Brake light curcuit failure 1995 E36 325i stick
After about an hour of driving and then when I pull up, the brake curcuit failure light comes up on the OBC and the check engine light starts blinking then goes to full light. I've switched off the engine and tried to check the error code with the Peake tool but nothing, as the check engine light won't come on again and the tool reads "--". So I replaced the 4-pin brake light switch and same thing happened. I replaced the OBC (very cheap from junk yard) with the same year vehicle and no difference. The curcuit failure light still comes on and the brake lights do work, at least temporarily until the failure light comes up.
I checked the Bentley manual but no clue. The check engine light has me baffled. I thought that was usually related to emission equipment failure. I'm reluctant to take it to a mechanic as I know he'll say to replace the brake light switch, but how many times do I have to do that? I don't know why this would be time dependant and why the check engine light comes on? any help would be appreciated. As a last ditch effort, I've got another switch so I could try that, but it doesn't seem logical.