1989 Transmission problem. Please help

[MaitreG]

I have this 1989 635 CSi E24 BMW with an automatic transmission. She can only be driven when the selector switch is on 123. On Economy or Sport, she is stuck on first gear. Could this be the AT.EGS control unit that has gone bad? She is a pretty thing and I hate to let her go to waste.
She use to slip on and off and the next day when she is cold acts right; now it is permanent symptom.
Thanks in advance for any help.

[tsjazz2002]

I had a very similiary problem. During my research and couple of trips to the local garage I found a myriad of things that it "Could" be. In the end my problem was nothing more than some loose connections at the selector switch itself. While driving home one day I noticed my amplifier power wire creeping out from under the center console. I reached over to tuck the wires back in and the car switched from 3rd to 4th. I pulled my hand back and the car slipped back into 3rd. Hmmmmmmm? I pulled over to the side of the road, removed the ash tray and reached down inside just kind of moving things around. From that point on I have not have a problem at all. The transmission changes smoothly in both modes now.

[MaitreG]

Thanks, I will look into it.

[CW6er]

Check the canon plug on the side of the transmission as well and make sure it is clean and tight. You might also try cleaning and reseting the Transmission Control Unit plug

[MaitreG]

How would I reset the Control Unit? Is there a resetting tool?
Thanks for the help.

[pumpedTSI]

unplug it..........or disconnect the battery.........

[CW6er]

Sorry, should have been "re-seat the plug to the TCU", I.E. plug and unplug the connector and make sure it is tight. Maybe use some contact cleaner on it. There is nothing to "reset" in the TCU. My bad.

[Bluesman]

Also behind the glove box where the ECU is sits another 11 prong plug. Check and make sure they have a good seal or connection. That controls the system and when that connection is broken you endup in limp mode which is 3rd gear.

[CW6er]

Do you have an ETM? There is a diagnostic chart for the transmission in it:

http://wedophones.com/BMWManualsLead.htm

Here is just the chart if you can't download large files, it's the first on the list to the left:

http://www.europeantransmissions.com/Bulletin/BMWtechlib.htm

[Bluesman]

Also while investigating a problem I had with a 528e and the tranny slipped I was told it might just need a thorough cleaning and flushing out. The screens can get clogged up and not let the fluid get where its supposed to. That should be under $200.00 at a transmission shop. I am going to do that with mine as a safty measure and I just bought the filter and gasket off ebay for 20.00 just in case the shop wants to stick it to me for parts. I know its kinda like bringing eggs and a slab of bacon to a resturant and say can you fry these up for me but I am tired of"sorry we have to order that and its gonna cost you my trip to the bahammas.

[MaitreG]

This particular car has a "Transmission Control Unit" under the steering column right over the left kneecap. It is specified as an AT-EGS Control Unit by the dealer with different numbers, 24 61 1 216 558, 24 61 1 216 557 or 24 61 1 216 123.
This weekend, I will be starting the engine to run the fluids and warm it up a bit and follow the advices. Will keep you up to date. Thanks a million. It is good to know that this glitch may be cause by poor contact. I will have a can of CRC cleaner handy.

[jdkirkk]

This is an excellent line of comments that should be in everyones file. About one half of the auto transmissions returned to the factory for overhaul are just fine (I've been to the factory in Chicago); there is nothing wrong with them. I suspect that many Sixers are sent to the boneyard because someone didn't want to spend the money to replace the trans when it might be a relatively simple wiring problem.
I recently pruchased an '88 635 that had recent transmission work done and when the trans pan was dropped for routine service there were three bolts just laying in the pan!
Changing the oil and filter is good; "flushing" may not be.

[MaitreG]

The knob used to return back to E, now it no longer does. Any other ideas?

[av8r4aa]

The knob you are speaking about has 2 sets of wires.
1 wire goes to the lower portion of the selector, that is a electrical solenoid.
When you start the car in Sport mode it is supposed to click back to E.
I would first check that the wires are hooked up.
Secondly I would do a diagnostic check on your Throttle body Sensor. On our cars
that TPS IS A DIRECT LINK TO THE TRANSMISSION COMPUTER. I found mine to be faulty and am awaiting parts. If you have a Bentley book there is a excellent description of the procedure. My car will not shift until the engine is COMPLETELY warmed up. Then it shifts perfectly. Keep us informed.

