The brake light or tire pressure light being illuminated will not affect your BMW's smog check results. A vehicle can pass the smog check with these lights on. The only light to make sure is not illuminated is the check engine light or MIL malfunction indicator lamp. On late model vehicle's certain faults with the vehicle's drivetrain will cause the check engine light to illuminate, so you want to make sure this is not the case with your BMW 550i.
We should also note that if the smog technician feels there might be an unsafe condition which is causing your BMW's brake or tire pressure light to illuminate he or she may refuse to conduct the smog inspection. If an unsafe condition occurs during the smog inspection he or she may need to abort the smog test. This is typically unlikely with 2000 and newer model year vehicle since they are not driven on a dynamometer during the smog test, but we do need to advise vehicle owners of it.
posted by SmogTips Support 01-07-2017 05:56 PM