5 Causes of a Damaged ECM or ECU, Anything?

5 Causes of a Damaged ECM or ECU – The ECU is your vehicle’s engine control unit. It is also commonly referred to as a PCM (powertrain control module) or ECM (engine control module). Then what is the difference between ECU vs ECM vs PCM in cars?

This electronic module is an internal computer that car manufacturers use in their vehicles. Its purpose is to manage various systems, especially engine management or power transfer and its functions. In simple terms, we can think of it as the vehicle brain. The engine and drivetrain are most dependent on the ECU or ECM.

Through various electronic sensors, chips, and components in the vehicle, the ECU or ECM can send data feedback to the engine via the attached actuator. The nature of this feedback will determine which function the machine will perform next.


This mini-computer is very helpful in calculating the amount of air and fuel needed for the internal combustion process. That way, better fuel efficiency can be achieved properly.

5 Causes of a Damaged ECM or ECU

5 Signs the ECM or ECU Has Been Damaged

ECU or ECM regulates almost every important system and function in a car. If you have experienced damage to the ECU or ECM, then many visible symptoms will present themselves. It doesn’t take long for you to realize that the ECU or ECM is the one responsible.

However, what you may need to ask is why the ECU or ECM is not working. There are many internal causes that can contribute to this. Below are the top 5 causes of a damaged ECU or ECM. Investigate them as soon as you notice a problem with the ECU or ECM.

First – Dead Battery

The first cause that causes the ECU or ECM to experience problems or damage is a dead car battery. Car batteries have electronic cells that need to function for the ECU to function. If one of the cells in your car battery dies, your ECU or ECM can be damaged immediately or start with a problem. After all the cells die, the battery is considered dead and your entire vehicle will not function.

You won’t even be able to start your vehicle and start the engine after that at all. So, pay attention to the early warning signs of a malfunctioning ECU or ECM and immediately check the condition of your car battery.

Second – Corrosion Problems

The ECU has a seal around it that should prevent moisture from getting inside. However, after several years, this seal tends to break with age. If the seal is too worn, the ECU or ECM will be easier to damp and then moisture can easily enter the ECU or ECM.

Moisture is a bad thing for ECUs. This is because water vapor will form corrosion on its components. If the corrosion is not cleaned immediately it will cause the component to be damaged. So I can confirm your ECU or ECM will be damaged.

Third – Low Voltage

The average ECU is expected to have at least 9 volts, but preferably 12 volts. There is a wire attached to the ECU harness through which you can check the total voltage.

All you need to do is connect a voltmeter meter to it. This device will be able to detect how much voltage is flowing through the ECU. If the voltage is 6 or less this is most likely causing your ECU problem.

Fourth – Bad Battery Jumper

Whenever a jump start is made to your battery, you need to make sure that the jumper cables are properly attached. If you try to start your vehicle with an incorrectly attached cable, then your ECU or ECM could short circuit as it causes it to spike too fast.

It will ask you to repair the ECU or ECM and you may even have to replace it. This can cost thousands of dollars.

Fifth – Bad Starter

Many vehicles have a starter with its own sensor in it. One such sensor is a sensor override which regulates how many volts the ECU or ECM will accept.

If this sensor is damaged, the ECU or ECM will not receive the correct amount of voltage. Then it will fail to function and cause further problems to your vehicle.

2 thoughts on “5 Causes of a Damaged ECM or ECU, Anything?

  1. Pingback: 2 Ways to Manually Reset ECU when Check Engine is On | Hi-tech for Future

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