2011 adblue heater and processor failure
Hope this helps someone. I got $3,000 worth of parts covered because of this thread.
I am curious after reading some of the failures, there does not seem to be a lot of details about the failure mode. The "change in resistance" suggests material degradation in the heating element, or caking/coating on the element.
Has anyone looked into pulling the heater and just cleaning it? My mom's Sprinter Motorhome had a failure with the DEF because it sat for a long time and the DEF degraded and plugged up the lines. If the DEF can do this, it can cause problems with the heaters too.
As far as I could tell, the pump works by injecting air pressure into inner core within tank, it does not actually pump the fluid itself. I think the DEF fluid is then fed to a higher pressure pump upstream near the injectors.
Whatever the case, I suspect you're in need of a new pump if you have low pressure code. At the point I realized this, I just threw my hands up and handed to the dealer to fix. Lesson learned for next time I need a DEF pre-heater replacement.
Fortunately, I had purchased an extended warranty for this vehicle in December, so it only cost me additional my $250 deductible.
I take it with a grain of salt when a service advisor says " this really doesn't happen that often". Yes - they said that to me as well in May. I think it's one of the mechanisms they use to "soften the blow."
The Best of Mercedes & AMG
Anyway after my timing chain had issues right when I miled out of warranty, this heater failed. They initially were arguing they would not cover it as they had just good willed the timing chain fix. I had to ask all the questions of give me the part numbers, do my research to star to deduce the heater was part of the adblue tank. So after I yelled at the service advisor, the head of parts and service, I then got a call from the dealership general manager (mind you I was about ready to call him after I had to find out who he was and what his email and phone number was b/c I document everything in writing). My argument was I believe the heater is part of the tank (buy the tank get the heater). I said if I have to do that legwork to prove that then what he needs to know is I'm about ready to light a fuse under him, the head of MileOne, MBUsa and all the way to the EPA. That if I have to connect those dots it will agitate me that much and at that point it is very clear to me this part is covered under the emissions warranty. The adblue tank is covered under the emissions warranty which was still in effect. If the car is throwing a check engine light because of the heater failure and the heater impacts the effectiveness of the emissions system (i.e. indicated with a check engine light) then that was in fact the EPA intention of the adblue tank being listed on the emissions warranty. That the EPA does not care to cover just the plastic of the tank for the warranty but every component that you get if you replace the whole tank if you buy the tank. The tank is in fact all components contained in it that make the tank do its job role. I told the dealership to figure it out with mercedes, I don't care how he covers it but find a way. I'm happy that mercedes has a cheaper way to fix the issue (i.e. just replace the heater) but that does not mean they stick me with the bill. To say I was agitated over it is putting it mildly.
After that I suspected this was a trend of more issues to come (honestly had other things that had already happened) so I started the process of trading the ML in for a E wagon but it had to be ordered. Then I started getting another check engine light that would come on and off. I pulled the code myself and I believe it was the oil cooler seals issue. When I had to argue for them to cover the heater fix, in my tirade to with the general manager of the local dealership I mentioned I feel I can predict the things about ready to go just by reading the forums and it is very clear these are not rare occurrences. It was proving me right when I saw that so all I wanted was out of that vehicle.
I believe regarding the adblue heater and the oil seals people should complain to the government now and get mercedes to stand behind covering these things. On the adblue heater I believe the EPA should make all the manufacturers cover the heater as I have read about it happening to all the manufacturers.
I actually like diesels but I'm wondering if the newer mandated emissions systems are not mature yet. So I took a break from diesels. My husband thinks I'm a fool for staying with Mercedes. I do try to keep a pulse on different transmission issues that seem to keep happening so I fear he may be correct and I make sure every visit whatever I have noticed is documented because that will be my best friend regardless of the extended warranty. There are times I consider maybe I just trade in the wagon and be done with it when I read these things. This time around though I got a much better price on the extended warranty. I had multiple good quotes. The dealership wanted a considerable amount more and initially wouldn't budge. My reply to the finance guy was look, I'm fine if you want to make a hundred off of me for this but you can't charge a huge margin (it was either $1500 or maybe even $2000 more for it). So either you come as close as possible to this number or I'm clearly not buying it through you. I have to decide if I will buy another chunk of prepaid maintenance now as I'm about to use up the last of what I bought soon with the next service. I also need to decide if I should be taking the car to a dealer a lot further away.
