What Is Cummins SPN 1761 FMI 9, 10, 17, 18, 19? Helpful Guide
This is a simple code to decipher and fix. When you see this code on your screen all it is saying to you is that the DEF tank is below 10% and you need to add more fluid to the tank.
The exact wording for this error code is “1. Add DEF fluid to the tank until the gauge needle is above the 'yellow' zone that is near 'Empty' or until the yellow gauge light goes out.
2. Clear DTC's with ServiceMaxx.
3. Verify light(s) and DTC(s) do not return
You should be able to handle this error code yourself and fill your DEF tank without any hassle. Just make sure you fill it up far enough so that you do not have to face this code for some time.
If you can, you should carry some extra DEF with you just for this situation. Being prepared is the best way to cut your delays down and make your reservation on time.
SPN 1761 FMI 18
The same fact sheet we used in the previous section lists this code with the previous code. When you see FMI 18 all it is telling you is that your DEF tank is almost empty and you need to refill it.
If you are near a city, finding DEF is not going to be that difficult. It should be on sale at all the major auto parts and supply outlets or even at some of the box stores that also have a service center.
You can just call the location nearest you to see if they have any DEF in stock. Just do not drive your vehicle that much after this code lights up. You do not want to run out of DEF before you can refill the tank.
If you run out, your engine should derate and you won’t be able to go above 5 mph in most cases. That situation means it will take longer for you to get to the store to replenish the tank.
SPN 1761 FMI 19
We checked this data sheet for Cummins fault codes, available at this link, and we did not find this number on it. In fact, we did not find any SPN 1761 codes listed on this data sheet.
When we searched the internet, no website came up listing what this code is for or how to fix it. This code could refer to the DEF level in your DEF tank but we cannot be sure.
We did find a better code sheet for Cummins fault codes. It is 5 pages longer than the other one we linked to. That is a good thing as there are several 1761 fault codes listed on this version. However, FMI 19 was not listed on this fault code sheet either. You can view it at this link.
This may be what is called a fake code that may pop up on different screens and to get rid of it, you just may have to clear the code. Ask your mechanic if he knows what that code is for as there is no information in authorized locations on the internet that we could find.
Or check with your dealer who sold you the vehicle and see what they say.
The Purpose Of DEF
You may wonder why your newer diesel truck has a DEF tank and requires DEF fluid. Then you may wonder why they put the fill spout right next to the fill spout for diesel fuel. That is like asking for people to contaminate their DEF system.
The reason truck makers began putting DEF systems on their diesel trucks is due partly to government emissions regulations. Truck builders had to cut down on those emissions and stop polluting the air.
Their solution was DEF and which is a simple fluid made from ionized water and synthetic Urea. How this system works is that as you drive, the DEF is injected into your exhaust system before the emissions reach the end of the tailpipe.
Once injected, the DEF causes a chemical reaction with the harmful particles and removes them from the exhaust. The DEF also cleans up those harmful pollutants and keeps the air you breathe cleaner.
The DEF system is part of the Selective Catalytic Reduction or SCR, system that is designed to cut down on harmful emissions that are released into the air.
What Happens When You Run Out Of DEF?
It is a good question and the answer is simple. Your truck may be derated and you will not be able to drive it above 5 MPH or whatever level the truck maker set it at.
You have to be careful when filling your diesel or DEF tank. If the DEF gets into your fuel system, you are looking at a hefty repair cost. The if the reverse happens,m the result is the same.
Once the DEF system is corrupted, it has to be replaced completely or you will just have more troubles down the road. Running out of the fluid should not be so bad as all you need to do is refill the tank and your truck should get its power and performance back.
If you contaminate the DEF, you are looking at not using your truck until it is fixed and that might take a while given the supply chain shortages that have been going on.
The Risk Of Running Out Of DEF
When there is no fluid in the system, it is possible that debris and soot can get inside. When that happens your truck's efficiency should go down. At least the DEF system will not operate as it should and that will influence your truck’s performance.
That situation can help parts fail. When they fail, you are looking at spending a lot of money to get the system cleaned and parts replaced. The overall cost will dep[end on the type of vehicle you own but to give you a ballpark figure you are looking at paying around $800 for the DEF heater.
Cleaning the filter can run you up to $1500 and replacing failed parts can be in the neighborhood of $2000 and $5000. In some cases, that cost can get as high as $8000.
This is why you want to take care of your DEF system and make sure it never runs out of fluid or gets contaminated. It is just too costly to repair or get cleaned.
How To Keep Your DEF System Lasting a Long Time
There are several steps you can take to protect your DEF system from being contaminated or failing at some point.
1. Do not put diesel fuel in the DEF spout- you would not believe how often this takes place. People pull up to the gas station and just go to automatic mode when filling their diesel tank.
Unfortunately, they removed the blue DEF cap and put the diesel fuel in their DEF system. If you catch this mistake before you start your truck, then do not drive it as your DEF system will have to be completely replaced. Watch what you are doing when filling up.
2. Regenerate frequently- what the regeneration does is clean out the filter of any solid debris, etc. Usually, your engine will regenerate often but sometimes that function is not often enough.
By the time the yellow light comes on it is too late to truly clean your filter through this option. That is why you need to regenerate about every 200 miles to make sure the filter stays clean in between automatic regeneration.
3. Use the correct DEF fluid- while DEF fluid basically does the same job, not all brands of this fluid are the same. Try to stick with one brand over the life of your ownership, that way you know your DEF system is protected.
Also, make sure you never run out of DEF.
4. Use a higher-quality diesel fuel- the lower-quality option is not good for your DEF system. It will make it work harder as there are more emissions for it to neutralize and clean up.
Some Final Words
When you buy a new truck you will find that there will be lots of error codes to learn. The best thing to do is download the best chart linked above and keep it handy. That way you can look up the code and see what is wrong with your vehicle.
Or find a better chart that lists all the codes as some fault codes are missing on many of the charts you can access. Keeping up with the meanings of those codes helps you have a worry-free driving experience.
