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

Engine 157.9, 276.8, 278.9 in model 217, 222 (except 222.163/173) 

Function requirements for ignition OFF, general points 

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

Ignition OFF, general points 

With the ignition OFF, first the 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.

If the ME-SFI [ME] control unit receives the signal "circuit 15 OFF" via the circuit 15 engine compartment relay, the engine is cutout through the following assembly parts being switched off and the computer run-on is started.

• Fuel pump (M3)
• Cylinder 1 to 6 ignition coils (T1/1 to T1/6) (Engine 276.8)
• Cylinder 1 to 8 ignition coils (T1/1 to T1/8) (Engine 157.9, 278.9)
• Cylinder 1 to 6 fuel injectors (Y76/1 to Y76/6) (Engine 276.8)
• Cylinder 1 to 8 fuel injectors (Y76/1 to Y76/8) (Engine 157.9, 278.9)

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".