Tail light/ brake light failure

[ADM0993]

Has anyone experienced a lingering problem with brake/tail lights continuing to fail on a 95' 325i? I have had this problem for years. I recently spent $700 for new assemblies and have consistently had to have bulbs changed with no luck solving the problem. I'm not sure I can take it much longer! Any input would be greatly appreciated.

99.9% you have to disconnect the pin connections and clean each one with steel wool. That's it. I bought some from Advanced and cost me $3. Twist the steel wool into a point and go to town in each hole. Don't forget the male pins too. Thoroughly shine each one no half assing. The apply some dielectric grease. REMEMBER It's the pin connection I think the brake lights are the brown wire but do them all as mine were green not copper color. I think its a black pin with 6 or 8 you just squeeze the 2 tabs to disconnect it.

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99.9% of the time you have to disconnect the pin connections and clean each one with steel wool. That's it. I bought some from Advanced and cost me $3. Twist the steel wool into a point and go to town in each hole. Don't forget the male pins too. Thoroughly shine each one no half assing. The apply some dielectric grease. REMEMBER It's the pin connection I think the brake lights are the brown wire but do them all as mine were green not copper color. I think its a black pin with 6 or 8 you just squeeze the 2 tabs to disconnect it.

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99.9% of the time you have to disconnect the pin connections and clean each one with steel wool. That's it. I bought some from Advanced and cost me $3. Twist the steel wool into a point and go to town in each hole. Don't forget the male pins too. Thoroughly shine each one no half assing. The apply some dielectric grease. REMEMBER It's the pin connection I think the brake lights are the brown wire but do them all as mine were green not copper color. I think its a black pin with 6 or 8 you just squeeze the 2 tabs to disconnect it.

[MSpeedAddict]

So, replaced all the bulbs, and the brake switch behind the pedal. All lights come on with the headlight switch all the way to the right.

Hit the brake pedal, no change.

Thoughts?
Gonna try tracing the wire from the brake switch back to the taillights to see if it's making it.

Also haven't checked fuses, but that wouldn't make sense since the lights come on with the switch.

[CMG]

Have u checked trunk wiring?

[MrJaderman]

Ugh, mine is acting up too. It was fine until I had it out while I was doing bodywork and I dropped it. Only the blinker works now and all the rest doesn't work at all and one was blown which was not blown before.

jandxjets - you're in upstate too?? Im not alone! No one around here doesn't even seem to know what a bimmer is. It's all trucks, ricers, and junkers around here.

[JDStrickland]

So, replaced all the bulbs, and the brake switch behind the pedal. All lights come on with the headlight switch all the way to the right.

Hit the brake pedal, no change.

Thoughts?
Gonna try tracing the wire from the brake switch back to the taillights to see if it's making it.

Also haven't checked fuses, but that wouldn't make sense since the lights come on with the switch.

Your diagnosis assumes the running lights and the brake lights use the same power source, which is a false assumption.

You should also open the trunk with the lights on and manipulate the harness that goes from the left fender to the trunk lid and see if you can change the symptoms. The license plate lights -- also a source of a tail lamp failure message -- have a wire in this harness that likes to break and take out other lights in the circuit.

And, just because you put in a new brake light switch does not mean that the universe will automatically spin in the right direction, you have to look to see that the switch is actually working. It is relatively easy to put the switch in, but not have it hitting anything.

[MSpeedAddict]

Your diagnosis assumes the running lights and the brake lights use the same power source, which is a false assumption.

You should also open the trunk with the lights on and manipulate the harness that goes from the left fender to the trunk lid and see if you can change the symptoms. The license plate lights -- also a source of a tail lamp failure message -- have a wire in this harness that likes to break and take out other lights in the circuit.

And, just because you put in a new brake light switch does not mean that the universe will automatically spin in the right direction, you have to look to see that the switch is actually working. It is relatively easy to put the switch in, but not have it hitting anything.

I'm aware they're on different switched power, but my diagnosis was only attempting to rule out the tail light assembly contact points with the bulbs, since power is getting there.

I opened up the wires going to the trunk lid and they seem to be in good condition.

The blue/brown wire going into the tail lights had electrical tape on it, I removed it revealing a nick in the wire on both sides (left/right tails) presumably checking continuity.

I'm making the assumption that the brake light switch is working, only in the sense between the OBC and the switch, as it no longer says brake light switch failure. However I'm not sure power is getting from the switch to the tails, although the OBC is able to determine when I have a single side bulb disconnected (1 brake light failure message).

