New Key cannot be Registered [11/2021 - 03/2023]: Description

WARNING: This page is about a different car, the 2025 Lexus NX 350h, 2024 Lexus NX 350h, 2023 Lexus NX 350h, and 2022 Lexus NX 350h. However, it is still accessible from the selected car via links, so may be relevant.

If a new electrical key transmitter sub-assembly could not be registered, wave interference or a malfunction of the certification ECU (smart key ECU assembly), electrical key transmitter sub-assembly, steering lock ECU (steering lock actuator with ECU assembly), ID code box (immobilizer code ECU), electrical key and tire pressure monitoring system receiver assembly is suspected.

The registration procedure to add another electrical key transmitter sub-assembly (without replacing any parts) is called "additional key ID registration".

If additional registration is not possible, refer to Additional Key cannot be Registered.

Refer to Additional Key cannot be Registered [11/2021 - 03/2023]

HINT:

If any of the following have been performed, registration of all electrical key transmitter sub-assemblies is necessary:

The certification ECU (smart key ECU assembly) has been replaced.
The certification ECU (smart key ECU assembly) and ID code box (immobilizer code ECU) have been replaced.
The certification ECU (smart key ECU assembly), ID code box (immobilizer code ECU) and steering lock ECU (steering lock actuator with ECU assembly) have been replaced.