1991 525i trans problem!!!

[jrod540i]

i own a 1991 525i with 4l30 auto trans. my trans shifts just fine for about 15 to 20 min of continous use, but then all of a sudden with no apparent failure it goes into trans program & stays on default mode which doesnt allow the trans to shift. it stays on 2nd -3rd gear. when this happens i have to park the car for about 2hrs , then i can start the car right up with no trans program appearing. once again it shift well for about 20min and once again i'm back to step one. thinking of replacing the trans cpu. any ideas guys???
note: trans was rebuilt about 3 mo. ago.

[russiankid]

did it do this before the trans rebuilt?

[jrod540i]

No, not that i could remember...

[russiankid]

well you should take it back to the people that did it, and complain that before the trans rebuilt it was fine, and now its screwed, could be some sensor

[imnprsd]

If the previous author knows something about transmissions then perhaps you can tell us what sensor you are referring to.

My 4L30E was poping out of gear (between 2nd & 3rd) for over 2 years, and it would only do this in Auto-D or Auto-S3. This means it was fine when manually shifting so I thought my problem was with the solenoids. However, there were no codes to help us diagnose the problem except a general falut code 100, when the "Transmission Programme" light came on. In my case however, I was able to reset the computer after turning off the key and waiting only 5 seconds.

What I concluded was that my tranny was temperature sensitve. That it was operating at 90% efficiency around town, and that my problem could be fixed by doing a valve body overhaul.

My 4L30E (1992, 525) also took 2 seconds before it would shift into reverse and overhauling the valve body did not help this condition.

If there is a temperature sensor in the wiring harness, but there is no way to test it, and in my case I did not replace the wiring harness, but I did have a noticable improvement after I O.H. the V.B. And now my car does not pop out of gear.

I would first service your tranny and drain you fluid 2 or 3 times to get as much dilution as possible.

I'm thinking my seals are not in good shap so at some point a complete O.H. will be necessar.

[bump0122]

any luck with the trans program message? I have a '95 525ia with a similar problem. I had the trans overhauled and about 8 mths later the trans program light repeatedly goes on and off. When the computer is hooked up the analysis shows no messages. I have had the shifter grommet and modules rebuilt, a new control module put in with no success. The transmission works fine but the sensor signal ringing on and off is driving me crazy. Any ideas?