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2010 ML350 P20BE Reductant Heater

16K views 18 replies 4 participants last post by  clowrym  
#1 ·
I was completing some General Maintenance on my ml this weekend, Air filters, Oil change, Cabin Air filter & the following day after about 50-60k of driving my Engine light came on showing a P20BE code. I cleared the code & immediately received a Check add blue on the display, Ad Blue was low, so I added . Code came back a few km later. Searching the forum it looks like this code is related to the reductant heater for the add blue, but I also see a couple people who also have pump and processor failure. One post noted this code started after change the Air filters / Cabin air filter, which I also just changed... not sure if this is just a coincidence.......

Is there some way to test the reductant heater to ensure that is the only issue before I purchase the rebuild kit?

Thanks in advance!!
 
#3 ·
I have only called the dealer for a price on the rebuild kit...Havent spent alot of time looking online yet. Dealer price was $934. I can likely find it a bit cheaper on the internet somewhere when I go to purchase, I just didnt want to purchase it & find out something else was wrong!!
 
#10 ·
Ok so they now have the whole tank assy in stock for 1333.19.

https://www.ecstuning.com/Search/SiteSearch/ES2769786/ES2769786/

Here is the pump itself
https://www.ecstuning.com/Mercedes_...4.125-Bluetec_4Matic-Sport_Utility-V6_3.0L_642.820/Exhaust/Emissions/ES2546794/

If you think about it and do the math you might as well just buy the whole tank. I have found the heaters on ebay for as low as 625.00 and as high as 1100. If you think about it its probably easier just to replace the whole assembly as one unit.

I have been told the 166 preheater will work for all 164, x164, 166, and x166 models as its the same part all around they just put a different part number for the complete kit. I have not verified this with the dealer, but my independent thinks that as long as the connectors are the same which I have seen they are in the photos that it should work.
 
#18 ·
I purchased the reductant heater rebuild kit from the dealer in the end, reading through some posts on replacement, one noted that he failed to prime the pump after replacing the heater & cause it to fail. I haven't been able to find any info on priming of the pump? Does anyone have any experience with this? or any instructions?