PEUGEOT 206 diagnostic light

[mikemkm910]

The diagnostic light ( orange picture of engine ) is not going out as it should, according to the manual, it should go out after a few seconds once the car is started, on mine sometimes it will, however if you turn the car off and restart it the light will go out as it should every time, we have had the car tested for emisions etc and all is well, anyone able to shed any light on this please, mike.