ME-SFI ignition system, function - GF15.12-P-0001V
ENGINE 272.942 in MODEL 171
ENGINE 272.963 in MODEL 171
Shown on engine 272 in model 171
Cylinder arrangement and ignition firing order
The ME-SFI control unit essentially analyzes the following signals for determining the ignition angle:
- Air mass
- Position and RPM of crankshaft
- Positions of intake camshafts
- Positions of exhaust camshafts
- Coolant temperature
- Intake air temperature
- Knock sensor signals
- Intake manifold air pressure
- Engine torque requests
The ME-SFI [ME] control unit interrupts the respective ignition coil at the moment of the ignition timing of the primary circuit to "terminal 1".
Ignition angle adaptation
For the following partial functions an ignition angle adjustment in the direction "retarded" or "advanced" can take place:
- Catalytic converter heating-up
- Idle speed control
- Overheating / knock protection
- Deceleration fuel shutoff
- Transmission overload protection (with automatic transmission 722.9)
- Anti-knock control [AKC]
- Engine torque requests
The ignition angle can only be checked using the DAS.
| Component description for the ME-SFI [ME] control unit | GF07.61-P-6000V |
| Component description for the knock sensor | GF07.04-P-6030V |
| Component description for the pressure sensor | GF07.04-P-6060V |
| Component description for the crankshaft Hall sensor | GF07.04-P-6220V |
| Component description for the camshaft Hall sensor | GF07.04-P-6020V |
| Component description for the coolant temperature sensor | GF07.04-P-6040V |
| Component description for the hot film mass air flow sensor | GF07.07-P-6000V |
| Component description for spark plugs | GF15.10-P-2000V |
| Component description for ignition coils | GF15.10-P-2100V |
| Component description for the accelerator pedal sensor | GF30.20-P-2010V |
| Component description for the throttle valve actuator | GF30.20-P-2020V |