If it is the orange light it is not the ECU but the vehicles anti-pollutant system fault. Often caused by an overheated CAT or the like. There may be nothing wrong with the car though it may just be a faulty light.
The ECU wanring light is the red light which looks like a fuel injector. Usually called the 'injector light' rather than ECU light incorrectly.
This is assuming the car is a Punto Mark 1 Sporting if this is in the correct section.
If it is a Mark 2, indeed it is the ECU warning light, but please get this thread moved to the correct Mark 2 Section.