'95 525iT Check engine light and trans prog message

[atomicDog]

Help!! As I was driving home from work on the highway, noticed that the check engine light began to flicker on then turn off a couple of times over the span of 5 minutes, then the dreaded "TRANS PROGRAM" message flashed up on the dash. The transmission locked into third gear and I limped it home. After a day or so, I started the car again and the check engine and TRANS PROGRAM lights come on almost immediately. Does anyone have any idea as to what may be causing this symptom and how I might fix it?

Lastly, does anyone know of any good repair shops in the Richmond, VA area for handling this sort of issue?

[cobb535]

Do the stomp test to retrieve codes. Someone here may be able to point you in the right direction with the codes you have retrieved.

[atomicDog]

Do the stomp test to retrieve codes. Someone here may be able to point you in the right direction with the codes you have retrieved.
Thanks for the advice, but can you please explain what the "stomp test" is and how I can retrieve the codes without a scanner?

[whiskychaser]

Check your battery/charging sytem are OK, clean the selector and mode switches, read fault codes. There are loads of threads on here for trans prog
fault.

[whiskychaser]

Thanks for the advice, but can you please explain what the "stomp test" is and how I can retrieve the codes without a scanner?

Try this link

http://www.bmwe34.net/e34main/trouble/engine_codes.htm

[atomicDog]

Thanks for the info. I will check the codes this evening and report back. Charging system should be OK, as I have a new battery and alternator, but I will check the voltages, too. With the car running, what are the normally expected voltage ranges for this vehicle?

[whiskychaser]

Thanks for the info. I will check the codes this evening and report back. Charging system should be OK, as I have a new battery and alternator, but I will check the voltages, too. With the car running, what are the normally expected voltage ranges for this vehicle?

With a meter across the battery you should get about 12.6V if the battery is fully charged (key off). With the engine running this should go up to about 13.8V. Turning on the headlights/heated screen etc shouldnt affect it.

[atomicDog]

Thanks again. I'll check it tonight to understand what my voltage range is. I thought I saw a voltage of 17.3 volts with the car running the other day, but I need to verify that. I replaced the alternator with a new one less than 2 months ago. Am I correct to assume that the voltage regulator is internal to the alternator?

[Dr. evil]

http://www.realoem.com/bmw/showparts.do?model=HJ63&mospid=47414&btnr=12_0480&hg=12&fg=22

[atomicDog]

http://www.realoem.com/bmw/showparts.do?model=HJ63&mospid=47414&btnr=12_0480&hg=12&fg=22
Thanks for the info, Dr. Looking forward to verifying my voltage range tonite.

[whiskychaser]

Sounds way too high to me. Would suggest either your regulator or meter at fault :-) We dont have stomp test on EU cars so I'm not sure if it will show an EGS fault. If not you will have to get the codes read. Sure someone will confirm

[atomicDog]

Sounds way too high to me. Would suggest either your regulator or meter at fault :-) We dont have stomp test on EU cars so I'm not sure if it will show an EGS fault. If not you will have to get the codes read. Sure someone will confirm
I had borrowed a friend's Snap-On MT2500 scanner and connected it via the diagnostic port. The scanner didn't do a good job of displaying the codes, but it displayed some other info and I thought it showed a voltage in the 17 volt range while the car was running. I will check it for sure tonight, with a voltmeter at the battery. I also thought 17 volts was too high and perhaps it should be in the 15 volt range. Again, I will check tonight for sure.

[atomicDog]

Well, looks like the alternator is overcharging big time. I put a voltmeter on the battery and it registered in the 16.5 - 17.3 range when the engine is lightly revved. This alternator is a remanufactured unit that I purchased and installed about two months ago as preventive maintenance, since the starter had gone out and I was in the process of replacing the oil canister seal, belts and tensioners. I called the local parts store I bought the reman'd alternator from today and they stated that they would swap it out for another one.

I suspect this may take care of my issue. I had only driven the car in this condition for about 6 miles. Does anyone think that any damage has been done to the computers or other electrical components??

[whiskychaser]

Doubt any damage will have been done. Would check the levels in your battery as overcharging could have 'boiled' it dry

[atomicDog]

Well, I swapped in another rebuilt alternator and drove it around for awhile and no more trans program or check engine lights. I guess the overcharging alternator was the issue. The only other issue I've run into is that the OBC displays an outside temperature of -535 degrees. For some reason, it won't display the correct outside temp and will stay stuck at the -535.

[whiskychaser]

Well, I swapped in another rebuilt alternator and drove it around for awhile and no more trans program or check engine lights. I guess the overcharging alternator was the issue. The only other issue I've run into is that the OBC displays an outside temperature of -535 degrees. For some reason, it won't display the correct outside temp and will stay stuck at the -535.

Good to hear you got it sorted. If the OBC displays other functions (like mpg) correctly it may be something as simple as an outside temp sensor. Thats normally located behind one of the panels under the front bumper - the one with the hole in it :)

[atomicDog]

Yes, all other functions of the OBC are working just fine. When I turn the ignition on to start the car, the OBC displays a temp of -535. I'm going to try disconnecting and re-connecting the sensor and see if that fixes it. Also, noticed others disconnection the battery for 10 minutes and re-connecting it to fix this issue. Just strange that this was working fine prior to the over-charging issues.

[whiskychaser]

Dont have my Bentleys handy but I would guess its just a simple resistance change depending on temp. Cant guess how/why it would be calibrated to read -535 though! Obvious answer is to substitute a good known one but thats easier said than done:)

[atomicDog]

I've already disconnected the wiring connector from the temp sensor and it was pretty dirty. Started cleaning it with solvent, but came in to catch the evening news. Hope to have it back together shortly and perhaps this may fix it.

[Scott C]

I've already disconnected the wiring connector from the temp sensor and it was pretty dirty. Started cleaning it with solvent, but came in to catch the evening news. Hope to have it back together shortly and perhaps this may fix it.

Can't explain it, but when my temp sensor was disconnected it took so long to get back to right temp, that I ordered a new one. The next day it worked its way back to normal.

Scott

[atomicDog]

Yes, that's what seems to be happening with mine. It started off at -535. About an hour later, it's down to -117. A few hours later, it was down to -57. I joked with a friend that it started at Pluto, then onto Venus and now it's in Chicago :D

I suspect that by tommorrow, it will be back to normal. FWIW, my battery was disconnected for a couple of weeks before I got around to swapping out the alternator.

[atomicDog]

The OBC temp is now back to normal. Just took about a day for it to get back to normal on its own.

[whiskychaser]

The OBC temp is now back to normal. Just took about a day for it to get back to normal on its own.
Good to hear its sorted. Wish all car problems sorted themselves out if you left them alone for a day :)