E320 CDI MAF sensor code
 

My 2006 E320 CDI has the check engine light on, hooked up carsoft and it has codes:

P0102 - Mass or Volume Air Flow A Circuit Low
P0101 - Mass or Volume Air Flow A Circuit Range/Performance

To me, on a 214,000 mile car, that means buy a new MAF. I used the CRC Maf sensor cleaner on it, cleared the code, and the light immediately came back on. Figured I'd double check with you guys before I ordered a MAF just to make sure someone doesn't know something about the 648 I do not.

The car does have an EGR delete, but it has been deleted for 2 years and this code just appeared so I seriously doubt its interrelated.

New MAF makes sense.

Out of curiosity, how did you accomplish the EGR delete?

In my experience the MAF sensor cleaner is only marginally effective.

I agree that the MAF needs replacement.

Check around, the Bosch sensor can be found online and if you find the right tamper proof bit you can swap the sensor instead of having to get a whole new tube.

This was the plan, the price seems to come down dramatically without the whole tube too which is a bonus.

You can buy an emulator that intercepts some signals once you unplug the EGR solenoid. So the egr valve is there, its just always closed and unplugged. Then the ecu sees a fake signal, if I scan it with carsoft you can actually see the EGR value change as the ecu thinks its moving the solenoid.

Anyway, you'll find them on ebay or similar, cdi3 egr emulator, they're like $75.

On the aftermarket MAF just be sure it matches the Bosch p/n to the last digit.

I went thru hell on my W210 with a CKP (crank position) that was one digit off from the original, the computer went nuts until I got an identically numbered sensor from the MB dealer. Even though the Bosch cross reference guide listed the one digit off number as the replacement for that OM606 engine.

Unfortunately the MB dealer will only sell you the whole MAF tube at 4x the cost...

It’s currently not available from the dealer. Doesn’t show as discontinued, but zero stock in the world.

With my discount it wasn’t insane, around $200 but they couldn’t supply it so it didn’t matter if it was $2 or $2,000.

Thanks for the insights, I’ll be vigilant when i order. I’ve got a set of the security bits so it shouldn’t be an issue
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Link to EGR Emulator
 

Here is link to the EGR emulator I purchased:

EGR Emulator for E320 CDI 2005 and 2006 (OM 648)

It arrived within a week or so. It seems to work well and should add life to my engine. Further, I have had to clean my EGR valve twice since I purchased the E320 CDI and the emulator should eliminate me having to do it in the future.

Any noticeable differences in fuel economy using an EGR emulator?

Without a diagram in front of me, P0102 tells me that the sensor output voltage is zero at all times or, if the system has a very sophisticated diagnostic routine, output is lower than expected even at higher air flows.

Generally, the MAF output is a few 10ths of a volt even at zero air flow so the computer knows the circuit is intact. The output may stop just short of 5V at high air flow so the computer knows if the sensor has not failed and gone full scale. I'd hang a volt meter on the output.

The P0101 is likely just a result of the first code.

If this ( Bosch ) sensor is like the 97 era diesel / gas cars, there are 2 voltage sources required to make the sensor work, 12V from a fuse to power the MAF circuit and 5V from the computer that becomes the variable MAF signal output.

Attached is a file I came across a while back

www.auto-consulting.it/DWN/Mass_Air_Flowsensor.pdf

I am curious but it is too early to tell. After I take a long road trip, I will make a report on any MPG improvement.