View Full Version : O.B.F'n C.

11-06-2005, 02:27 PM
ok, heres the deal:

i upgraded my 95 m3 tailights from crap stock to inpro white n red. Looks great anyways so i go to check if the lights are working, as soon as i turn the key over the obc is telling me that both my break lights are out, so whatever i go to check, turn indicators on, ok, get my bro to step on the break pedal its fine, go in reverse those bulbs are fine to so everything works, can someone please explain to me why my onboard says otherwise.



Justin e36
11-09-2005, 05:29 AM
hey, didn't see this post earlier.
you still need help with this?

11-09-2005, 10:54 AM
your brake sensor might be shot, Sometimes I get the same thing, and the lights are fine. The connection could also be loose, take off the cover, and wiggle it around, make sure its making direct contact. Then turn the car on. It should work.

11-09-2005, 06:52 PM
Thanks to those that posted, i found the problem, it was the brake light bulbs, yah they worked fine, but i put in l.e.d. style bulbs, and for some reason the m3 obc didnt like that, so when i switched to the regular bulbs the warning went off. :)

AMI Motorsports
11-09-2005, 06:58 PM
Add in a resister to the LED ones and you'll be fine.

Justin e36
11-09-2005, 08:11 PM
LED bulbs don't have enough resistance. If you put it as your turn signal bulbs, you'll notgice your signals will blink faster too.

As AMI wrote, you need to put a resistor in the circuit to 'trick' the computer into thinking there is full resistance on the circuit and it won't trip the brake light failure warning.

11-09-2005, 10:04 PM
ahhh, nice i will do that thanks justin/AMI/Ital, for all your input.