Hello all..
Having a very wierd transmission problem and I was hoping to get some advice.
I have a 2000 328i that has 107K miles on it. I commute about 120 miles a day both highway and stop and go traffic. Have never had an issue with my BMW until last week. I was riding home, and towards the end of my commute, the transmission downshifted to 4th, and would not come out of 4th at all. Even when trying to use the Steptronic, it would not allow me to up or down shift. Stopping the car, it would accelerate until it hit 3rd gear, and then proceed to stick in 3rd. Shutting down the car completely didn't help. Several hours later I took the car out again, and it was fine.
This happened 3 days in a row, and only on the commute home and towards the END of the commute.
Took it to my BMW dealer, and they ran diagnostics, called the BMW Help center, looked into a computer problem (not sure what, but it turned out not to be an issue) and now they are just saying the tranny needs to be replaced!
Any advice or help on this would be MUCH appreciated. Don't want to have to have the transmission replaced if it is not necessary.. They want almost $4k at the dealer to replace it!
Thanks
Darin
If you do have to replace it, you might want to get a rebuilt one from a reputable independant BMW shop. It could end up being about half that price.
So much for the "life time" automatic transmission fluid.
Your BMW is going into "limp" mode. Did a warning light show up on the dash? Once an auto-tranny BMW is in limp mode, it stays in 4th gear and doesnt downshift, nor shift into 5th.
Did your check engine light come on?
Most people end up replacing the tranny or the tranny ECU, or flat out doing a manual transmission swap.
-Eddie
Thats the interesting part, no warning light whatsoever.... and they find no faults when they check either..
Excuse the ignorance... what is the Tranny ECU?
Darin
Tranny ECU - I think its actually called the TCM ? (transmission control module)
I'm no elec. guru but in layman terms, it's the "brain" that controls all the shift points, etc....It has input/outputs that manipulates the solenoids in an auto tranny.
In my E36, its located in the passenger side firewall. Right above the engine ECU.
Thats really odd how your problem is not tripping any CELs or Limp Mode lights. I know that what I'm suggesting next sounds VERY KOOKY, but you may want to try it before plunging for a transmission swap.
Try reseating the wiring harness that connects to the Transmission ECU (TCM). Locate the TCM and unlock the mechanism that attaches the wiring harness to the TCM. Clean off all the gunk and maybe even lightly spray some of that electro-board cleaner that is used to clean computer electronic boards and components. Then reattach the harness to the TCM.
This method "magically" fixed the tranny problem that I had. I have no idea how or why... (fyi: my problem was identical to yours) I havent had the problem for close to a month now. knock on wood!
-Eddie
I have been having the same problem. Brought it to the shop and had the Tranny replaced. Couple of days later same problem occured. Took it back and they said the tranny was defective and i needed a new one. They replaced it for free but now the same problems are occuring. Your car is a 2k i would bet it would be your TCM. Change that before you change your tranny. I need to replace mine (process of eilmination) 96 w/80kmiles. It sucks because I cant push my car out of corners without being worried that my teanny light would come on.
Mpower was it hard for you to find and reseat the wiring harness. I want to try that before i get a new TCM. I am just scared i might do something stupid knowing me.
-LWRNCE
LWRNCE: Finding the TCM wasn't difficult. It's located in a cavity located on the passenger side firewall near the secondary air pump. Remove the damping material and then then cover. There is a big clump of wires leading into the cavity because that is where your engine and tranny ECU are. The TCM is located on top of the engine ECU.
Reseating the TCM is another story. Both ECUs are mounting in this metal "cage" that is inside the cavity. Each ECU is suppose to slide in and out of this cage. Thus, the tranny ecu is on the top shelf of this 2-tiered cage. The engine ECU on the bottom. I had an impossible time removing the TCM from the cage althought I could slide the engine ECU out. I was able to release the wiring harness from the TCM and cleaned off any dirt, etc...and eyeballed the wiring harness to make sure there wasnt any pinched wires, frayed wires thats grounding out, etc... My trouble was re-attaching the wiring harness back onto the TCM. Since I could release the TCM from the cage, I was very limited because it was working in such a confined space. After a good 30-45mins fight with it, I got it reattached. :( no joke.. it was a b$itch.
But it did something for my car. I havent had to start thinking about budgeting $$ for the tranny repair again....and havent had to drive white-knuckled worried that the tranny will slam into limp mode when I'm doing 65-70mph... and THAT my friends, is as close as us auto-tranny owners will ever come to experiencing a E36 $money$ shift. :stickoutt
-eddie
Thanks for the replies folks...
I told the dealer not to replace the tranny, and on your advice had them take apart, clean, and reseat the wiring harness to the TCM. I will let you know today (car should be here any moment) how things went.
If the problem continues, I will have them replace the TCM. I gotta believe that is easier ( read: less $$$) then replacing the entire tranny..
Thanks again!
Darin
Wow what a bitch to do.... Thanks M.
yeah darin how much is it going to cost you for them to do that? I dont really wanna tackle this thing myself I would rather have someone else do it. Good luck.
Good luck guys!
I can't guarantee that the "reseating" of the TCM wiring harness/connector will do anything at all. But spending that $100 (1hr labor).....just may be the answer over a $2-3K tranny job.
I have a spare TCM that I bought off a BF member. He said it was for a '97 M3 and I bought it in case my own TCM was defective. I havent had to try it out yet.
Reseating the TCM connector may sound like a stupid idea, but you can't deny the fact that sometimes something so simple may be the answer. I remember plenty of times where I reseated my Nintendo64 game cartridge and that meant the difference between a blank screen and GAME ON! :redspot
once again.... good luck. hope its the cure-all.
-eddie
Continuing saga...
Got the car back on Friday, and all was well. Drove 150+ miles, no issues, weekend was good...
Then yesterday...
Commuting back home, it started all over again, this time going into 3rd instead of 4th and staying there for about 10 miles. Then it finally decided to go to 4th for about 5 miles, then 5th again. Pattern continued all the way home...
Sigh... looks like a new tranny is in my future.
Thanks for all the help and advice folks.
Darin
did you have them replace the tcm? if not have them check that out... it is better than replacing the Tranny (IMO).
-LWRNCE
I agree. If the tranny was fixed, then was fine for 150 miles before getting messed up again, I would think it is some kind of electrical problem. Mechanical problems usually don't come and go, they just get worse. Electrical gremlins seem come and go at random
I don't know what they did exactly, but I can tell you what I would do:
1-Disconnect the offending connector
2-Spray liberal ammounts of aerosol electronic contact cleaner
3-Attempt some abrasive action with the cleaner (perhaps with a q-tip)
4-Carefully Apply dielectric grease to each pin
5-Reassemble and see what happens.
I would NOT go to the dealer for this. I don't know where the connector is, but unless you have to take a lot of the car apart to get to it, I can't think of a reason not to do this yourself. The dealer will not put nearly as much TLC into somebody else's car as you would put into your own. I don't know what your personal level of do-it-yourself ability is, but if you can change your own oil, you can probably clean this connector (and do it better than the dealer) no problem.
