Trying to reset the wifes car (Saxo VTR) which appears the same as my 306 as far as resetting the service interval? Not having much luck, press the button and turn ignition on. Display shows what I expect and I can press the button to change the mileage shown but when I let the count go down from 9 to zero, it then shows 0 miles to go before next service! What am I doing wrong? Need to reset it after a battery disconnect to sort out an airbag light problem. TIA cheers, Len