Also checked fuse 46, intact.
Unfortunately left my voltmeter somewhere else and don't have it at home.

Anything else to check? (Without a voltmeter). I'm headed to my buddy's shop Sunday however it would be nice to have it fixed so I can not only drive the car sooner but also safely drive to the shop.

[MDeMayo]

Been reading through tons of posts and cannot really find a solid solution. Have a 94 325is and my issue right now is my driver's side tail light running light is not working. Brake lights and turn signals/hazards are fine. I've seen "Tail light failure", "Replace brake light circuit" and the other I guess you could say typical messages on my OBC intermittently in the past, although my brake lights and everything else seemed to be working fine, EXCEPT for my night time running light. Replaced my brake light circuit (knowing it wouldn't fix the running light, but to get rid of the other messages) and I haven't seen any messages for anything tail light related. I've replaced the bulbs, and the entire tail light itself and neither fixed the running lights. I've looked a little into if the tabs for the bulb assembly are making contact and they seem fine but I haven't ruled that out as a possibility. Haven't tried cleaning up the connections yet, but they also don't look like they have corrosion. I've seen people talking about trunk connections, the light switch itself on the dash to the left of the steering wheel, etc. Just a college student without much time to work on it and need a passing inspection by the end of the month. I'll take any suggestions. Thanks.

[UnderCoverGuy11]

Been reading through tons of posts and cannot really find a solid solution. Have a 94 325is and my issue right now is my driver's side tail light running light is not working. Brake lights and turn signals/hazards are fine. I've seen "Tail light failure", "Replace brake light circuit" and the other I guess you could say typical messages on my OBC intermittently in the past, although my brake lights and everything else seemed to be working fine, EXCEPT for my night time running light. Replaced my brake light circuit (knowing it wouldn't fix the running light, but to get rid of the other messages) and I haven't seen any messages for anything tail light related. I've replaced the bulbs, and the entire tail light itself and neither fixed the running lights. I've looked a little into if the tabs for the bulb assembly are making contact and they seem fine but I haven't ruled that out as a possibility. Haven't tried cleaning up the connections yet, but they also don't look like they have corrosion. I've seen people talking about trunk connections, the light switch itself on the dash to the left of the steering wheel, etc. Just a college student without much time to work on it and need a passing inspection by the end of the month. I'll take any suggestions. Thanks.

Its not working for BOTH sides? And Yea there's a bundle of wires on the drivers side that you'll see when you open the trunk that leads from the trunk to the chassis. The trunk opening and closing over the years frays the wires.

I would certainly check the fuse for it first, then the bundle of wires (takes like 20 minutes tops) . It could simply be the bulb assembly, i always thought that the e36 was fairly well designed except for the taillight bulb system, its so stupid

[gc325is]

I was cleaning the engine bay and sprayed some water around. The brake light warning went on and no brake light. I was thinking what a bad time for the brake light switch to break. However I needed to finish my engine work and left it alone. A few hours later the Brakes lights were working. I think there is some connection in the engine bay that water must have gotten into. Check light computer? Fuse box? I do not know hope this helps.

[MDeMayo]

No, only driver's side is out. But last night I noticed that my running light for my head light is also out. So I'm actually thinking it's my light switch inside the interior. There is some play in the switch so I'm hoping that will fix the issue if I replace it.

[elvisaintdead]

Hello all,
I have had the "brake light failure" on my 98 328 for a while. It was the passenger rear brake light - BUT it turns out it was still lighting when I hit the pedal- enough to keep the cops from writing me a "no brake lights" ticket, but apparently not enough to satisfy the OBC. I hope the 'before' pic illustrates my situation. I also have vehicle inspection for new tags in a couple of months, so I knew I had to rectify it soon.

Checked this thread, pulled the bulb and socket and assembly to inspect all the connections, condition, etc. Knowing the circuit was still live, I got some steel wool and hit all the contact points.

Success, and it was only a bit of steel wool to fix it! Damn cheap too! I know this won't work for everybody, but give it a shot if you're only down one light, according to the OBC. Thanks for the help and good luck!

BMWsemiDimBrakeLight-4web.jpg

[BMW525i]

I've been looking through this thread and yet to see this problem. I'm getting a tail light failure on a 97 328i, both outer tail lights will not work. The inner tail lights, brake lights, turn signals, and every other light on the car work fine. Tried switching the sockets/bulbs from each side with no success. Fuses all seem to be okay. Any suggestions?

