Evaluation: idle speed smooth running control display
WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2006 Volkswagen Golf, 2005 Volkswagen Jetta, 2005 Volkswagen Golf, 2004 Volkswagen Jetta, and 2004 Volkswagen Golf. However, it is still accessible from the selected car via links, so may be relevant.
- The fuel injection system is equipped with an idle speed smooth running control. There may be power differences between the individual cylinders (component tolerances, jet sizes, compressions etc.) which are recognized and equalized via selective injected quantities.
- Recognition at idle speed is via the signal from the Engine Speed Sensor G28 which delivers four signals per crankshaft revolution to the Engine Control Module (ECM). If the signals are delivered at the same rhythm then all cylinders work the same. If one cylinder is weaker the crankshaft takes longer for the next half revolution. Conversely a more powerful cylinder accelerates the crankshaft so less time is taken.
- If the ECM recognizes a difference, then the relevant cylinder is given more or less fuel, until the engine runs evenly again.
- +... mg/H: The relevant cylinder is less powerful than No. 3 cylinder and is therefore supplied with more fuel.
- -... mg/H: The relevant cylinder is more powerful than No. 3 cylinder and is therefore supplied with less fuel.