brake circuit light warning

[thegooch325]

a friend of mine has a 94 325i...on board computer shows brake circuit light message...from what he's told me, this problem seemed to popup after he installed an aftermarket stereo...also one brake bulb keeps burning out...any ideas???? thanks ya'll

[olds72]

From what I have read, this could be related to the brake light switch. Seems like a very common problem.

[e36mike]

i had very similar if not exact problem. u didnt give details as to wheter the lights go on or not if he pushed the brake pedal down.. but when i had the problem my brake lights wouldnt go on at all when pressing it. so the problem was easily fixed by buyin a new brake light switch , very cheap 20$ at most ( make sure uget the right one) easy fix, second problem that i also had which u described is the bulb burning out, or not working. thats most likely the housing, i actually still have this problem , might need new taillights. or new light adapter things. pm me for help

[heidifleiss]

a friend of mine has a 94 325i...on board computer shows brake circuit light message...from what he's told me, this problem seemed to popup after he installed an aftermarket stereo...also one brake bulb keeps burning out...any ideas???? thanks ya'll


okay this morning I received the brake light circuit warning as well as the low coolant message. However, after shutting the car down and restarting it both messages disappeared. Do u think this just resetting the warning messages and that it will soon in time reappear again? Do u guys think this was just a glitch or do u think I should actually have both the brake light switch replaced and maybe the sensor for the coolant?

If so do u know how much the estimate would be for repairing both? Thanks again guys for all your outstanding help!

[e36mike]

yea my low coolant message did the same thing to me, just check the level, mine was low so i filled it, really simple thing to do, the brake circuit message wont show up until you hit the brake pedal, so go in your car and hit the brake pedal and see if it says brake light circuit, if not put a rock on the brake pedal to ensure they are still lighting up.

[heidifleiss]

yeah I checked my coolant level and it was just fine. I'm thinking that when someone gave me a nice christmas present and smashed in my whole entire grill and left without even leaving a note that he or she might have messed up my sensor. So at this time due to the annoyance of it appearing just about everyday on my display I will just have the darn sensor replaced. And I guess if that doesn't fix the problem then I should look into bleeding my system out? What do u think? I am on the right track?

And as far as the brake light circuit I think there might have been a piece of nature from a tree or something that got caught underneath my pedal that caused the light to go off because I checked all brake lights including the third one and all are working fine. Do u think this may have been the case? Because after vacuuming underneath my pedal the message has disappeared.

[e36mike]

well for the coolant if the level is fine and it keeps telling you that its low then your sensor must be messed up. as for the brake light switch idk thats weird, but if it happens again what you should do is take of the knee bolster (theres like 4 screws) and look for the brake light switch and see whats goin on down there, its a very simple mechanism. also if it completely does stop working its a very cheap and easy DIY so dont worry bout it. the little sensor might have just got stuck or something.

[Corey Milne]

yeah I checked my coolant level and it was just fine. I'm thinking that when someone gave me a nice christmas present and smashed in my whole entire grill and left without even leaving a note that he or she might have messed up my sensor. So at this time due to the annoyance of it appearing just about everyday on my display I will just have the darn sensor replaced. And I guess if that doesn't fix the problem then I should look into bleeding my system out? What do u think? I am on the right track?

And as far as the brake light circuit I think there might have been a piece of nature from a tree or something that got caught underneath my pedal that caused the light to go off because I checked all brake lights including the third one and all are working fine. Do u think this may have been the case? Because after vacuuming underneath my pedal the message has disappeared.

If you noticed just one of the lights out, intermitantly, it is most likely the housing not making a good connection, I have replaced countless tail-light housings because of this very fault, it is very easy to fix before it gets to the point of having to replace the entire housing. Determine which side brake light has the problem, take the bulb out, and look to see if there are small burn marks (tiny arcs) on the connection, if this is the case, mearly bend the connection out gently with a small screwdriver, and apply a small amount of di-electric grease to the connection to assure conductivity. If you see no burn marks I would assume it is the brake control unit, as the brake light switch would cause both lights to be out.
P.S. even if the problem has magically dissapeared you are probably not in the clear, check the housing and don't risk it. OEM housings are roughly $500 CAD.