.20-P-3012V ME-SFI Electronic Accelerator, Function

GF30.20-P-3012V ME-SFI Electronic Accelerator, Function







The electronic accelerator function is integrated and controlled in the motor electronics control unit depending on the driver input and the operating condition, the opening angle of the throttle valve.

Input signals for the electronic accelerator pedal:
- Accelerator pedal position
- Brake actuation (from ESP control unit)
- Cruise control operation (from ESP control unit)
- Engine torque requirements (via CAN)
- Gear ranges (over electronic selector lever module control unit (N15/5)) (for automatic transmission 722.9)
- Clutch operating system (for manual transmission 716.6)
- Reverse travel (for manual transmission 716.6)

The position of the accelerator pedal and speed at which the position of the accelerator pedal changes are transmitted to the sensor located on the accelerator pedal mechanically. The Hall sensor in the accelerator pedal sensor sends an appropriate voltage signal to the ME-SFI [ME] control unit. The ME-SFI [ME] control unit analyzes the voltage signal and, depending on the performance map, activates the throttle valve actuator. The opening angle of the throttle valve is altered appropriately by the actuator motor (M16/6m1) in the throttle valve actuator.

The opening angle is only determined by the accelerator pedal request if no limiting functions are active (e.g. idle request or a torque reduction).

The throttle valve actual value potentiometer (M16/6r1) reports the current throttle valve position back to the ME-SFI [ME] control unit.

Throttle valve damping
The throttle valve damping function closes the throttle valve up to the idle speed range with a time delay if the accelerator pedal is suddenly released. In this way, the engine torque goes down slowly and the vehicle does not slow down with jerks.

Following input signals are processed:
- Change in the speed of the accelerator pedal position.
- Engine speed
- Coolant temperature
- Throttle valve position
- Vehicle speed

Reversing
If the ME-SFI [ME] control unit recognizes a reverse travel, the throttle valve will be opened more slowly and the maximum opening angle limited to about 50%. This function has the task of optimizing ride comfort and safety when reversing.

Adaptive accelerator pedal
The ME-SFI [ME] control unit evaluates how the accelerator pedal is being actuated and switches between characteristic curves. After a 50% pedal travel, about 80% of the engine load is released for a sporty driver and 40% of the engine load is released for a quiet driver.

There is no further difference felt above a pedal travel of about 90%.

If, for example, the characteristic curve for a quiet driver is active after a long drive on the freeway then the accelerator pedal must be pressed down unusually hard to obtain a higher acceleration level.

Additional functions of the electronic accelerator pedal:
- Idle speed control
- Cruise control (CC [TPM])
- Torque interface
- Emergency running

If the brake pedal is operated, this always means idle speed input.