Keyless Entry: Service and Repair

NOTE: Lexus does not offer a reprogram procedure for the keyless entry system on this model. Reprogramming is only achieved by replacing the ROM chip in both the transmitter and the door lock ECU with matching ROM chips.

Parts Replacement






Removal of door lock ECU:
(a) Remove luggage compartment LH side cover.
(b) Remove the two nuts.
(d) Disconnect the connectors.
(e) Remove the ECU.
Installation of door lock ECU:
(a) For installation, follow the removal procedure in reverse.
Replacement of wireless door lock ECU and Transmitter:

Note: Each part is a precision electronic component so handle with care. Destroy old ROM and transmitter to prevent reuse.












For malfunctioning transmitter:
(a) Prepare the new transmitter (with ROM).
(b) Remove the ECU from the vehicle.
(c) Remove the ROM from the ECU.
(d) Install the new ROM into the ECU.
(e) Install the ECU into the vehicle.
(f) Check that door lock remote control operation works.
(g) Cut the new key to the shape of the replaced key.

For non-functioning battery:
(a) Prepare new battery (with 0-ring).
(b) Remove battery and 0-ring from transmitter.
(c) Install new battery and 0-ring into transmitter.






For malfunctioning ECU:
(a) Prepare the new ECU (without ROM).
(b) Remove the ECU from the vehicle.
(c) Remove the ROM from the ECU.
(d) Install the ROM in the new ECU.
(e) Install the new ECU in the vehicle.







Removal of ROM from door lock ECU:
(a) Remove the cover from the hole for ROM insertion.
(b) Using long nosed pliers, grasp the center of the print board (ROM) and remove it.

Note: When replacing the ROM, always disconnect the ECU connector first. When removing the ROM always grasp the board and do not touch the IC parts or print wiring on the board.






(c) Insert the new print board (ROM) along the rails on both sides and push it in with your finger until the terminal on the end is completely inserted.
(d) Install the cover to the hole for ROM insertion.






Replacement of battery for transmitter:
(a) Remove the screw from the transmitter.
(b) Remove the cover.







(c) Remove the 0-ring battery.
(d) Set the new battery and 0-ring into the transmitter.
(e) Install the cover to the transmitter body taking care not to twist or displace the 0-ring.
(f) Tighten the screw.