2011 Volkswagen Routan SE Van (daily driver) gave a transmission code P0841: transmission fluid pressure sensor switch A.
We had a friend change the engine oil and the ATF. They also changed the transmission filter which requires removing the pan. They added 5/6 qts of engine oil to the crankcase, and x/5.5 qts to the ATF. I hope they replaced what was taken out but there are some bigger questions. We cleared the codes and continued driving. We then did a Seafoam Top Cleaner through a Vacuum hose of the intake, bypassing the throttle body. This produced a very smoky exhaust, which we expected. But the transmission started having trouble changing gears, accelerating over 40mph. Checked the codes again and now we have transmissions ABC
P0841: Transmission fluid pressure sensor switch circuit A
P0846: Transmission fluid pressure sensor switch circuit B
P0871: Transmission fluid pressure sensor switch circuit C
All this happened over the course of 2-3 weeks. When I searched for parts for a pressure sensor switch A, the results did not look like an electric sensor. My questions, if I can fix the A circuit will that save our transmission? How do I purchase the proper 2011 VW OEM circuit? Could the sensor be dirty, would a transmission cleaner like Seafoam Hydra Trans Tune + flush have the desired sensor cleaning capabilities?! enter image description here