What-Is-Code-SPN-1209-FMI 2-(Cummins-SPN-1209-FMI-3,-4,-18)

What Is Code SPN 1209 FMI 2? (Cummins SPN 1209 FMI 3, 4, 18)

There are a myriad of fault codes. That is one thing about these modern engines. The regulations engine makers have to meet are astronomical. Thus the engines themselves have far too many parts that can go wrong. When they do, they trigger some of those thousands of fault codes. It is hard to keep up with them all.

This is what the Cummins data sheet says this fault code means “Exhaust Gas Pressure 1 - Data Erratic, Intermittent, or Incorrect” There are roughly 10 possible sources for this code to be triggered.

To learn more about this fault code, just continue to read our article. It has the information you want to know about so you can take the right action when you see it illuminated on your dashboard’s screen.

What is Code SPN 1209 FMI 2?


Cummins says this code means “Exhaust Gas Pressure 1 - Data Erratic, Intermittent, or Incorrect’ but that could basically describe several different parts in your engine system.

A mechanic says that if you have replaced the sensor, then it may be that the exhaust gas pressure tube is plugged with soot and needs to be cleaned out. The other possibilities are in the following list:

1 Check for primary fault codes

2 Exhaust gas pressure sensor stuck in-range

2.1 Plugged or damaged exhaust gas pressure sensor tube

2.2 Exhaust gas pressure sensor stuck in-range

3 Exhaust gas pressure sensor voltage check

3.1 Exhaust gas pressure sensor voltage check at the ECM

4 Plugged or damaged exhaust gas pressure sensor tube

5 Variable Geometry Turbocharger Hysteresis Test

6 Exhaust gas pressure sensor open circuit check

7 Exhaust gas pressure sensor circuit pin to pin short

8 ECM calibration revision history check

9 Exhaust gas pressure sensor is malfunctioning

Then if you go to this link you will find all the explanations on how to fix this fault code for each part involved. As you will read in the first fault code explanation, you need to fix any other fault codes that have been triggered before you can fix and clear this one.

If you do not have a diagnostic tool to help you, then you will have to go to a mechanic skilled in a Cummins engine or back to your dealer. Clearing this code may take some time so be patient.

Cummins SPN 1209 FMI 4

This fault code is identified as “Exhaust Gas Pressure Sensor Circuit - Voltage Below Normal or Shorted to Low Source”. The explanation according to the Cummins data sheet is as follows:

Exhaust Gas Pressure Sensor Circuit - Voltage Below Normal or

Shorted to Low Source. Low signal voltage detected at the exhaust gas pressure circuit.”

The good news is that this code should not have any effect on your vehicle’s performance. The fix also has some good news. You should only have to replace the exhaust gas pressure sensor.

But sometimes, the wiring harness will be damaged as well. So you should check that before replacing the sensor. If it is damaged, a replacement can cost between $1000 and $1500 approx.

The wiring harness is not an inexpensive part to replace. But check around to see if you can get a better price for it. To find the sensor, it is on the front end of the exhaust manifold and it is plumbed into that manifold.

What happens when you see this fault code is as follows:

- The ECM illuminates the amber CHECK ENGINE lamp and/or the Malfunction Indicator Lamp (MIL) immediately when the diagnostic runs and fails.

- A default value is used of the exhaust gas pressure reading.

- Diesel exhaust fluid injection into the after-treatment system is disabled.

- Active and stationary regeneration of the diesel particulate filter will be disabled.

- The EGR valve will be closed.

- Engine torque will be reduced if the engine is operated for an extended period of time with this fault active (source)

What you need to be aware of is that this sensor shares the same harness wires for supply and return. If this shorts out, you should see more codes from other sensors illuminated as well.

The source will be a short to ground somewhere in the harness.

SPN 1209 FMI 0


The meaning of this code does not come from Cummins. It is for various MaxxForce engines and the code applies to different MaxxForce engines in the following way:

- For EPA 2010/2013 MaxxForce 9 and 10 engines, the Exhaust Gas Temperature (EGT) sensor may have failed causing SPN 1209 FMI 0 fault in calibrations ending in XHRD and newer.

- For EPA 2010/2013 MaxxForce DT, 9 and 10 engines, high EBP fault may occur if there's an issue with the wastegate actuator or BCS.

To clear this code, we found about 15 steps you need to go through. It is best to go to the source link we provided as the document provides all the information for each step.

What makes that document so valuable is that it also provides pictures and drawings so you can see what needs to be done and where it needs to be done. On top of that, if you scroll down, you will get the names of the different parts and their parts number in a little chart.

The drawings provide extra information you should not skip over. Everything you need information-wise is on that document. It is easy to understand and there should be no confusion.

