Remove the door control switch assembly.

Using a screwdriver wrapped with protective tape, disengage the 4 claws and the 2 clips.

Lexus IS250 IS220d GSE20 ALE20 DOOR LOCK

Install a new battery in the slot at an angle with the positive side facing up.

Inspect operation of the transmitter.

Remove the mechanical key.

Lexus IS250 IS220d GSE20 ALE20 DOOR LOCK

This is the power source circuit of the certification ECU.

The certification ECU controls the following:

If the certification ECU detects that the luggage compartment open switch is pressed when the driver is carrying the electrical key or when the electrical key is locked in the luggage compartment door, the certification ECU sends a luggage compartment door open motor drive request signal to the main body ECU LH.

The certification ECU activates the front and rear cabin oscillators. The power is supplied from the certification ECU to both the front and rear cabin oscillators. The front and rear cabin oscillator circuits have the same wiring. If the smart access system with push-button start does not operate properly inside the vehicle, check the circuit for their oscillators.