07 4.8 trans fail after fluid/filter service
 

I changed oil/filter along with sealing sleeve and the seals for the mechatronic. After reassembly and filling i drove the car maybe once. My wife drove it once after and the following day the dash lit up like a christmas tree faults were 2dca and cdb0 no messages from egs module. I found somewhere the plug could be the culprit but when trying to find more information i see none. Ive pulled the plug out and cleaned at least 3 times now plugged it back in and cleared the codes and it would run but in almost no time it comes back so I wonder if there is a poor connection. I tried finding repair pigtails or harnesses and outside of the entire engine harness i see none. Does anyone else have some insight into this they can help me with? Im about to pull the pan and the mecha again to make sure everything is OK or not.

I also wanted to add that when other people stated trans failsafe mode they were able to drive the car. When i put it into drive or reverse and press the gas it does nothing. Could i have an issue with the throttle body?!?!

Hey Marcus,
Did you do the trans service as preventative maintenance or were you having issues prior that prompted the service?

Im at 67k miles some of the shifting was somewhat jerky attributed to fluid at end of life. Besides this it drove great. I also did valley pan and water pipe just before i started having issues but i travel for work so the car sometimes gets driven maybe once or twice a week i did the trans service one weekend drove it once maybe twice then following weekend the water pipe. Then it was only driven maybe two or 3 times before the limp mode

Have you checked for bent pins on the trans side of the plug? And your codes are not BMW codes. You may want to scan with something that can get you BMW codes.

Im using foxwell nt510

if you google BMW 2DCA bent pin...guess what?


;)

good call, lets see if it was right.

07 4.8 trans fail after fluid/filter service
 

+1 for above, I know it’s a tight fit but grab a mirror and a BRIGHT flashlight and check the pins in the mech, also check the pins in the cable end - that would be my step one.

From there I would question whether the filter may have slipped out of the receiver or... potentially... maybe the bridge seal moved or possibly the pickup tubes were installed in backwards order causing them to hold for a little bit but once seated and up to temp they’ve lost seal. (I forget if they’re long to short or short to long but you get the idea [emoji106])

As crazy as it sounds I’ve also seen the cam position sensor throw a 2DCA and cause loss of power and the trifecta lights.

If you don’t see any bent pins, try a heat gun to make sure it is ABSOLUTELY DRY and then hit it with a little dielectric grease, plug it back in and try her again. I’m

Gonna find my small mirror and check it out if this rain stops tomorrow. If its bent should i replace the harness or remove it and attempt to straighten?

07 4.8 trans fail after fluid/filter service
 

If it’s already bent I’m a try and straighten it with a long thin pair of needle nose pliers guy myself.

That said, the harness is one thing but the mech is super sensitive to static so I would rig up some form of ground strap for your needle nose before you go in for the fix.

Pins are real tight but if you’re careful enough you may be able to pinch any offending pins between the pliers and straighten them out, I wouldn’t “bend” them per say, I would “pinch” them straight if your pliers fit - assuming you find any bent.

Good luck [emoji106]

I think I recall seeing BMW sell pins for repairs... not sure about this connection tho. If you do need it (id try to 'correct' it as above) then look up some of the parts diagrams

Doesn't add much information to this thread, but see: SI B 24 13 07 "Various Complaints Due to Poor Connection at Transmission Connector"

I forgot i took a video checking the plug because i couldnt find a mirror at the moment. To me it looks OK but I think im going to pull the unit and the sleeve and reinstall everything if it checks out ok.

Video:
https://we.tl/t-VcQ016axTO

07 4.8 trans fail after fluid/filter service
 

Hmm, wasn’t able to play the video. I’ll try again from my pc when I’m home this afternoon.

Question- did you change the sleeve in the trans body as well? Only asking as it’s possible if it is “loose” or not seated all the way that the harness won’t fully seat in the mech. It’s also possible, just asking, but are you sure you are getting a full turn on the harness when you’re re seating it?

I would hate to tear it down again before I triple checked everything...

Keep us posted.


Just re-read what LT posted above, if you’ve e had that plug in and out a few times (or more) now, he may be on to something. You may take a small pic and see if you can tighten up some of those clips in the harness socket and possibly improve the connection. - just thinking out load.

(Back in the day I used a very small jeweler screw driver to “pull in” the clips on the 20 pin connector under the hood of my 325, that’s kind of what I’m thinking towards here..)

Sorry about my code comment earlier. I was not paying attention. It is tough to tell because of the focus but your pins look to have some electrical grease on the tips of the pins. Almost like the female end is not sliding all the way down. Check the sleeve to make sure it is all the way seated in the housing. The locking mechanism can sometimes bend and appear to lock even if the sleeve is not all the way in.

After the sleeve is properly seated, push the locking mechanism to the locked position. Install the vehicle connector plug and check that the sleeve is properly seated. The locking ring gap should be between 2.5 to 3.0 mm.

https://ibb.co/WW9BHN5
https://ibb.co/zVKkYmS
Mecha is out and this is what both sides look like i see more pins on the mecha than on the harness side but it looks normal?

Looking at the harness it looks like you have one of the sleeves pushed back in the plug, bottom left?

looks like one of the female sockets has pushed up into the body, no??


at about 6 oclock in the second picture

Ok give me a few i just bolted mecha and pan back up. Ill pull that plug again and check again

https://ibb.co/JxbbRwJ
There is like a white plastic locking layer that looks like pins

I was messing with the sleeve when i was putting everything back together. I lubed the seals with dialetric grease and made sure it was inserted. I somehow was able to get the retaining clip to clip prematurely and I wonder if this happened to me earlier and only the tips of the connector was making contact. I just drove roughly 30 min with no issues. To scared to drive it to work or the airport so for now itll be sitting with occasional test drives. I need to order dme box fan anyways but i really appreciate everyones feedback. I hope this problem is gone for good.

We’ll keep our fingers crossed 🤞

Hope she’s fixed for you [emoji106]