[PattyE90]

Hello,

Ive had my E90 328i (N52) 108k miles, for almost 5 years now and never really had many problems. Doing all the preventative maintenance I could. I recently changed my tranny fluid, gasket, and filter. Everything was smooth after the change, no outstanding problems. It felt as though it had too much fluid, foaming, not pulling very hard, or running through the gears for a bit too long, as if the solenoids were receiving too much pressure. Id heard lots of good things about a product called Trans Tune, made by the sea foam company, so I thought Id take some of the fluid out and put some of the trans tune in to clean things up from the inside. Fixing both issues at once. So I did so and everything went well, the car ran much better and seemed like it was having less of a struggle with less fluid in the pan. But after about 1000 miles, things were acting up. Every up shift started to feel like someone was break-checking the car, only at low throttle, and the car would slip every now and then. I have a feeling I might have taken too much fluid out and now it Isnt able to adapt to the new amount of fluid, which is supposed to be reset every time using ISTA-D apparently. From what Ive read on the forums. I have the Carly adapter so I can run and check anything I need to. Im getting tranny codes (00578E) which is a “fluid deteriorate” code and it seems to be common with these GM trannys after the lifetime fluid cycle of 100k miles. So I will be using ISTA to reset that. The one Im worried about is the code (0056c1) which says “Torque Converter Ueberbrueckungskupplung - hard off” which is really concerning. I know a bit of german, so I tried to understand what it was saying but my knowledge is far from whatever that says. LOL. Its translated to “torque converter lock” or something of that sort. I cant find any information anywhere in regards to this code. This is my last resort to find help. Any thoughts and info you might have would be a huge help to me. Also im a 19 y/o who has done all of his own work. With COVID going on, there are no shops or bmw dealers open. So dont expect deep pockets from me. Ive done every peice of work on this car myself on a budget. Including installing an entire new engine to changing the oil. So any amount of experience and support is much appreciated. I dont know to much in detail about the GM tranny they used. Thank you.

[NinetyEight740]

First off, auto repair shops are open as they are essential business.

Second, do you know the proper procedure to fill the transmission fluid? From the way you’re saying you took a little out to add an additive to it I’m concerned you’re not filling it properly.

[gbalthrop]

Originally Posted by PattyE90

... E90 328i (N52) 108k miles... the car ran much better and seemed like it was having less of a struggle with less fluid in the pan... The one Im worried about is the code (0056c1) which says “Torque Converter Ueberbrueckungskupplung - hard off” which is really concerning. I know a bit of german, so I tried to understand what it was saying but my knowledge is far from whatever that says. LOL. Its translated to “torque converter lock” or something of that sort....

Here is the Google Translate English translation of "ueberbrueckungskupplung" = "Lockup Clutch" (for Torque Converter):
https://translate.google.com/#view=h...ckungskupplung

Here is the BMW Fault Code Lookup DEFINITION of 56C1:
N52 | P0741 | 56C1 | EGS: Converter lockup clutch: stuck in open position | GS1912 | Transmission control

I have NO experience with GM6 AT, but that code definition SOUNDS like a mechanically STUCK clutch solenoid, as opposed to an electrical circuit issue, but it COULD be either. I assume you are NOT getting Torque Converter Lockup in top gear? You do NOT indicate your model year, so here is the "Mechatronics" Functional Description for my 2007 328xi GM6 with GS1912 Transmission Module:
https://www.newtis.info/tisv2/a/en/e...ontrol/XiAGpET

Googling "GM6 Torque Converter Lockup Clutch" yields this page of links:
https://www.google.com/search?source...4dUDCAk&uact=5

I would try to find a local transmission shop that would tell me if that suggests the Clutch (~ $70 part?) appears to be the issue, and if so THIS appears to be the part, although I would check with someone MORE knowledgeable:
https://www.getbmwparts.com/oem-part...ch-24327532013

Since there is NO transmission dipstick, you have to fill until fluid runs OUT with ENGINE RUNNING, per this TIS Procedure:
https://www.newtis.info/tisv2/a/en/e...l-sump/PBKVWwt

If you have NOT already done that procedure CORRECTLY & SAFELY, check back BEFORE getting under the car, which MUST be elevated & LEVEL.

Please let us know what you find,
George

[gjm120]

The TIS referenced above seems incomplete as no mention is made of getting the transmission fluid to the correct temperature (30 - 50 deg C ).

Here are a couple of good threads:

https://www.e90post.com/forums/showthread.php?t=573490

https://www.1addicts.com/forums/showthread.php?t=995991

I changed the fluid and filter in my AT (same GM as yours) and did not reset adaptations and all is well. Mine was done at 50k miles so may not be entirely relevant to your situation.

If you did not follow the procedure for refilling I'd first do a drain and refill and get the level perfect. I would probably do it anyway since there is a chance the Trans Tune might have loosened up some crud and a drain might just get it out of the system.

[213e90n51]

You using manual mode alot in your e90? Does the car still keep the revs high when its cold for the warm up sequence? Do u drive it hard?

[PattyE90]

Thanks for your input George. So as you said, i didnt state my procedure, but i did do the exact fill/spill level procedure with the car at running temp and going through the gears. Just like your supposed to. But im thinking there isnt enough fluid from the second time i got under the car. The 56C1 code looks to be exactly what your talking about from the research ive done. I think its a good idea to talk to a shop like your saying. Thanks again!

[PattyE90]

Im new to the site, how do i quote someone for a response?

[PattyE90]

Originally Posted by 213e90n51

You using manual mode alot in your e90? Does the car still keep the revs high when its cold for the warm up sequence? Do u drive it hard?

