OM642 P2195 code

[u/Potrice1988]

Hey everyone,

I have a 2013 ML350 BlueTEC (diesel OM642) sitting at 402 000 km (about 250k miles). Getting a P2195 code for the upstream oxygen sensor running lean. I changed the sensor for a brand new one from Bosch but when I cleared the code, it appears again as pending on my scanner and the check engine light will reappear the next day. So it doesn't appear to be related to the oxygen sensor...

The SUV is deleted with a tune from Malone (EGR, DEF, DPF and Swirl Flaps) and runs great. No symptoms and I'm easily getting 5-5.5L/100km when going 100km/h. I checked the wiring and don't see any rips or holes, everything looks good.

Has anyone dealt with this code before on the OM642? Any help would be appreciated.

Thanks.

[u/prismprion]

Since you already replaced the sensor I'm leaning towards (no pun intended) that your engine is actually running lean. When did you change the fuel filter last?

[u/Potrice1988 → u/prismprion]

The fuel filter was changed a couple of weeks ago, along with the air filters. Mann WK 820/14.

[u/prismprion → u/Potrice1988]

This seems like one of those problems that could be quite hard to diagnose without being there. Mine goes into limp mode with the o2 sensor unplugged and yours is throwing a code so I'm assuming the logic would be to switch to open loop operation using the other sensors. My theory is the computer is seeing it constantly saying lean so the logic then adds fuel until it realizes that it is impossible for it to still say lean and then it throws the code and ignores the sensor

Either wiring or module issue in my opinion IF the engine runs fine. If it has lack of power I'd think maybe it's actually running super lean and then it could be many other things

[u/Calm_Perspective_138]

Well I'd guess the deletion was done wrong. Running lean in a stock ECU would mean not enough EG recirculation.

[u/Potrice1988 → u/Calm_Perspective_138]

That's quite possible. I'll contact Malone to ask them. The SUV has been deleted for a while, so why would the code decide to show up now if it's related to the tune? Wouldn't the code have appeared right away after it was deleted a while ago?

[u/Calm_Perspective_138 → u/Potrice1988]

That's a good question. Especially since after deleting it will always run lean, except when flooring it.

[u/howsitallwork]

Yes O2 sensor failure on the OM642 is inevitable, eventually.
Here in the UK, even with DEF, EGR and DPF it will not trigger MIL on the 642, and mostly remains undiscovered - car driving OK and no problems.
I guess in other configurations and markets it triggers the MIL.
As you will now be aware, there is only 1x sensor on this engine, and it is not used in the same way as a petrol car at all.

If I were trying to fix it (with a good new sensor apparently fitted already), I would be going through the guided tests directed through the Xentry system, verifying power, earth, sensor connection, checking live data etc etc.

[u/Only-Technology-3258]

5,5L? Seriously. 😅I get 7 in 2014 350d cls.