Engine Control Module Symptoms

One of the most important components found on modern vehicles is the engine control unit (ECM), which is at times referred to as engine control unit (ECU) or powertrain control module (PCM). Typically, it works as the main computer for a number of car’s engine performance and drivability functions. The engine control unit gathers the data from the engine’s various sensors, and utilize the data to compute and tune engine spark and fuel for maximum power and excellent performance. So, before you go to the mechanic to repair the engine control module, you can learn about the various signs of a bad ECU and know what to pay or expect when visiting.

  • Check engine light comes on

A common sign of a bad ECM is the check engine light. So, when the check engine light comes on, this should be a clear indication that your ECM has a problem. This is because the engine check light normally illuminates when the computer notices an issue with one of its sensors or circuits. The best way to prove this is by scanning the computer for trouble codes which can assist show if the problem is with the ECU.

  • Engine performance problems

If you experience engine performance problems, this might be another indication of damaged or bad ECM. In case the engine control module has a problem, it might throw off the timing and fuel settings of the engine. These in turn negatively impact engine performance. A bad engine control unit may make the car to undergo a reduction in fuel efficiency, acceleration and power.

Related: Use the best synthetic oil to reduce engine problem.

  • Engine misfiring

Engine misfiring or engine stalling is another sign of a damaged or bad engine control module. When the car computer is damaged, it can make the car to sporadically have problems like misfires and stalling. These signs normally come and disappear, and may not seem to have any kind of pattern to their occurrence.

  • Vehicle not starting

When your car doesn’t start or it is very hard to start, this might be an indication of a bad engine control unit. And when the ECU totally fails, it will leave the vehicle without engine management control and will completely not run due to this. Sometimes, the engine might crank, but still it will not be capable of starting without the important inputs from the computer. This sign can be brought about by some other issues and that’s why it is recommended to use a diagnostic scanner to know the cause.

  • Excessive fuel usage

When the engine control module is bad, a lot of fuel will be used. If you notice such an issue, you should take your car to the mechanic to scan codes and discover the issue. Although excessive fuel usage can be linked to a bad ECM, it’s good to be sure as it can mean something else.

  • Loss of communication between the engine control module and the scan tool

Last but not least, the last sign of a bad engine control unit on our list is the loss of communications between the diagnostic scan tool and engine control unit. If the light comes on and you attempt to diagnose it but there is no communications, you should know that your car has a bad computer system or ECM.

Bottom line

Now that you know the various signs of a damaged or bad engine control unit, you should take your car when you notice one of the above symptoms. Leaving your car unattended to can be very dangerous and may cause more harm than good. Driving your car will be extremely difficult and the only way to ensure that your car is safe is by going to a professional mechanic to diagnose the PCM. The module will provide you with accurate readings and your car will be safe again after being repaired.


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