Modern cars use advanced computers to control and monitor their various engine and electrical systems.

The main unit that controls these systems is called a powertrain control module. Like any car part, powertrain modules will wear down over time and eventually need to be replaced. 

On average, you can expect to pay about $900 to have a professional replace your PCM module.

The typical price range is between $500 and $1,200. Alternatively, you can buy the part and replace it yourself for an average of $600.

However, if you want a DIY installation, you will also need a control module reprogramming tool, which itself costs about $1,200 on average. 

There are a lot of factors to consider when it comes to this crucial piece of machinery. So we put together this comprehensive guide on the costs to replace a powertrain control module.

We will cover the costs of professional installation, the cost of parts, and the costs to buy a diagnostic and programming tool for DIY installation. 

What is a Powertrain Control Module?

The powertrain control module (PCM) is an important component of your car’s engine. The powertrain control module consists of an engine control unit (ECU, a transmission control unit (TCU), and a body control module (BCM). 

In other words, your PCM is basically a computer that serves as the “brain” of your car. It monitors data from the other control units to detect performance issues.

When something goes wrong, the PCM flips the “check engine” light on your dashboard. PCMs consists of the main control unit body and a series of sensors that are located in the car’s various mechanical and electrical systems. 

Functions the PCM is in control of include, anti-lock brakes, traction systems, fuel injectors, emissions systems, and exhaust systems. In modern cars, PCMS are powerful processors, so they can cost a premium to replace. 

How Much Does it Cost to Replace a Powertrain Control Module?

The powertrain control module is one of the more expensive components of cars. This is because they are sophisticated processors. On average, you can expect to pay about $900 to replace a PCM unit.

The typical price range is between $500 on the low end and $1,200 on the high end. Luxury brands and high-performance vehicles can cost nearly $2,000 to replace the PCM. 

Below is a table showing the average cost to replace PCM units for various popular car models. These prices are averages and depend on the age of your car and your mechanic’s location. 

As you can see, luxury brands such as Audi or BMW will cost more to repair as they have advanced onboard computing systems.  Sometimes, you don’t need to replace the PCM, but just need to update it.

Keep in mind that most modern cars have a single PCM unit that integrates both the engine control unit and transmission control unit.

So if there is a problem with only one of those systems, you will have to replace the entire PCM unit. Some cars still use a dual ECU and TCU system, but these are relatively uncommon.  

PCM Parts

If you don’t want to pay a professional, you can buy the parts and install them on your own. You can expect to pay anywhere between $200 on the low end to $1,000 on the high end for a PCM unit.

The average price is about $600. Below is a table showing the average cost for various PCM replacement parts. Keep in mind that these prices are averages and may be subject to change. 

As you can see, PCM units greatly vary in price depending on compatibility. This is because many modern cars have advanced computing systems. 

New vs Remanufactured PCM

Like most car parts, you have the option between a brand new PCM and a remanufactured and reprogrammed PCM unit. Fortunately, reprogramming a PCM unit is fairly cheap since it does not involve switching parts.

It typically costs about $100 to $200 to reprogram a used unit. Normally, your mechanic will have to download any new updates to reprogram your module. 

PCM Reprogramming Tool Cost

Keep in mind that even if you get a new PCM with the same part number as the existing one, you will still have to reprogram it before you install it.

Normally, when you buy a unit, the manufacturer will program it to be compatible with your vehicle’s VIN. Without this programming, the PCM would not be able to communicate with the other computing or electronic components of your car. 

If you want to install a new PCM on your own, then you will need a special reprogramming tool. These tools let you interface with the unit so you can calibrate its sensor and monitoring processes. 

You can expect to pay approximately $1,200 on average for a diagnostic and reprogramming tool. The typical price range is between $500 on the low end to over $2,000 on the high end.

Diagnostic and reprogramming tools may have a simple interface with a few buttons or they may have an advanced touchscreen and internet connectivity options for downloading new codes and engine management specs. 

As you can see, prices for diagnostic and reprogramming tools vary widely depending on their interface and processing capabilities.

When you look for a programming tool, try to find one that will automatically search and download new engine codes and specs. That way you don’t have to hunt for and manually download them yourself. 

PCM programming tools are expensive but they have some benefits. First, you can save money in the future if you do diagnostic work on your car by yourself instead of taking it to a mechanic.

