Peugeot 208 engine management light

Eml came on this evening on way home from work, car is not running rough drove fine with light on.
Arriving home nothing is obvious so leaks no off noises, the only thing was the engine seemed a lot hotter than usual, coolant level fine and cooling fan not on, guage also was within normal range.
Any ideas?
The car is due to go in under warranty bought it used a 3 months back for a inner drives shaft bearing rattling, this will be done under warranty but this new fault will be out of it.
Overall I am regretting buying this car and debated rejecting it as its had since I bought it new coil packs, battery, plus other niggles it's seems they fix something and another fault appears.