DTC B1263: Luggage Room Junction Block ECU communication stop: Wiring Diagram

WARNING: This page is about a different car, the 2003 Lexus LS 430. However, it is still accessible from the selected car via links, so may be relevant.

See DTC B1291, B1292: LIGHT SYSTEM COMMUNICATION BUS MALFUNCTION (+B SHORT), LIGHT SYSTEM COMMUNICATION BUS MALFUNCTION (GND SHORT) .