How Much Does ECM Replacement Cost?

Last Updated on October 3, 2023
Written by CPA Alec Pow | Content Reviewed by CFA Alexander Popinker

The ECM, short for engine control module, also referred to as ECU, engine control unit, is a critical component of the car communicating with the engine to ensure proper functioning. This engine computer processes information from multiple sensors of the car and controls various functions of the engine such as ignition, fuel injection, and emissions. This circuit board manages power and the distribution of electricity throughout the car.

How much does an ECM replacement cost?

The cost of a new ECM car part ranges anywhere from $600 to $2,000 for premium cars just for the part itself. Based on online discussions, most people were quoted an average of $900, without including the labor for replacing an ECM. This cost to replace the ECM will greatly depend on factors like the make and model of the car, the type of ECU, and from where you purchase it.

To properly install the car’s ECM, going to an experienced and qualified technician will add $100 to $250 in labor fees to your overall cost. The installation fee at a repair shop will not vary too much, because the ECM only needs to be plugged in and and programmed.

Also, there are cases when the vehicle’s ECM does not need to be replaced. Reprogramming the computer will be enough and it will be significantly less expensive. Usually, the average cost for reprogramming the electronic control module is anywhere between $200 to $400, depending on your situation.

Another option when replacing a failing ECM can be with a remanufactured ECM. This will decrease your needed budget, being much cheaper than a brand-new one. A remanufactured ECM can cost from $250 up to $500, depending on the make and model of your car. Before purchasing, ensure that the ECM comes with a warranty or it is certified.

Other people look into purchasing used ECMs that are working properly. These can be found at your local junkyard or the used parts store, for a cost of around $100, plus the cost of tests and reprogramming. Remember to test these parts before installing them onto your car. A bad circuit board will damage your car.

Also, several people choose to repair the faulty ECM to maintain the original part. According to Howstuffworks.com, the total cost of repairing an ECM may be a little more expensive than a new one. Unfortunately, some car models will only work with their original ECM.

Engine Control Module replacement overview

The engine control module, ECM, is one of the most important electrical components of the car, as we stated above. It continuously monitors numerous sensors, ensuring that the car’s engine functions at its optimum performance and guaranteeing low fuel consumption. This main computer system is considered to be the ”brain” of the vehicle.

You might also like our articles on the cost of car diagnostic tests,  wiring harness replacement, or car computer reprogramming.

The ECU is normally found in the engine compartment, however, it can also be found under the passenger seat depending on the model and make of the car.

ECU influence is also felt in the control of the air and fuel mixture, control of idle speed, injection, and also when it comes to ignition.

A primary function of an ECM is to control emission production by adjusting fuel injection. Through an air-fuel combination, it controls the air, fuel, and ignition. This process is crucial for the car to comply with the standard limit values of exhaust emissions.

For instance, During combustion, the composition of air and fuel is adjusted, to inject the proper amount of fuel. After this, the ignition sensor will synchronize and activate the spark plug. When the car is idling, the ECM gives the command to the idle speed sensor to prevent the needless consumption of fuel. The valve timer regulates the period of the valve’s opening and shutting for optimal engine ventilation.

Also, for the proper function of the engine, ECM measures the air stream in the intake manifold and cooling system. ECM can control subsystems such as skid brakes, transmissions, ABS, cruise control, and others.

The ECM is replaced with a new one within 30 to 60 minutes, which is a simple procedure. Once it is located and the tester does its diagnostics, the mechanic will remove the ECM’s bolts and brackets to detach the plugs. After this, some vehicles have a memory chip (PROM) that must be replaced. Finally, the new unit ECM is plugged in, bolts and brackets are tightened, and the “check engine” light will switch off. If the dash light stays on, additional tests will be required to pinpoint the problem.

Important things to consider about ECU

Driving a car with a bad ECM, also called ECU, may cause substantial engine damage.

There are cases when the ECM can be repaired or it only needs to be reprogrammed. You should get your car a diagnosis from a competent car service or shop to ensure that this is the right course of action.

Usually, the most common symptom of a faulty ECM is the ”check engine” light. Also, a stalled engine, performance issues, increased fuel consumption, or even failure to start the engine may be indicators of a bad engine control module.

If you have a more recent vehicle, their PCM software needs to be upgraded. To do it properly, consult the manufacturer’s operating instructions.

To prevent engine ECM failure, practice regular maintenance, such as oil changes, and avoid sudden starts and stops.

It is recommended to get multiple quotes from different mechanics and car part stores to compare the costs for an engine control.

According to CarsDirect.com, the equipment in charge must be up to date in order to provide the correct diagnosis. They note that most dealerships have their software updated on a regular basis.

ECM vs. PCM:  What’s the difference?

Most people are confused by the similarities between ECM and PCM and don’t really understand the differences.

As stated above, the engine control module, known as ECM and often referred to as ECU (electronic control unit), receives sensory input from all areas of the vehicle and processes it before sending it to electronic systems for increased performance. It collects data from different components to examine the state of the engine. The cooling system, exhaust, intake, and other internal components, all send their info to the ECM.

The PCM, the power control module, can also coordinate operations, from gearbox control to the primary engine, in order to improve fuel efficiency and power delivery. The PCM is mainly in charge of the powertrain control proper function. Usually, most devices have their own TCM and ECU, as well as their own processor.

How can I save on the average cost?

A used ECM purchased from a junkyard or a used parts car store with all the proper verifications will be around $250. This will definitely save you a large amount of money. Remember that the ECM has to be checked and certified and that it is the right model for your vehicle.

Also, a great way to save money is to purchase a remanufactured engine control module, which comes at an average cost of $400. Many companies are able to provide rebuilt ECMs and you can find them on websites such as eBay, Amazon, and Craiglist as well.

To save money, buy the part from a local auto parts store rather than ordering online. In this way, you will not have to pay extra for shipping and handling charges.

Also, some auto shops may provide free installation if you purchase the ECM from them. When you go and shop around ask them if any free services are included.

In order to save some money in the future, look for providers that offer a warranty for faulty ECM.

Installing the ECM yourself eliminates the fee you pay for labor, lowering the overall cost dramatically. However, keep in mind that proper tools and electrical knowledge are required to complete the installation effectively.

Take into consideration asking for multiple quotes from different providers to compare the costs.

ECM repair

Because some ECMs can be fixed rather than replaced, replacing the entire unit isn’t always essential, and fixing will result in a lower bill. Look for mechanics that are certified to do the repairs properly.

The best way to find out if your ECM needs to be replaced or repaired is to get a diagnosis. Take into consideration that there are car shops where you will get the diagnosis for free. So try contacting different shops in the area to see what they offer.