Modern cars are full of computers to keep them running smoothly. One of the most important ones is the Powertrain Control Module or PCM. If you’re noticing weird behaviors with your car, the PCM might just be faulty and reprogramming may be necessary. We’ll discuss the PCM reprogramming cost in this post, along with everything else you need to know about the Powertrain Control Module.
- What Is A Powertrain Control Module?
- Signs & Symptoms Of A Bad PCM
- Diagnosing The PCM
- Reprogramming Costs
- Frequently Asked Questions (FAQs)
- Final Conclusion
Powertrain Control Module
Before we get to the PCM reprogramming cost itself, we always like to explain what the component in question does and how it does it. This will give you a better understanding of why a repair may be necessary. The Powertrain Control Module is a computing unit consisting of the Engine Control Unit (ECU) and the Transmission Control Module (TCM).
The PCM controls everything that’s related to the car’s powertrain. This includes engine operation, gear changes in the transmission, and more. Basically, whenever you drive the car, the PCM is there to command the powertrain components on what to do according to your command.
And when something isn’t working properly, it will make appropriate adjustments to fix the anomaly. It does this by monitoring the information that the many sensors in the car give it. By using the information from these sensors, the PCM will make appropriate adjustments where necessary by using actuators.
For example, let’s say the O2 sensor detects a high amount of oxygen in the exhaust gases. This means that the engine is burning a lot of air, but not enough fuel (lean fuel and air mixture). This isn’t ideal, since car engines need to run on a stoichiometric ratio. As a result, the PCM will tell the fuel injectors to put in more fuel to balance out the mixture. The PCM will make these sorts of adjustments wherever necessary.
PCM vs ECU
It’s easy to confuse this, so let us try to make it a bit more clear. The ECU or Engine Control Unit gathers data from multiple sensors and then it can adjust the ignition and fuel injection timing to make sure the car runs smoothly. Meanwhile, the Transmission Control Module or TCM determines when the transmission needs to shift gears. It uses throttle input, the wheel speed sensor, and traction control to determine when to shift.
But wait, isn’t that what the Powertrain Control Module does? Well, the PCM integrates the function between the ECU and the TCM. The ECU and TCM still function independently, but the PCM integrates them for better regulation of the car’s setting. For example, when the transmission needs to shift gears, the PCM can regulate the throttle for better shifting.
Reprogram Powertrain Control Module
The PCM rarely fails, but as with any computer, it can still fail over time. Sometimes, the software just goes awry and it needs reprogramming or is sometimes referred to as a reflash. Think of it when your phone’s or laptop’s software isn’t working properly and there’s a lot of bugs. Oftentimes, a software reinstallation or a complete factory reset is necessary. This resets your device to factory specifications so it’ll work properly, and a PCM reprogramming is similar to that.
A PCM reprogram may be necessary when the powertrain isn’t operating properly but the mechanical components are fine. If the PCM is faulty, it can disrupt the operation of various components hence why a reprogram is necessary. A PCM reprogram may change the engine’s idle speed, spark timing, and fuel mixture amongst other things. This brings the powertrain to the factory specification and should help it to operate as intended.
Additionally, this is quite rare, but sometimes manufacturers will have software updates for your car’s PCM. There may be a non-optimal setting or a bug in the PCM’s program, and a new software brings a more optimal control for the PCM. In this case, a PCM reprogram is needed to update the software and may improve your car. It may improve performance, fuel consumption, and emissions control among other things.
But how do you know your PCM is faulty and you need a PCM reprogramming? Well, this segues us nicely to our next section:
Bad PCM Symptoms
Since the PCM controls the engine’s operation, you’re bound to see some obvious signs:
PCM Reprogramming Cost, Symptoms #1. Difficulty Starting The Engine
Since the PCM controls many aspects of the engine, a faulty PCM can make starting the engine difficult. In some cases, it may refuse to start altogether. This is because the PCM controls things like the ignition timing, fuel and air mixture, camshaft positions, and more.
