Transmission Warning Light AKA Yellow Gear With Exclamation Point

[Jay11]

2000 Z3 2.5 86k miles, mostly a garage queen but wife's been driving it for 7-10 miles a day all of last week, I think with AC on-it's still hot in Texas.

&&&&&

EDIT --- Its Automatic transmission

#######

Car has a transmission warning light.
While backing up from garage to pack car outside, transmission warning came on. Turned it off, parked with hand brake, waited, started it again and warning light was gone. Same thing next day. However, later while pulling the car in, warning light popped up and remained on; car must have been in 3rd gear because it took a lot of gas to get it to move inside, parked and trany light was still on. I was in a rush so I didn't have the time to test it again.

While fiddling on a small screen at the doc's office I remember reading something about changing something ... maybe a module of some sort or something, either near the shifter or brake pedal. I just can't trace that page any more. And that, that replacement has to be a genuine BMW part from BMW, any other and people were having the issue/trany light recur. That if you do the turn engine off-park-handbrake-wait-start again, test, and the warning light's gone that you don't necessarily have a trany problem but a module that's needing to be changed. Would appreciate if someone can please point me to a solution and the item that's to be replaced.

[328 Power 04]

If it's shifting fine, it's the brake light switch.
Otherwise you must scan for BMW codes.

[Wertles]

Most likely, it is the brake light switch. Mine was intermittent like yours. When it’s acting up, your torque converter won’t lock up, your top may not go up or down, your brake light won’t light up and I think your cruise control won’t work either. The part was cheap on amazon and took about 15 minutes to replace. Transmission light and all other things fixed immediately.

[rf900rkw]

They do not shift correctly when the brake light switch fails. The most notciable change will be there will be no TCC lock-up.

[328 Power 04]

They do not shift correctly when the brake light switch fails. The most notciable change will be there will be no TCC lock-up.

Thanks for the clarification. Will correct my error.

[Jay11]

For good measure i will check trans fluid tomorrow and do a short roady.

Now that you guys mention cruise control...This car's actually doesn't work. Turned key to accessories, I suspect a reset has occurred-brake lights were ok and roof works ok. Batt is low won't crank but I will jump it tomorrow. Does this definitely indicate a bad brake switch?

Think i will go ahead and replace the party any way. Is this the part? http://www.pelicanparts.com/BMW/tech...eplacement.htm

[gmushial]

For good measure i will check trans fluid tomorrow and do a short roady.

Now that you guys mention cruise control...This car's actually doesn't work. Turned key to accessories, I suspect a reset has occurred-brake lights were ok and roof works ok. Batt is low won't crank but I will jump it tomorrow. Does this definitely indicate a bad brake switch?

Think i will go ahead and replace the party any way. Is this the part? http://www.pelicanparts.com/BMW/tech...eplacement.htm

Looking at that writeup - it looks like the switch is a DPST switch, ie, two switches in one module, ie, it could be possible for one half to still be good, and the other bad, ie, some functions that it drives will still work, but others won't... I think I would replace the switch, especially given the minimal cost, and see if things don't improve.

[rf900rkw]

It is a primary switch that drives everything you would expect, and then a light secondary switch that is used as a redundancy check. It's the redundancy check that fails. Replace the switch. I've written up how to do it multiple times in this forum.

[Vintage42]

... Replace the switch... I've written up how to do it multiple times in this forum.

Brake switch:
http://www.bimmerforums.com/forum/sh...6#post28358366

[Jay11]

Brake switch:
http://www.bimmerforums.com/forum/sh...6#post28358366

Thanx everyone.

Sounds like a simple err procedure. Switch arrived today will fit it tomorrow. Had removed lower panel and found a wire with a purple clip not attached any where. Is this supposed to be connected somewhere? If so, where?

[Jay11]

Brake switch:
http://www.bimmerforums.com/forum/sh...6#post28358366

Replaced the brake switch, but there's a little issue. The brake lights are staying on. I have to left-leg pull up brake pedal by just a slight tap, towards me. Did this at night, didn't get a chance to investigate. What could be the cause?

Also found that wire hanging in the previous post above. Do you have an idea what's it for and where it should be plugged in to?

[rf900rkw]

Pull the switch plunger out a few clicks. Let the pedal set the return.


Wiring is likely for one of the clutch pedal switches.

[Dadof3rd]

R u still experiencing the issues u describe? I experienced the dreaded yellow gearbox in the past. Once it came in, it felt like gear was stuck on 3rd or 4th. Had to turn engine off and wait 1/2 a minute and turned key back on and found the gearbox is gone. I replaced my transmission thermostat and everything is running smooth now. It is located underneath the water expansion tank. U will need to remove the expansion tank to access it. When i opened mine, the thermostat was broken. But again, this is only for automatic transmission e46

[rf900rkw]

Z3s are the last of the air cooled. They do not have a transmission thermostat.

[Jay11]

Pull the switch plunger out a few clicks. Let the pedal set the return.


Wiring is likely for one of the clutch pedal switches.

Worked like a charm! Nice trick, that's!

I will keep an eye on this and see how it behaves.

[mpire]

I got the gear indicator on the tranny again today. Scanned the codes and found the brake light switch code.

Ordering a replacement $10

Stop light switch 4-POLIG/MECH. 1 61318360417

Lets hope that they are the same issue.