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.
CDI limiting maximum engine speed, function - GF07.16-P-3007P
ENGINES 642 in MODEL 219.3, 209.3, 211.0/2, 209.4, 211.6
ENGINES 642 in MODEL 461.3
ENGINES 642.9 in MODEL 463.3
ENGINES 642 in MODEL 221.0, 203.0, 164.1, 203.2, 251.0/1, 164.8, 221.1 up to model year 2008/YoM 07
The maximum engine speed limitation is used to restrict the engine speed to approx. 4500 RPM. This counteracts mechanical damage to the engine caused by overrevving. To do this the CDI control unit (N3/9) reads in the crankshaft Hall sensor (B70) and uses its signal to determine the motor speed. Above an engine speed of around 4500 RPM, the CDI control unit interrupts actuation of the fuel injectors (Y76) and reduces the fuel pressure in the rail via the quantity control valve (Y94) and the pressure control valve (Y74).
If the engine speed falls back down to under around 4500 RPM, then the CDI control unit reactuates the fuel injectors and increases the fuel pressure in the rail via the quantity control valve and the pressure control valve.
| Component description for fuel injector | Y76 | GF07.03-P-6120P |
| Component description for crankshaft Hall sensor | B70 | GF07.04-P-6220P |
| Component description for rail pressure sensor | B4/6 | GF07.04-P-6210P |
| Component description for quantity control valve | Y94 | GF07.05-P-6010P |
| Pressure regulator valve, component description | Y74 | GF07.05-P-6020P |
| Component description for CDI control unit | Model 203, 209 N3/9 |
GF07.16-P-6000P |
| Model 211, 219 N3/9 |
GF07.16-P-6000T | |
| Model 164, 463 N3/9 |
GF07.16-P-6000GZ | |
| Model 221 N3/9 |
GF07.16-P-6000SX | |
| Model 251 N3/9 |
GF07.16-P-6000RT | |
| Model 461 N3/9 |
GF07.16-P-6000GX | |
| Accelerator pedal sensor, component description | Model 203, 209, 211, 219 B37 |
GF30.20-P-2010P |
| Model 164, 463 B37 |
GF30.20-P-2010GZ | |
| Model 221 B37 |
GF30.20-P-2010SX | |
| Model 251 B37 |
GF30.20-P-2010RT |
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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.