What is a PCM
PCM stands for a Powertrain control module, usually found in motor vehicles. Think of it as a control unit and just as the control unit of a computer has some components abstracted to form it so is the PCM, its control unit encompasses the ECU (Engine Control Unit) and the TCU (Transmission Control Unit). This component (PCM) is like the brain of a car and is able to control over a hundred subsets in a vehicle. When a subset of a car or truck has an error, it is the work of the Powertrain Control Module to alert the driver. This usually happens when you see an alert message on the dashboard saying "Check Engine." What feeds the power-train control module every information about a car are mostly the sensors, and they have the ability to fail more than computers do.
Things You should Know About PCM
Earlier on I stated that Engine Control Unit is a subset of the Powertrain Control Module. When this subset has issues, all kinds of complications may arise in a car. This happens to most of the new vehicles all the time since many of the functions are being run by the Engine control module and this might even render your car useless, and you may never be able to drive it.
Like many car parts, Powertrain control modules are subjected to wear and tear or failure at some point. When this happens you won't be able to tell whether your vehicle engine is in good condition. Since it controls transmission and the engine in general, it is always advisable that you keep track of your Powertrain control module at all times and know when and when not to change it.
When you notice a Check engine message on the dashboard which is usually a light, beware because something definitely is wrong with the Engine Control Module. So if one of the sensors is faulty, you will see that light. Sometimes the Powertrain control Module could be having a problem with code errors, and this could result in a check engine alert light by mistake. So it is always advisable to scan the computer so that you can diagnose whether it is really the sensors with the problem or the power-train control module.
There is nothing tormenting to the mind as a car that fails to start especially in the morning when you happen to have a workload at your office desk, and you are getting late simply because your car engine won't start. This behavior clearly indicates that there is a problem with your Powertrain control unit specifically the Engine control Module. Engine management control is lost in a car causing it not to start. Like I stated, you will have to cross check the possible causes because this fault may not be on the computer but other possible factors. So it is better to troubleshoot every possible cause before changing your powertrain control unit.
PCM Troubleshooting
You only have to change your Powertrain control module if and only if you have correctly identified the root cause of a failure in your vehicle. Research states that most of the people always get fixated on the power-train control module every time their engine has a problem which is mostly wrong. This conclusion was arrived at when it was found out that over half of the powertrain control modules that were returned under warranty had no problems with them. So it is not always obvious that failure of the engine is only the computer being faulty.
Short circuiting and voltage overloads can guarantee a failure of a power-train control module. It happens mostly in solenoids and actuator circuits. Factors such as corrosion might as well damage the power-train control module due to lack of earlier diagnosis and therefore resulting in a pile of voltage overloading thereby damaging the entire computer. This is when you will have to change your Powertrain control module.
Corrosions is mostly caused by water. Water and the power-train control module don't get along at all. If this happens, then be sure that short-circuiting and corrosion are bound to destroy your computer. Having a warranty on an issue like this won't even save you from the manufacturers because they already know that it can't be fixed. You will be left with no choice but to replace the entire power-train control module.
So many companies out there manufacture different kinds of powertrain control modules. So it is always wise to know the type of control module running your car and how to replace it carefully and accurately is important if you don't want the unnecessary returns. In order to do all this, you have to identify the make and model of your vehicle, the year of your vehicle and the engine size. There is also the OEM part number found on the power-train control module.
Power-train Control modules are expensive, and if they happen to be faulty, the only way manufacturers remanufacture it is by isolating the damaged units, remanufacture it once again, assemble the subsets in the single unit and then test to see if it is working properly. Most of the companies sell their powertrain control modules either in stock or they can customize a used one. So if it happens that the power-train control unit you want isn't available in the market, they can customize your old one by remanufacturing it again.
Powertrain control units play an important role in how the engine performs and we all know that the engine is the car itself. Computer systems in new models of cars are getting sophisticated as the day goes by. This makes it hard to identify the possible defect, so it is always advisable that you have a qualified technician to have a look at your Powertrain control module and avoid all the hassles of having to replace the entire computer just because a quack technician told you to do so. Remember that these gadgets are fairly expensive and it is always business out there. So don't make Christmas come early for the PCM manufacturers.