Been throwing codes for the both the fuel venting system and the aux fan over the past weeks. The fuel vent system is going to be a struggle I think, because the valve tests fine via my foxwell, and seems to be working on the live data. Although the live data I am seeing seems quite odd. That’s a problem for another day though. I do smell fuel on start up though, but no visible leaks.

Turns out the plug to the “AUC sensor” (pn 64118391470) had come off. Not the easiest to secure, but it’s back on now and no codes. I thought this strange little sensor was for the function that shut off the ambient airflow when it sensed particulates, but it seems it’s part of the aux fan. Oddly, the fan was running with the AC on, with the sensor unplugged. It didn’t go much over 50% unplugged, but with the thing plugged in it’s hitting 60+% in the 100 deg heat here.

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Current
Original owner 2002 E53 X5 4.4i to 4.6i swap
2025 G06 X5 50e
Former
1972 Audi Fox
1986 Saab 900S
1996 BMW Z3
1998 BMW E36 M3 Sedan
2004 BMW E46 M3
2006 Audi A3 Quatro
1993 Mopar 318 Jeep Grand Cherokee
2015 V6 Jeep Grand Cherokee