Ignition Off, Function - GF07.10-P-1002MMK

Engine 276.8 in model 222.163/173 

Engine 276.9 in model 222 

Function requirements for ignition OFF, general points 

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

Ignition OFF, general points 

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

Function sequence for ignition OFF 

For ignition OFF, the engine compartment circuit 15 relay (K40/8kG) is switched off by the electronic ignition lock control unit (N73) via interior CAN (CAN B) and the front SAM control unit (N10/6). The "Circuit 15 OFF" signal is sent redundantly via suspension FlexRay (Flex E) to the powertrain control unit (N127) and via drive train CAN (CAN C1) to the ME-SFI [ME] control unit.

The ME-SFI [ME] control unit transmits the signal "terminal 15 OFF" via the hybrid CAN (CAN L) to the power electronics control unit (N129/1) and the battery management system control unit (N82/2). The request "open contactor" is transmitted by the ME-SFI [ME] control unit via the hybrid CAN to the battery management system control unit. If the ME-SFI [ME] control unit receives the "circuit 15 OFF" signal via the circuit 15 relay, the combustion engine is switched off by shutting off the fuel pump (M3), the fuel injectors (Y76) and the ignition coils (T1), and computer power-down is started.

The "circuit 31" ground connection is made by the on-board electrical system battery (G1) over the battery ground point (W10) and over a number of ground lines to the ME-SFI [ME]/CDI control unit (W25) ground point.

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".