There are so many error codes in the modern engine that no one may see all of them in their lifetime. Modern engines have so many parts to them and are so complex, you may also trade your truck or car in long before you get halfway through the fault code list. There are just that many.
Sometimes the SPN codes stand alone. But not in this case. SPN 411 has to do with your vehicle’s EGR but it is also always accompanied by an FMI code. There is no stand-alone SPN 411 code. To start, check for leaks in the EGR system.
To learn more about this code, just continue to read our article. It has the information you want to know about so you can diagnose, repair and get moving again in as little time as possible. Take a few minutes to see how this information will help you.
If you have a Paccar engine then this code would be equivalent to P1495 P1496. Those codes for this model of engine tell you that the EGR has been disabled. When that happens, your vehicle will go into preventive safety measures to keep the engine from racking up more repair costs.
This code is set in the Paccar engine only when another fault code is set. There is a long list of fault codes that will trigger this one. Also, this is a very difficult code to trace.
If you have the P1496 code active for 10 hours, then you will go into P1495 EGR disabled permanently derate. To clear this problem, you would need to go to a dealer and have them use their dealer level equipment to solve the problem.
For a Detroit Diesel, the problem is described as EGR differential pressure failed. The cause of this code would be leaks, blockages, loose clamps, or damage.
Simply repair the problem that you find and you should be on your way.
This is not the first code for SPN 411. The first code would be 0 but that is a topic for another day. This code is as described already. You have a problem with your Detroit Diesel EGR.
With the lack of pressure, the source will be leaks, damaged pins, or loose clamps, etc. It takes a visual inspection to find the source of the code. Then once you find the problem, fix it as needed.
That means replacing any damaged pins with new ones. That damage may be bent, corroded or the pins separated and the repair is straight forward. If there is no damage, then go to remove the EGR Delta P Sensor.
Once it is off, look for any blockage in the hoses, etc. If you find any, clear those obstructions and put the EGR Delta P Sensor back on. Make sure to verify any repairs you make so the code can be cleared.
There are 4 possible sources for this code and they start off with Egr Delta Pressure Sensor Out Of Calibration. The next three are:
- Egr Delta Pressure Sensor Out Of Calibration Low
- Egr Delta Pressure Sensor Out Of Calibration Low: Engine Exhaust Gas Recirculation 1 Differential Pressure Data Erratic, Intermittent Or Incorrect; Zero Offset Compensation Too Low
- Insufficient Change In Egr Venturi Signal
This code is the same as Cummins 1866 and the first step in resolving this problem is to make sure the ECM’s calibration is correct. If it is, the problem may lie with the differential pressure sensor. It may be malfunctioning on you.
This part may have to be replaced if all other repair steps did not correct the problem and cleared the codes. You can find all the information about this code and its repairs at this link.
There are four pages to go through and each one has its own repair sequence to follow.
The Cummins equivalent to this code is 2274 and it is defined as Engine Exhaust Gas Recirculation 1- Differential Pressure- Exhaust Gas Recirculation Differential Pressure Sensor Circuit - Voltage below normal or shorted to a low source.
You should see a yellow light illuminate on your dash when this code is set. As you can see, you have a voltage supply problem. The possible sources will be one of the following:
- a signal circuit open or shorted to ground in the harness or the sensor
- a supply wire shorted to ground or is open
- the EGR differential pressure sensor is malfunctioning.
Before you look for and fix those possible problems, make sure the EGR’s calibration is correct. You probably will need access to the QuickServe Online feature for applicable fixes.
In the meantime, you may lose your EGR valve actuation as it will be disabled.
One owner found that when he was accelerating to beyond 65 to 70 mph, his truck would start shaking. But when he let off the gas pedal or the turbo kicked in, the shaking would disappear.
This code and problem are due to a possible failure of the EGR differential pressure sensor. With that suggestion, the owner changed the part and the code and the problem went away.
While there may be other possibilities for this code to be set, this seems to be the go-to option. Replace the sensor and most likely the code will disappear. The sensor that was bad was the Delta p sensor on the Ventri tube.
If it isn’t the sensor, check the wiring to it. It may have come loose, been damaged, etc. Those little wires can create a lot of problems if they are corroded as well.
Not many people are talking about this code either. But when you look up the FMI code you will see that #7 has this to say- Mechanical system not responding or out of adjustment.
This won’t be an electrical problem unless it has to do with communication. You may want to look at the exhaust gas pressure sensor as they get clogged with soot very easily.
However, most likely, the EGR pressure sensor went bad and that is the part that was replaced by the dealer. The sensor is placed between the radiator and the engine, making it almost inaccessible.
There are 3 possibilities for this fault code. The first is- Egr Delta Pressure Sensor Out Of Calibration. The second is- Egr Delta Pressure Sensor Out Of Calibration High.
And the third possibility is- Egr Delta Pressure Sensor Out Of Calibration High: Engine Exhaust Gas Recirculation 1 Differential Pressure Out Of Calibration; Zero Offset Compensation Too High.
The fix for this little problem is not that difficult. You do have to visually inspect the EGR Delta p Sensor for bent, corroded, or separated pins. If you find any, then you need to make the repair that is appropriate for the damage you find.
Or you may have to replace the sensor. It will be up to what is wrong with the component that determines the repair.
The EGR or exhaust gas recirculation differential pressure sensor has two ports. What these two ports do is monitor the exhaust pressure. Then the sensor sends out an electronic voltage that represents the difference in pressure between these two ports.
Upon receiving this information, the ECM uses the data to determine how much exhaust gas is flowing in the EGR connection tube to the intake manifold.
After all that, this information helps the ECM operate the EGR valve to make sure the correct amount of emissions are released.
Unlike other sensors, this specific one is located near the air intake. Or you can find it near the EGR valve behind the upper intake manifold. This manifold is between the engine and the firewall.
It looks like a small square and it should have two tubes coming out of its bottom while a wire harness comes out of its side. That is the good news. The bad news is coming.
The exact location will depend on the make and model of your vehicle. It all depends on the design of the engine and its components exactly where this small part will be located.
Check your owner’s manual to see if it is listed in one of the diagrams on its pages.
One of the signs of a faulty sensor will be the rough idle. Another sign will be a lack of power in the engine. When you see those signs, you should replace the sensor as quickly as possible. You should not drive with a bad sensor.
When you go to replace this component, regular mechanic’s tools should suffice in getting the old one out and the new one in.