- 1 What is the Powertrain Control Module?
- 2 Function of PCM
- 3 Symptoms of a Bad PCM
- 4 Powertrain Control Module location
- 5 PCM Replacement Cost
- 6 Difference between an ECM and a PCM
- 7 FAQ Section
- 7.1 What is reprogram powertrain control module?
- 7.2 What are the causes of powertrain control module failure?
- 7.3 How do I know if my powertrain control module is bad?
- 7.4 How much does it cost to reprogram the PCM Reprogramming?
- 7.5 Can a car run without a PCM?
- 7.6 How long does it take to fix a PCM?
- 7.7 Can a PCM be repaired?
- 7.8 What does a powertrain control module do?
- 7.9 Can I replace my ECM myself?
The powertrain control module (PCM) is one of the most important parts of the vehicle. It is also known as an engine control module (ECM). It controls the function of the different engine parts and sensors. As any part or sensor of your engine goes bad, it immediately alerts you by sending a signal on your car dashboard. This article mainly explains the function, symptoms, and causes of a bad PCM.
What is the Powertrain Control Module?
A powertrain control module (PCM) is an automotive control unit used on motor vehicles. PCM takes the information from the engine’s various sensors and uses that information to calculate and tune engine spark and fuel for maximum power and efficiency.
When this flow of information between the PCM and other onboard computers and sensors works properly, the result is smooth and efficient performance, with the PCM seamlessly making necessary changes without any fuss.
The PCM is one of the potentially several onboard computers, or essentially the “brain” of the engine control system.
The PCM commonly controls more than 100 factors in a car or truck. Many hundreds of error codes can occur, which indicates that some subsection of the car is experiencing a problem. When one of these errors occurs, usually, it will turn on the “check engine” light on the dashboard.
Function of PCM
The PCM is the brain of the power delivery unit in your engine. The main function of the PCM is to control various features, including ignition timing, fuel delivery, emissions, turbo boost pressure, idle speed, throttle control, and so much more.
The PCM controls all of these functions through various sensors that communicate with it. It starts by sending control to an actuator and then measuring the actual results through a sensor.
The PCM is programmed to tell each actuator what to do when specific commands are met – like when hitting the throttle – and then it’s programmed to know the acceptable readings in response.
When something isn’t working correctly, it shoots a warning to the driver through a check engine light. No, it’s not an easy component to understand, and unless you have the proprietary software, it’s not a component you’re going to fix either.
Symptoms of a Bad PCM
The efficient working of the powertrain control module is very important for the efficient working of the vehicle. The PCM collects information from multiple sensors and then delivers fuel according to the requirements.
As the powertrain control module (PCM) goes bad, it gives one of the below-given symptoms:
1) A Check Engine Light
The illuminating check engine light is one of the first symptoms of a bad PCM. The light could be for anything related to the powertrain. Just keep in mind that the problem is more likely with the sensor, wiring, or just about anything else.
If your vehicle has a check engine light, rule out every other possible cause before jumping to the PCM. Check the trouble codes with an OBD2 scanner.
Read More: Causes of Check Engine Light Flushing
2) Shifting Issues
If your vehicle is having problems shifting into different gears, then the PCM might be the problem. Your PCM controls everything that both your engine and your transmission do. So, if you’re having any issues with your powertrain, you might be able to trace it back to the PCM.
If your vehicle is having problems shifting, it’s a severe condition that you need to have addressed immediately. Otherwise, your vehicle is going to handle erratically, which can quickly lead to an accident.
3) Poor Engine Performance
Engine performance issues are another symptom of a possible problem with the PCM. If the powertrain control unit has any issues, it may throw off the timing and fuel settings of the engine, which can negatively affect performance.
A bad powertrain control unit may cause the vehicle to experience a reduction in fuel efficiency, power, and acceleration.
If the engine misfires a lot or backfires, it can have various issues, so it’s best to take your car to the mechanic. They can then analyze the error codes and tell you the nature of the problem.
While causes of engine misfires are usually ignition related or a problem with fuel delivery, it’s possible a faulty PCM is to blame.
Read More: Causes and Symptoms of Engine Misfiring
5) Starting Issues
The PCM ensures that everything is in the correct position for the engine to run as it should. It also coordinates the timing of the ignition. If the timing is off, the spark plugs won’t ignite at the right times.
If your PCM problems get bad enough, you might not be able to get your vehicle started. At the very least, it might be hard to start, especially in colder conditions.
