1994 525i tranny problem (a curious one)

[pcross]

Here's a curious tranny problem. 1994 525i, A4S27/310R tranny. When I start the car, dash light shows E P. Goes into reverse and backs up just fine. When I shift to D, nothing. If I rev the engine a few times, the tranny engages and the Trans Program light comes on. I then shift to L and it goes into 1st gear. I move off and shift to 2, it shifts. Then to 3, it shifts to 3. then to D and were cruising along in 4th gear, 60 mph at 2300 rpm. Runs like a dream. As I slow down to a stop, I down shift to L and start all over again. OR, when I start the car, I immediately move the MODE switch to M. Then, it shifts and runs in M D mode just great... 1st, 2nd and 3rd. Settles into 3rd at speed, 60 mph at 3300 rpm. I think I have a 2nd/3rd or a 1st/2nd/3rd/4th solenoid valve problem in the tranny. I switched the EGS unit to a new one and the switch made no difference. Tranny has new filter and was properly filled. BTW, all shifts are smooth as silk. No clunks, no jerks. The tranny itself performs flawlessly after I go through all the steps I listed above. Any ideas? Thanks.

[RobPatt]

there's a lot of oddities which cause this.... so.

- search and keep a list of trans program threads, note that many are for the 540's auto trans...

- check charging system
- recheck the EGS and all cables seated properly ?
- hook up a diag computer and see (then write, clear and check next time it happens) any stored tranny codes in the computer...

Good luck, at least you can still get around....


Here's a curious tranny problem. 1994 525i, A4S27/310R tranny. When I start the car, dash light shows E P. Goes into reverse and backs up just fine. When I shift to D, nothing. If I rev the engine a few times, the tranny engages and the Trans Program light comes on. I then shift to L and it goes into 1st gear. I move off and shift to 2, it shifts. Then to 3, it shifts to 3. then to D and were cruising along in 4th gear, 60 mph at 2300 rpm. Runs like a dream. As I slow down to a stop, I down shift to L and start all over again. OR, when I start the car, I immediately move the MODE switch to M. Then, it shifts and runs in M D mode just great... 1st, 2nd and 3rd. Settles into 3rd at speed, 60 mph at 3300 rpm. I think I have a 2nd/3rd or a 1st/2nd/3rd/4th solenoid valve problem in the tranny. I switched the EGS unit to a new one and the switch made no difference. Tranny has new filter and was properly filled. BTW, all shifts are smooth as silk. No clunks, no jerks. The tranny itself performs flawlessly after I go through all the steps I listed above. Any ideas? Thanks.

[pcross]

RobPatt...Charging system checks OK. I reset the cables to the ECU and the EGS after cleaning them and applying dielectric grease. I run Carsoft 6.5 and diagnosis reads "EGS module - OK" No stored tranny codes. That's why it's so curious. Thanks.

[pingu]

Maybe the transmission switch (that tells the transmission ECU in which position the auto lever has been placed) has got bad internal contacts and needs cleaning. I think there's been a post on this - maybe by Shogun.

[whiskychaser]

Sounds like the box may be good but the mode switch is playing up in drive. Its just a switching matrix that gives different voltages to the ECU like this:
Switch 1 2 3 4

P 1 1 0 1
R 1 0 0 0
N 1 1 1 0
D 0 0 0 1
4 0 0 1 1
3 1 0 1 1
2 0 0 1 0

1=+V, 0=0v

Worth getting the mulitmeter out to check?

[pcross]

Pingu and Whiskeychaser: Thanks. My next step will be to pull the shift lever switch and thoroughly clean the contacts. Then, I'm going to run Whiskeychaser's voltage check (that I hadn't thought about). Thanks to both of you. I'll get back on the results.

[whiskychaser]

when I start the car, I immediately move the MODE switch to M. Then, it shifts and runs in M D mode just great... .
Hang on a mo. Is MD like sport mode on yours -it changes gear automatically but just revs higher between gears? And doesnt M limit you to 3rd gear on yours? That would account for the higher revs. If its working fine in MD but not ED then it may just be the 3 button mode switch. Stand to be corrected, but I think you can check it using the sunroof switch. Selector switch is worth checking but dont want you wasting your time:)

[Chad535]

Just a curious question guys.......could it happen that the contacts get dirty or corroded so that the cluster would show the right shift position while the ECU wouldn't resulting in strange behaviors ?

[Chad535]

Sorry for the second post but i forgot to say that i have the same problem with reverse....i have to wait a minimum of three minutes before i get the tranny locked in reverse and meanwhile if i try to rev high i will get a trans program error.

[pingu]

From what I've heard, if you need to wait 3 minutes to get into reverse then the valve body of your auto box may be kaput. There's a "check valve" which is a plastic ball; when it wears down it get stuck within a bore of the valve body. It's not a problem I've had but you'll probably find loads of stuff if you search this forum using words selected from: plastic ball check valve body reverse Kirk

[pingu]

Good idea - I also seem to remember seeing somewhere that the sunroof switch is the same.

