Cummins nox sensor readings. Hopefully, others will chime in.
Cummins nox sensor readings However, specific problems may arise with your Cummins NOx sensor, leading to poor detection of NOx levels. I am now experiencing my third failed upstream NOX sensor. If a Cummins coverage is available for the failed component Apr 28, 2022 · A NOx sensor is placed in exhaust systems to observe nitrogen oxide (NOx) levels in the exhaust. Mar 26, 2025 · Learn how to test NOx sensor with multimeter, using step-by-step instructions to diagnose sensor performance. I am not sure if the NOX sensor would cause this without a NOX trouble code. On most systems, there are usually two NOx sensors. When a NOx sensor fails it can prompt multiple fault codes; capping the engine output, placing it in limp mode. Check the NOx sensors located before and after the SCR catalyst for contamination or wiring issues. Hopefully, others will chime in. I’m getting P2201 and P1C55. As part of the aftertreatment system, the most common reason for a faulty NOx sensor is soot build-up. It won’t read properly until DEF starts spraying so keep that in mind. The first was codes P2201 and U059E, the second Apr 20, 2017 · After observing this a couple more times I have confined that this is normal. Jun 1, 2019 · 2015 Cummins 4x4- 136000 miles . Oct 26, 2015 · So my check engine light came on last night after going out to eat. all NOX sensors are currently on mandatory return. Benefits of a Functional NOx Sensor in a Cummins Engine Apr 22, 2021 · Trucks been throwing a CEL and dealership diagnosed it as a faulty downstream NOx sensor. Do these readings suggets the sensor is For Cummins ISX engines, normal intake NOx values during regen typically range low, while outtake NOx should significantly drop post-regeneration. 00 in parts to just turn Sep 26, 2017 · No, ammonia sensor is different. When they replaced my cat, they reused the NOx sensor, which, unfortunately, is how FCA has the recall setup, unless the code for the bad sensor is present at the time. To troubleshoot, inspect sensor connectors for corrosion, check wiring continuity, and clean or replace sensors if contaminated Description g issued to address System Outlet NOx Sensor failures on certain ISB6. Jul 24, 2025 · Your expert guide to heavy-duty NOx sensors. Took it to autozone and read the code mentioned NOx If you’d rather start by learning what to look for in an aftermarket replacement for a Cummins NOx sensor, we recommend reading our blog. Aug 26, 2025 · Is your NOx sensor failing? Learn the symptoms, common fault codes, and how to replace it fast to avoid derates. Faulty readings may stem from sensor contamination, wiring issues, or exhaust leaks. And, many have not noticed any difference in DEF usage, but I go through so much, and tow heavy so much, that I probably notice more than the average owner. Using the Cummins diagnostic steps is the best bet. A healthy sensor outputs low voltage at idle and higher voltage under load. The NOx sensor monitors exhaust emissions for SCR catalyst efficiency. Understanding the behavior of NOx sensors during regeneration is essential for maintaining optimal engine performance, reducing A faulty Nox sensor can cause incorrect readings, triggering engine warning lights and poor fuel efficiency. After the EGTs heat up - over 300* the NOx 1 will ramp up to 1791 PPM for about 10 seconds, come back down then start reading. Early DEF/SCR systems had an NH3 sensor. The service advisor said not to tow with the truck and only drive it minimally because it can go into limp mode. I have been wanting to Here we have a nox sensor code 3649, you can use data monitor to verify sensor function before you buy a new one. Sep 17, 2025 · What are the most common Cummins NOx sensor fault codes? The most frequent fault codes include those for "SCR Efficiency Below Threshold," which indicates the system isn't cleaning the exhaust effectively, often due to a sensor issue. Nitrogen Oxides (NOx) sensors are front and center in this effort, vital components instrumental in ensuring emissions stay within legal limits. When monitoring the NOx sensors, if the inlet reads 0PPM during fuel injection that is the sensor coming off line, the outlet will read 3000 when it shuts down during driving. Remember to run a full regen after. Understanding NOx Sensor Readings During Park Regeneration on 2016 Cummins N2 and Freightliner M2 The primary failure mode the NOx Sensors is internal failure, which will generate a sensor specific fault code. This combination of codes is for the upstream NOX sensor which is right behind the turbo. If you’d rather start by learning what to look for in an aftermarket replacement for a Cummins NOx sensor, we recommend reading our blog. Inlet NOx Sensor (NOx 1) Diagnostic Trouble Codes - Potential Sensor Failure These codes in yellow below indicate that the inlet NOx sensor is potentially damaged, but further investigation is required to verify sensor condition. com: Rawze's ISX Technical Discussion and more / Big Truck Technical Discussion / ISX Related Help / Aftertreatment Outlet NOx reading stable - Reading Not Available This manual provides detailed information on the NOx sensor, its operation, diagnosis, and maintenance. Started the truck and it was lit. The unfortunate downside of this is that they’re delicate and prone to getting damaged or contaminated. I watched the entire event from cold start monitoring the NOx sensors, EGT sensors, reductant line pressure and reductant injector duty cycle. Learn how to troubleshoot and address common NOx sensor issues. 