Trans selector switch cleaning question

[arcsum68]

I posted in the e34 subsection but didnt get any answers, I doubt that its model specific though so I will ask here too.

I am getting a trans program error, as posted in the e34 subsection and needed some info on cleaning the switch.

I pulled the switch, but wasnt sure how to get it out of the housing to I could clean the contacts inside of it. I pulled the tabs out but the actual switch part that you touch is preventing me from sliding it out. I assume you just pull on it and it will come out, but I dont want to break it, can anyone verify if thats all I do or if there is a secret?

Thanks all

[Qsilver7]

Hmmm, I read both threads and some things still aren't too clear...but I'll try some suggestions (and you did get a response on the e34 specific forum...it may not have given you an answer...but again, neither of your posts are written clearly...we know that you're trying to convey what's going on...but for myself...I've had to read both threads multiple times...and I come away with more questions than suggestions).

You mentioned you get the transmission fail warning, you mentioned the battery dying and you replaced it, you wrote you tried to remove the A/M switch to take it apart, you asked did the little slider thingy in the switch come off by itself, you mentioned something about pulling tabs out (???) by the switch (that totally lost me in translation ).

So since I really didn't get the gist of what's going on and what you actually were trying to do...I'll start with some stuff and we can go from there.

First, the transmission is an electro-hydraulic hybrid. It relies on some electrical input to determine some of what it is asked to do and how it will perform. Because of this...there are some simple things that can gum up the works that many wouldn't obviously consider.

The tranny gear select lever AND the A/M tranny switch can both create a glitch from a simple electronic standpoint...and that can come from if they are dirty or gummed up from dust/dirt/grime/spilt drinks etc over the years.

The gear select lever has a switch that has electronic traces in them. As the lever is moved back-n-forth across these "traces"...it electronically communicates to the tranny as to what gear the car is in. As well...the tranny selector switch ( the A/M switch) can do the same...and if someone has at one point spilt a coffee or soda that has sugar etc in it...it can make the switch not work correctly...and like you tried...cleaning it should fix the problem.

The A/M switch can be removed from the center console. You can use the online part database to see where all the screws etc are...and Don Gale did a great write-up years ago....that is still very useful and relevant as to removing the center console, removing the A/M switch, and cleaning the gear select lever switch.

Here's a direct link to Don's website...and the page that discusses how to do all of the aforementioned stuff: http://www.nmia.com/~dgnrg/page_13.htm

The A/M switch (after removing it from the console)...should be opened in a gallon size plastic bag (so you can see) or a large bag because there are some spring clips inside that MIGHT spring out...would hate for you to lose them! AND NO...THE SLIDER SWITCH (that you touch) DOES NOT SNAP OUT OF THE SWITCH as it sits in the car...you'll see this if you remove the switch from the console.


The traces of the gear select lever switch (the white thing in pics below) can keep the the tranny form going into the correct gear if they are dirty. It can easily be cleaned with electrical contact cleaner and a Q-tip (I recommend NOT to use sand paper) once the center console is removed:



Also, make sure that the car is not staying in "M" mode...because if it is and you're not manually selecting the gears...then the tranny is staying only in the gear your have selected (and that would be 4th gear if the lever is in "D"). Is "M" always displaying in the gear select display on the instrument cluster? The default is to always return to "A" when ever the car is is turned off then restarted...if it is staying in "M" mode then something is probably wrong with the switch. YOU CAN SWAP THIS SWITCH WITH THE SUNROOF SWITCH...to test if the A/M switch is the problem. The sunroof switch has the same slider action as the A/M switch..and it can also be plugged directly into the electrical harness for the A/M switch. If you do this swap and the tranny goes automatically into "A" mode (and stays there) then you'll know the problem is the A/M switch.


There may be some hidden screws holding the trim pieces to the center console (especially if you have the wooden ctr console). The first thing to do is remove the handle off the gear select lever...you do that by pulling it back at least to "N" and remove the small hex screw that secures it which is on the side that faces the dash. There are two screws below the PRND321 on my 525iT (but it has the illuminated gear select lever). I have to "peel" up the label (#13) in the diagram below. Then remove the trim which will allow you to also remove the A/M switch.



Good luck...these suggestion may not solve your problem...but it will give you something to look at and cross off the list as possible culprits.

[arcsum68]

Thanks Q

I made this big ol post with pictures and everything and the board denied me, said I could'nt post pics or links yet. Kinda unhappy about that, but oh well. Everything I was talking about was with the A/M switch, not the gear selector traces, sorry for the confusion.

Your post really helped clear things up for me, the picture you have of the assembly with the little screwdriver in there prying on the tabs are what I was referring to.

I did that, but could not pull the assembly apart because the "knob" you use to move the switch back and forth was preventing me from sliding it out of the housing. I am going to tinker with it some more.

The instructions and link you sent me are great, thank you very much.

[arcsum68]

So, I pulled the A/M switch out again, but this time pulled it apart and its working both ways now.

I also pulled and cleaned the traces on the gear selector, which was absolutely filthy and seemed to be covered in an oil grime.

Niether of those things seemed to have helped, as the car once again when into trans program mode this morning.

Guess I keep going through the list of things to try.

[bbarry7]

Can the gear selector switch prevent you from not going into first gear ? Second and third gear are fine but when the car warms up i don't go into first and the rpm go real high

[danlau]

Hi, I have a 1995 BMW 525i, and I want to clean the gear select lever switch (the white part above). Do you know of a way of cleaning it without removing it. I was not able to remove it for cleaning because there is a lock lever in the way, and it blocked one of the screw. Thanks, danlau

[CFella540i]

Hi, I have a 1995 BMW 525i, and I want to clean the gear select lever switch (the white part above). Do you know of a way of cleaning it without removing it. I was not able to remove it for cleaning because there is a lock lever in the way, and it blocked one of the screw. Thanks, danlau

You ever figure out how to get this screw out? I am in the same position and I cant figure out how to get if off either.