Display Group 013

NOTE: Engine at idle, coolant temperature not below 80°C.





Idle Speed Smooth Running Control, Display Evaluation:
The injection system is equipped with an idle speed smooth running control. There may be power differences between the individual cylinders (component tolerances, jet drillings, compressions etc.) which are recognized and equalized via selective injection quantities.

Recognition at idle speed is via the signal from the engine speed sensor which delivers four signals per crankshaft revolution to the Engine Control Module. If the signals are delivered at the same rhythm then all cylinders work the same. If one cylinder is weaker, then the crankshaft takes longer for the next half revolution. Conversely a more powerful cylinder accelerates the crankshaft in less time.

If the Engine Control Module recognizes a time difference, then the relevant cylinder is given more or less fuel, until the engine runs evenly again.

The measuring value block displays the injected quantity differences of the individual cylinders compared with cylinder No. 3 which is required to ensure an even engine idling speed.

+ to mg/H: The relevant cylinder is less powerful than No. 3 cylinder and is therefore supplied with more fuel.

- to mg/H: The relevant cylinder is more powerful than No. 3 cylinder and is therefore supplied with less fuel.