Ignition On, Function - GF07.10-P-1000KJ

ENGINE 281.910 in MODEL 453.0/3/4 

Function requirements for ignition ON, general points 

• Terminal 30

Ignition ON, general points 

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

Function sequence for ignition ON 

With switching on of the ignition in the ignition lock (S2), the on-board electrical system voltage is led from "circuit 30" to "circuit 15". The ME-SFI control unit is supplied by "circuit 15 g" over the FIR fuse and relay module (F2).

If there is a voltage present at the ME-SFI [ME] control unit at "circuit 15", engine circuit 87 relay (F11k1) is actuated by means of a ground signal. This causes the relay to close its power contact and, according to the corresponding electrical fuses, the "circuit 30" voltage is passed on as "circuit 87" to the ME-SFI [ME] control unit and to the corresponding sensors and actuators of the engine management.

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

The "circuit 31" ground connection is made from the on-board electrical system battery (G1) over the on-board electrical system battery ground point (W10) and over a number of ground lines to the ground point for the left internal combustion engine ground point 2 (W11/16).

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

• For secure full running the fuel pump with fill level sensor and temperature sensor (M3/3) is actuated over the ignition coils/fuel pump relay actuation (F11k3).
• In the instrument cluster (A1) the engine diagnosis indicator lamp (A1e58) is actuated via the interior CAN (CAN B) for a lamp check.
• 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 deleted via the diagnostic connector (X11/4). The diagnostic connector is networked over the interior CAN with the ME-SFI [ME] control unit.