ECM stands for Engine Control Module- that is nothing but an electronic control device that regulates a series of components to ensure optimum engine performance. An engine performance complication is another sign of a probable issue with the ECM. When ECM goes bad, it will throw off timing that can affect the engine performance adversely. With a defective ECM, the engine will consume more fuel and produce starting issues consistently. A thorough diagnosis can reveal the cause. And for that, you need to consult a knowledgeable car technician.