Ignition ON function - GF07.10-P-1000MI

ENGINES 272.9 (except 272.98) in MODEL 204.0 /2 as of model year 2009/YoM 08 

ENGINES 272.9 (except 272.98) in MODEL 204.9, 207.3 /4, 212.0 /2 

ENGINES 273.9 in MODEL 207.3 /4, 212.0 /2 

Function requirements for ignition ON, general points 

• Terminal 30

Ignition ON, general points 

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

Ignition ON function sequence 

When the ignition is switched on, the electronic ignition lock control unit (N73) switches on relay terminal 15 (N10/1kJ) via chassis CAN (CAN E). The terminal 15 relay conducts the electrical system voltage from "circuit 30" to "circuit 15". If a voltage is present at 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 connected from "circuit 30" (depending on the respective fuses) as "circuit 87 M1" to the ME-SFI [ME] control unit and as "circuit 87 M2/3/4" to the respective engine control sensors and actuators. If a voltage is present at "circuit 87 M1", the engine control is switched on and an output stage driver in the ME-SFI [ME] control unit takes over actuation of the engine circuit 87 relay.

Ground is connected to "circuit 31" from the vehicle electrical system battery (G1) via the battery ground point at the front right (W10) and over a number of ground lines to the ground point for the electronic assemblies compartment on the left (W16/5).

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

• In order to provide full security, the fuel pump (M3) is actuated via the fuel system control unit (N118) (directly and via the drive train CAN (CAN C)) (only the first time the ignition is switched ON after the vehicle is unlocked).
• In the instrument cluster (A1) the engine diagnosis indicator lamp (A1e58) is actuated via the chassis CAN for a lamp check.
• Data is exchanged with the electronic ignition lock control unit (circuit 50 signal and drive authorization) over the chassis CAN.
• The throttle valve actuator (M16/6) checks its return spring (via the position of the throttle valve) and may lead to a positioner adaptation.
• The fault memory in the ME-SFI [ME] control unit can be read out and deleted via the chassis CAN, the diagnostic CAN (CAN D) and the diagnostic connector (X11/4).
• Correction programming or diagnosis can be accomplished over the diagnostic connector using Xentry diagnostics.

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

• Ignition maps for adaptation to different fuel grades (research octane number correction) (except code (494) USA version)
• Mixture maps for enrichment of the fuel/air mixture in different operating conditions (except code (494) USA version)
• Basic setting for idle speed
• Idle speed for engaged gear range (for automatic transmission)
• Fault setting conditions for smooth running detection
• Temperature correction for switching on/off the combustion engine fan motor and air conditioning system with integrated control (M4/7)