Great they developed a new seal but it wasn't your fault they had a substandard part when they manufactured the vehicle. I know I didn't get the guinea pig price when I bought the car. I wish you all luck. Find as much supporting evidence as you can make your case and just don't back down.
I only hooked up 4 wires since I used my Mercedes star software to do the settings.
I only hooked up 4 wires since I used my Mercedes star software to do the settings.
I purchased a SCR Emulator from a Vladmir in post 12 and other related posts above in this thread. After wiring this into the SCR controller (under the floor of the trunk), I literally removed the entire adBlue tank and system and sold it on eBay piece by piece (that was functioning...). The emulator tricks the car's ECU into thinking that the ENTIRE SCR system is back there functioning perfectly. It even emulates the NOX sensors as well.
So I will never replace another expensive component of that SCR system again....ever.... Also this emulator cannot be detected by a STAR scanner, and emissions place, etc. Only way you would know is if you look under the back of the car.
I got the 6 wire version and use the can bus wires so that way I didn't need a STAR tool to make the system recognized it.
Car runs perfectly. No MIL lights. Nothing. VERY HIGHLY recommended
I purchased a SCR Emulator from a Vladmir in post 12 and other related posts above in this thread. After wiring this into the SCR controller (under the floor of the trunk), I literally removed the entire adBlue tank and system and sold it on eBay piece by piece (that was functioning...). The emulator tricks the car's ECU into thinking that the ENTIRE SCR system is back there functioning perfectly. It even emulates the NOX sensors as well.
So I will never replace another expensive component of that SCR system again....ever.... Also this emulator cannot be detected by a STAR scanner, and emissions place, etc. Only way you would know is if you look under the back of the car.
I got the 6 wire version and use the can bus wires so that way I didn't need a STAR tool to make the system recognized it.
Car runs perfectly. No MIL lights. Nothing. VERY HIGHLY recommended
Can you give me eBay item number which one to get?
Thanks
I purchased a SCR Emulator from a Vladmir in post 12 and other related posts above in this thread. After wiring this into the SCR controller (under the floor of the trunk), I literally removed the entire adBlue tank and system and sold it on eBay piece by piece (that was functioning...). The emulator tricks the car's ECU into thinking that the ENTIRE SCR system is back there functioning perfectly. It even emulates the NOX sensors as well.
So I will never replace another expensive component of that SCR system again....ever.... Also this emulator cannot be detected by a STAR scanner, and emissions place, etc. Only way you would know is if you look under the back of the car.
I got the 6 wire version and use the can bus wires so that way I didn't need a STAR tool to make the system recognized it.
Car runs perfectly. No MIL lights. Nothing. VERY HIGHLY recommended
He sends you a detailed PDF of how it works, why it works, and how to connect it and is very quick to respond to any of my questions. It is shipped from Eastern Europe (he sends tracking and snapped a pic of it before mailing) so it takes a few weeks to show up.
I imagine he would not want his email posted in a forum but if you PM me l'll send his email and you can send him a message and he will respond promptly.
I am in no way affiliated with the guy, just happy I found a smart solution to this poorly designed system. If it worked properly, I certainly would rather have just kept my emissions down and filled up the AdBlue tank. But my cost for this emulator was less than half of the AdBlue heater...
See other post as to where to get.
As far as mounting location, I simply cable tied to to the SCR wiring harness. The SCR controller and harness are under the W164 trunk, and then under the black foam molding that holds the jack/manuals/etc. to take out the foam molding, unscrew two screws to the rear door entry plate and pull that off. The. The foam lifts straight out (I have airmatic, so if you do, carefully remove the bottle for that from the foam molding and let it slide off the back). The SCR controller is the module in the dead center of the trunk floor behind the housing where the AdBlue tank is. (Traveling, not near my car for a pic)
He sends you a detailed PDF of how it works, why it works, and how to connect it and is very quick to respond to any of my questions. It is shipped from Eastern Europe (he sends tracking and snapped a pic of it before mailing) so it takes a few weeks to show up.
