E36 auto transmission warning light (!)

[Jude]

Well, this evening, after driving around the neighborhood at a leisurely pace, I stomped on the gas pedal when going on to a main road. This act was met with the automatic transmission warning light coming on and staying on. The car drove with no problems, and did not limp home or anything. I drove for only two more minutes actually. I didn't turn the car back on since I had had enough for one day.

Note, two weeks ago, I DID change the filter and fluid. Would this suggest that I did not replace enough? Would the light indicate an overheating or general lack of fluid?

I have done every type of search on this board for auto transmission/tranny/transmission warning light etc, but most do not help, so I have to ask.

One thread I read suggested that driving into a puddle would wet a solenoid underneath the car and that this would cause the light to come on. It has been really wet here today, and I definitely could have ran over some water.

Car is a '94 318i with GM transmission, with Dexron III, which is the correct fluid, by the way.

Thanks!

[johnjack11]

Check the fluid level, it may just be low.

Do it quick though!

[10kken]

It should be Dextron III, but it should also be listed on the spec plate on the transmission.

Here's a really good write up on changing ATF, in case you haven't seen this before.

http://www.pelicanparts.com/bmw/tech...Fluid_Auto.htm

[Jude]

Thanks. However, I wasn't asking a question above, just stating what I have found out already. That is what the dealer told me for definite. I found that it is in the owner's manual too, of all places! That's the last place I look for information.

I read the pelican parts instructions before, and I followed the instructions when I changed the filter and fluid. I had someone fill the fluid for me via a length of tube but now I'm going to have to go look for one of these transmission pumps they supposedly have at auto stores:

I'll report back if a topping up with fluid solves it.

[Jude]

hmmmm.

Topping up the fluid didn't do anything.

I have found that the light comes on when I kickdown i.e. pushing the gas pedal all the way to the floor. Doing this will let the transmission go to the next lower gear, but the light will come on and I cannot get it to kickdown again afterwards.

Turning off the ignition and starting the car again clears the (!) light. It will stay off if I do not use the kickdown.

This would suggest a fault in the logic of the kickdown sequence itself. The transmission will still automatically choose the gear depencing on the speed, and will work just fine as long as I don't depress the gas pedal past halfway.

Well, time for more investigation, it seems.

[10kken]

How many miles do you have on your car BTW?

[thejlevie]

Have you had the fault codes read out? If so what did they say was the cause?

[Jude]

How many miles do you have on your car BTW?

168xxx miles.

Yes, that's a lot. Still, the transmission fundamentally works. I would think I have a fault in a sensor or wiring somewhere, rather than a blown seal or something.

[Jude]

Have you had the fault codes read out? If so what did they say was the cause?

I haven't had the codes read out. This would mean taking it to the dealer or a mechanic, no?

[mvelimir]

and after weekend, turned on a car, and it's working fine. I took it to mech today and had them do a diag - pressure regulator error was stored in my ECU. He had ECU reset and everything is still fine. He told me the following:
1. It might be a piece of dirt going through the system causing the error
2. Water causing it (I ran car through car wash a night befor I had problem)
3. Week battery
4. Faulty pressure regulator.

Anyhow, I'm going to drive it through car wash few more times these days and see if it happens again - then I'd know what to do (...or would I?)

[toopercentmlk]

arent the auto trannys sealed? ive never had my fluid checked..

[Jude]

arent the auto trannys sealed? ive never had my fluid checked..

Take a look at the bottom of your transmission. On one corner (rear passenger on mine) there is a drain plug, just like you have on the oil sump (is that the right term?). Anyways, for my transmission, there is another plug on the driver's side by the kickdown cable that is where the fluid goes in. It is at a higher level of course than the drain plug.

See the pelican parts tech article.

[Jude]

Well,


this was an easy fix.

It seems I had to adjust the throttle cable. With the gas pedal fully to the floor, it wasn't pulling on the throttle enough. Evidently, my mechanic (me), did not put it back right after taking it off to work around the intake manifold.

The resistance across the throttle position sensor was around 2500 Ohms, so I back the screw on the cable until the throttle was wide open at full depression of the gas pedal and the resistance went to about 1500 Ohms. It should be about 1000 Ohms, according to Bentley, but it is close enough for me for tonight. It kicks down and now I can race minivans again

Thanks anyways, everyone.

[usarmy188]

I haven't had the codes read out. This would mean taking it to the dealer or a mechanic, no?

Mine throws 02 sensor code. Could this cause it?

