DTC B1242/42: Wireless Door Lock Control Receiver Malfunction: DTC Detecting Condition
WARNING: This page is about a different car, the 2002 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.
DTC B1242/42 is set when RDA circuit (Blue/White wire) between body control ECU and wireless door lock control receiver is shorted to ground.