CDI zero quantity calibration, function - GF07.16-P-3009IC
ENGINE 647.961 in MODEL 211
ENGINE 648.960 in MODEL 220
ENGINE 648.961 in MODEL 211
Via zero quantity calibration, the time delay between the start of actuation and injection of the fuel injectors is determined. The actuation period increases steadily with mileage based on the friction which arises due to wear when opening and closing the fuel injectors.
When the engine is coasting, a constant rail pressure is adjusted by the CDI control unit via the quantity control valve or the pressure regulator valve. The CDI control unit then extends the actuation period of the fuel injectors, until a speed increase is established via the crankshaft position sensor.
The actuation time determine is used by the CDI control unit as an adaptation value to calculate the injection time and is known as the "zero quantity".
| Component description for the fuel injectors | Y76 | GF07.03-P-6120IC | |
| Component description for the crankshaft position sensor | L5 | GF07.04-P-6010IC | |
| Component description for the rail pressure sensor | B4/6 | GF07.04-P-6210IC | |
| Component description for the quantity control valve | Y94 | GF07.05-P-6010IC | |
| Component description for the pressure regulator valve | Y74 | GF07.05-P-6020IC | |
| Component description for the CDI control unit | N3/9 | GF07.16-P-6000IC | |
| Component description for the accelerator pedal sensor | B37 | GF30.20-P-2010IC |