[mikisman]

I am experiencing the same: right lights out, no instrument cluster--- fuses are all good

good call on the switch,, i will look into that now as these are all controlled by the switch

This is the EXACT thing i have with mine.. today I put it in reverse and got tail light failure. SUre enough my tail lights on the right side dont work and my intrument cluster is out too. Did you fix it?

[MDeMayo]

I can't believe I never posted my fix..but it was my switch to turn my lights on that was causing the issue for me. It was an odd fix but it worked like a charm

[deayge]

Hope this is not too old for a little up action

Any one know if I can test the switch without buying new one?
I have the symptoms described.Drivers side Front parking light and drivers side rear tail lights do not work.

Everything worked great until I started playing with LED lights.

Here is what happened....

*Install led lights from ebay (mistake 1)
*Turn on blinker to check, and I herd a noise near the dash. I looked at the dash, my turn signals were light up green, yet not flashing.
*I played with the LED lights some more, when testing keep hearing noise (mistake 2, 3, 4, 5)
*eventually the parking lights and the tail lights quit, drivers side only.

After readign this thread I am hopeful it is just the switch, but how can I test it?

[JDStrickland]

Hope this is not too old for a little up action

Any one know if I can test the switch without buying new one?
I have the symptoms described.Drivers side Front parking light and drivers side rear tail lights do not work.

Everything worked great until I started playing with LED lights.

Here is what happened....

*Install led lights from ebay (mistake 1)
*Turn on blinker to check, and I herd a noise near the dash. I looked at the dash, my turn signals were light up green, yet not flashing.
*I played with the LED lights some more, when testing keep hearing noise (mistake 2, 3, 4, 5)
*eventually the parking lights and the tail lights quit, drivers side only.

After readign this thread I am hopeful it is just the switch, but how can I test it?

Your LED lights just piss the car off. And, in your travels around the garage hooking them up, you screwed up some wiring. Your trouble is not the brake switch, it's the work you have done. Sorry.

Your car does not like LEDs because the Lamp Out Detection Circuits work by measuring the resistance in the circuit(s). The LEDs, by design of the LED, do not have the necessary resistance for the lighting monitors to be satisfied.

[e36fiend]

Hope this is not too old for a little up action

Any one know if I can test the switch without buying new one?
I have the symptoms described.Drivers side Front parking light and drivers side rear tail lights do not work.

Everything worked great until I started playing with LED lights.

Here is what happened....

*Install led lights from ebay (mistake 1)
*Turn on blinker to check, and I herd a noise near the dash. I looked at the dash, my turn signals were light up green, yet not flashing.
*I played with the LED lights some more, when testing keep hearing noise (mistake 2, 3, 4, 5)
*eventually the parking lights and the tail lights quit, drivers side only.

After readign this thread I am hopeful it is just the switch, but how can I test it?

Check your fuses. I believe the left and right side parking/aux lights are on their own discrete fuses. Are any other lights out? Interior, dash, license plate lights...

[johnf]

... Your car does not like LEDs because the Lamp Out Detection Circuits work by measuring the resistance in the circuit(s). The LEDs, by design of the LED, do not have the necessary resistance for the lighting monitors to be satisfied....

FYI, the check control measures the current flowing to the lamp, not its resistance. This difference can be crucial since LEDs do not behave like simple resistors, nor do current or voltage regulators, if the LED lamps have them.

...
*Turn on blinker to check, and I herd a noise near the dash. I looked at the dash, my turn signals were light up green, yet not flashing.
*I played with the LED lights some more, when testing keep hearing noise (mistake 2, 3, 4, 5)
*eventually the parking lights and the tail lights quit, drivers side only....

Wrong bulbs? For example, single-filament replacements are in a dual filament socket or the plastic bulb carriers are in the wrong positions?

Check fuse 33.

[JDStrickland]

Current flowing in a circuit is a function of the resistance of the circuit. If the resistance changes, then the current changes. The CCM is looking for this change to set the message. Ohm's Law says that since the voltage is staying the same and the resistance is changing, then the resulting current sets the message. Therefore, the circuit is measuring the resistance to detect changes in current.

Either way, the message is caused by the LEDs, not a circuit fault.

ALL turn signal and emergency flasher signals pass through the Hazard Relay -- this relay is what causes the blinking. A fast flash is caused by a lamp that is not on, which changes the total resistance -- load -- of the circuit, and this makes the circuit blink fast.

