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

GF07.10-P-1002MMC Ignition OFF, Function
- ENGINES 157.9 in MODEL 216.3, 221.0 /1
- ENGINES 278.9 in MODEL 216.3, 221.0 /1

Function requirements ignition OFF, general points
- Circuit 87M ON (engine control ON)
- Circuit 15 ON

Ignition OFF, general points
For ignition OFF, first the engine and then the engine control is switched off in the ME-SFI [ME] control unit (N3/10).

Function sequence for ignition OFF
When ignition is switched OFF the circuit 15 (2) relay / reserve 1 (changeover contact) (N10/1kD) is switched off by the EZS control unit (N73) via the interior CAN (CAN B) and by the front SAM control unit with fuse and relay module (N10/1). The signal "circuit 15 OFF" is sent redundantly via the chassis CAN (CAN E) to the ME-SFI [ME] control unit.
If the ME-SFI [ME] control unit receives the "circuit 15 OFF" signal via the circuit 15 relay the engine is switched off by shutting off the fuel pump (M3), the fuel injectors (Y76) and the ignition coils (T1) are switched off and the computer power-down is started.

Computer power-down is determined by the ME-SFI [ME] control unit and lasts about 4 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 computer power-down is complete, the engine circuit 87 relay (N10/1kC) is deenergized and the engine control is disconnected from the on-board electrical system (switched off).

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

The "circuit 31" ground connection takes place from the on-board electrical system battery (G1) via the battery ground (W10) and over a number of ground lines to the electronic ground (footwell on the left) (W34/1).
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".