try this Vectra C
1
"Ignition OFF".
2
Press reset button (trip odometer), the display in the instrument cluster shows the odometer and trip odometer.
3
Press and hold down reset button (trip odometer button), and service interval indicator appears after approximately 3 seconds.
4
Keep pressing reset button and also depress brake pedal, holding both down.
5
"Ignition ON". Keep reset button and brake pedal pressed, "InSP - - -" appears on the display (flashing). Continue to hold down both until the service interval display changes.
6
The maximum distance to be travelled ("InSP 35,000 km" for petrol engines or "InSP 50,000 km" for diesel engines with ECOService-Flex) and ("InSP 30,000) with ECOService 1) is displayed after approx. 10 seconds. The service interval has been reset.
if it don't work try it with ignition on ( briefly)
i had to do this on my corsa d to reset
it didn't say ** insp 30 000 ** it said** insp - - - - **