Courtesy Lamp Module or Roof Rail Courtesy/Reading Lamps
WARNING: This page is about a different car, the 2008 Cadillac DTS. However, it is still accessible from the selected car via links, so may be relevant.
The courtesy/reading lamp is a duel purpose lamp that can be illuminated two different ways. First, the lamp can be turned ON during courtesy lamp operation as described above. Second, the lamps can be turned ON individually for reading lamp operation by the lamp switch. The BCM supplies battery voltage from the INT LAMPS fuse through the inadvertent power courtesy lamp circuit to the courtesy lamp module, overhead console lamp, or the roof rail courtesy/reading lamps for reading lamp operation only. Ground for these lamps is provided at G402.