6 Signs Your Powertrain Control Module (PCM) Isn't Working

The majority of your engine's electronics are under the supervision of the powertrain control module. How to determine whether your PCM is damaged

The entire interior of your car is crammed with computers, whether you like it or not. When everything is functioning well, these computers are a dream come true, but when circuits start to fail, they may soon become a nightmare.

Fortunately, modern machines don't break down very often. Because replacing them when they break costs a lot of money. The Powertrain Control Module, one of the enchanted computers, regulates the entire powertrain, as the name suggests.

We'll explain all you need to know about your PCM and what to do if it starts acting up in this comprehensive guide. Let's start by taking a look at the warning signs.

Poor engine performance combined with a check engine light on your dashboard is the most typical sign of a faulty PCM. Additionally, you can observe gear changing issues with the transmission. Additionally, increased emissions and poor fuel economy are rather typical.

The most frequent cause of a MOT test failure, according to an online search for "check MOT history," is an illuminated dashboard warning light.

A PCM breaking is not frequent, although it does occur occasionally. However, you should rule out any more probable causes before moving directly to the PCM.

The six most typical signs of a malfunctioning PCM are listed in further detail below, with the following warning:

1. A Check Engine Light - This is probably the first indication that there is a problem with your PCM. The light could be for any powertrain-related issue. Just remember that the sensor, wiring, or just about anything else is more likely to be the issue. Find car garages in Reading and schedule an appointment with a mechanic if your car's check engine light is on to rule out any other potential causes before assuming the PCM is to blame. An OBD2 scanner will be used by the mechanic to examine the fault codes.

2. Poor Performance - Since your PCM is in charge of controlling performance, it stands to reason that if it isn't functioning properly, performance will be compromised. The more broken your PCM is, the more probable it is that you'll experience several problems that affect performance. However, if only one component of your PCM is malfunctioning, you might only experience poor performance when accelerating or idling. As was already indicated, in this situation you should leave the examination and repairs to a trained technician. To do this, check online for garages in Reading and make an appointment as soon as your car starts to function poorly.

3. Starting Issues - If the PCM issues get severe enough, you might not be able to start your car. It might, at the very least, be challenging to start, particularly in cooler weather. You should get the PCM examined if your car is having trouble starting and the issue is related; else, you risk damaging your engine.

4. Increased Emissions – When everything is running smoothly, your PCM optimises performance to reduce emissions from your car. When something isn't functioning properly, performance suffers, and emissions are probably going to go up. You generally won't notice any difference, though, unless you're taking your car in for an emission test. Check MOT status of your vehicle and have a qualified mechanic make any necessary repairs to fix the emissions issue if you want to pass the emissions test at your next MOT.

5. Poor Fuel Economy – It makes sense that if something isn't working properly, your fuel economy will suffer. For instance, if the PCM isn't instructing your turbo to generate adequate boost, you'll need to accelerate more. There are several instances like this, however if your PCM is malfunctioning, you'll probably be burning fuel.

6. Problems With Gear Changes - The PCM may be at blame if your car is experiencing trouble changing gears. Everything that your engine and transmission do is under the supervision of your PCM. So, if your powertrain is giving you any trouble, you may be able to pin it down to the PCM. If your car is experiencing trouble changing gears, it's a serious problem that has to be fixed right away. Otherwise, your car may behave unpredictably, which could result in an accident very soon.

PCM Operation

Your engine's power delivery unit is controlled by the PCM. It regulates a wide range of functions, including throttle control, idle speed, fuel supply, emissions, turbo boost pressure, and ignition timing.

A PCM regulates both the transmission and the engine, even though you may be familiar with the terms transmission control module (TCM) and engine control module (ECM). Therefore, if your car has a PCM, it either combines both of those parts into one unit or the same computer does both tasks.

Through numerous sensors that interact with the PCM, it manages all of these operations. It begins by providing a control to an actuator, and then uses a sensor to measure the real outcomes.

When certain directives, such as pressing the throttle, are fulfilled, the PCM is programmed to tell each actuator what to perform. It is also programmed to know what the appropriate readings are in response.

The check engine light serves as a signal to the driver when something is malfunctioning. No, it's not a simple component to comprehend, and you won't be able to solve it unless you have the proprietary programme.

Location PCM

The PCM is typically found within the vehicle, close to the fuse box, or in the engine compartment. It is frequently concealed under several covers behind the front windscreen.

The engine bay is the most typical position for the PCM, though the manufacturer has a few other options as well. The PCM is just a metal box with some cables coming out of it; it doesn't appear to be anything unique.

If the PCM for your car isn't in the engine, it can be in the passenger area. Even though it's not very frequent, this place is often under the passenger-side dashboard, hidden below all the plastic covers.

In the extremely unlikely event that your PCM isn't in either of those places, it might be in the boot of your car. Since all of the engine's cables must go to the vehicle's rear in order to connect with the PCM, this is less frequent.