[MaitreG]

The knob is well connected. I did make sure of that after a member of this forum had me thinking I could have done something to it when I had to remove the whole console to change the expansion valve. This tranmission glitch was manifesting itsef long before that little adventure.The throttle-positioning sensor and control valve control the idle of the engine. The following is what I am working with.
My research leads me to understand that when a fault is detected, the vehicle can only be driven in 3rd and reverse gears. Voltage in terminal 1 is not present. Speed is T21, Ground T6. Has anyone tested the ground of the terminal going to the control unit? Need to know which pin is which. My E-24 stays on 1st and can only be driven under 123 selection and that sucks
Is this fault detected by the control unit, hence the control unit is working properly?
Here is what I am faced with:
1. Buy a control unit to see if it works.
1a. Find someone with the same car and install my control unit to see if it works.
2. Check system for ground to isolate the problem and hence save myself a bucket of money.
3. Buy another tranmission and be wrong.
4. Change the transmission to a 5 speed manual, thus acquire an older version of an E24.

I am leaning on #2 and love # 4 but rather not.


Thanks for the help.

[CW6er]

Yes, if the system detects a fault it stays in third, not first.

The Automatic with the electronic control system has two throttle switches, one is a micro switch that tells the DME if the throttle is off idle or wide open, the same as the manual transmission or the non-electronic auto. The second is a variable position "Pot" that is only connected to the Transmission Control Unit.

Pin 6 is the reference ground for the throttle position switch, pins 5 and 19 appear to be the grounds

Have you downloaded the ETM and gone through the troubleshooting chart? The first test is checking the grounds. The pin positions in the plug are given on page 8500-7.

[MaitreG]

Thanks for you patience CW6er. This is uncharted territory for me. I have looked at the chart, reached the control unit but short of testing it. The more I read about it the more it starting to make sense. By the way, on drive, she use to get stuck on first gear and never change. The last time she seems to be stuck as you said on third.
Found the page and will keep you posted. Thanks a million.

[MaitreG]

This is the update that I have. After having looked for a BMW for the past two years that has a five speed transmission and a running 3.5 engine, I finally found one. I am trouble shooting the engine and so far it seems that the fuel pump is not pumping after having sat for two years in the former owner's driveway. I will be tranforming my 89 to a five speed now that I have a whole manual system including pedals.

http://images.autotrader.com/images/2008/3/20/241/194/6535064079.241194218.IM1.MAIN.240x180_A.240x180.jp g
What do you guys think?

Thanks for the help. I guest I will be able to bypass all that GM electronic transmission trouble shooting oil leaking everywhere system.

[jdkirkk]

You will never regret getting rid of the slushbox. These cars were not originally designed with an autmatic transmission in mind. To shift it yourself is challenging the driver in you again, and awakening the sporting spirit of the vehicle.

[CW6er]

To test the fuel pump, you have to pull the fuel pump relay and jump socket 30 to 87 in the relay base. I made up a switch with flat blade spade connectors that fit in the relay base.

[MaitreG]

You will never regret getting rid of the slushbox. These cars were not originally designed with an autmatic transmission in mind. To shift it yourself is challenging the driver in you again, and awakening the sporting spirit of the vehicle.

Thanks and I can't wait.:redspot

[MaitreG]

To test the fuel pump, you have to pull the fuel pump relay and jump socket 30 to 87 in the relay base. I made up a switch with flat blade spade connectors that fit in the relay base.

Thanks! Next time I will keep 30 and 87 in mind. I already ran a direct 12 volt line:smash to it and nothing. I hate to pull out the one in the 82 that the engine is going to be dropped in and have to put it back. I have spark, so that is a good thing. I am reluctant to put new sparkplugs in an engine that has been seating this long unless I have to. I cannot do too much mechanic outside in my drive way. I had to power spray wash it for it to look decent in front of the house before the stealth surgical strike in my single car garage. I'll be calling the inspector on me:D. I have a friend who has a 535 in front of his shop that he has been chopping up. I am zooming on that fuel pump for now and giving him time to wake up this Easter morning.

[MaitreG]

Got it started. Looks and sounds like a strong engine needing a valve adjustment. A monster if if you ask me. Will pull out the engine and transmission in the morning. My baby is ready to receive her new engine.

[MaitreG]

The monster.

http://i298.photobucket.com/albums/mm251/LeTutankhamen/DSC01100.jpg

[MaitreG]

The monster is in.
http://i298.photobucket.com/albums/mm251/LeTutankhamen/DSC01128.jpg

[MaitreG]

Do you think this engine where these pistons came from was still running?


http://i298.photobucket.com/albums/mm251/LeTutankhamen/DSC01165.jpg


http://i298.photobucket.com/albums/mm251/LeTutankhamen/DSC01163.jpg

[MaitreG]

L:cool:coolking good!

http://i298.photobucket.com/albums/mm251/LeTutankhamen/DSC01194.jpg

[MaitreG]

I finally installed the five speed manual transmission in. It was all worth it. The sludge box is no more so is all the fluid and fluid tubing associated with it. The monster is alive!
Thanks!:redspot