Originally Posted by Mister Bally

Love those locomotive generator and motor ring terminals. Some are the size of my old VW Beetle engine!

Originally Posted by richard-tx

A locomotive generator is larger than the Audi 4.2 engine by a factor of at least 3 and possibly 4.

Originally Posted by MP4.2+6.0

Go for the car side connector, or actually what is the wiring leading up to it. Given you changed the sensor, but still have a connection type code, that most likely puts it in the wiring. The individual conductors that lead to the connector are small enough they can be prone to internal breakage or other issues.

After I went through this drill on mine, I finally bought a set of the pre-made connector jumpers and new plug from audiusaparts, plus some all in one heat shrink tube and solder splice connectors. Cut out the connector a few inches back--where the (small conductor) wiring could still get broken due to repeated movement or stress. I spliced in the new jumpers after threading them into the new connector end, used a heat gun on the pre fab connectors to melt the solder and think the tubing cover all in one step, and taped it up with some black cloth tape. Presto, no more codes ever since.

Although I had forgotten it at the time, there is actually a W12 specific TSB for 2005s and 2006s that covers exactly this connector/wiring issue, with exactly the same fix path as I eventually went down after eliminating other scenarios like the particular sensor. The TSB said it was corrosion at the wire terminal connectors. What ever it was, mine was cured.