SPN 1569 FMI 31 Code in Cummins: Problems and Fixes (2024)

Gone were the days when engine problems were mostly mechanical in nature. Now, we have to contend with electrical faults associated with them, too. This is not entirely a bad thing though, because the presence of onboard computers and sensors in our vehicles also provides plenty of ways to confirm budding problems before they become worse, and these make diagnosis easier.

There's one code that may prove to be trickier to diagnose in many cases though, and it comes in the form of the "SPN 1569 FMI 31" in the Cummins engine. So, in this article, we will dive into the possible causes of the issue as well as the potential solution for each root of the problem.

What the SPN 1569 FMI 31 Code Means

The code stands for "Engine Protection Torque Derate Not Available Or Condition Exists". The fault code does not adhere to SAE J1939, which can make it such a pain to diagnose.

Basically, the SAE J1939 Protocol is a set of standards crafted by the Society of Automotive Engineers (SAE). These pertain to the uniformity of the design and use of devices that transmit electronic signals and control information among vehicle components.

Over time, the standards of SAE have become the industry norms for different vehicle applications in the fields of construction, mass transportation, military, agriculture, forestry, shipping, and many more. Thus, in more ways than one, the fact that the SPN 1569 issue is non-compliant to this means you might need professional help diagnosing it.

Depending on the circ*mstances, the fault may also be accompanied by other SPN codes. This can be a good scenario as this will give you more information about the possible root of the trouble you are getting. If the consensus is to be relied on as a basis though, these can stem from torque derate conditions.

What is Torque Deration?

The Cummins engine is designed with a "torque derate curve". This basically means that as certain conditions are met, the ECM will automatically adjust the torque output of the motor to compensate. These conditions can be changes in atmospheric temperature and pressure, fuel quality, and altitude. By reducing torque output, the engine is protected from damage that could be brought about by these conditions.

The problem occurs when the ECM is not able to adjust torque output as it should. This can be due to a number of reasons. When this happens, the code SPN 1569 FMI 31 will activate and cause the check engine light to come on.

Possible Causes of Code SPN 1569 FMI 31

There are a few possibilities as to what can cause this code to trigger. Here are some of those:

1. Corroded or Damaged Wiring Harness

The wiring harness is responsible for carrying electrical signals from one component to another. If it is damaged or has corroded wires, it can cause the signal to be disrupted or not received at all. This can result in the ECM being unable to properly adjust torque output.

2. Damaged ECM

The ECM, being a computer, is susceptible to damage just like any other electronic device. If it is damaged, it may no longer be able to process information properly, thus causing code SPN 1569 FMI 31 to be triggered.

3. Failed Sensors

There are various sensors in the engine that relay information to the ECM. If any of these sensors fail, it can cause the ECM to receive inaccurate data which can then lead to torque derate or a condition that it exists. Among the possible culprits here are the exhaust back pressure sensor, throttle position sensor, and oil pressure sensor.

The exhaust back pressure sensor evaluates the amount of pressure in the exhaust system. If it is damaged or has failed, it can cause the engine to run at lower power, leading to the issue.

The throttle position sensor sees to it that the throttle is in its right position. If it is damaged or has failed, it can cause the engine to perform poorly which can cause torque deration.

The engine oil pressure sensor measures the amount of pressure in the engine oil. If it is damaged or has failed, it can cause the engine to run at a lower output which can force a torque to derate.

4. Glitching Software

The ECM runs on software that tells it how to function. If this software is not calibrated, it can cause the ECM to glitch out and trigger code SPN 1569 FMI 31 as well as other faults.

5. Failed Turbocharger

The turbocharger is responsible for pressurizing the air coming into the engine. If it is damaged or has failed, it can cause the engine to run at a lower power which can then lead to torque deration.

6. Faulty Injectors

The injectors are responsible for spraying fuel into the cylinders. If they are damaged or have failed, it can cause the engine to run lean which can lead to torque derate conditions.

7. Damaged Fuel Pump

The fuel pump supplies fuel to the engine. If it is damaged or has failed, it can cause the engine to run low on fuel which can result in the error message.

These are only a few of the potential causes of code SPN 1569 FMI 31. There may be other factors that contribute to this code being activated as well. It is important to have the vehicle properly diagnosed by a qualified technician in order to determine the root cause of the problem.

Trying to diagnose and repair this code on your own can be difficult and dangerous. If you are not familiar with how engines work, you could end up doing more harm than good. It is always best to leave repairs like this to a professional.

Possible Solutions to the SPN 1569 FMI 31 Problem

Of course, one of the best ways to tackle the problem head-on is by having the part causing it to be fixed or replaced. Meanwhile, simple software-induced glitches can be gone the next time you start your vehicle or when you have driven it at least a hundred miles.

If that does not fix it, you may get rid of the issue via reflashing, which is a process of downloading and installing the latest software in your engine control module. You may also reset the fault code using an OBDII scan tool, which is very common in automotive shops nowadays.

A final solution to this particular problem is to have the vehicle undergo a regeneration process. This will help clean up soot and other particles that have accumulated in your emission system, which might be causing your truck to torque down.

The regeneration process can either be performed manually or automatically, depending on which is the more convenient course of action for you. If you want to do it manually, you will need to drive your truck for at least 30 minutes while maintaining a speed of 55 mph. If you would rather have the regeneration process done automatically, all you need to do is hook up your truck to a diagnostic computer and let the machine do its job.

Again, it is important to note that these are only some of the possible solutions to code SPN 1569 FMI 31. There may be other factors that contribute to this code being activated as well. Therefore, when all else fails or the issue is a recurring matter after you have exhaustively explored all possible solutions take your car to a certified mechanic and have it diagnosed and repaired as soon as possible. Do not wait for the problem to get worse before you seek professional help because that would only end up costing you more money in the long run.

Ways to Avoid the SPN 1569 FMI 31 Problem

Here are some of the best ways how you can avoid or at least mitigate the risk of running into the SPN 1569 FMI 31 problem:

• Get regular maintenance and checkups for your vehicle to ensure the optimum performance of your engine and other important parts of your vehicle.
• Be careful when working on your vehicle. Seek help from professional mechanics if needed.
• Use high-quality parts and fluids when servicing your vehicle to mitigate the risk of failure in the numerous moving parts of your vehicle.
• Follow the manufacturer's recommended servicing schedule for your vehicle to maintain your engine's condition.
• Keep an eye on the warning lights on your dash as these can be signs of bigger problems at play.

These are just some of the many ways to dodge the SPN 1569 FMI 31 problem. By following this simple guide, you can help keep your engine running at its best and evade the risk of encountering this specific fault code.

Conclusion

Many factors can activate the SPN 1569 FMI 31 fault code, which can range from faulty mechanical parts to electrical issues. No matter what the cause is, it is important to have the root of the problem plucked before things get more complicated. With that, have your auto checked by a mechanic right away if you happen to be experiencing this.