midnightgolfer

The MAF sensor (which was one I had purchased off of eBay, at a reduced price, and which had the same part number, as well as the same Bosch serial number, but which had had a resistor soldered into it, for some reason,) has been replaced with a proper one, by the dealer.

Apparently, this made the errors go away, and the car passed the government emissions inspection, with flying colors, minutes after leaving the dealership's garage. (The emissions inspection station and the dealership are on the same block, on the same street.)

It may have been my imagination, but it even seemed to run much more 'properly', than even it had run back when I first bought it, and it allowed me to use the Tiptronic functionality of the transmission.

Arriving back near home, a little over an hour later, and tiptronic is again overridden by plain-old normal auto-mode, despite being tilted over into the tiptronic position, and when I checked with VCDS, vagcom shows that the exact same errors, from the MAF, O2 lambdasonds, and the ECU<->Tranny coms are back, just as before.

Since my ultimate goal was the inspection sticker, I'm giving it a rest, (looking for a solution, at least for this month,) especially since the stealership said that only explanation, although no guarantee, would be a senile ECU.

And I can't even remember the price they quoted for replacing it, because my brain shut down when it heard the number.

What would you do? Can a used ECU be worth the hassle of trying it out?

The sticker on the side says, 4D0 907 557 A
4D0907557A

silverd2

Tough question...would be great to have a friend with an ABZ motor, so you could test with their ECU.

Dealer price for new is $1600-1900...best I've seen on ebay is $200 for a really rough lookin one...who knows if it's ok?

midnightgolfer

That's another doubt I have. The motor in the car is definitely the AEW 3.7, but the ECU ends with "A" not "C" so I'm not sure if it's the right ECU in the first place.

silverd2

Sorry..thought you had a 4.2L and maybe copied down the part # wrong.

That IS the correct number for your car for OEM module...4D0 907 557 A

The replacement part number (new or recent used) is now 4D0 997 557 PX....but a good used 4D0 907 557 A would still work correctly.

I know nothing about this service...just a reference to the part numbers >>>

http://www.atpelectronics.co.uk/p/au...onic-m541.html

midnightgolfer

Much obliged, thank you.

aTOMic

Did you ever get this sorted out, MidnightGolfer? I see you're in an A8 now... good choice.

I have the 18265-P1857 error from ecu adnd am wondering what that turned out to be. Also having O2 sensor issues and had the MAF problem. Mine's a 4.2.

Tom