I am still having a problem with my 2004 a4,3.0l. My cooling fan run after my vehicle is off. I replaced the cooling fan ecu, the 2-pin sensor, the 4-pin sensor and relay #53? What am i missing??i scanned the ecu and i got these codes? P1672-fan open/short, p1850 missing powertrain ? What do you think is the problem? Any help??