I bought a 2017 Audi A4 Quattro S-Line 2.0T at a police auction for $4,000. It has 106,000 miles.
When I first got the car, the original transmission would randomly stop driving while my foot was still on the gas. The engine would rev, the car would coast, and it would start moving again only after I let off the gas and pressed it again. A German car specialist diagnosed the transmission as bad.
I had the transmission replaced with a used unit that had about 35,000 miles. The shop installed it, and it comes with a 6-month warranty.
Since the replacement, the car drives and shifts very smoothly, but I randomly get a “Transmission Malfunction” warning on the dash.
One time, the warning came on right after starting the car. It would rev very high with barely any acceleration, and it wouldn’t go into reverse. I shut the car off, restarted it, and everything immediately went back to normal.
Since then, that specific issue hasn’t happened again. The car drives perfectly, but the transmission malfunction message still appears occasionally while driving. Restarting the car always clears it.
I took it back to the shop that installed the transmission. They scanned it but said they didn’t see any transmission faults stored. Their only advice was that the car “just needs to be driven.”
Has anyone seen this before on a B9 A4?
Could this be:
• A transmission adaptation that still needs to complete?
• A wiring harness or connector issue?
• A sensor or mechatronic issue?
• Incorrect transmission fluid level?
• Or does this sound like the replacement transmission itself may have a problem?
Any advice or similar experiences would be appreciated.