When you turn the key to start the engine, a starter motor will crank the engine. The engine then needs to burn fuel and air inside it to start the combustion process and that lets the engine run on its own. If for example, let’s say the spark plugs aren’t firing because of incorrect ignition timing, it can’t start the combustion process, hence why the engine won’t start.
Of course, bad spark plugs, clogged air intake, and other bad sensors may contribute to this problem. Read our guide on how to diagnose an engine that won’t start here.
PCM Reprogramming Cost, Symptoms #2. Poor Performance And Fuel Economy
Again, since the PCM controls the engine, your car’s performance and fuel economy are bound to suffer when you have PCM issues. It could be because the PCM is putting in too much fuel, which can increase fuel consumption. It’s also possible that the engine is misfiring due to incorrect ignition timing, which leads to poor performance.
However, these problems may stem from other issues. For example, bad spark plugs or faulty ignition coils can result in engine misfires. An overdue oil change can also reduce your car’s performance. You’ll need to check these components first and rule them out before concluding that it’s the PCM that’s faulty.
PCM Reprogramming Cost, Symptoms #3. Increased Emissions
In addition to poor fuel economy, excess fuel burning will also result in increased emissions. When the engine is burning too much fuel, the catalytic converter won’t be able to filter out all of the toxic gases. As a result, your car will emit more harmful gases than it’s supposed to. You may also notice black smoke coming out of your car’s exhaust.
You may notice this when you do an emissions test. Cars are now designed with emissions regulations in mind, and under normal operating conditions, they should meet these requirements easily – provided that the catalytic converter is in good condition.
PCM Reprogramming Cost, Symptoms #4. Transmission Shifting Problems
As mentioned, the PCM also controls the function of the Transmission Control Module. As a result, a faulty PCM may result in shifting problems. Symptoms include rough shifting, early or late shifting, and even refusing to engage certain gears. Keep in mind that a bad transmission solenoid may also cause this, or it’s possible you’re low on transmission fluid.
PCM Reprogramming Cost, Symptoms #5. Check Engine Light
The check engine light is your car’s way of warning you that there’s something wrong with the engine that it can’t fix on its own. When a sensor detects something wrong, the PCM will receive this signal and try to rectify the problem by making the appropriate adjustments such as to the camshaft position and the amount of fuel it puts in, depending on the problem.
If it can’t fix the problem and it persists, the PCM will register an error code on the On-Board Diagnostic (OBD) system. This error code then lights up the check engine light to warn the driver that there’s a problem they need to fix. Of course, many problems can trigger these such as bad spark plugs, faulty Mass Airflow (MAF) sensor, and more.
A check engine light is unnerving, but it’s somewhat a blessing in disguise. When there’s a check engine light, this means you can scan the OBD system for the error codes. These error codes then will tell you the problem the engine is experiencing, which helps to narrow down the possibilities and diagnose the problem. And yes, it can help you diagnose a faulty PCM.
PCM Reprogramming Cost, Symptoms #6. Engine Stalling or Surging
Your engine’s behavior is influenced by the PCM. Stalling or surging can occur if it’s not functioning properly. An engine stall happens when it suddenly turns off while you’re driving, leaving you stranded momentarily. On the other hand, an engine surge is when the RPM unexpectedly rises. This is often because of the PCM misreads data from sensors, leading to incorrect air-fuel mixtures or ignition timing.
Bear in mind, that other components like a malfunctioning idle air control valve or dirty fuel injectors might cause these symptoms too. Thus, it’s wise to rule them out before blaming the PCM.
PCM Reprogramming Cost, Symptoms #7. Faulty Readings on the Dashboard
Your car’s dashboard provides crucial data about your vehicle’s performance. If your PCM is malfunctioning, you might notice erratic behavior from your speedometer, tachometer, or fuel gauge. In extreme cases, you might even see false warning lights, even if those particular systems are fine.
However, faulty instrument clusters or grounding issues can also cause these symptoms. Always get a comprehensive check before drawing conclusions.
