I had the same problem on my 2008 Doblo, and the solution was that only the dealer could reset the service light and would only do it if they had actually done the service.

This was a particular pain in the bum for the Doblo as the service indicator also reset the oil degredation counter. So when I had the oil changed it constantly beeped at me thinking it still needed new oil.

I suspect only the Peugeot dealer has the right kit to turn it off sadly, although try turning the heater on full, flashing the headlights three times, beeping the horn and shouting "Expelliarmus Bipperium!"

Good Luck!

Procedure to Reset Peugeot Service Light as follows:

1. Switch the Ignition Off

2. Press and hold the tripmeter (mileage reset) button on the dash

3. Now switch the ignition to the ON position

4. Keep the button pressed for 10 seconds

5. The display will read '0' and the service symbol will extinguish. Jobdone.