[Koolsilver]

This is in regards to my 2009 335i 6AT. Today I swapped out my valve body to help fix some shifting issues. While I was at it I replaced the seals inside the transmission. Once I was done I went to start up the car to swap through the gears per the fluid filling procedure but my car won't start because it think's that it is neutral. The shifter is in the park position and won't budge since the car won't start. At first I thought maybe the shift selector on the valve body and TCM was misaligned with the selector on the transmission so I double checked it but it was installed properly. At this point I am at a loss I don't know what to check next.

Does anybody know a way to test the TCM as I fear there may be an issue with the TCM. How does the TCM interpret the gear selector position, there is a brown slider that moves with the selector but I don't understand how it can transmit any information.

[marmit2017]

Originally Posted by Koolsilver

This is in regards to my 2009 335i 6AT. Today I swapped out my valve body to help fix some shifting issues. While I was at it I replaced the seals inside the transmission. Once I was done I went to start up the car to swap through the gears per the fluid filling procedure but my car won't start because it think's that it is neutral. The shifter is in the park position and won't budge since the car won't start. At first I thought maybe the shift selector on the valve body and TCM was misaligned with the selector on the transmission so I double checked it but it was installed properly. At this point I am at a loss I don't know what to check next.

Does anybody know a way to test the TCM as I fear there may be an issue with the TCM. How does the TCM interpret the gear selector position, there is a brown slider that moves with the selector but I don't understand how it can transmit any information.

I ran into a similar problem when my car wouldn't move when put in drive or reverse. I had to replace my gear selector valve. While under there I also replaced the gaskets. However, getting the mechatronic unit plug back into its sleeve was THE BIGGEST PAIN!! Idk if you removed the plug, but they may be your issue. So my issue was that even though the clip for the mechatronic sleeve was pushed in, it still wasn't in the plug (if that makes sense). So the car wouldn't turn on or shift into any gears. I had to remove the plug from the back then slide the mechatronic unit into its sleeve in the correct orientation then I put the plug back into the sleeve from the back. However, you have to make sure the mechatronic unit is in the EXACT position or else it will NOT lock in because there are tabs on the sleeve that push into the mechatronic unit that allow it to them lock into place. Hope this helps