Benz 2010 ML350 Bad MAF Solved by MB Star Xentry

 Problem:

My Mercedes Benz 2010 ML350 Bluetec is going crazy again. Fix one issue and another comes up in a matter of weeks. Annoying!

So now I have some intermittent acceleration issues, as well as intermittent rough idling. Also have horrible mpg.

I am suspecting a vacuum leak. When I accelerate, I can hear a whistling sound. I can also hear a "whoosh" air sound when I accelerate with the windows down.

I scanned with Autel AP200 and got the following codes:



- 146100 Control deviation is too large (Current)

- 111500 The regeneration frequency of the diesel particulate filter is not ok. (Stored)

- 14B200 A plausibility error exists in the component 'hot film Mas airflow (MAF) sensor'. (Current & Stored)

- 123900 Charge pressure is too low (Stored)

- 153600 An internal fault exists in the component 'Nitrogen oxide (NOx) sensor upstream of the selective catalytic reduction (SCR) catalytic converter. (Stored)

- 16F700 Disregard this fault. (Current)

I cleared these codes and 16F700 is the only one that comes back immediately. 146100 and 14B200 and 123900 come back in a couple of days to a couple of weeks. 153600 comes and goes on its own. 111500 typically goes away until I force a regen (The dpf seems to be getting more soot faster since these issue began, so sometimes I force a regen to clear the soot).

I'm building a smoke machine to test for vacuum leaks based on YouTube videos. However, I'm new to engines so I have no idea what hose in the engine to plug in the smoke machine for a smoke test. I believe there are different components... exhaust, intake, and others. Please if you know about this, let me know where I have to plug in the machine to smoke test each component.

I removed the silver pipe and examined the green seal and it looks fine, but I replaced it anyway. I examined the other seal for the black plastic pipe that connects to the silver pipe, and that seal was pretty much destroyed. I replaced it thinking I had found the problem, but the car is still giving the same intermittent issues. I'm going to check it again to see if the seal isn't seating right. That particular pipe just seems a little loose to me even after I tighten the clamp screw.

Solution:

For anyone who might have a similar issue, here's how I solved it:

After replacing the water pump, I found a guy that fixes alternators and he restored mine. Reinstalled it and got the car started.

After that, I was finally able to get a hold of MB SD C4 Xentry/DAS. I ran a number of tests on the air/vacuum system with DAS, especially the MAF sensors and Boost. All tests passed with flying colors so that convinced me that none of the components were faulty.

Next step was adaptations. I reset pretty much everything that has to do with the air/boost system. Apparently, you even have to perform a reset after replacing your air filters, and I had replaced mine twice before without ever performing a reset!

After all adaptations/resets with DAS, the car seems to be back! Moral of the story is to get your hands on Xentry ASAP! If you own a Mercedes and are into DIY, Xentry is simply a must have. I am now a believer.