The code description is - EBP Above Desired During Acceleration

SPN 1209 FMI 3

Unfortunately, there is no data sheet for this code that we have seen so far. It does exist and it may be related to the MaxxForce engines listed above. The FMI 0 code means “Data valid but above normal operational range (that is, engine overheating)”

But that may or may not apply in this situation. According to what we have been able to find out, this code means that the “egr cooler on the side of the engine was plugged causing high ebp”.

This may cause the overheating FMI code to be triggered. You may experience a cut back in fuel supply as well. Check the EGR first as one owner had this code and when the mechanics pulled the EGR off, it was plugged.

The EGR was only 4 months old at the time. This may be a common problem with this part so regularly check it so you can avoid this code. To clean the EGR you may need lots and lots of carb cleaner, a high-pressure water supply as well as an air supply.

Other solutions are to do a MAF calibration twice and also clean the tube. Another possible solution is to update the ECM as well as run the MAF calibration 3 times.

We say possible because these solutions may still trigger the code after all is said and done. If that is the case you may have to replace the EPB sensor, replace the top turbo, and replace the EGR cooler.

If the MAF won’t calibrate you may have to update the ECM to get that fix done. Just be aware that if you replace the EPB sensor, the new one may be bad. You will know this if the MAF calibration does not work.

Cummins SPN 1209 FMI 18


Again, no one is talking about this code combination but the FMI 18 stands for - Data valid but below normal operating range - moderately severe level. This means you may experience some performance issues if you do not take care of the problem right away.

The SPN 1209 code is something that Cummins has had a bad history with. This code refers to the exhaust gas pressure sensor and this is a common failure. If you want to change the sensor yourself you may save a lot on labor costs.

The sensor will run you around $100 depending on where you buy it. When you remove the sensor, look for soot. If there is a lot of it on that part, you may have trouble elsewhere.

For example, the parts that are failing will possibly be the EGR valve, turbo, and EGR cooler. If they are failing, then your After Treatment system may be damaged as well. The exhaust pressure sensor is located at the front end of the exhaust manifold.

It is the part lifted up in this diagram:


The yellow arrow points to the sensor.

What Are Diagnostic Fault Codes?

These are generated by the onboard computers modern engines have. These computers monitor the different parts of the engines as well as control their performance.

Since 1996, vehicles have had an OBD-II diagnostic system and you would need an OBD-II diagnostic scanner to do the communication with the system. You may or may not be able to buy one of these scanners.

The confusion comes in when different brands of auto and truck and engine makers use different code systems. We should add in transmission makers as well. Your fault code may be model specific to the brand of car you own.

Then while the code may not be brand or model specific, the solution will depend on the type of car or truck you own. If you do not have a code reader, some local auto parts suppliers often will provide the service for you.

Or you can go to a local mechanic that has one to see what the code means when it is illuminated on your dashboard’s screen

FMI Errors


Out of most fault codes the FMI series seems to be the most sensible and practical. There are only 21 of these codes that are the most common you will see. In comparison, the SPN code list reaches over 50,000 different fault codes.

Generally, these codes do not change. They remain the same no matter which SPN code is triggered. The difficulty you may have is finding the SPN FMI code you see on your screen.

The SPN list goes in a weird numerical order but they also do not list all the possible FMI codes that would be attached to the fault code. What that tells you is that most SPN code lists are incomplete and not comprehensive.

You have to keep looking for lists till you find that specific code listed and explained. That is not always easy to do.

Common FMI errors from 0 to 21 numbers.

Code Explanation

0 Data valid but above normal operational range (that is, engine overheating)

1 Data valid but below normal operational range (that is, engine oil pressure too low)

2 Data erratic, intermittent, or incorrect

3 Voltage above normal or shorted high

4 Voltage below normal or shorted low

5 Current below normal or open circuit

6 Current above normal or grounded circuit

7 Mechanical system not responding properly

8 Abnormal frequency, pulse width, or pending

9 Abnormal update rate

10 Abnormal rate of change

11 Failure mode not identifiable

12 Bad intelligent device or component

13 Out of calibration

14 Special instructions

15 Data valid but above normal operating range - least severe level

16 Data valid but above normal operating range - moderately severe level

17 Data valid but below normal operating range - least severe level

18 Data valid but below normal operating range - moderately severe level

19 Received network data in error

20 Data drifted high

21 Data drifted low

Some Final Words

Finding out what a fault code means is not always easy. Sometimes, they just do not appear on any list. That is when you have to go to a dealer or mechanic who may have a comprehensive list of fault codes handy.

That is not a given either as many times the dealers and mechanics end up not knowing what is wrong. The modern technology these engines have did not make engine repair any easier when it was added to different motors and transmissions.

Sometimes, you just have to do a lot of searching till you find the failing or failed part causing all the problems.

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