Fuel Supply, Function - GF07.10-P-1003KJ

ENGINE 281.910 in MODEL 453.0/3/4 

Function requirements for fuel supply, general points 

• Circuit 15 (ignition ON)
• Circuit 87 (Engine management ON)

Fuel supply, general points 

The fuel supply provides an adequate quantity of filtered fuel at an adequate pressure (injection pressure), under all operating conditions, from the fuel tank to the cylinder 1 injection valve (Y62/1) to the cylinder 3 injection valve (Y62/3).

Function sequence for fuel supply 

The function sequence for fuel supply is described in the following steps:

• Function sequence for fuel pump control 
• Fuel feed function sequence 
• Function sequence for safety fuel shutoff 

Function sequence for fuel pump control 

Switching on of the fuel pump with fill level sensor and temperature sensor (M3/3) takes place over the ignition coils relay actuation/fuel pump (F11k3) occurs over the ME-SFI [ME] control unit (N3/10).

The pressure is set statically in the fuel pump. This manual pressure controlling always, at any time, achieves sufficient fuel and fuel pressure.

Fuel feed function sequence 

The fuel pump with fill level sensor and temperature sensor draws fuel from the bottom of the fuel feed module through the fuel strainer and pumps it through the fuel filter with fuel pressure regulator to the fuel distributor (one-line system, without return line). The fuel pressure is limited to about 5 bar by the fuel pressure regulator.

Function sequence for safety fuel shutoff 

The safety fuel shutoff system is designed to ensure traffic and passenger safety.

The ME-SFI [ME] control unit controls the safety fuel shutoff on the basis of the following sensors and signals:

• Crankshaft position sensor (L5), engine speed
• Actual value potentiometer 1 (M16/6r1) and actual value potentiometer 2 (M16/6r2), throttle valve position
• Supplemental Restraint System control unit (N2/10), indirect crash signal via interior CAN (CAN B) to the ME-SFI [ME] control unit

The safety fuel shutoff is activated by the ME-SFI [ME] control unit for the following conditions:

• Mechanical fault in throttle valve actuator 
• Absence of the engine speed signal 
• Crash signal 

Mechanical fault in throttle valve actuator 

When evaluating the throttle valve position, if the ME-SFI [ME] control unit detects a mechanical fault in the throttle valve actuator (M16/6), engine speed is limited to about 1400 rpm at idle and about 1800 rpm in driving mode by shutting off the cylinder 1 injection valve to cylinder 3 injection valve.

Absence of the engine speed signal 

If the engine speed signal generated by the ME-SFI [ME] control unit is missing, the fuel pump with fill level sensor and temperature sensor is shut off over the ME-SFI [ME] control unit.

Crash signal 

If the ME-SFI [ME] control unit receives a crash signal indirectly via the interior CAN, it switches off the fuel pump with fill level sensor and temperature sensor in order to make the fuel system unpressurized.

	Electrical function schematic for fuel supply		PE07.10-P-2703-97BBA
	Electrical function schematic for safety fuel shutoff		PE07.10-P-2733-97BBA
	Overview of system components motor electronics (ME-SFI) fuel injection and ignition system		GF07.61-P-9997KJ