[deayge]

I have checked the fuses and relays. I don't think any other lights are out just tail light/ parking light.
ive seen many threads and videos that are saying the light switch it self can cause the car to have a "stroke" so I'm going to start there unless you can tell me where these "descret" fuses are

Video mentioned... at 30 seconds he says it an cause car to have a stroke.
https://m.youtube.com/watch?v=DV_wuezn3VE

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To whoever asked the domelight and the trunk light didn't work anymore either...What's so my question does that mean that the switch is bad

[johnf]

Current flowing in a circuit is a function of the resistance of the circuit. If the resistance changes, then the current changes. The CCM is looking for this change to set the message....

Here is the datasheet for the ULN 2457A, the 24V version of the ULN 2455A quad lamp monitors used in the BMW check control. A schematic on page 7-22 gives the resistance for the current monitoring shunts. Measure the shunts in the BMW check control and you'll know the minimum current the different lamps need to draw. If anyone needs it, somewhere I may still have the datasheet for the 2455A, from when I was designing a switch-preserving, brake light check control.

[JDStrickland]

I have checked the fuses and relays. I don't think any other lights are out just tail light/ parking light.
ive seen many threads and videos that are saying the light switch it self can cause the car to have a "stroke" so I'm going to start there unless you can tell me where these "descret" fuses are

Video mentioned... at 30 seconds he says it an cause car to have a stroke.
https://m.youtube.com/watch?v=DV_wuezn3VE

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To whoever asked the domelight and the trunk light didn't work anymore either...What's so my question does that mean that the switch is bad

I must be confused. I thought you were asking about the brake pedal switch. This switch only controls the brake lights, and disables the Cruise Control if set, and does nothing else. You said that your trouble started with LED lamps, and this is your trouble. Your car looks at the current flow in the brake lamp circuit to know if the brake lights are working or not. LEDs cause the circuit to have the wrong current flow, and this triggers the error.

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Here is the datasheet for the ULN 2457A, the 24V version of the ULN 2455A quad lamp monitors used in the BMW check control. A schematic on page 7-22 gives the resistance for the current monitoring shunts. Measure the shunts in the BMW check control and you'll know the minimum current the different lamps need to draw. If anyone needs it, somewhere I may still have the datasheet for the 2455A, from when I was designing a switch-preserving, brake light check control.

But if the new lamps (LEDs in this case) have a different resistance, then the current changes. The new resistance causes current that does not meet the needs for the circuit, and this makes the error message come up. I don't care what the proper resistance is, or current flow, I only care that a lamp and an LED are different loads, and the LED sets a fault on the OBC. If I was putting LED brake/tail lamps in my car, then I would care.

Just a casual guess (without doing the math) says that I would need something like a 1/2w, 470 ohm resistor to mimic a light bulb with an LED. I could run the numbers and figure this out, but that's not my interest. I only am trying to explain where the LEDs make the train jump the rails. The OP is on the wrong path.

[johnf]

...ive seen many threads and videos that are saying the light switch it self can cause the car to have a "stroke" so I'm going to start there unless you can tell me where these "descret" fuses are

Why the scare quotes?

Fuse 33 is in the rectangular, black plastic, main power distribution box on the left side of the engine compartment between the shock tower and the firewall.

The inside cover has a diagram and a chart showing the fuse numbering and sizes. I use an ohmmeter to check a fuse because I can't always see if a fuse is blown.

... Just a casual guess (without doing the math) says that I would need something like a 1/2w, 470 ohm resistor to mimic a light bulb with an LED. I could run the numbers and figure this out....

The calculations are more complicated if you treat incandescent and LED lamps as simple resistors: they are anything but when you start and run the engine. I find it is much easier to calculate the needed currents and then the load resistors. But, I bet you are right and this is off topic.

[spyderg0d]

What he said^... I just drove 50miles to help a friend with his. Lifted the trunk boot. Three wires puller exposed. Whaullah. Problems solved.

[deayge]

Well I pulled fuse 33 adn 37 both look good but one did not resistance test with a multimeter. Replaced it and magic!

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[QUOTE=JDStrickland;28331537]I must be confused. I thought you were asking about the brake pedal switch. This switch only controls the brake lights, and disables the Cruise Control if set, and does nothing else. You said that your trouble started with LED lamps, and this is your trouble. Your car looks at the current flow in the brake lamp circuit to know if the brake lights are working or not. LEDs cause the circuit to have the wrong current flow, and this triggers the error.


I was talking about the head/running light switch. It is not the break lamps it is the tail lights that run in conjunction with the parking lights up front. The light switch on the dash can cause the problem Im having according to what ive seen and read. Ne ways problem solved.
Thanks yall


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