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CAT sensor willnot reset!!!!! 2010 ML350BT

3K views 10 replies 5 participants last post by  yakky 
#1 ·
After replacing the AdBlue pump and processor, the CAT sensor will not rest. I have varied my driving, and included several 50 - 100 mile jaunts. & days and 500 miles later the SA at the dealership tells me to just keep driving it. Tags expire at the end of the month, and cannot be renewed because of emissions testing.

Any suggestions on how to get the CAT sensor to reset?

2010 ML350 BlueTec
 
#2 ·
If you don't have a CEL, you need the OBD monitor to reset and show complete? Do an internet search for OBD drive cycle, requires specific start stop on off and such to get the monitor to show complete. Some scanners will clear the cycle as soon as you tell them to read it, so you might be reseting it.
 
#3 ·
The MB dealer performed the work! Per my conversation with the SA this AM; there is no specific drive cycle for BlueTecs. He may be drinking the Kool-Aid. My Centech scanner does not show any codes. There is no CEL; yet the emission readiness test on my OBDII scanner indicates that the vehicle is not emissions ready due to the CAT sensor not ready!!!!! I started out (post $1,800 worth of reapirs) with 3 sensors not ready: Heated Oxygen sensor, NOX sensor, & CAT sensor. Only the CAT sensor remains un-reset!

My particular scanner requires effort to get to the reset screen. BTW, the Service Manager at the stealership will not return my calls. Tomorrow will be an unscheduled visit to the dealer to meet him face-to-face. Wish me luck.

owengrad
 
#6 ·
BlueTec vehicles have a CAT. In fact the parts diagram indicate 2 CATs plus a pre-cat. I love the torque of turbo-diesels, but hate the poorly engineered urea injection systems. This is our 3rd diesel since 2009: VW, BMW, & MB. The other 2 were trouble free!
 
#7 ·
10 days and 1,200 miles later, and still no DPF regen! It is my understanding (from an independent repair shop with significant late model diesel experience) that the sensors that are not ready are the pre-dpf and post-dpf sensors. Once a DPF regen occurs, they should indicate that the are ready, per mechanic. Since the shop does not have the specific MB software, only dealer can initiate an active dpf regen; or can they? The dealer says no, but they have not impressed me with their knowledge of diesel emission systems. Anyone have comments or suggestions regarding forcing the dpf to regen?

Thanks in advance,
owengrad
 
#9 ·
Thanks vortecpwr! The service manager has agreed to investigate the issue
With MBNA and force a regen, if that will resolve my problem.

The standard reply from the dealer
Has been: just drive it; it'll reset on its own. Our Jetta Sportwagen had a specific drive cycle, as does our BMW 335D. I find it odd that MB does not have a specific drive cycle to set the sensors to ready.
 
#10 ·
Annnndd............ the saga continues! The dealer's Mater Certified Technician/Shop Foreman has opened a case with MBNA. The response is to drive it from a cold start for at least an hour with the rpm's above 3,500!!!!!! Well, that did not help anything, other than shortening the life of the engine, alternator, etc. 14 days and 1,300 miles, without a resolution.
 
#11 ·
Emissions Readiness on BT350

I purchased a 2010 ML350 (82k mi) back in November, I STILL do not show my CAT as ready even after almost 2000 miles since clearing codes. No history of any emissions items being replaced according to VMI. I'm wondering if this isn't a software bug of some sort. On a "normal" OBD2 scanner it took a regen to get the heated 02's to pass, which interstingly enough show up as a NOx sensor when connected to Torque. My cat still shows as not ready. I also have a Carsoft MB2.0 and have no active codes, only historical code is an ABS sensor. Luckily my state allows 1 sensor to be not ready for emissions testing. Anyway, posting to this thread to keep it all in one place.
 
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