The ECU (The Engine Control Unit) is like the brain of a vehicle, co-ordinating all the elements which make up the fuel, ignition and emission system. The engine warning light appearing on the dash, vehicle stalling, excessive fuel consumption or eratic idle signs are telltale signs that the ECU has reached the end of it’s life cycle.
If engine warning light is displaying, it is not always ECU failure. Maybe a faulty catalytic converter , fuel injector or oxygen sensor could be the cause of the problem.
If you have checked all these potential factors and you are still experiencing performance issues then it is most likely the ECU will need replacing.