PCM Reprogramming Cost, Symptoms #8. Car Doesn’t Respond to Acceleration
This can be particularly alarming. You press the gas pedal, expecting a smooth acceleration, but your car doesn’t respond or hesitate. This might be the PCM misinterpreting the pedal position or delivering the wrong throttle responses.
That said, issues with the throttle body, throttle position sensor, or even clogged fuel filters can exhibit similar symptoms. Always check these first.
PCM Reprogramming Cost, Symptoms #9. Constantly Running Cooling Fans
Your cooling fans play a pivotal role in maintaining the engine’s temperature. They should turn on or speed up when needed and switch off once the engine is cool. A malfunctioning PCM might misread temperature data, keeping the fans running longer than necessary, and draining your battery over time.
However, faulty temperature sensors or fan relays can also cause fans to run incessantly. It’s crucial to get these checked out before assuming it’s a PCM issue.
PCM Reprogramming Cost, Symptoms #10. Battery Draining Overnight
A faulty PCM might fail to enter the “sleep mode” after you turn off the car. This means that it’s still drawing power, and over time, this could drain your battery. If you notice your battery repeatedly dying overnight or over short periods of inactivity, a malfunctioning PCM might be the culprit.
Nevertheless, there are other reasons for a draining battery: like parasitic draws from other components, or simply an old battery. A thorough electrical diagnosis can pinpoint the exact cause.
PCM Reprogramming Cost, Symptoms #11. Harsh or Delayed Engagement of Gears
Beyond the shifting problems, you might notice a harsh or delayed engagement when you try to shift from park to drive or reverse. This could indicate the PCM not adjusting hydraulic pressures correctly in the transmission.
However, low transmission fluid, clogged transmission fluid filters, or internal transmission problems could also be at play. Thus, it’s imperative to inspect these areas thoroughly.
PCM Reprogramming Cost, Symptoms #12. Absence of Communication with Diagnostic Tools
In some instances, a faulty PCM will not communicate with diagnostic tools or OBD scanners. If you or your mechanic plugs in a scanner and it doesn’t read any data, the PCM might be the issue. This symptom is often a clear indication that the PCM is on its way out or has already failed.
However, ensure your scanner is working correctly, and there’s no issue with the OBD port itself before jumping to conclusions.
In conclusion, while these symptoms can hint at a faulty PCM, it’s essential to understand that many overlap with other car issues. A systematic approach, considering all possibilities, is the best route to pinpointing the problem. If your car exhibits multiple symptoms simultaneously, the likelihood of a failing PCM increases. But always consult with a professional mechanic to get a definitive diagnosis.
How To Test A PCM
There are two ways to diagnose the PCM: by doing an OBD scan, and by checking for physical damage. Keep in mind that this is a method for scanning OBD-2 systems, which has been present virtually in all cars since 1996. If your car still has an OBD-1 system, you’ll need to scour the internet on how to do it for your specific car. This is because OBD-1 systems are proprietary, meaning they are unique from one manufacturer to another.
With that being said, here’s how to scan an OBD-2 system:
How To Scan OBD-2 Systems
- Get an OBD-2 scanner/reader. They cost $100 at most, and the more expensive ones are unnecessary since they are for professional mechanics. They’re universal, so they will work with any car as long as it has an OBD-2 system.
- Plug the reader into the car’s OBD port. This port is often located underneath the dashboard area, either above your pedals or knee. Keep in mind that some cars might have their port hidden out of sight. Check your owner’s manual or online to see where it’s located in your car.
- Once plugged in, turn on the OBD scanner. It should immediately scan the car. However, some scanners might require you to input additional information such as make, model year, VIN, etc.
- It will then display the error codes it has found. A more complicated scanner might also display a description of what’s wrong with the car, but if you have a simpler scanner then it’s recommended to take note of the codes displayed.
