Ignition ON, function - GF07.10-P-1000MI

ENGINE 272.9 (except 272.982) in MODEL 204.0/2 as of model year 2009 

ENGINE 272.9 (except 272.983) in MODEL 212 

ENGINE 272.9 (except 272.984) in MODEL 207 

ENGINE 272.9 in MODEL 204.9 

ENGINE 273.9 in MODEL 207, 212 

Function requirements for ignition ON, general points 

• Terminal 30

Ignition ON, general points 

With ignition ON, the engine timing in the ME-SFI [ME] control unit (N3/10) is switched on and the engine prepared for starting.

Function sequence for ignition ON 

Upon switching on of the ignition the terminal 15 relay (N10/1kJ) is switched on by the electronic ignition lock control unit (N73) via the chassis CAN (CAN E). The circuit 15 relay conducts the on-board voltage from "circuit 30" to "circuit 15". If a voltage is present on the ME-SFI [ME] control unit at "circuit 15", engine circuit 87 relay (N101/kN) is actuated by means of 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 M1" to the ME-SFI [ME] control unit and as "circuit 87 M2/3/4" to the respective engine timing sensors and actuators.

If a voltage is present at "circuit 87 M1", the engine timing is switched on and an output stage driver in the ME-SFI [ME] control unit takes over actuation of the engine circuit 87 relay.

The ground connection "circuit 31" is made from the on-board electrical system battery (G1) over the ground point battery at the front right (W10) and a number of ground lines to the ground point for the electronics assemblies compartment on the left (W16/5).

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

• to ensure full flow, the fuel pump (M3) is actuated by the fuel system control unit (N118) (both directly and via the drive train CAN (CAN C)) (only with first ignition ON after unlocking the vehicle).
• in the instrument cluster (A1) the engine diagnosis indicator lamp (A1e58) is actuated via the chassis CAN for a lamp check.
• data are exchanged with the electronic ignition lock control unit (circuit 50 signal and drive authorization) via the chassis CAN.
• the throttle valve actuator (M16/6) checks its return spring (by the position of the throttle valve) and adapts the position of the actuator, if necessary.
• the fault memory in the ME-SFI [ME] control unit can be read out and cleared via the chassis CAN, the diagnostic CAN (CAN D) and the diagnostic connector (X11/4).
• correction programming or diagnosis can be carried out with the Diagnosis Assistance System (DAS) using the diagnostic connector.

Different performance maps for the engine timing can be stored and activated with the correction programming in the ME-SFI [ME] control unit, such as:

• ignition maps for adaptation to different fuel grades (RON correction (R  esearch-O  ctane N  umber)) (except code (494) USA version)
• mixture maps for enrichment of the fuel/air mixture in different operating conditions (except code (494) USA version)
• basic setting for idle speed
• idle speed for engaged gear range (for automatic transmission)
• fault setting conditions for smooth running detection
• temperature correction for switching on and off the internal combustion engine fan motor and air conditioning system with integrated control (M4/7)

	Electrical function schematic, ignition ON	MODEL 204	PE07.10-P-2700-97FAB
		MODEL 207	PE07.10-P-2700-97EAB
		MODEL 212	PE07.10-P-2700-97DAB
	Overview of system components motor electronics (ME-SFI) fuel injection and ignition system		GF07.61-P-9997MI