I imagine he would not want his email posted in a forum but if you PM me l'll send his email and you can send him a message and he will respond promptly.
I am in no way affiliated with the guy, just happy I found a smart solution to this poorly designed system. If it worked properly, I certainly would rather have just kept my emissions down and filled up the AdBlue tank. But my cost for this emulator was less than half of the AdBlue heater...
As far as mounting location, I simply cable tied to to the SCR wiring harness. The SCR controller and harness are under the W164 trunk, and then under the black foam molding that holds the jack/manuals/etc. to take out the foam molding, unscrew two screws to the rear door entry plate and pull that off. The. The foam lifts straight out (I have airmatic, so if you do, carefully remove the bottle for that from the foam molding and let it slide off the back). The SCR controller is the module in the dead center of the trunk floor behind the housing where the AdBlue tank is. (Traveling, not near my car for a pic)
Pm inbound
I followed instructions here and got adblue heater replaced in my 2010 R350.
Originally had P20BE and after heater replacement got P20E8 reductant pressure too low code that has been cleared by itself after 3 days of driving. I think I have an explanation.
First, I have to tell you, never leave Adblue connections exposed once disconnected. All those tabs came with heater kit are for closing those connections. There are 2 holes you have to close at the pump, tube ends, etc. Supplied tabs for all ends. Please close as soon as you disconnect them.
I figured this out bit later, had some crystallization inside pump holes. But I always believed they may be flushed out some point of time and it did, cleared CEL by itself.
Don't be hard on electrical connections, go easy and take your time disconnecting.
Not a hard job but takes time.
Good luck !!
I have to wonder if some of the pump and pressure codes could be just a dirty system that could benefit a flush. Buildup on the heater could be an issue too
Anyone got any ideas on what could be used to flush the system?
I followed instructions here and got adblue heater replaced in my 2010 R350.
Originally had P20BE and after heater replacement got P20E8 reductant pressure too low code that has been cleared by itself after 3 days of driving. I think I have an explanation.
First, I have to tell you, never leave Adblue connections exposed once disconnected. All those tabs came with heater kit are for closing those connections. There are 2 holes you have to close at the pump, tube ends, etc. Supplied tabs for all ends. Please close as soon as you disconnect them.
I figured this out bit later, had some crystallization inside pump holes. But I always believed they may be flushed out some point of time and it did, cleared CEL by itself.
Don't be hard on electrical connections, go easy and take your time disconnecting.
Not a hard job but takes time.
Good luck !!
I have to wonder if some of the pump and pressure codes could be just a dirty system that could benefit a flush. Buildup on the heater could be an issue too
Anyone got any ideas on what could be used to flush the system?
Low pressure codes can be either leak, crystals clogging flow or pump going bad. I'd run it few days and see, if it's due to minor clogging, it should clear as in my case.
Last edited by drgeeforce; Aug 30, 2016 at 06:08 PM.
My ML is a 2010 with only 46K miles. So I researched the EPA's * years 80 000 miles Federal mandatory warranty for all cars and light trucks.
It clearly states that all major Emissions components must be covered by the warranty. That means all components that makes the emissions system inoperable.
I handed the printed version of the EPA document describing the Warranty to the dealer this morning so we will see what they say. Replacing the Adblue tank is $4000. That's what they quoted me.
I will post a followup as this progress.
Could you provide a reference to the "EPA document" you provided the stealer? I googled and found the following... https://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=P100NNQH.pdf
...but wouldn't exactly call that conclusive. In fact it looks like they've been very specific about what is included and mostly that is control / monitoring components. If you've got something in addition to this doc or a reference within the doc that is more broad that would be most appreciated.
Thanks in advance, as the $1700 news today was unpleasant, to say the least.




