Ignition OFF, function - GF07.10-P-1002MI

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 OFF, general points 

• Circuit 87M ON (engine timing ON)
• Circuit 15 ON

Ignition OFF, general points 

With the ignition OFF, first the engine and then the engine timing are switched off in the ME-SFI [ME] control unit (N3/10).

Function sequence for ignition OFF 

For ignition OFF the terminal 15 relay (N10/1kJ) is switched via the chassis CAN (CAN E) from the electronic ignition lock control unit (N73).

If the ME-SFI [ME] control unit receives the signal "circuit 15 OFF" via the circuit 15 relay, the following components are switched off and the computer run-on is started:

• over the FSCU (N118) the fuel pump (M3)
• injection valves (Y62)
• Ignition coils (T1)

Computer power-down is determined by the ME-SFI [ME] control unit and lasts about 5 s. It can, however, last for some minutes due to various functions (such as On-Board Diagnosis (OBD), Drive Authorization System (DAS), thermal management).

When the processor power-down is finished, the engine circuit 87 relay (N101) is switched off and the engine timing system is disconnected from the on-board electrical system (switched off).

System tests are conducted by the ME-SFI [ME] control unit during the computer run-on and the fault memory is updated.

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 the ignition is OFF, the ME-SFI [ME] control unit is supplied with power from the on-board electrical system battery via "circuit 30 fused".

	Electrical function schematic for ignition OFF	MODEL 204	PE07.10-P-2702-97FAB
		MODEL 207	PE07.10-P-2702-97EAB
		MODEL 212	PE07.10-P-2702-97DAB
	Overview of system components motor electronics (ME-SFI) fuel injection and ignition system		GF07.61-P-9997MI