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Symptoms of a Bad FICM

Symptoms of a Bad FICM

2nd Nov 2022

by Jordan Davidsen

When you’re running a diesel engine, it is important to know about the parts within it to be able to diagnose and treat any problems that come your way. One of the most essential parts of a diesel engine is the fuel injector control module, or FICM. This piece’s job is one of the most important parts of ensuring the quality and longevity of your engine and, in turn, your vehicle. This article will give you insight into how you can know if you have a damaged FICM.

The FICM is absolutely necessary for any diesel engine. This module controls the electrical supply that opens and closes the fuel injectors in your engine. It sends a 48-volt pulse to the injector coil, which allows the spool valve to open and activates the fuel side of the injector using the highly pressurized oil in the engine. A diesel engine runs on a specialized, pressurized flow of fuel and air. These high pressure conditions would cause many systems to fail immediately, but the FICM avoids that. Because of the fuel injector control module, you will instead receive the highest level of performance and efficiency from your diesel engine.

In simple words, the FICM is what makes your engine run, and a bad FICM can render your engine useless until any problems with it are rectified. Luckily, there are physical signs of a bad FICM, and while these may be inconvenient, they can help you fix something that would become a much bigger issue otherwise.

The major signs of a damaged FICM are hard starting or failing to start, rough running, lower power, and a greater than normal amount of exhaust releasing from the tailpipe. It is important to note that, while these symptoms can always exist, they can worsen significantly when the weather is colder. If the engine is hard to start on a warm day, it will almost certainly be more difficult on a cold one. If your vehicle cranks upon starting or refuses to start, drives worse, or emits larger-than-normal puffs of smoke, it is likely that a bad FICM is to blame.

Arguably the most prominent cause of bad FICMs is a low battery voltage. You need to ensure that your battery is charging, and if it doesn’t hold a charge, it needs to be replaced. The battery voltage matters in this situation because a low battery voltage can cause the current reaching the FICM to increase, damaging its circuitry. These issues can also be related to a FICM power supply side failure, in which the power to the injectors is not adequate to start or run the engine. Regardless, there are luckily easy ways to fix a faulty FICM.

A bad FICM can be fixed through a few avenues. The first, and most cost-effective, is to remove the FICM from the engine and replace the power board. The power board is what converts voltage from your car battery to the voltage needed to fire the injectors, and it is almost always the culprit of a bad FICM (the other half, the logic side, is almost never at fault). If you’re uncertain about changing the power board yourself, you can always get your FICM checked out by a specialist. Having a professional perform your FICM repair can lead to more peace of mind and a more accurate fix. If, for whatever reason, neither of these options work, purchasing a brand-new FICM is possible.

If you’re wondering where you can get the most reliable and high-quality FICM parts, look no further than US Diesel Parts. We offer a variety of FICM parts that you can count on if you’re having FICM trouble. If you have any questions about your situation or which FICM parts would be best for you, don’t hesitate to contact us for whatever you may need.