Common ECM Failure Symptoms

9 Common ECM Failure Symptoms

It’s a bit of a brawl to deal with faulty engines while you’re on the road. If you’re into driving and know your way around cars, then you know how big of a hassle it is to deal with ECM problems.

But any problem can be avoided when you know the symptoms. To our knowledge, there are 9 common ECM failure symptoms you can come across anytime.

Some of these symptoms include- misfiring engine, reduced power, low fuel, engine not starting, gear shifting issues, etc. Diagnosing the symptoms first can help you detect the problem. And when you know where the problem is, you can get rid of it before letting it cause additional harm to your vehicle.

To further know what other symptoms you can face, keep an eye on this article so that you can learn everything about ECM and the symptoms it shows when prone to failure.

Types of Controlling Module for Vehicle

There’s always a system that helps in operating various electronics. And a control module is the system used for a vehicle. It’s a collection of actuators, sensors, and basic controls of an engine. In short, a device that acts as a regulator and operates the whole engine.

But the control module is a combination of three modules or computers. Without these modules, it’s impossible to call this device a module. Not to mention, these computers carry out most of the control functions of your car. They are:

  • Engine control module (ECM)
  • Powertrain control module (PCM)
  • Transmission control module (TCM)

Here, we will discuss some of the common symptoms of ECM. These symptoms are the initial stage of your car’s engine problems. These symptoms should not be taken softly at all, but should be taken as a warning message.

1. Engine control module (ECM)

The ECM or the engine control module is a component that works as the chief key in ensuring that your vehicle gives optimal engine performance.

Instead of manually done mechanical and pneumatic controls, this is the new type of control that gets operated electronically.

ECM ensures your vehicle’s solid performance by controlling the actuators, internal combustion, multitude sensors, and lookup tables.

2. Powertrain Control Module (PCM)

The powertrain control module (PCM) is the other component, which works alongside ECM. It’s known to control more than 100 factors inside your car or truck.

Running hundreds of error codes, highlighting the problematic area, and warning you about the engine’s problem are some of the key functions the PCM carries out.

3.  Transmission Control Module (TCM)

A Transmission control module or TCM is an automotive computer that controls clutch automation, semi-automatic transmissions, and actuation. It’s a modern transmission that works automatically.

 TCM also uses sensors and data to calculate when and how to change the gears of your vehicle.

What is an ECM and What Does it Do?

ECM or Engine Control Module is also commonly known as the Engine Control Unit (ECU). In general, it manages your vehicle’s air-fuel mixture and monitors the majority of the sensors by regulating the emission control systems.

The ECM works by regulating four major parts of the operating system of your vehicle. These are:

Controls Air Fuel ratio: By using sensors, the ECM regulates the oxygen fuel ratio to get detected in the vehicle’s exhaust. It also works to identify the engine lean reading. These sensors include- oxygen sensor, air-fuel sensor, and mass airflow sensor.

Controls Idle Speed: The ECM calculates the idle speed by monitoring the rotation speed of the engine. It tracks your vehicle’s RPM and engine load by relying on sensors that are situated in the camshaft and crankshaft.

Controls Valve Timing Systems: The variable valve timing system gets controlled by the ECM. This control opens the valve in the engine to either increase fuel economy or power.

Controls Ignition Timing: The ignition timing is also controlled by the ECM. Doing this allows the engine to generate more power and fuel economy.

So, when ECM uses these sensors to operate the engine, it tends to be drowned towards failure. As a result, various symptoms are noticeable while using the vehicle.

The Most Common ECM Failure Symptoms ( 9 Symptoms)

There’re some common symptoms you’ll get to see when there’s an error with your engine’s ECM. And the most common ones are-

1. Illuminated Engine Light

The dashboard of every vehicle has a light to indicate a warning sign about the engine. Sometimes it might be for nothing but, most of the time, it starts to click light when there’s an issue with the ECM of the engine.

Keep checking if the light clicks, as it could mean your ECM is causing problems.

2. Engine Misfires or Stutters

Turbulent engine behavior is one of the common symptoms of an ECM failure. This behavior is caused by rich fuel air. The engine starts to stutter when a lean ratio fails to ignite. Nevertheless, it indicates an ECM issue.

3. Loss of Acceleration

To make the right adjustments for acceleration, the ECM works with the TCM. When TCM controls shifting, the ECM leads to an effortless and smooth transition by adjusting the throttle.

So, if you see the shifting is shaky and has no acceleration, that would mean the ECM isn’t adjusting the throttle.

4. Engine Shuts off

Due to improper fuel-air ratio, the engine Shuts off randomly when your vehicle is sitting back. That’s when the engine runs slow and doesn’t have the momentum to keep your vehicle running.

Check out your engine if it stalls when it’s sitting back to avoid further damage.

5. Drop-in Fuel Economy

Sometimes, a sudden drop in Fuel Economy can be seen for fuel-air ratio and engine timing.

This problem doesn’t happen over time. Instead, if it’s the ECM that’s causing the problem, then you’ll see the mileage drop suddenly over a couple of weeks.

6. Car won’t start

During engine start-up, your car might not want to start. At that time, even turning the keys multiple times doesn’t help in starting the engine.

This scenario is seen when the ECM fails to send proper ratio data to the fuel-air ratio.

Thus, it’s your faulty ECM that causes these hiccups and doesn’t start your car.

7. Rough Shifting

If you notice rough or clumsy shifting, that means the ECM isn’t sending proper signals to the TCM.

When TCM doesn’t get the relevant data for transmission, there’s a loss of acceleration and causes rough shifting.

8. Car Overheats

The ECU works as a trigger switch that automatically limits the engine’s powers when the car gets overheated. Thus, the risk is reduced as the heat tones down.

But when your vehicle keeps getting overheated and the heat doesn’t tone down at all, that would mean your ECM isn’t working and can prove to cause further damage to your vehicle.

9. Loss of Spark

At times there’s a case of misfiring due to loss of spark. This loss happens when a problematic ECM prevents coil voltage from bouncing at the end of the spark plug.

Incorrect or a loss of spark can cause misfiring, which indicates a problem with the ECM.


The ECM or Engine Control Module can work as the driving brainpower behind every engine. But, that doesn’t mean it’s immune to failure or dysfunction. Generally, It’s hard to detect the problems revolving around the ECM.

For that reason, we’ve put together the 9 common ECM failure symptoms, so you can detect the problem.

In this way, you can get rid of the problem and solve it at the right time. Thus, it can help you in preventing your car from facing more issues

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