ME-SFI ignition ON, function - GF07.61-P-3005G

ENGINE 273 in MODEL 463.202/222/236/237 up to 31.5.12 as of model year 2009/YoM 08

Fig 1: Identifying ME-SFI Ignition ON, Function Chart

Courtesy of MERCEDES-BENZ USA

Function requirements for ignition ON for the ME gasoline injection and ignition system (motor electronics) (ME), general points

Circuit 15 On

ME-SFI ignition ON, general points

For ignition ON, the engine control in the ME-SFI [ME] control is switched on and the engine prepared for starting.

ME-SFI ignition ON, function sequence

When the ignition is switched on, the EIS control unit connects the on-board voltage from "circuit 30" to "circuit 15" via the circuit 15 relay. If voltage is present at ME-SFI [ME] control unit "circuit 15", engine terminal 87 relay is actuated with a ground signal.

This causes the relay to close its power contact and the voltage is connected from "circuit 30" (depending on the respective fuses) as "circuit 87 M4" to the ME-SFI [ME] control unit and as "circuit 87 M1/2/3" to the respective sensors and actors of the engine control.

If voltage is present at "circuit 87 M4", the engine control is switched on and an output stage driver in the ME-SFI [ME] control unit takes over actuation of the engine terminal 87 relay.

The "circuit 31" ground connection runs from the battery via the battery ground and several ground lines to the ground of the RH major assemblies compartment (power ground).

When the engine control is switched on, the ME-SFI [ME] control unit carries out the following functions:

For complete security, the fuel pump is actuated through the fuel pump relay () (only the first time the ignition is switched on after the vehicle is unlocked).
The engine diagnosis indicator lamp or the CHECK ENGINE indicator lamp is actuated by the ME-SFI [ME] control unit in the instrument cluster via the drive train CAN for a lamp check.
Data are exchanged with the EIS control unit (circuit 50 signal and drive authorization) via the drive train CAN.
The fault memory in the ME-SFI [ME] control unit can be read out and deleted through the data link connector (X11/4).
Correction programming or diagnosis can be carried out with the Diagnosis Assistance System (DAS) over the data link connector.
The throttle valve actuator checks its return spring (via the position of the throttle valve) may lead to a positioner adaptation.
The tumble flap switchover is actuated and the end position of the tumble flaps is checked.

The following partial functions which are active for ignition ON are described in the following documents:

ME-SFI [ME] fuel supply, function
Correction programming, function
ME-SFI tumble flap switchover function

	ME-SFI fuel supply, function		GF07.61-P-3004G
	Correction programming, function		GF07.61-P-3031G
	ME-SFI tumble flap switchover function		GF07.61-P-4017G