Your car's electronic control unit, or ECU, does a lot for your car. The ECU is a fancy name for your car's computer and most modern cars have one in some form. Over the decades, the computer has evolved from a small box that controls ignition to a full-fledged computer that runs all your car's engine systems. Generally, these computers are long-lasting and rarely need anything more than an occasional software update. Now and then one can go bad and when it does, your car will seem like it's in chaos.

Signs of a faulty ECU

Since the ECU controls so many systems that are connected to your check engine light, the first indicator that something is wrong is that the light comes on and stays on. Though this can indicate that any number of components is having trouble, a technician can easily read any codes and find out if the computer is the problem. If your car's check engine light isn't on, then other symptoms you may notice are that your car has difficulty starting or that your car is running very poorly.

How an ECU can be damaged

Other than the rare possibility of being bad at the time of manufacturing, it is unusual for the ECU to fail on its own. One way they may go bad is from physical damage. If your car gets in an accident and gets hit near the computer, or it is exposed to an excessive amount of water, the boards may short-circuit or break apart. Jump-starting a car with the cables attached to the wrong terminals can short out the computer as well. A faulty alternator can also fry an ECU by pushing too much electrical charge through the system.

ECU repairs

After your mechanic checks to make sure than your car's problems aren't caused by more common issues and has determined the ECU is faulty, the unit will have to be repaired or replaced. Replacing the unit is a potentially expensive process. However, in many cases, the ECU can be repaired especially if the unit was only partially damaged. Boards can be removed and replaced and components can be soldered together.

It is not common for an ECU to have problems, but when they do, it affects your car's drivability. Since it is a critical component to the engine, ignoring any issues with it can potentially cause permanent damage to your vehicle. If your car's check engine light is on, or you are having staring and running problems with your car, take it to a mechanic like Dean's Automotive Service Center for a full diagnostic just to make sure the ECU is not a problem.