Modern engines come with a lot of bells and whistles and due to the upgraded technology, you also receive a lot of error codes. Owning a Nexus code reader may not help to clear any error codes that pop up on your screen. You may be stuck where you are if no help is sent to your location.
Unfortunately, there is no simple trick to clear this code and get back up to speed. Usually, you would need to get to a dealer and have them use their dealer level service tool or you would have to buy an OTR reset tool for Cummins to clear the code.
To learn more about this issue just continue to read our article. The article comes with lots of important information to help you get your RV back on the road again. For example, there is another tool you can buy and it is called the OTR diagnostics.
This code is letting you know the final issue that will be implemented. The code is called the Regulatory Fault Ignored - Final Action (speed Limit). What that means is that your engine will be derated to 5 mph and no higher.
You can try to drive above the 5 mph restriction but you run the risk of damaging other important components in your motor. The advice is to crawl as quickly as you can to the nearest dealer to have the engine investigated for possible problems or have the code cleared.
This code seems to pop up frequently when you stop your engine at the border. When you start up again, the screen flashes this code and limits your driving speed to the aforementioned 5 mph.
This code pops on Freightliner trucks but it also pops up on different models of vehicles. A Volvo had this error code and part of the problem is that the ECM does not accept the reset command or does a complete regen.
This can mean that after you have done repairs, you may have to update the ECM software and then reset it. There is no other way to do this reset if you made all the right repairs to the motor.
Also, when you do the reset you will need the dealer diagnostic tool attached.
This is an information code telling you that there is a problem that needs addressing or your RV or truck will be limited to 5 mph. There are several components that can trigger this code and get your vehicle derated. here are a few of them:
- DEF Fluid- this could be bad or it is not at the right levels
- DEF Doser Valve- this could go bad and its purpose is to monitor the injection of DEF Fluid into your SCR Catalyst
- DEF Pump Assembly- it may fail and if it does your engine will be derated immediately
- NOx Sensors- there are inlet and outlet sensors that tell the SCR/DEF system to inject more urea into your system. They can go bad and send the wrong message.
- DEF Control Module- this part controls the emissions system and it talks constantly with the ECM if it goes bad that communication will be lost and you may get derated right away
- ECM - this is the overall control module that controls most of the devices on your motor. If it goes bad your engine will be derated and you need extensive repairs.
The error code you will get will be the Cummins fault code 3712 or you will get the SPN 5246 FMI 0 error code. The notification you also get on the screen will read ‘Red Stop Engine Light’.
You should also be given some information that reads - After treatment SCR operating inducement- Data valid but above normal operating range. This is the most severe level you can get.
The result you get will be an immediate derating to 5 mph or 8 kph if your vehicle is in metric. As we said earlier, there is no quick fix or fancy way to clear this code. You will have to go to the dealer to get it done and make any repairs needed.
The best and most advised way to clear this code is to go to your dealer. Unfortunately, some dealers will not send a mechanic to your location with their diagnostic tool and save the day.
If they won’t come, you will have to drive at 5 mph to them to get the work done. This can be expensive. The Nexus error code reader does not clear the code. Some owners have tried without success.
If you do not want to go to the dealer then you would need to buy the OTR Diagnostics or the OTR reset tool for Cummins and use them yourself. They should not be that hard to use.
But you will still need to investigate what triggered the code. You may have an actual problem that needs addressing. Then when you have done the repairs, and you can’t reset the ECM, you have to update the system using the dealer level tool.
One important fact, you should not drive in a derated state. You could cause major damage to the engine or emissions system.
The SPN 5246 FMI 0 Cummins and Freightliner code can be confusing as it is an information code only. Unfortunately, there are many components that may trigger this code and derate your RV or truck almost immediately.
If you do not own the right diagnostic tool, you will have to go to the dealer and get the code cleared as well as make any repairs. It is possible to do it yourself if you are equipped and mechanically inclined.