Μπορεί σε μερικά αυτοκίνητα το consumsion factor να θέλει εκ νέου ρύθμιση για να δείχνει σωστα το bc

This "test" is actually a way to adjust the OBC's fuel consumption factor. There's a sensor in the fuel injector system that indicates fuel consumption back to the OBC. This "KVBR" value is used to calibrate that sensor using the following process:

1. Reset one of the OBC mileage indicators and the trip odometer, and fill your tank.
2. Record the actual fuel consumption for your car over a long period (one to two months at least).
3. Divide this reading into the trip odometer value to calculate your actual mileage.
4. Divide this result by the OBC indicated mileage over the same period and multiply by 1000.

You now have your fuel consumption factor. To enter the factor into the OBC, get into Test 20 and press Reset. This will start the KVBR value counting down. It will count down to 750, then start over at 1250. A crude user interface to be sure, but it works.

You probably don't need to change the KVBR value; the default value of 1000 should be accurate. And if your calculated fuel consumption factor is outside the 750–1250 range, there's probably something wrong.