I checked it and the MAF is fine connector was ok and I changed it not too long ago. I drove it with one TCM in and it shifted ok 2nd gear it revved high and then it'll shift and every other gear fine but the reverse jolts still and the engine still has movement after replacing the mounts. Then when that TCM went into limp mode, I came to a complete stop and pressed the gas and it struggled to move and there was a whining. I turned the car off and plugged the other one in and drove it. The other one shifted in first gear fine but all other gears were terrible then it went into limp mode and I came to a complete stop and then pressed the gas and it went fine but once it went into second gear it went into high rpms and wouldn't shift. So I have no clue what to check it probably is the TCM or some wiring but I don't know what to check anymore I feel like I've checked everything.I did not go back and read everything, but the P1857 is often a MAF sensor and that will certainly screw up the trans behavior .
I will try that tomorrow so I just stick it against the metal pieces and get the reading? What if the reading is bad that means the wiring is bad?have you checked the pin-outs at the plug that goes into the TCM for specified resistance i.e. MV-1 solenoid should have a value of 30-34 ohms, when checking with multimeter (ohm setting) between pin numbers #30 & #52. The numbers are difficult to see, but are marked at the ends of the connector (illumination a must). As a sidebar to this, pin numbers #52 & #53 should read 0 (zero) ohms between themselves and 0 ohms individually to the car body (ground) they are the internal valve solenoids ground and are redundant in nature, if one fails the other is a "backup". The reason I check there at the TCM connector is because it can check all the wiring from the TCM to the internals of the transmission shifting module. I do not have the wiring diagram from the ECU to the TCM yet, however ,if you can find it (wiring pin out diagram) you could check/verify the communication continuity between those two components also.
Passats are a headache ? but I just love the way it drives and the information I've got from you guys and working on this car will go a long way.to help with cross referencing the solenoids as they are numbered different in each of the previous posted diagrams they are as follows with the last number 1-7 solenoids being in reference to the wiring diagram you provided;
N-88=MV1=1 N-89=MV2=2 N-90=MV3=3 N91=EDS1=4 N-92=EDS2=5 N-93=EDS3=6 N94=EDS4=7
as an example, according to the solenoid logic chart solenoid N93 looks like it could be a possible "suspect" since it deals with not only reverse, but shifting thru 2nd gear.......to check it, you would measure ohms between the pinouts numbers #29 and either #52 or #53 (they are redundant grounds for the solenoids) on the TCM connector. Thus the ohm reading on the chart (post #90 on thread) should be 6.2-7.8 ohms for that solenoid. Hope this helps, I need to go take an aspirin, whew!
btw MV valves are used to control flow direction, EDS valves are used to direct pressure with EDS1=N91=4, being modulated pressure
You're welcome glad I could help and thank you for your help Ive got some probes small enough to fit in the tcm so I'll try that.hang in there ,key is being methodical and patient which at times can be a PAIN IN THE ASS......anyway hopefully I helped you now and in the future ,that wiring diagram was spot on, and really helped me turn the corner hopefully to solving my problems