1999 E36 M3 Coupe.
So, 1000 points to anyone who can lead me to the answer. I'll even take you out for beers if you're in the GTA.
Here's what I know and what's been done.
-Brake Light Circuit code shows up on console
-Brake lights DON'T work
-All other rear tail light bulbs DO work
-Brake light switch has been replaced and even the original was tested and works.
-Rear Taillight assemblies have been replaced to LED taillight with different bulbs and still same problem
-CM Module has been inspected and has no blown capacitors, shunts, resistors or anything else.
-Trunk wiring looks good. There was one wire that was exposing the copper, but it's been taped and it is not the problem.
-Fuse 46 (and all other fuses) are fine and haven't been blown. I checked their consistency with a multimeter.
-Fuse 46 has a constant 12V whether or not the brake is depressed or not.
-Brake light circuit error comes on as soon as the two contacts in the brake light switch cause the circuit to close (I used my hand to test the brake switch as well as checking them for a 12V output of the leads when it was released).
-I've opened the fuse box and looked at each and every contact and cleaned/tested the few that had corrosion on them (PITA).
History: I would be driving and suddenly the brake light circuit error would come up. Eventually it got to a point where it would come any time I started the car and pressed the pedal.
It seems to be a wiring issue perhaps under the carpets or under the fuse box.
Is there any way to know which wires from the rear lights go to whichever wires in the fusebox? It could help me troubleshoot.
Here's what's puzzling: If it was a short circuit, the fuse would blow (which it is not doing). If it's an open circuit, shouldn't the code read "Brake light bulb", rather than "Brake light circuit"?
NEED HELP PLEASE!