Ignition ON, function - GF07.10-P-1000MM

ENGINE 276.9 in MODEL 204 

ENGINE 276.9 in MODEL 207, 212 (except 212.095), 218 up to model year 2014 

Function requirements for ignition ON, general points 

• Terminal 30

Ignition ON, general points 

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

Function sequence for ignition ON 

When the ignition is switched on, the electronic ignition lock control unit (N73) operating over the interior CAN (CAN B) and the front SAM control unit with fuse and relay module (N10/1) switches on the engine compartment circuit 15 relay (N10/1kJ). The signal "circuit 15 ON" is sent redundantly via the chassis CAN (CAN E) to the ME-SFI [ME] control unit. The circuit 15 relay conducts the on-board voltage from "circuit 30" to "circuit 15". If a voltage is present on the ME-SFI [ME] control unit at "circuit 15", engine circuit 87 relay (N10/1kN) is actuated by means of a ground signal.

This causes the relay to close its power contact and the voltage is forwarded from "circuit 30" (depending on the respective fuses) as "circuit 87 M4" to the ME-SFI [ME] control unit and as "circuit 87 M1/2/3" to the respective sensors and actuators of the engine timing. If a voltage is present at "circuit 87 M4", the engine timing is switched on and an output stage driver in the ME-SFI [ME] control unit takes over actuation of the engine circuit 87 relay.

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

• To ensure full flow, the fuel pump (M3) is actuated by the fuel system control unit (N118) (both directly and via the drive train CAN (CAN C)) (only with first ignition ON after unlocking the vehicle).
• In the instrument cluster (A1) the engine diagnosis indicator lamp (A1e58) is actuated via the chassis CAN for a lamp check.
• Data are exchanged with the electronic ignition lock control unit (circuit 50 signal and drive authorization) via the chassis CAN.
• 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 via the chassis CAN and diagnostic CAN (CAN D) with the ME-SFI [ME] control unit.
• Correction programming or diagnosis can be carried out with the Xentry diagnostics over the diagnostic connector.

Different performance maps for the engine timing can be stored and activated with the correction programming in the ME-SFI [ME] control unit, such as:

• Ignition maps for adaptation to various fuel grades (RON correction (R  esearch-O  ctane N  umber))
• Mixture maps for enrichment of the fuel/air mixture in different operating states
• Basic setting for idle speed
• Idle speed with engaged gear range
• Fault setting conditions for smooth running detection
• Temperature correction for switching on and off the internal combustion engine fan motor and air conditioning system with integrated control (M4/7)