I just bought a ML350 Bluetec with 88,000 miles. While driving from FL to TN the CEL came on. When I was able to check the OBD2 code it had a P2459 Diesel Particulate Filer Regeneration Freq. code set. It came on at 290 miles on a 750 mile trip. Not knowing the history of this vehicle, I have no idea if it was used primarily in city driving or what...but the code did set after 290 highway miles which would have been usually where it would clean. Frankly, I don't even know what is in the DEF tank (although it has a fair level of fluid in it). Note that I did not see/feel any performance decrease in the vehicle on the trip.

I may have to replace the DPF, but I would like to hear other people's experiences. Are there any DPF cleaner fluids that are recommended?

TIA, Bill

 

The code reader you have is using their own "P" codes which are not M/B codes

Here are the codes for Bluetec which have 36 pages.

You must have your own scanner which can read all of your modules.

 

Thanks for the list and link to a scanner that will read the specific brand codes. My Innova code reader does read the standard OBD2 DTC codes, but not the specific MB codes. Guess I am going need that to diagnose this problem.

...Bill

 

The Autel will read all M/B codes correctly and will also work on any other vehicle manufacturer as per vin#

 

Thanks, I have one on order. Be back once I can scan with it.

 

When you get the scanner find the section on how to read all modules In one shot.

 

Received the Autel MaxiDiag Elite scanner. Scanned the vehicle, the MB specific code is "111500 The regeneration frequency of the diesel or gasoline particulate filter is not OK". (basically the same as the standard OBD2 code P2459). Interestingly the scanner lets me dig deeper and I found "Fault has not occurred in 2 or more drive cycles", "Freq Counter 1", "ODO Reading when first occurred 42444.0", and "ODO Reading when last occurred 42444.0".... Ahhh.... it now has 89000 miles. So figuring it was never reset, I reset the code. I'll see if it comes back, but my guess is it probably won't.

 

Try this reset procedure. Then delete codes.

 

Thanks Maj Dundee, Greatly appreciate all your help for this Bluetec newbie.

Do I turn the vehicle off after step 6 or start it? Does it matter?

...Bill

 

I would say START.