Second, PCM tools can help you identify issues early so you can mitigate their negative effects. Lastly, a programming tool can actually fix smaller issues through the interface, so you may not have to take your car to a pro at all.

Keep in mind that if you buy a PCM reprogram tool, then you will also need a special connector cable to interface.  Modern cars use what is called a “J2534” interface that is designed by the Society of Automotive Engineers (SAE).

This kind of interface creates an API that nearly all automotive manufacturers have adopted. 

Factors that Affect Powertrain Control Module Replacement Costs

Make/model car

Most modern cars use a single PCM unit that integrates the engine control module and transmission control module.

Many modern cars use advanced computing systems so PCMs can be quite expensive to repair. 

Type of engine

The type of engine you have also affects PCM costs. For example, PCM units for diesel engines typically cost more than ones for traditional gasoline engines because they are more complex and require more monitoring. 

Replace vs reprogramming

Sometimes you will not have to replace the entire PCM unit but just reprogram it so its specs are up to date.

Reprogramming is much cheaper than replacing and should be the first option that you consider. 

Replacement tools

If you want to replace the module on your own, then you will need the right tools. Diagnostic and reprogramming tools can cost a premium. You will also need a basic wrench set. 

Signs of a Bad Powertrain Control Module

Here are the most common signs of a broken PCM unit.

Car Won’t Start

If your PCM is broken, then it can’t use its engine management codes. In that case, you won’t be able to start your car at all. The engine may crank, but this just means that the ignition is working.

If the computer does not send the right signal, the car can’t start.

Trouble Codes Swapped

Normally, the PCM monitors your car’s systems and flips a corresponding error code when it detects a problem. However, if your PCM is broken, these codes can get mixed up or not trigger at all.

For example, if several indicators come on at once, your PCM may be broken. Alternatively, your car may flip error codes when there is no issue. 

Poor Fuel Economy

The PCM includes the ECU which monitors and modifies engine performance based on feedback. If the ECM is broken, then your car may inject too little or too much fuel.

If your fuel levels are off, your engine will be less efficient. 

Car Stalling

Your car can also randomly stall when your PCM is broken. The PCM controls the engine’s emissions and fuel systems, so if it loses control your engine could stall.

The tricky part is that it can cause random stalling, so it may be hard to diagnose the PCM as the problem. 

Poor Engine Performance

The last most common sign of a broken PCM is poor engine performance. The PCM monitors various aspects of the engine and uses feedback to modify performance.

If the PCM is broken, then your engine may not respond to conditions and may run poorly. 

Failed Emission Tests

Another common sign of a PCM failure is failed emission tests. the PCM normally monitors emissions from your engine and adjusts performance to meet required standards. If your PCM is broken, then your car could fail emissions tests.

Frequently Asked Questions

How much does it cost to replace a PCM?

It costs about $900 on average to have a professional replace your PCM. The typical price range is between $500 on the low end and $1,200 on the high end. As far as parts go, a PCM unit costs an average of $600. 

How often do I need to replace my PCM?

Powertrain control modules are designed to last the lifespan of the car, so most people won’t even have to replace them. That being said, you should consider getting your PCM unit checked out once every 100,000 or so miles.

That comes out to about once 7 to 8 years, assuming an average yearly driving distance of 13,000.

Can I drive with a broken PCM?

It depends on the nature of the damage. If your module is just flipping bogus error codes, then you should be able to still drive the car.

However, if the engine management codes are corrupted, then your car may not start at all. Either way, you should get a broken PCM fixed as quickly as possible. 

Can I replace a PCM on my own?

It is possible but it can be difficult. Aside from the fact that the PCMs rarely need replacing and might be hard to access, the PCM is a complex processor that needs to be calibrated to work with the other car components.

You will need special diagnostic equipment and programming equipment to make sure that the unit is set up correctly. Diagnostic and reprogramming tools can cost upwards of $2,000, depending on the model that you get. 

Do all cars use a PCM?

Most modern cars use a single PCM unit that integrates both the ECU and TCU. However, there are some models that still use a dual ECU/TCU setup.

Make sure that you know what kind of equipment your car needs before buying anything. 

Final Words

Powertrain control modules are an extremely important part of your car’s control systems and basically function as the brain of your car. Without a properly functioning PCM, you will notice problems in virtually all of your car’s systems.

So it’s in your best interest to get a broken PCM replaced as soon as possible. As always, make sure that you get quotes from several mechanics so you can get the best price possible.