12xi -> 130i/32xi -> 330i GM Transmission Guide

[Cbeitler12]

Hello everyone just wanted to create a consolidated guide on everything we've been able to figure out as a community as far as the GM transmission x30i tunes and how you can get it done for yourself. I'm happy and also sad to say this was quite easy to figure out it just simply was an adventure I don't think any of us even thought to go on.

To keep it short and sweet you can actually look at the DATEN data files for the GM1912 ECU. Any of the .0da files can we opened in any text editor, I just used notepad. The attached screenshots I've highlighted exactly where you'll want to be looking. For those who don't know N52B30O1 is the x30i engine with the 3 Stage IM. I've only posted the RWD GM Transmissions in the screenshots, I've not found the AWD but it won't specify AWD like it does RWD. If anyone comes across it or needs help finding it I'm happy to help search but either way I'd like to get that out there for those who need it just don't wanna go on a search until I have too.

As far as understanding the .0da and ZB# differences its simply the .0da # - 1 = ZB#. So for the 130i the .0da file # is 7614242. Subtracting 1 gives us 7614241 which is the ZB# you'll want to be looking for in WinKFP when coding. For using WinKFP to update your ECU, open the program and select "Comfort" or press F1. Then select "Custom File" or press F2. A popup will appear with 3 boxes for our selections to keep it simple just focus on the two on the left. Scroll down until you find GM1912 in ECU Family. Click it and in the middle box find your ZB# and double click it. Now the box should be gone and it should look similar to my screenshot. With that done please take the time to verify the Assembly Identification Number matches the ZB# you selected. If it doesn't match please repeat the selection process until it does. The Assembly Identification Number is another term for ZB#. The Hardware number should also be checked to ensure it matches your Transmission Hardware ID. RWD seem to all be the same of 7614313. I'm unsure of AWD's HW #.

Anyone out there trying to do more digging and find more out about the GM Ga6l45r should checkout the wiki page on the GM 6L50 transmission as it was widely used in Cadillac's and other V6 Chevy's. Funny enough quite a few Caddys used the 6L45. Also note that their are multiple variants of the 6L45 obviously RWD and AWD on RealOEM I've found at least 3 different variants supported for my E88 128i. RT4, RBH, and REH are what I could find but I haven't looked very hard into exactly what those differences are. GM's website gives some general data and information about the transmission technology which can give you a little insight and understanding on what and why your transmission is doing. I've come to learn the D is just not for me regardless of resetting everything. Something with how it works doesn't sit well with my driving style of only ever driving manuals even a manual 128i prior to this. It just bogs down the engine until it just can't take it anymore and finally shifts. To be fair this is only in D, DS is a different story.

A little info on what all I've done to my car. 3 Stage IM, Mishimoto Silicone intake boot, 350mL catch can, trans oil changed after initial purchase after 500 miles replaced mechatronic seals, filter and oil again. New spark plugs as well. Car just passed 95k and it's my daily. I've taken the entire interior apart twice since i've had it for various things.

That's everything I've got for now if anyone has anything to add please comment below! Also if anyone has questions or needs help as far disassembly and reassembly goes PM me.