P0101 Code Won't Erase
 

Hi guys,

My dealership seems perplexed, so I thought I'd throw this out to you all.

My idiot light came on, threw a P0101 MAF voltage code on Sunday, I checked, cleaned the sensor, but then discovered a vacuum leak in the intercooler hose (LH). Figured the two were interrelated, but truck is still under warranty, so took it in Monday.

Dealer has had it since then, replaced the hose, cleared codes, light came back, replaced MAF sensor, cleared, code came back. Now they're on their 4th day of having the car, and now heading to test the engine harness.

Saying nothing in STAR is giving any other leads for them, so they seem stumped.

Any ideas on where to possibly point them?

Thanks!

Update for the follow along -- they tested the entire engine harness, pin by pin, no faults there, so today, they are replacing the entire ME hoping that will clear the code.

Very very fishy. If the ME is anything like the AAM in the W163's, I would have expected the truck to be behaving more strangely if the engine computer was on the fritz.

To bring this to a head, truck was at the dealer for a week. Ended up having to replace the whole engine computer. Would have been a $3500 repair bill with the labor and parts. Thank god for the CPO warranty. This seems to odd and specific of a problem, that at the end of the day, the dealership didn't even have an answer of how the vacuum leak and P0101 code were interrelated, and how the only way to clear the fault code was to replace the entire ECU.

Here's the service bill:
https://cimg4.ibsrv.net/gimg/www.mbw...47118e0ccd.png
https://cimg5.ibsrv.net/gimg/www.mbw...ae44cfb95f.png

Did the dealer ever fix your problem?

Since it's a turbo the P0101 code of MAF sensor is related to everything from the MAF to the cylinder valve. Good youtube video on the subject but long. In a nut shell, any leak or bad sensor along this will throw a P0101 error code. No MAF sensors r have never died (25 year) on my cars). Cleaning needed yes. Try cleaning the boost pressure sensor (it worked for me) or other sensors along the air pathway. Also any loose connection/leaks on the air path can also cause in issue. It's also much cheaper that the MAF sensor.

His last post pretty well establishes that the issue was corrected. How I missed this thread is what surprises me. Glad you got it sorted out, and on warranty to boot!

My bad. Didn’t see replacing the ecu fixed it.

No biggie Dave!!!

P0172 system to rich bank 1???
 

My 2010 E350 check engine light went on so I stopped in auto one hooked up a scanner and it said code P0172 most likely solution replace MAF sensor…. I got the part replaced it and check engine light still on, do I have to reset the check engine light or should it just shut off ? Also since light still on what else could it be? I’m going to go back and run the scanner again see if same pops up now that new one in there.