Check Engine Light On

[Docevil87]

Check engine light on. OBD scan says
Component A97/1(NOx sensor control unit upstream of SCR catalytic converter)
has a plausibility error.
Anyone familiar with this or experienced this. Able to clear code but returns after several hundred miles. Engine performs fine. Like to do my own maintenance, hate the idea of going to dealer but sounds like a trip is in order.
Thanks

[Alex AVI]

Originally Posted by Docevil87

Check engine light on. OBD scan says
Component A97/1(NOx sensor control unit upstream of SCR catalytic converter)
has a plausibility error.
Anyone familiar with this or experienced this. Able to clear code but returns after several hundred miles. Engine performs fine. Like to do my own maintenance, hate the idea of going to dealer but sounds like a trip is in order.
Thanks

DOCEVIL87 - Emissions system should be covered by your MB Warranty. I woudnt mess with it unless you have the equipment to deal with checking the rest of the emissions system and/or you are out of warranty

[MJAI]

I have this problem in my MB S class, took it to local mechanic, plugged into his computer return emission failure, he would not mess with it, took it to MB, part $20, overnight delivery $200, problem fixed.

[Docevil87]

Originally Posted by MJAI

I have this problem in my MB S class, took it to local mechanic, plugged into his computer return emission failure, he would not mess with it, took it to MB, part $20, overnight delivery $200, problem fixed.

Ok thanks out of warranty. Will have to call dealer. I’ll finaly get my air bag recall done as well

[Alex AVI]

À

Originally Posted by Docevil87

Ok thanks out of warranty. Will have to call dealer. I’ll finaly get my air bag recall done as well

DOCEVIL87 - Not neccesarily, emissions warranties could be 7 or longer depending on state. Check your manual for your model year & state to confirm, you could be on the fence if 2013.

[Docevil87]

Thanks for the great info talked to dealer, out of warranty 5 years emissions,
needs to do do work up to determine issue. Hopefully not too $$$, already replaced def heater and 6 tires this year. But worth it love the vehicle drive it everywhere year round.

[Titus]

Federal emissions warranty is 5 years/100,000 miles, whichever first occurs. Only exception I am aware of is MB extended warranty on EGR valve for 2010-2014 Sprinters to 10 yrs, 120,000 miles. California (and other States?) may have extended this to 7yrs/70,000 miles, but only on certain parts. Don't know if the NOx sensor is one of those parts.

[Alex AVI]

Originally Posted by Titus

Federal emissions warranty is 5 years/100,000 miles, whichever first occurs. Only exception I am aware of is MB extended warranty on EGR valve for 2010-2014 Sprinters to 10 yrs, 120,000 miles. California (and other States?) may have extended this to 7yrs/70,000 miles, but only on certain parts. Don't know if the NOx sensor is one of those parts.

TITUS - Yep, you right - CA & west & certain east coast states have 7 yrs 100k (at least for my 2017 MY) and only for "long term" parts, whatever that means and if/where that long term parts list can be found, I have not been able to locate.

Update: Found it. NOx sensor is considered "long term" emissions part.
https://assets.mbvans.com/Mercedes-B...843.1564459501

But how does that 7 yr warranty work? If my MY 2017 is a CA compliant & delivered van (which it is) but now resides outside of CA, does the CA warranty follow it or is it based on where the car now resides?

[6sixweeds]

This will be a bit lengthy...Our 2012 with only 20,000 on it had a check engine light come on two years ago while traveling from Washington State to Nova Scotia and back. Finally was able to make it to a dealership when we were in Ohio and took it to Vin Devers Autohaus of Sylvania. The aftermarket extended warranty didn't cover emissions components, and since it was 2018, the 3/36 factory didn't either. So I shelled out $870.00 to replace the NOx (nitrogen oxide sensors).

After leaving the dealership, I looked in the Sprinter Warranty book and discovered that since it was purchased new in Washington State, (one of 10 states listed), the warranty for emissions related components is 7/70k. The dealer said they'd refund my money, but then quit taking my calls and wouldn't answer my emails. So I called MB headquarters. Finally got the Executive Customer Service (very nice and understanding lady) who advised me to take the invoice to my local dealer and they'd refund the money. Nice service manager at the Spokane MB dealer who promised me they'd refund the money. They did...but it took two more months.

