WARNING: This page is about a different car, the 2004 Lexus LS 430. However, it is still accessible from the selected car via links, so may be relevant.

SMART KEY SYSTEM DESCRIPTION
1. In addition to conventional mechanical key and wireless door lock remote control functions, the small system enables door locking/unlocking, steering lock releasing, engine starting and trunk opening without operating the key. The only requirement is that the key be in the driver's possession.
  - This system is controlled by the theft warning ECU. When the theft warning ECU detects the presence of the smart key in one of the detection area, it identifies and checks the ID code, and outputs operation signals to the related ECUs in accordance with their functions.
  - The detection areas are formed by 8 oscillators (4 door oscillators, 2 trunk oscillators, and 2 room oscillators).
  - The smart function is only available for the master key and is not available for the sub-key and flat key.
Function of Main Component

Fig 1: Function of Main Component Description Chart (1 Of 2)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Chapter Navigation

Return to Chapter: Section 249 (Smart Key System - Diagnosis)

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

System Description

Use the Manual With the Right Hardware

When to See a Mechanic