I have a similar situation where when I step on the brake, the tailights is not working, only the 3rd brake lights are working. So when I did my search, someone posted that you need to replace the tailight sensor box by the drivers side (this should be brown or green color). So to be sure, I remove the sensor box and borrowed my friend. And sure enough, when I replaced it, the brake light start working again. Bought a new one on the dealer.. $90.
