Diesel SCR Systems Explained: How to Diagnose and Replace a NOx Sensor
In this video we are going to take a look at the Selective Catalyst Reduction System in a modern diesel vehicle because my 2.8 Duramax Colorado has developed a P11DB NOx Sensor Performance code. I’ll start by explaining what NOx or Oxides of Nitrogen are and how they pertain to a diesel engine.
Once you understand what NOx is I’ll talk about how Diesel SCR systems work, including their key components and overall function. Learn about the critical parts that make up the system and how they contribute to reducing emissions.Once you have a basic understanding of how the Diesel SCR system works we will start to diagnose the NOx Sensor code that I’m dealing with on this truck and what exactly causes these sensors to fail.
Links to Parts/Tools used in this video:
Idash: https://amzn.to/47gPUls
Ammonia Glass Cleaner: https://amzn.to/4gj2qVG
Test Light: https://amzn.to/3AW7j7b
Oscilloscope: https://amzn.to/3TjXXsf
OEM NOx Sensors:
16-18 2.8 Duramax UPSTREAM: https://amzn.to/4guAbDV
16-18 2.8 Duramax DOWNSTREAM: https://amzn.to/3ASf1iH
19-22 2.8/3.0 Duramax UPSTREAM: https://amzn.to/4dZcvpy
20-23 6.6 Duramax UPSTREAM: https://amzn.to/3XgdCtx
20-23 6.6 Duramax DOWNSTREAM: https://amzn.to/3XfGFO6
I was not able to find any OEM Ford NOx Sensor on Amazon.
13-15 6.7 Cummins Downstream: https://amzn.to/3ZbctWU
My Amazon Store: https://www.amazon.com/shop/repairgeek
Help support the channel, buy using my Amazon links
As an Amazon Associate I earn from qualifying purchases and your cost is exactly the same.
I source all of my service data from the same place that professional shops do. You can as well: https://www.pntrac.com/t/SENKSUZKRktDSEpOTEtGQ0dKRk9LTw
Questions? Shoot me an email at repairgeek365@gmail.com
Chapters:
00:00 Intro
00:04 What is wrong with my truck?
1:46 Disclaimer: “Just delete it”
2:48 What is the SCR System?
4:30 How does the SCR System Function?
7:11 What is De-Rate?
8:42 Reading the NOx Sensor datastream
9:41 Attempting to diagnose a NOx sensor
14:19 What causes a NOx sensor to go bad?
15:21 NOx Sensor removal
19:36 Resetting the sensor values in the ECM.
21:14 Test drive after the repair
22:10 What can you do to prevent a NOx sensor failure
24:19 Outro
#diesel #emissions #nox #EPA #dieselengine #repair #diagnosis
Disclaimer:
The information, demonstration and any content contained in this video is for informational purposes only. The user Repair Geek makes no warranty, express or implied, regarding the effectiveness or safety of the contents of this video. In no way should the contents of the video, including the tools used, be repeated or tried by anyone. Viewers should only seek the help of a trained professional located at a licensed auto repair shop for any fix, modification, alteration, or any change to their vehicle. Repair Geek shall not be liable for any injury, damage, or loss to any person or property that may result from use of the tools, equipment, or any content contained in this video. In addition, there is no way to guarantee that the video is not altered or modified or is not in the final form submitted by Repair Geek and therefore, Repair Geek does not warrant that the video is unaltered or not modified. The links on this video to products are for informational purposes only and in no way are an endorsement of the safety or effectiveness of the particular product. Viewers understand that anything contained in this video or linked to or from this video is the sole responsibility of the viewer and in no way provides an express or implied warranty as to the safety or effectiveness of any linked tool, product, or video. Therefore, viewer agrees to release, waive, and discharge Repair Geek or anyone affiliated with Repair Geek, from any and all liability, claims, demands, actions, and causes of action whatsoever arising out of or related to any loss, damage, or injury, including death, that may be sustained by the viewer, or to any property belonging to viewer, regardless of whether the loss is linked to the use of the contents of this video, or otherwise and regardless of whether such liability arises in tort, contract, strict liability, or otherwise, to the fullest extent allowed by law.
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Links to Parts/Tools used in this video:
Idash: https://amzn.to/47gPUls
Stanadyne Fuel Additive: https://amzn.to/4eipYbH
Ammonia Glass Cleaner: https://amzn.to/4gj2qVG
Test Light: https://amzn.to/3AW7j7b
Oscilloscope: https://amzn.to/3TjXXsf
OEM NOx Sensors:
16-18 2.8 Duramax UPSTREAM: https://amzn.to/4guAbDV
16-18 2.8 Duramax DOWNSTREAM: https://amzn.to/3ASf1iH
19-22 2.8/3.0 Duramax UPSTREAM: https://amzn.to/4dZcvpy
20-23 6.6 Duramax UPSTREAM: https://amzn.to/3XgdCtx
20-23 6.6 Duramax DOWNSTREAM: https://amzn.to/3XfGFO6
I was not able to find any OEM Ford NOx Sensor on Amazon.
13-15 6.7 Cummins Downstream: https://amzn.to/3ZbctWU
My Amazon Store: https://www.amazon.com/shop/repairgeek
Help support the channel, buy using my Amazon links
As an Amazon Associate I earn from qualifying purchases and your cost is exactly the same.
I don’t think the de-rate is the biggest issue people have with these systems and why they delete them the real reason is because whether it’s Chevy Ford or Dodge like you said within certain variations depending on the make and model they recirculate dirty crap out of your exhaust back into usually the number seven and number eight cylinder which even if you’re the most conservative driver on the planet you end up burning up cylinder seven and eight in a lot of cases. The EPA and the manufacturers don’t care about the longevity of these engines they only care what comes out of the tailpipe and you the consumer end up paying the cost of burned up pistons and blown up engines that otherwise could’ve gone a lot more miles.
I've found those O2 sockets are generally only good for installation. Usually I use a wrench to take them out, or cut the harness like you did, but I have also run hose clamps around the split sockets before if I had to.
I agree 100 hundred percent
In a pinch I have used a hose clamp over the socket and it was just enough to remove a nox sensor.
In my ship we get in shit for cutting the wires becuase theh usully have a 150$ core charge.
Torches also help alot.
When I'm diagnosing a nox. All you can check is power and ground. And if you don't have an ociliscope you can use a volt meter to see if it's getting the CAN signal. CAN low is usually 1.5-2.5 volt and CAN high is 2.5-3.5 volts.
You measure from CAN high or low to ground.
In most causes it's a bad sensor
Thanks for yet another upload, I'm looking forward to watching it tomorrow morning, as it is late in the day in Denmark.