Entry Exterior Alarm and Answer-back Buzzer do not Sound [06/2018 - ]: Description
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2024 Lexus ES 300h, 2023 Lexus ES 300h, 2022 Lexus ES 300h, 2021 Lexus ES 300h, and 2020 Lexus ES 300h. However, it is still accessible from the selected car via links, so may be relevant.
The smart access system with push-button start (for Entry Function) uses the wireless door lock buzzer to perform various vehicle exterior warnings. When the conditions of each warning are met, the certification ECU (smart key ECU assembly) sends a buzzer activation request signal to the main body ECU (multiplex network body ECU) via CAN communication and the buzzer sounds.