Has anyone ever had theirs come on & stay on?

Had mine running like a sack of ****e before & the lamp stays out!

Which faults cause it to come on, can find no list in RAVE??

you need good code reader for the ecu to test the diag light is two stage major sensor failure registers pre faults if they happen 5 times then become a hard fault then light or an emissions related fault then the light on

Have a BBS Faultmate & can drive light 'on' via PC.

Have had car running very rough but no light but also no sensors shown as failed.
I know some other makes of car that seem to switch them on every few hundred miles & the engine seems to be running fine, The Vauxhall cars & vans at work seem to have that habit...

Thanks for the infomative reply.