95 525 with Trans Program message

[scottm525]

To start with, I have read several postings about this issue others have had. Kinda want some additional advice, second opinions about what my mechanic is telling me. when the problem first occurred, I experienced the loud pop and down shift that threw me into the steering wheel at about 50 mph. crept home with it in safe mode. then took it to my mechanic. His first diagnosis was the Eprom failed. He replaced and said it should be fine. I drove it home, but I could tell it was not shifting beyond 3rd gear. then my son was driving about 70 mph on the highway and got the code again. I took back to my meahanic (he only works on BMW) and he checked the codes and found it had thrown an error code about 50 times. Told me he thought it was either the speed sensor or the trans is slipping. Either way, he said it was going to cost me 3000 for rebuild because you have to open up the trans to replace the speed sensors.

so, not wanting to spend 3000 right now before Xmas, i am trying to figure out if there is something else to be done or is he full of it when he says the speed sensors cannot be replaced w/o the rebuild.

also, history on the trans servicing. I bought the car with 98K on it. Had the trans serviced by a reputable shop that service all German cars at about 100K with Dexron II ATF. Car seemed fine until last month just before Thanksgiving. my 525 has 125K miles now and its been almost 2 years since i serviced the Trans.

I am still driving it, but the trans program code will pop up on the highway anytime I get over 60 mph. It seems to lock into 3rd gear as well until I shut it off and let it reset itself.

Does anyone think it really needs a rebuild?

[RobPatt]

have your mechanic:
- clear all the codes
- check you have the proper fluid levels
- check your alternator battery and REST of the electrical system are in good working order... if not, get that up to snuff....

You or your mechanic:
- pull the wood plate around the shifter console.... (get a bentley's for guidance or look here on the forum) and make sure the contacts/connections down there where the shift lever makes contact are clean and clean again... THEN make sure the contacts sync w/the gear selection indication in the dash (when the lever is in D position, make sure ED shows on the dash).

AFTER ALL THAT:
- drive like normal and keep a pen/paper around.
- when you get the BONG and lock in 3d gear limp mode (IF you do) then take a note and go DIRECTLY to the mechanic.
- go direct 'casue you want him to get the code that caused the limp mode... not other codes

THEN: go w/what the code is.

NOTE there's a TSB out for a revised eeprom for our trans computers.

In my case, I needed the updated EEPROM and a higher pressure ??? (think it was a fliud pressure regulator?) Anyway got mine squared away nearly 4 years ago without futher issues.... I DOUBT you need a full rebuild.

these (GM, built in france) trannies were also used in Honda/Isuze Rodeos, some types of Cadillacs, etc...

Hang in there, you'll be fine.

[whiskychaser]

There are lots of posts about this, even a guide to DIY rebuild if you have the GM box which I think is the 4hp22. You didnt mention what code was being thrown up but you can find a list of trouble codes here:
http://www.e38.org/e32/bmw%20code%20defaut.pdf
If you conclude its the speed sensors, you can check them at the cpu inside the car with a multimeter on the ohms range. I'm sure there is a write up on changing them on e34.net if you have to. I can tell you on my box, they sit on top of the valve body and you dont need to take the box out to replace them. HTH

[shogun]

see on my website ABS faults (almost at the end, scroll down).
Then remove the plug at the gear and see if there is oil inside, that could lead to wrong signals. The tranny fluid comes thru the surrounding plastic of the pins.

[scottm525]

Thanks for all the input and guidance. I did check back with my mechanic and the fault code it threw was a 100, which i believe is either the speed sensor or slip is too high.