2007 328xi auto trans prob. No reverse, then drive for 20 yards then no movement

[jmkcc]

Hi, new to the site and first post related to my son's 07 328xi with 107k. Only had car a few months and ran fine accept for occasionally on highway the cruise would shut off and 4 x 4 warning and abs light would come on. That would go away when you shut the car down and restarted - not sure if that could be related to the total failure today.

took a short drive to dog park today. Went to leave and the car hardly moved in reverse but we were able to pull out in drive. Drove about 30 yards and lost tranny power. Engine runs fine, idles and revs, but no movement. Had to tow it to my parents who we are visiting. Hoping I don't need to tow it 130 miles home!

We jacked up the car and opened the transmission fill plug and nothing came out so I was hoping fluid was low. There was a bit of fluid around the bell housing but no major leak. The skid plat or whatever covers the tranny was dirty and grimey but not saturated. I opened the drain plug and hardly any fluid came out (1/2 quart?). That got my hopes up that it was just low fluid. Replaced the drain plug and pumped almost a quart of fluid into the fill hole, then it started leaking out which did not bode well for the low fluid theory. Still no tranny action, so we tried warming up the tranny by running the car for a few minutes cycling through reverse, neutral and drive and then drained again. This time a quart or so drained but not the 5 or so I expected. Again filled 3/4 quart and it started dripping out the fill hole. Started the car and actually more fluid leaked out - I thought we would be able to add more fluid while running, but not able to.

I have several questions.

1. Would low fluid cause no reverse but allow drive for a short time and then nothing?
2. Is it abnormal that I can only drain around a quart and fill around a quart? Is there any problem that would block the fluid from draining or not allow fluid to properly fill?
3. Probably going to replace the filter. Would clogged filter cause the issue or impact draining the fluid?
4. What is the correct filter? The Vin shows this should be a GA6L-45R tranny, but when I search some parts sites show a different transmission for the 07 328xi.
5. Does this tranny have the mechatronic sleeve? The only wiring I noticed was a rectangular plug in the bottom rear of the tranny. I did not disconnect as there was no fluid - but will check that next. is there any other wire connectors/sensors?
6. I saw a post mentioning the gear selector valve - if that fails would we have been able to drive the car and then lose tranny power? Or would that make it impossible to move the car in drive and then have the tranny fail while driving slowly?
7. I could not get a pan gasket so did not want to drop the pan, when i get a filter kit anything else to look for?
8. I will probably load one of the phone APP BMW OBD readers. We just got a cable that also has a phone adapter but was planning on using a laptop program. Since we're not home I will need to make due with a phone app. If i get one working Ill post the codes.

[relative4]

The fill procedure is very specific, read it carefully.
Since you're filling anyway and obviously need to replace the pan gasket and/or Mechatronics sleeve, replace the pan and all seals between the valve body and transmission.
Use the proper fluid!
Do NOT drive the car till this is fixed properly.

[jmkcc]

i pulled the following codes usin deep obd for bmw.
EGS:
Gear R incorrect ratio, Error currently available, OBD debounced
185768 km

EGS:
Clutch and gears 1, 2, 3 and 4 Indicated a Neutral test failed, Error currently available, OBD debounced
185768 km

no risk driving car as it does not move.

[Codes2]

As mentioned, ensure the correct process when adding trans fluid.

In my case, my symptoms were similar, though I would get a pop up on my GPS screen stating 'low torque mode'.
I'd turn it off, turn it on and be OK for another two minutes.
Then it stopped moving in any direction. The internal pump died.

I installed a used tranny rather than rebuild. All has been well since.
In hindsight, I would have gone with an upgraded model as I'm running higher output, but the stock is still decent. (mine died before I did any modding)

[jmkcc]

Thought I'd give an update which might help others in the future. First off, one of the tutorials I found on tranny fluid flush showed pics of a front differential fluid change but text for the tranny flush. Don't laugh, the car broke down at my parents and I was working on it with small jackstands, limited tools and hardly any light. For round two I brought better jack stands and tools. Then I realized I had tried to flush the differential and would be spending some additional time to reflush that with proper gear lube.

Once I had room and found the tranny, it was relatively quick to drop the pan and the valve body and remove the broken shift pin. Installed new shift pin and valve body seals along with a new machatronic sleeve and put hte pan back on. Then did the absolutely insane BMW tranny fluid fill procedure. I mean really???? They could not use a regular fill hole with hot and cold fluid level checks? Anyways car drove again. Deleted all codes and took the 2.5 hour drive home. SAS and AWD limphome error message came back on in 1/2 hour and I am still battling that. But the car drove fine and a "flare" we had between gears under hard throttle was gone so the valve body seals were warranted.

Fast forward two weeks and while reversing out of driveway we were treated to an error code collage and lost transmission drive. Too many codes to mention and scan tool could not connect to transmission controls at all. Got ready to drop the pan again but when I pulled the mechatronic plug - noticed it was soaked in fluid. There was no external fluid leak but obviously fluid was pouring into the socket connection on the inside. Cleaned everything up, blew out all fluid and purchased another new mechantronic sleeve. The original did not show signs of failure and seemed to be installed correctly - but figured what the heck. Put it back together and it's been running for a month now - so the new sleeve seems to have done the trick.

Cannot get rid of the transfer cas limphome code - it pops on immediately after clearing it. At first it was the only code but then the SAS chimed in. Replaced the entire SASS/SZL with a used one and reset the longitudinal sensor but still have errors. The DSC sensor shows up as "coded" and the SAS shows zero degrees while straight and tracks as you turn the wheel. I guess it's time to start playing with INPA to see if I can trace the transfer case issues.