Yea i have used it quite a bit, i do drive the car to its limits at points. But i also do what it takes maintenance wise to do so. It does do its normal warm up and i can read the temps through the carly app. Its a very healthy car, which is why this was such a concern for me. Great questions.

[PattyE90]

Originally Posted by gbalthrop

Here is the Google Translate English translation of "ueberbrueckungskupplung" = "Lockup Clutch" (for Torque Converter):
https://translate.google.com/#view=h...ckungskupplung

Here is the BMW Fault Code Lookup DEFINITION of 56C1:
N52 | P0741 | 56C1 | EGS: Converter lockup clutch: stuck in open position | GS1912 | Transmission control

I have NO experience with GM6 AT, but that code definition SOUNDS like a mechanically STUCK clutch solenoid, as opposed to an electrical circuit issue, but it COULD be either. I assume you are NOT getting Torque Converter Lockup in top gear? You do NOT indicate your model year, so here is the "Mechatronics" Functional Description for my 2007 328xi GM6 with GS1912 Transmission Module:
https://www.newtis.info/tisv2/a/en/e...ontrol/XiAGpET

Googling "GM6 Torque Converter Lockup Clutch" yields this page of links:
https://www.google.com/search?source...4dUDCAk&uact=5

I would try to find a local transmission shop that would tell me if that suggests the Clutch (~ $70 part?) appears to be the issue, and if so THIS appears to be the part, although I would check with someone MORE knowledgeable:
https://www.getbmwparts.com/oem-part...ch-24327532013

Since there is NO transmission dipstick, you have to fill until fluid runs OUT with ENGINE RUNNING, per this TIS Procedure:
https://www.newtis.info/tisv2/a/en/e...l-sump/PBKVWwt

If you have NOT already done that procedure CORRECTLY & SAFELY, check back BEFORE getting under the car, which MUST be elevated & LEVEL.

Please let us know what you find,
George

Just figured this out. My response is above.

[DaveR0462]

Originally Posted by gbalthrop

Here is the Google Translate English translation of "ueberbrueckungskupplung" = "Lockup Clutch" (for Torque Converter):
https://translate.google.com/#view=h...ckungskupplung

Here is the BMW Fault Code Lookup DEFINITION of 56C1:
N52 | P0741 | 56C1 | EGS: Converter lockup clutch: stuck in open position | GS1912 | Transmission control

I have NO experience with GM6 AT, but that code definition SOUNDS like a mechanically STUCK clutch solenoid, as opposed to an electrical circuit issue, but it COULD be either. I assume you are NOT getting Torque Converter Lockup in top gear? You do NOT indicate your model year, so here is the "Mechatronics" Functional Description for my 2007 328xi GM6 with GS1912 Transmission Module:
https://www.newtis.info/tisv2/a/en/e...ontrol/XiAGpET

Googling "GM6 Torque Converter Lockup Clutch" yields this page of links:
https://www.google.com/search?source...4dUDCAk&uact=5

I would try to find a local transmission shop that would tell me if that suggests the Clutch (~ $70 part?) appears to be the issue, and if so THIS appears to be the part, although I would check with someone MORE knowledgeable:
https://www.getbmwparts.com/oem-part...ch-24327532013

Since there is NO transmission dipstick, you have to fill until fluid runs OUT with ENGINE RUNNING, per this TIS Procedure:
https://www.newtis.info/tisv2/a/en/e...l-sump/PBKVWwt

If you have NOT already done that procedure CORRECTLY & SAFELY, check back BEFORE getting under the car, which MUST be elevated & LEVEL.

Please let us know what you find,
George

I'm new here to this forum, but After reading this I think I figured out my problem on my drain and fill job. My car would run fine after the D&F but when it set and I restarted, it went into limp mode and my tranny fault gear
light would show. After reading the above referenced TIS Proceedure, I think I have too much fluid. I watched a video and filled the transmission from the plastic plug hole above the shift linkage on the side of the transmission and not the threaded plug on the back, which is higher! I'm a long time DIY'er so I should have know better, but hey it happens! Gonna drain it to the referenced fill plug level and hope that was the issue! Anyone else have any issues with too much fluid?

[gjm120]

Originally Posted by DaveR0462

I'm new here to this forum, but After reading this I think I figured out my problem on my drain and fill job. My car would run fine after the D&F but when it set and I restarted, it went into limp mode and my tranny fault gear
light would show. After reading the above referenced TIS Proceedure, I think I have too much fluid. I watched a video and filled the transmission from the plastic plug hole above the shift linkage on the side of the transmission and not the threaded plug on the back, which is higher! I'm a long time DIY'er so I should have know better, but hey it happens! Gonna drain it to the referenced fill plug level and hope that was the issue! Anyone else have any issues with too much fluid?

and make sure you fill it at the correct fluid temperature (30C to 50C I think - it's labeled on the transmission) after running thru the gears as specified. I'm sure Carly has the ability to show ATF temp.

[nsjames]

too much fluid is a problem.

and an IR temp gun on the pan is the easiest way to know when it's the right temp, and be in a position to put the fill plug back in.

IIRC it's 50C.

[DaveR0462]

Originally Posted by nsjames

too much fluid is a problem.

and an IR temp gun on the pan is the easiest way to know when it's the right temp, and be in a position to put the fill plug back in.

IIRC it's 50C.

By having it overfilled, should I drain it while cold and turned off, then refill, or can I run it to operating temperature, then remove the fill plug while running until it stops coming out?

[nsjames]

run it to temp, pull plug, put plug back in when the fluid starts just being a dribble.