[bmwdirtracer]

Welcome to the forum. For future reference, you'll usually do better by starting your own thread, than joining a 13 year old thread referring to similar issues on a different car, with a different transmission.

Your car (unlike the '94 318) will likely have significant clues in the transmission codes, and perhaps the DME codes also, if you use a BMW specific diag tool to look for them.

A bad MAF, or a large intake / ccv system leak could cause a Transmission failsafe issue, AND an O2 sensor code, but I'd start by reading all the codes in all computers, then probably a smoke test.

When was the last time your transmission was serviced (filter and fluid).?

[usarmy188]

Welcome to the forum. For future reference, you'll usually do better by starting your own thread, than joining a 13 year old thread referring to similar issues on a different car, with a different transmission.

Your car (unlike the '94 318) will likely have significant clues in the transmission codes, and perhaps the DME codes also, if you use a BMW specific diag tool to look for them.

A bad MAF, or a large intake / ccv system leak could cause a Transmission failsafe issue, AND an O2 sensor code, but I'd start by reading all the codes in all computers, then probably a smoke test.

When was the last time your transmission was serviced (filter and fluid).?

Thank you and I'm sorry I tried to start a new thread and looked for it and it never posted. But I do appreciate the response. I changed the tranny 2 times already. Within the last 20k. I just dont understand. Now it's cooler out it doesnt turn on. I'll drive on a hotter day and I'll get 7 miles before it turns on. But I restart the car and it goes away. I'm really baffled right now. Could it have been my throttle cable? I just adjusted it and it was half closed and now I hit the pedal down but not hard enough for the button to hit and it actually kicks to a different gear. But to describe what happened when the transmission light went on it would run fine shifts fine. Soon as it turns on the tranny shifts hard and everything. Fluid level is up and everything. Thank you btw

[MauiM3Mania]

Thank you and I'm sorry I tried to start a new thread and looked for it and it never posted. .....

Here it is. https://www.bimmerforums.com/forum/s...ranny-light-on You can locate things like this by visiting your PROFILE. There's a link at the top of every page that will take you to your profille.

Good luck with the issue.

[bmwdirtracer]

Thanks, Mr. Moderator, for that link. USARMY had been given some bad information there.

USArmy, you need to have the codes read, from the engine computer, transmission computer, and the ABS too....using a real BMW specific diagnostic computer. Ignore anyone who tells you that you can use an OBD generic tool to diagnose this.

The O2 sensor code is setting at the same time because that's the moment the car's trying to go into closed loop operation, and setting codes for faults.

Get the codes read with a BMW tool, and get a smoke test of the intake / ccv system. You've replaced the transmission twice; that's clearly NOT the problem....neither is a post-cat O2 sensor.

[usarmy188]

Ok sweet cause I got a generic tool so that's why I'm guessing no other codes popped out. Could advanced read the codes for me?

[bmwdirtracer]

No, Advance can't read the codes in your transmission computer, or any BMW specific codes in the engine computer either.

If you have a bad intake leak, or a faulty MAF, eventually that will set an emissions code that can be read by an OBD2 scanner....probably.

If you want to have GOOD information to correctly diagnose your issue, you need to start with 2 things: Have the codes in ALL your computers read with a real BMW specific diagnostic tool, and get a smoke test of the intake / ccv system.

Or, you can just keep throwing transmissions at it, and listening to people who tell you that replacing primary O2 sensors will fix a heater circuit malfunction on the secondary sensor.

[usarmy188]

No, Advance can't read the codes in your transmission computer, or any BMW specific codes in the engine computer either.

If you have a bad ibrake leak, or a faulty MAF, eventually that will set an emissions code that can be read by an OBD2 scanner....probably.

If you want to have GOOD information to correctly diagnose your issue, you need to start with 2 things: Have the codes in ALL your computers read with a real BMW specific diagnostic tool, and get a smoke test of the intake / ccv system.

Or, you can just keep throwing transmissions at it, and listening to people who tell you that replacing primary O2 sensors will fix a heater circuit malfunction on the secondary sensor.

Thank you my buddies coming over kater with the scanner I'm having the battery tested too cause it didnt wanna start earlier but it finally kicked on

[bmwdirtracer]

I do not frequent that forum, but I'm glad to see that someone finally chimed in there who knows what he's talking about (JD Strickland). Ignore the rest of the nonsense over there, check that all main hot and ground leads are clean and tight. There are three main hot connections between battery and starter, and three main ground connections. If any one of these is dirty or loose, it can cause your starting issue. Or....so can a bad battery, bad starter, or half a dozen other items.