Electronic accelerator pedal emergency running mode, function - GF30.20-P-4026V

ENGINE 272.920 in MODEL 203 up to Model Year 8

ENGINE 272.922 in MODEL 211

ENGINE 272.940 in MODEL 203 up to Model Year 8

ENGINE 272.941 in MODEL 203 up to Model Year 8

ENGINE 272.942 in MODEL 171 up to Model Year 8

ENGINE 272.943 in MODEL 211, 219

ENGINE 272.944 in MODEL 211

ENGINE 272.945 in MODEL 251 up to Model Year 8

ENGINE 272.946 in MODEL 221 up to Model Year 8

ENGINE 272.960 in MODEL 203 up to Model Year 8

ENGINE 272.963 in MODEL 171 up to Model Year 8

ENGINE 272.964 in MODEL 211, 219

ENGINE 272.965 in MODEL 221 up to Model Year 8

ENGINE 272.966 in MODEL 230 up to Model Year 8

ENGINE 272.967 in MODEL 164, 251 up to Model Year 8

ENGINE 272.970 in MODEL 203 up to Model Year 8

ENGINE 272.972 in MODEL 211

ENGINE 272.975 in MODEL 221 up to Model Year 8

ENGINE 273.922 in MODEL 221 up to Model Year 8

ENGINE 273.923 in MODEL 164 up to Model Year 8

ENGINE 273.924 in MODEL 221 up to Model Year 8

ENGINE 273.960 in MODEL 211, 219

ENGINE 273.961 in MODEL 216, 221 up to Model Year 8

ENGINE 273.962 in MODEL 211

ENGINE 273.963 in MODEL 164, 251 up to Model Year 8

ENGINE 273.965 in MODEL 230 up to Model Year 8

ENGINE 273.967 in MODEL 209

ENGINE 273.968 in MODEL 221 up to Model Year 8

ENGINE 272.940 in MODEL 209

ENGINE 272.960 in MODEL 209

Shown on Engine 272.963 in Model 171

Fig 1: Electronic Accelerator Pedal Emergency Running Mode Function Diagram

Courtesy of MERCEDES-BENZ USA

The task of the emergency running consists of enabling a safe continuation of journey if interference occurs at the electronic accelerator.

Accelerator pedal sensor, emergency mode

If a Hall sensor fails, the system switches over to the second Hall sensor. The throttle valve opening is limited to approx. 60%. In addition, the throttle valve opening rate is dynamically limited, in other words the throttle valve opens with a time delay. If the result of the plausibility check is negative, or if both potentiometers are faulty, only the idle speed is then controlled.

Throttle valve actuator, emergency mode (electrical)

If a potentiometer fails, the system switches over to the second potentiometer. The signal from the hot film MAF sensor is used as an additional comparative size.

If the plausibility check is negative or if both potentiometers are faulty, the throttle valve adopts a mechanical emergency running position (approx. 8 10°) which is fixed by the spring capsule in the throttle valve actuator (EPC malfunction indicator lamp comes on).

Throttle valve actuator, emergency mode (mechanical)

If the actuator motor is defective or there are other faults present the power supply to the throttle valve actuator will be shut off. The throttle valve is resting against the mechanical stop (spring capsule) as a result of which the throttle valve opening is maintained constantly at approx. 8 to 10°.

In neutral at engine speeds of > 1400/min, the fuel injection valves are deactivated and at engine speeds of < 1200 RPM actuated again.

While driving, depending on the engine load, engine speed is controlled by switching the cylinders on and off on the fuel side. The maximum engine speed is approx. 1800 RPM and is fixed by the mechanical stop.

Faults detected by the accelerator pedal sensor and the throttle valve actuator are stored in the diagnostic trouble code memory and can be read out and deleted with the STAR DIAGNOSIS. Emergency mode is recognizable on a clearly surging engine running.

	ME-SFI [ME] control unit component description		GF07.61-P-6000V
	Accelerator pedal sensor component description		GF30.20-P-2010V
	Component description of throttle valve actuator		GF30.20-P-2020V
	Crankshaft Hall sensor, component description		GF07.04-P-6220V
	Hot film MAF sensor, component description		GF07.07-P-6000V