2 days ago · - Aftertreatment Outlet NOx - 139 Raw value from the sensor. Jun 22, 2018 · I need to buy some time on putting together my deletes for my 2014. Read the full guide at AftertreatmentParts. Nox sensor ,outlet DPF #2 bad code. Anyone put the Dorman sensor in versus the Mopar? The Dorman one is only $290 versus Mopar is $900+ NOx sensors in the 2012 F550 6. Most likely gonna land on a bad nox. 0 Comment (s) Attached Files P0420. The test compares the readings of the two sensors as the engine cycles through multiple conditions to confirm they are in agreement. May 18, 2024 · Understanding the causes, effects, and symptoms of a failed NOx sensor in Cummins equipment is crucial for maintaining optimal engine performance and emissions compliance. . want to clean and not replace , would love to keep truck stock but with the prices of these sensors and "they from reading forums not dealer" recommend inlet and outlet replace in pairs are over $700. High NOx readings can indicate sensor faults or incomplete regen. NOTE: A NOx conversion test only checks NOx sensor function. Im not sure about the TSB but if you’ve got access to quickserv run through the troubleshooting tree. Jun 23, 2025 · A faulty NOx sensor can lead to several issues, including inaccurate NOx readings, leading to inefficient SCR system operation. The results of the NOx Conversion test do not indicate anything about the condition of the SCR itself. Introduction The following procedure is to aid in graphing NOx sensor readings and temperature sensor readings using the GDS2. Mar 10, 2018 · The best way to check the sensor would be with a scope and check the waveform, though many don't know how. The over-fueling condition most likely causes the code. Maintain a constant highway speed to ensure the sensors are reading stable (not fluctuating all over the place with no change in engine operation. 7 CM2350 engines. a Hello all new to the forum! :grin2: I have a 2014 ram 3500 that has recently been showing a P2201 code (I have around 67k). This TRP authorizes certified repair locations to replace the System Outlet NOx Sensor if fau that are no longer covered by a Cummins Base, Extended, or Emissions warranty program. I took it to the dealer and they diagnosed it as the upstream NoX Sensor, and want almost $900 to replace it. Whether you're troubleshooting an emissions light, planning a replacement, or just wanting to understand your diesel engine better, knowing Outlet nox sensor is a common failure item. Take vehicle on a test drive with someone else driving and you watching both nox sensor values. Perform continuity checks on the Signal wire. When the sensor is smothered in soot it gives inaccurate readings, disrupting the ECU Dec 2, 2024 · NOx sensor readings during regen are critical for monitoring and controlling emissions in diesel engines. Oct 9, 2022 · I have a 2013 Ram 2500 Cummins 4x4 which I purchased in 2017 with 18K miles on the odometer. Direction: Run the applicable PTT Operation per OBD Level. Depends on engine operating state and Inlet NOx. What Are the Most Common Cummins NOx Sensor Problems? Cummins NOx sensors are an extremely sensitive part that measures fluctuations in microscopic NOx particles in your exhaust stream. I can’t have a truck that I can’t drive P0420 - Bad NOX Sensors? See the attached troubleshooting information for the P0420 code. com. Jul 5, 2022 · What Causes NOx Sensors to Fail? A sensor has to be highly sensitive to accurately detect NOx levels. Apr 13, 2025 · Struggling to find the outlet NOx sensor on your Cummins engine? You're in the right place. Aug 30, 2024 · My NOX sensor readings are as follows: Voltage after SCR 40800 mV Voltage before SCR 14400mV Downstream SCR -10ppm (negative) Before SCR 106ppm Is there information anywhere on what these readings should be as I still have the fault Sensor 2 Bank 1. Start is 0ppm for a bit then I'd get a crazy high number for both then they'd drop to readings in the 220 to 300ppm range for sensor 1 and numbers between 1 and 60ppm for sensor 2. But you should monitor the sensor readings while performing a forced regen. The part is nation wide back ordered for a month. In this detailed exploration, I will delve into the key distinctions between inlet and outlet Finally unplug the DEF doser and run a regen, make sure the two NOx sensors are reading about the same. The first failure was at 39K miles, the second at 44K miles, and now my third at 58K miles. 4 days ago · Rawze. Cummins ReCon® NOx sensors are the smart, low-cost replacement choice to help keep your engine’s aftertreatment system operating normally. Usually not much deviation from the corrected value. Jun 22, 2024 · As vehicle emissions standards become more stringent worldwide, technologies to monitor and reduce emissions have become integral parts of modern engines. Dec 15, 2019 · After reading this post I did a date log of the sensors and am getting odd readings. It covers topics such as sensor functionality, wiring, mounting, and diagnostic procedures. I did see a video with an inactive code for the Nox In sensor, the ppm reading was moving around quite a bit, so much that the data showed this: By comparing the two NOx sensor readings, the ECM can decide how much DEF needs to be dosed into the exhaust. These sensors can also contribute to diagnostics, telling the ECM is DEF is ineffective or the SCR in damaged. 7L typically read between 0 to 5 volts depending on exhaust conditions. Also, insect the wires, and connector for d The primary failure mode the NOx Sensors is internal failure, which will generate a sensor specific fault code. 2 KB, 3 views) Jan 18, 2017 · '14 Cummins NoX sensor issues. This guide will discuss what causes NOx emissions from Cummins engines and how your machine can control them. To read NOx sensor values on a 2012 ISX15 with SCR, use Cummins Insite software with the latest calibration files. pdf (96. Jan 6, 2024 · If the sensor cannot generate a Signal, then the Signal wire could be broken (open circuit), or shorted to another wire or to ground. These sensors measure nitrogen oxide levels in exhaust gases, providing crucial data for the engine control unit to manage regeneration cycles effectively. During an SCR test you could see these hover around 60-70ppm on a healthy canister during DEF injection. The NH3 sensor detected free ammonia in the SCR. This can result in increased NOx emissions, a malfunctioning check engine light, reduced fuel economy, and potential damage to the catalytic converter. Learn to diagnose fault codes, spot failures, and choose the right parts to stay compliant and avoid downtime. Cleaning the sensor is generally ineffective; replacement is recommended if malfunctioning. Verifying sensor functionality after repairs ensures that the sensors continue to provide accurate readings, which is crucial for maintaining emission standards and engine efficiency. v5qemsogqarueqowhbjeo6uxca6xqhkubrstnh3bf3deck