Circuit Description
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.
When communication between the telephone ECU (Mayday ECU) and the telephone transceiver is disabled, this DTC output.
(When power is not supplied to the transceiver, this DTC is also output because the communication is not possible.)