Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Motor electronics (ME) ignition system, function - GF07.61-P-3008MAS
ENGINES 156.984 in MODEL 216.377, 221.077 /177 as of Model Year 09 /AEJ 08
Function requirements for the ignition system, general points
- Circuit 87M ON (engine control ON)
Ignition system, general points
Every cylinder is fitted with a directly plugged in single spark ignition coil. For the ignition system, the ME-SFI (N3/10) control unit reads the following sensors and signals:
- Knock sensor 1, on the right (A16/1)
- Knock sensor 2, on the left (A16/2)
- LH and RH hot film MAF sensor (B2/6, B2/7), engine load
- LH and RH intake camshaft Hall sensors (B6/4, B6/5), intake camshaft positions
- LH and RH exhaust camshaft Hall sensors (B6/6, B6/7), exhaust camshaft positions
- Coolant temperature sensor (B11/4)
- Intake air temperature sensor (B17)
- Pressure sensor (B28), intake manifold air pressure
- Crankshaft Hall sensor (B70), engine speed and crankshaft position
The requirements of the engine torque requirement function are also taken into account.
For the following partial functions, ignition angle adjustment in the direction "retarded" or "advanced" takes place:
- Idle speed control
- Inertia fuel shutoff
- Transmission overload protection
- Knock sensor system
- Engine torque request
Ignition system function sequence
At the firing point, the ME-SFI control unit (N3/10) opens the ground end of the primary circuit (circuit 1) to the ignition coil concerned (T1).
Determination of the ignition angle takes place dependent on a performance map according to the input signals from the ME-SFI [ME] control unit.
Cylinder arrangement and ignition firing order
Diagnosis
The ignition angles can be checked only with the Diagnosis Assistance System (DAS).
| Electrical function schematic for ignition system | Model 216 | PE15.12-P-2050-97CAC | |
| Model 221 | PE15.12-P-2050-97SAC | ||
| ME-SFI [ME] control unit, component description | N3/10 | GF07.61-P-6000MAS |
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.