Afterward, look out for these codes:
- P0600 – Serial Communication Link
- P0601 – Internal Control Module Memory Check Sum Error
- P0602 – Control Module Programming Error
- P0603 – Internal Control Module Keep Alive Memory (KAM) Error
- P0604 – Internal Control Module Random Access Memory (RAM) Error
- P0605 – Internal Control Module Read Only Memory (ROM) Error
- P0606 – ECM/PCM Processor
- P0607 – Control Module Performance
- P0608 – Control Module VSS Output ‘A’
- P0609 – Control Module VSS Output ‘B’
- P0610 – Control Module Vehicle Options Error
All of the codes above indicate an error with the PCM, which a PCM reprogram may resolve. However, if there’s physical damage within the PCM, these error codes will keep occurring. Here’s how to check for physical damage:
How To Check For Physical Damage
The PCM is a silver box that sits in your engine bay. Some cars may have their PCM behind the dashboard or in the trunk, so check with your owner’s manual to find where it is. Once you find it, see if there’s any physical damage to the box. If there’s damage, well that’s confirmation of why your PCM is bad.
But if there isn’t, you will need to inspect it further. But before we proceed, keep in mind that this process can be risky if you don’t know what you’re doing. If you don’t see signs of physical damage right away, we recommend reprogramming the PCM first and see if the problem persists. Reprogramming a PCM is much cheaper than replacing it. With that being said, here’s how to inspect it further:
- Disconnect the negative cable from your car’s battery before removing the PCM.
- Ground yourself by touching metal to avoid the discharge of static electricity from your fingers which can damage the PCM, just in case the PCM is actually in good condition.
- Loosen the bolts holding the wiring harness, but you don’t need to remove the bolt. Remove the wiring plug from the PCM, and make sure you pull it straight off so you don’t bend the pins. If the plug doesn’t come off easily, loosen the bolt a little more.
- Remove the PCM insulator retaining nuts, and then pull the PCM out of the car.
- Check for bent pins in the connector.
- Smell the PCM (yes, smell it) for a burnt plastic smell.
- If you see bent pins or smell burnt plastic, this is confirmation that there’s damage to the PCM. You can open up the box to inspect it further, but it’s not necessary if you see bent pints or smell burnt plastic.
PCM Reprogramming Cost
So, how much exactly does the PCM reprogramming cost? Well, the PCM reprogramming cost is relatively cheap. In most cases, you’ll have to pay around $80 – $150 for a Powertrain Control Module reprogramming. The process entails connecting the car’s PCM to a computer with the manufacturer’s software and then updating the PCM with the latest software.
It’s a pretty simple process and takes an hour at most to reprogram the PCM and do a system check to make sure the car’s working well and there are no error codes. Can you do it yourself? Well, no, unless you have the software necessary to do a PCM reprogramming. There may be ways to reprogram the PCM yourself, but we’re strongly against it as it’s quite complex and risky.
Additionally, not every independent repair shop can do a PCM reprogram. You’ll need to ask whether they’ll be able to do it for your make and model. If not, you’ll probably need to go to the manufacturer’s dealership. Still, the PCM reprogramming cost shouldn’t be any different if you do it at a dealership. Also, check out our guide on the cost to replace alternator at dealership.
PCM Replacement Cost
But what if you have physical damage and you need to replace it? Well, this is where it gets expensive. The PCM itself will cost somewhere between $500 – $1,200 depending on your car’s make and model. Meanwhile, labor will cost another $120 to install and program the PCM. So, you can expect at least $600 for a PCM replacement.
Why is it so expensive? Well, that’s because the PCM is a complex piece of a computer. It needs powerful processors to be able to process all the information from the sensors and control the car, and computers really aren’t cheap. If you take a look at laptops, the most decently powerful laptops are at least $800 nowadays. And since the PCM is basically a computer, that’s why it’s quite expensive.
Can I Replace A PCM Myself
If your car has an OBD-1 system, you may be able to replace the PCM yourself. Most older cars with an OBD-1 system don’t require programming after installation, so it’s just a matter of swapping an old computer box with a new one. However, newer cars with OBD-2 are likely to require programming after installation. This means you will still need the correct software, and the process can be tricky.
The video above shows how to change the PCM in a 1997 Ford Contour. But in most cases, we wouldn’t recommend swapping the PCM yourself. Besides, most of the cost comes from the part itself and not labor, so you won’t be saving that much money if you do the job yourself. Best to leave it to professional technicians to avoid any further issues.