6) Poor Fuel Economy
Bad fuel economy may occur from a bad powertrain control unit. A faulty PCM disallows your engine from knowing how much fuel to burn in the combustion process. Typically, the vehicle consumes more fuel than it should in this situation. You’ll end up paying more for gas than you would with a functioning ECM.
7) Increased Emissions
When everything is working correctly, your PCM minimizes your vehicle’s emissions by optimizing performance. When it’s not working as it should, performance suffers, and you’ll likely have an increase in emissions. However, you probably won’t notice anything different unless you’re taking your vehicle for an emission test.
The last symptom on our list is the humble error code. When your PCM experiences a problem, it logs an error code, which will display on any connected code reader device. If this is your first sign of trouble, congratulations! You found the problem before it got any worse.
Powertrain Control Module location
The PCM is most commonly located in the engine bay near the fuse box or inside the car near the fuse box. It can often also be located under the front windshield behind some covers.
There are a few different locations where the manufacturer can place your vehicle’s PCM, but the most common location is in the engine bay. The PCM doesn’t look like anything special, just a metal box with some wires coming out of it.
If your vehicle’s PCM isn’t in the engine bay, it might be inside the passenger compartment. While this location isn’t all that common if it is there, it is typically underneath the passenger side dashboard – behind all the plastic coverings.
PCM Replacement Cost
The PCM is a computer, and computers aren’t cheap to replace. The average cost for a Powertrain Control Module Replacement is between $950 and $1,030 but can vary from car to car.
Even worse, this is almost all in the cost of the PCM itself. Labor typically only runs between $70 and $110. But if you think you can save yourself $100 and replace it yourself, think again.
That’s because you need to program the PCM to your specific vehicle, and unless you have the proprietary software to do it, you’ll need to take it to the dealership.
Sometimes you may be able to purchase a used powertrain control module for a couple of hundred dollars, whether online or from a junk yard but keep in mind that reprogramming it will be necessary. So, you need to factor in the additional costs as well.
Difference between an ECM and a PCM
|An ECM, or engine control module, is a computer that controls the engine.||A PCM, or powertrain control module, is a computer that controls the transmission and engine in order to optimize fuel economy and power.|
|It controls specific parts of the engine, regulating and sending commands.||It is used in the latest models to control almost all engine functions.|
What is reprogram powertrain control module?
The PCM, or powertrain control module, is your vehicle’s onboard computer. PCM Reprogramming is essentially a software upgrade and may be required to resolve a hot or cold starting issue, idle roughness, stalling, or an emissions failure.
What are the causes of powertrain control module failure?
The PCM may fail due to multiple causes. The following are the major causes of a bad powertrain control module:
- An improperly-balanced fuel-to-air ratio.
- Improper engine timing.
- A short in the wiring harness.
- Insufficient fuel supply
- Engine overheating issues
- Damaged or faulty engine sensors
- Thermal stress due to excessive heat and excessive vibration
How do I know if my powertrain control module is bad?
As the powertrain control module goes bad, it gives one of the below-given symptoms:
- Check Engine Light starts illuminating
- Shifting issues
- A reduction in the engine performance
- Engine misfiring
- Starting Issues
- Poor Fuel Economy
- Increased emissions
- Your vehicle dashboard shows PCM related error code
How much does it cost to reprogram the PCM Reprogramming?
The PCM reprogramming cost is relatively cheap. In most cases, you’ll have to pay around $70 to $160 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 to reprogram the PCM and do a system check to ensure the car’s working well, and there are no error codes.
Can a car run without a PCM?
No, a car can’t run without a PCM. The PCM (Powertrain Control Module) monitors and controls all the engine’s and transmission operating parameters, including fuel delivery, ignition timing, and emissions controls. Without a PCM, your car won’t start.
How long does it take to fix a PCM?
Fixing a PCM isn’t something that most people can do. Fixing the PCM software issue takes around about half an hour. However, if it’s a hardware issue, it could take several hours or even require replacing the entire PCM.
Can a PCM be repaired?
While it’s possible to repair or replace your own PCM, it requires specialized tools, which you may only need to use once.
What does a powertrain control module do?
The powertrain control module, aka PCM, is your vehicle’s brain. It manages the engine, transmission, and other systems based on the information it receives from various sensors around the vehicle.
Can I replace my ECM myself?
Before you attempt to replace an ECM yourself, it’s important to consult a repair manual or repair database to verify the steps involved. While ECM replacement is usually straightforward on vintage vehicles, most models built after 1996 require the module to be programmed with an OEM-level scan tool upon installation.