Reply With QuoteBUMP please
Would i need a new tranny computer?
I found a 1995 transmission that is the same one as my 1992 e34 tranny.. The only difference I am told, is the gearing is a tad different... Will I need to get a new tranny computer when I put this in? If so--Where do i get one and how much should i be looking into?
Thanks a lot for your help guys...
BUMP please
Grand Master
short answer is you shouldn't....trans computer calibration should be fine. Best of course to change both together provided the TPU connector buss is the same. Likely you have a ZF 4HP 22 EH trans. Shift points should still be relative to engine RPM/load and vehicle speed independent of vehicle gearing. As a corrollary, many have changed to a shorter diff gearing with 4HP trans without incident. The more important question is if the transmissions are truly compatible....serial port connector pin count is the same etc...should be fine between '92 and '95. I presume the transmissions are interchangeable if you did your homework.
Good Luck,
George
3 Grand Master
in light of what bill r said, you may or may not.....as i've seen you here for several days with no one responding, decided to go look around a little. bill said that 95??? had the GM 4l30e with the different gear ratios. i put in a junkyard search for a 95 525i tranny computer, and it said that the 94 interchanges with it, so i guess a 94 MAY be usable. secondly, looking in the ETK, apparently a different trans computer harness was used in all 25 cars from 9/91 production on, so you will likely have to provide last 7 digits of your vin, or tell us the production date of your car (because i have a 92 25 as well, but mine was made in 7/91, so it would use a different one). also, does your car have ASC or EML? that harness is different too. IMHO, since nobody else can help you, i'd say LIKELY that you will have to get another computer to match...is there something preventing you from using the computer on the donor car, or is it already sold or such? take what i say with a grain of salt, advice provided with no guarantee of working on your car. i'd think winfred would be best able to answer this to certainty.
I was told that the 525i's had a A4S 310R tranmission while it was the 535i that had the ZF 4HP 22/eh... I've also been told that this should drop right into my car and that my only problem would be whether or not I woud need a transmission computer for it...
Firstly, thank you for helping me out. How do I find out whether or not my can has ASC or EML? To be completely honest with you I do not know what these acronyms are/mean. As for the tranny computer on the donor car--it had an engine fire and it was toast... The owner said that even the dashboard and guages were melting. My last 7 numbers are BJ79947.
Thank you both for the help. This board is great.
Super Moderator
Here is my original post
Here
Some other factors that I know nothing about are the fact that the later 525 has vanos and knock sensors so the computer may also be different regarding this... As you may or may not know the engine computer retards the spark to the engine during shift points during normal driving to make the shift seem more seamless.. I don't know if the vanos motor is different or not..perhaps it changes the cam timing as well during shifts. I would check the connector to the trans computer on yours and determine how many pins it has and then check the connector on the 95 and make sure it takes the same connector.
Originally Posted by dubumb
Sorry for an upmost newby question, but can can someone tell me how to get to the tranny computer? If worse comes to worse and I need to new tranny computer--how much $$ are we looking at here? Thanks
4 Grand Master
Alot of $$$ and you may not have the proper wiring harness either. Just listen to Bill R... and take a look at the tranny yourself... if it looks alike, same connections, it will work just fine.
4 Grand Master
If you are saying you have a 535 and wants to put in a 525 tranny... don't bother.
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