Long story, but I got reimbursed and it only took about a dozen phone calls and equal amount of emails. When the check engine light comes on for this, you have 500 miles and like a dozen starts before you go into limp mode and are restricted to 25 mph. That's no way to travel cross country. What I did until I made it to a dealer in Ohio was to take it to O'Reilly's and have them scan it and tell me the code, then clear the check engine light. Then we were able to keep driving until the light came on again. No rhyme or reason as to how any miles it would take. 50? 1,000? But it would come on. They'd clear it for me and I'd be on my way.

Now, two years later, and with just over 51,000 miles on the OD, the check engine light came on again. I took it to O'Reilly's and, you guessed it, I got the same code for the NOx sensors. Cleared the code. But this time, I want to replace the sensor(s) myself. There's not much on YouTube about a simple fix. I've done all the maintenance so far (oil, air, fuel filters and oil. Add DEF every 1,000 miles or so. Use the recommended ultra-low sulfur diesel fuel (15 ppm sulfur maximum). Mobil 1 ESP (emission system protection) 5W30.

Some of the videos or articles say you have to have the computer recognize the sensors and "marry" them. Does anyone have any info on this or replaced the sensors yourself? Are they plug and play? Or do you have to take it to a dealer or mechanic with the proper MB computer scanner that will do the proper diagnostics and sync or "marry" the sensors?

It would be great if you could just buy the sensors, replace the old ones, and be on your way...

[ROBERT CROSS]

snip...."It would be great if you could just buy the sensors, replace the old ones, and be on your way...


You can...

Bank 1, rt side(or opposite side from cyl.#1) second sensor, the one after cat converter.

The problem can arise when they are very hard to remove. I have been able to do it with an LP torch and an air impact hammer to break the corrosion bond.

Bob
🇺🇸

[sixweeds]

Bob,

Thanks for that. Assuming I'm able to remove and replace the sensor, do I have to do anything with the computer, or will it automatically read the new sensor and adjust itself accordingly? Is that something I can do or do I need to take it to a German auto specialist?

Thanks,
Sixweeds

[ROBERT CROSS]

If you have a 'hand held' that can read and delete the fault codes you are good to go.

Here are some reviews...

Bob
🇺🇸

[sixweeds]

Bob,

I already cleared the code once with a local auto parts store hand held. So once I replace the NOx sensor, all I need to do is clear the code again the same way I already did?

If that is the case, then this should be an easy fix. Any suggestions on the best place to purchase the sensor(s)? Rock Auto?

Thanks,

Sixweeds

[BurntAsphalt]

Sixweeds
I’ve read a lot of posts on this subject on the Sprinter-Source forum, and my understanding is that the new Nox sensor must be married to the Sprinter’s computer with the proprietary Mercedes software(as you referenced in your post). That said, I don’t see any harm with replacing it yourself and seeing if the countdown/limp home mode resolves. If it doesn’t, you’ll need to take it to a dealership or independent shop that has the MB Xentry/Star system. Good luck and please report back on the final solution.

[Titus]

I was able to clear the failed wheel speed sensor code with an icarsoft MBII reader. But maybe emissions codes can only be cleared with the MB STAR. Based on my experience with wheel speed sensors, I would only use the genuine MB part. They have somehow set things up to force you to buy their part. Sneaky devils. I first tried a no-name speed sensor and the MB computer would not recognize it. I then tried one made by Bosch. Same problem. Finally bit the bullet and shelled out 2x the $ for a MB part and it worked. I wouldn't be surprised if it was made for them by Bosch, but they must have something unique put in it to make if acceptable to their system. I too woul appreciate hearing how things turned out.

[02interstate]

All,

Well I drove our 2012 interstate to KY (from San Diego) to see relatives. Check engine light came on..$3600 later and 2 new NOX sensors and new Catalytic converter..light is gone. Anyway, we had a great trip and love the van..I image there was a less expensive way to get this fixed but with 2 kids, dog, wife looking at me to return them home safely...what am I to do but pull out the amex?

[sixweeds]

How many miles were on your 2012 when you had this problem?

[02interstate]

58K miles on my 2012 airstream.

[BurntAsphalt]

Sixweeds,
Curious if you ever found out if the replacement Nox sensors had to be married to the Sprinter’s computer by a tech with MB software?

[02interstate]

The dealer told me that the box sensors (there are 2 on a 2012 interstate) need to be the same version. Evidently they keep coming up with new versions of this part. Sorry I am not sure their process when they installed it so I am not helpful with that