Display Group 13 at Idle

Conditions:
Engine warm
Engine Coolant Temperature not below 80°C

Display will appear as shown:

Read measuring value block 13 -->
0.82 mg/H -0.12mg/H 0.49mg/H

- The injection system is equipped with an idle speed smooth running control. There may be power differences between individual cylinders (component tolerances, jet drillings, compressions etc.) which are recognized and equalized through selective injected quantities.

- Recognition at idle is via signal from Engine Speed sensor G28 which delivers four signals per crankshaft revolution to the ECM. If signals are delivered at the same rhythm, 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, the relevant cylinder is given more or less fuel, until engine runs evenly again.

- Measuring value block displays injected quantity differences of individual cylinders compared with No. 3 cylinder to ensure an even idle.

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

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