[RobPatt]

..the 'clean connections, sensors, contacts, etc' for shift indication under the gear selection is in a post here somewhere....

also somewhere is a nice post on a common gasket failure on the GM tranny which allows fluid past and delays engagement into reverse.... "simple" fix for someone to do if they know tranny work, I read this tranny isn't so complicated....

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here's from the E32 forum at Roadfly.... (Know you have a diff tranny..)


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TRANS PROGRAM Error. Symptoms & Remedies: (480 views) (835 thread views)
Message: Trans Program Error:

I found literally thousands of posts on this topic on the board. Following is my best effort to present the information in some kind of systematic format.

Symptoms: (These were my symptoms, yours may be different)

• Occurs when cold, won’t shift up in “A” automatic mode.
• Chimes and goes into “limp” mode i.e.; transmission only operates in 3rd and reverse. Displays “Trans Program” on display on instrument panel.
• Error usually occurs on over-run when slowing down.

If you re-set the system (refer to Shogun’s reset procedure on the board) and shift carefully in “M” manual mode, trans will usually work normally when it is warmed up and you shift it back into “A” automatic.
However, mine would sometimes miss the 1-2 shift and select neutral. Be very, very careful, use a light foot on the accelerator and lift off quick if this happens so-as not to over-rev the engine!!

Remedies: (This is what I did)

1. Check the transmission fluid level.
2. Clean the A/M Switch on console using Radio Shack or similar contact cleaner.
(There is a procedure on Gale’s page for removing the console)
Symptoms of a bad or dirty A/M switch are inconsistent display on instrument panel.
3. Clean the PRND123 Switch contacts using Radio Shack or similar contact cleaner.
(The 735 is easy to get to, I believe the 740 is difficult)
Symptoms of a bad or dirty PRND123 switch are inconsistent display on instrument panel when you move or “jiggle” the shift lever from side to side.
4. Clean the connector on transmission using Radio Shack or similar contact cleaner.
(Don’t stick anything into the female part of the connector to clean it.)
5. Check and clean the MAF connections
6. Check and clean the TPS connections
7. Check and clean the harness connection to the transmission control unit which is located behind the speaker on the right side foot well (passenger’s side on a US spec car)
8. Re-set the system.

If the problem persists:

1. Consider removing the TPS, taking it apart and cleaning inside. I didn’t do this as it looked like you would lose your TPS adjustment. Someone else on the board said this cured their problem.
2. A transmission expert told me the soldered joints holding the pins for the harness connection to the transmission control unit are subject to cracking and failure. I removed the unit and very carefully took it apart. It looked new inside and re-soldering those joints was beyond my skill level and equipment. (My limit was an LKM module.) I put it back together and re-installed it.

This is about all you can do without spending money. At this point I took the car to an independent shop and had the transmission code read. Also, the dealer said they would read the codes for about $85

Although I don’t believe in “throwing parts” at a problem, if I had to do this again I would have replaced the speed sensor in the valve body. This is a very common cause of the TRANS PROGRAM error. It requires draining the fluid and removing the pan. I did not do this part of the job so I cannot give the exact steps but I understand it’s not difficult. Also, the part is not expensive (about $40 to $50 US)

Problem Solved:

This was the cause of my problem and I am now back on the road with the tranny functioning properly.

Other possible causes include:

• The MAF. My guess is if the car seems to be running and idling normally, it probably isn’t the cause.
• The transmission control unit.
• Also, I believe excessive slipping such as a worn “A” clutch pack will also cause the error.

I hope this will be of assistance as sooner or later you will probably have this problem with your E32.

Good Luck!

John aka Kenneth, ’91 735 IL 186K

[pcross]

Hang on a mo. Is MD like sport mode on yours -it changes gear automatically but just revs higher between gears? And doesnt M limit you to 3rd gear on yours? That would account for the higher revs. If its working fine in MD but not ED then it may just be the 3 button mode switch. Stand to be corrected, but I think you can check it using the sunroof switch. Selector switch is worth checking but dont want you wasting your time:)
Yes. MD is sport mode...only shifts up to 3rd, but does so very smoothly. I have substituted the sunroof switch and even bought another E/M switch. No change. I'm still going with the removal and thorough cleaning of the selector switch for now. Also, no problem with reverse in either mode, but I'll keep the worn check ball in mind, too. Thanks all...Keep your ideas coming, they are appreciated.

[pcross]

Symptoms of a bad or dirty PRND123 switch are inconsistent display on instrument panel when you move or “jiggle” the shift lever from side to side.

This does happen to me. Also thanks for the link. I copied it and will seriously go over it.

[ryan roopnarine]

try unplugging the a/m switch completely and driving the car.