How Much Does It Cost To Reprogram A Car Computer
There are two ways to reduce the cost, first, you can get non-OEM Powertrain Control Modules. These are control modules that are not made by the car’s original manufacturer but can be used for your car. You’ll need to identify your car’s PCM part number, and you should be able to find plenty of them online.
The second option is to use remanufactured PCMs. These are used OEM PCMs that have been restored to factory specifications and are now as good as new. You should also be able to find plenty of these on the internet, and both options typically cost somewhere around $250 – $400.
However, before buying either of them, you need to check the reviews. Make sure customers are happy with their purchases and that these PCMs work well, and ensure that they will fit your car. And finally, buy a PCM that has a warranty, so if it fails, you won’t have to buy a new one.
PCM Reprogramming Cost: Frequently Asked Questions (FAQs)
Got any more questions about the powertrain control module? We’ll answer some common questions below:
Why Do PCMs Fail?
PCMs can fail for a variety of reasons. As mentioned, physical damage can occur if you’ve been in an accident and it damages the PCM enclosure. This can bend the pins, or physically damage the processors inside the PCM. Another common reason is voltage overloads, often due to a short in a solenoid or the actuator circuit.
There might be external factors as well, such as excess heat, vibration, and water getting inside the PCM. Thermal stress and excess vibration can damage the components inside. And as we know, electrical components don’t play along well with water. This rarely happens, but driving through standing water may damage the PCM. It can also corrode the components inside it which can make the PCM fail.
Do All Cars Have A PCM?
Pretty much every car with a fuel-injection system has a PCM, or at least an ECU. It’s necessary since it needs computers to control the components such as the ignition coil and fuel injectors. However, most carbureted engines don’t have a PCM or ECU. They control the idle speed and fuel and air mixture mechanically via a mixture screw that you can adjust yourself.
Some carburetor engines may have a rudimentary electrical control system, but it’s nothing as complex as the powertrain control module in cars with fuel injection.
How Long Do PCMs Last?
PCMs, and the ECU and TCM for that matter, are usually rated to last for about 100,000 miles. The components inside the PCM will deteriorate over time, but in many cases, it can last the car’s entire lifespan as long as external factors don’t speed up the deterioration process.
PCM Reprogramming Cost: In Conclusion…
The PCM reprogramming cost is usually somewhere around $80 – $150. The PCM reprogramming will help your car run smoothly as intended if there are any errors or bugs in the software. However, if the PCM itself is damaged and has gone bad, you’ll need to replace it entirely.
Replacing the PCM is costly, at around $500 – $1,200 for most cars. You can get aftermarket or remanufactured PCMs, which cost around $250 – $400 but be sure to check the reviews and buy one that has a warranty if possible. As a reminder, we don’t recommend replacing (or reprogramming) the PCM yourself. It’s easy to get it wrong, and it’s a job best left to professional technicians.
PCM Reprogramming Cost Essential Knowledge
- The powertrain control module (PCM) is a crucial computer in your car, controlling many of its functions and managing the engine and transmission.
- The PCM combines the engine control module (ECM) and transmission control module (TCM) into one unit in most cars.
- Powertrain control module reflashing is essentially a software upgrade for your car’s PCM that can be done electronically without removing it from the vehicle.
- Reflashing can solve problems like false diagnostic trouble codes, hesitation, rough idle, emissions problems, hard starting, poor fuel economy, and others.
- Reflashing can also improve your car’s fuel efficiency, add more torque, or provide a faster throttle response.
- To reflash your PCM, you’ll need a J2534 pass-thru device or professional scan tool, a computer or laptop with Wi-Fi or LAN/ethernet connection, and access to the car manufacturer’s programming software.
- The reprogramming process takes around 30-40 minutes and requires constant battery voltage.
- PCM reprogramming can be a complex process, and there are common problems like loose cable connections, power loss, internet connectivity loss, and PC crashes that can occur.
- Only an updated program can be loaded into the vehicle computer, and there’s no going back to an earlier version.
