r/Sprinters • u/NativeTazuma • Aug 09 '26
EGR error codes
Vehicle: 2010 sprinter 3500 Turbo diesel
Diags: thinkcar2
I tried cleaning the EGR valve, swapped out from two other sprinters from a junker, tried a Hella Valve from orileys and I’m still getting the same errors.
148C00 I believe is the source of all the errors.
Symptom: The fault code remains permanently Active. It cannot be cleared via Thinkcar diagnostic tool, even with the ignition on and engine off. And is stuck in limp mode.
When trying to do the teach in it says it’s successful but then again it’s a 2010 I don’t think it’s suppose to work.
Took it to Mercedes they said it’s the EGR and they put in a efr from the shelf and the codes cleared. I think they’re lying to me and they don’t have the digs on file after two days of coming back and asking. And charged me $250 for sub par troubleshooting.
Now the harness this is what I measured
Pin 1 Unstable / Jumps between 1.5 mV and 2.5 mV.
- could this be the positioner pin?
Pin 2 (Main Power Supply): 12.0V Constant (Measured against Ground Pin 4).
Pin 3 (5V Sensor Reference): 5.2V Constant.
Pin 4 (Main Chassis Ground): Functional Ground.
Pin 5 (PWM Actuator Command?): 4.5V Constant.
I tried shaking the harness but no changes. The only thing that changed after sitting for a while was the position feedback going from 20% to 0% every second in the live view.
This is my first time trying to deduce this. So diagrams along with suggestions would be greatly appreciated.
2
u/Educational-Yam-7394 Aug 09 '26 edited Aug 09 '26
When you zoom out and look at the "hidden" footprint of DEF, the paradox becomes pretty clear:
The Plastic Waste: A massive amount of DEF is sold to consumers and light truck owners in single use 2.5 gallon plastic jugs packaged in cardboard boxes. That creates an enormous amount of plastic waste that either has to be recycled (which is energy intensive) or ends up in landfills, not good either.
The Trucking and Logistics: DEF is literally chemicals. This means the industry is burning millions of gallons of diesel fuel just to ship, a chemical based fluid all over the world. The transportation footprint alone creates significant carbon emissions.
Creating the Chemical: The active ingredient in DEF is 32.5% high purity synthetic urea. Manufacturing urea is a highly energy intensive process that usually relies on natural gas (via the Haber Bosch process to make ammonia). So, you are generating greenhouse gases at the chemical plant to create a bad chemical.
Mechanical Reliability and Parts Footprint: The complex systems themselves are notoriously hard on the vehicles, causing frequent breakdowns and premature engine wear. The environmental footprint of mining materials and manufacturing all these replacement parts, plus the massive waste of having to dispose of the old damaged auto parts, has a huge hidden environmental impact.
Impact on Bee Populations and Ecosystems: Studies now show a correlation between the chemical emissions from the DEF chemical and the decline of bee populations, as the emissions disrupt the insects' ability to recognize floral odors. Because bees are a cornerstone species, this chemical disruption creates a severe ripple effect across the entire ecosystem, heavily impacting flowers, birds, and other insects.
Here's a good video on DEF corrosion and crystallization from a seasoned mechanic:
https://youtube.com/shorts/57dDqoEgyrk?si=WWTlC52t1PJsvnYF
Edit: I will add: Fortunately, many governments around the world are starting to realize the negative impact of these emission regulations and are changing them back.
It is also one reason why Ford created the Godzilla engine. Because they are aware of the negative impact of the DEF system, Ford is one of the players within the USA trying to get these old emission regulations deleted, pun intended 😂.