Electronic Accelerator, Location/Design/Function

Electronic Accelerator, Location/Design/Function

ENGINE 120.982 in MODEL 140.056 /057 /076
ENGINE 120.983 in MODEL 129.076




B37 Pedal value sensor
B37r1 Set point potentiometer 1
B37r2 Set point potentiometer 2
M16/3 Right EA/CC/ISC actuator
M16/3m1 Servo motor
M16/3r1 Actual value potentiometer 1
M16/3r2 Actual value potentiometer 2
M16/4 Left EA/CC/ISC actuator
M16/4m1 Servo motor
M16/4r1 Actual value potentiometer 1
M16/4r2 Actual value potentiometer 2
N3/11 Left ME-SFI control module
N3/12 Right ME-SFI control module
CAN Controller Area Network databus
d, e Closed throttle position information

The electronic accelerator EA function in the ME-SFI control module determines the opening angle of the throttle valve through the EA/CC/ISC actuators.

Further functions are:
- Idle speed control
- Cruise control mode
- 30 km/h limit
- Reducing engine torque for ESP mode
- Electronic accelerator pedal emergency running
- Actuating EPC malfunction indicator lamp (up to 5/96)
- Storing faults
- Data transfer through CAN

If these additional functions are not active, the opening angle of the throttle valve is determined by the accelerator pedal input.

The accelerator pedal position is detected by the set value potentiometer (B37r1) in the pedal value sensor (B37) and information output to the right ME-SFI control module (N3/12). The right ME-SFI control module (N3/12) in this way determines the throttle valve position for both actuators.

The right ME-SFI control module (N3/12) actuates the throttle valve servo motor (M16/3m1). At the same time, it supplies information through the CAN data bus to the left ME-SFI control module (N3/11), which thereupon actuates the left throttle valve servo motor (M16/4m1.

The actual value potentiometers in the actuators (M16/3r1, M16/4r1) signal back the throttle valve position to the right ME-SFI control module (N3/12), and from the left ME-SFI control module (N3/11) to the right ME-SFI control module (N3/12) through the CAN data bus.

The second potentiometers in the actuators (M16/3r2, M16/4r2) or in the pedal value sensor (B37r2) supply a reference value as a plausibility check. In addition, the system switches over to the second potentiometer if the first potentiometer fails (emergency running - EPC malfunction indicator lamp does not come on).

Idle speed information is transferred between the ME-SFI control modules over two wires. If the CAN data bus fails, idle speed is thus regulated.