General Information

WARNING: This page is about a different car, the 2003 Lexus LX 470. However, it is still accessible from the selected car via links, so may be relevant.

A large number of ECU controlled systems are used in the LEXUS LX470. In general, the ECU controlled system is considered to be a very intricate system requiring a high level of technical knowledge and expert skill to troubleshoot. However, the fact is that if you proceed to inspect the circuits one by one, troubleshooting of these systems is not complex. If you have adequate understanding of the system and a basic knowledge of electricity, accurate diagnosis and necessary repair can be performed to locate and fix the problem. These articles are designed through emphasis of the above standpoint to help service technicians perform accurate and effective troubleshooting, and are compiled for the following major ECU controlled systems: The troubleshooting procedure and how to make use of it are described in the following sections.

CENTER DIFFERENTIAL FREE CONDITION

System	Section
1. Engine	BASIC DIAGNOSTIC PROCEDURES
2. Automatic Transmission	AUTOMATIC TRANSMISSION - DIAGNOSIS
3. Active Height Control Suspension & Adaptive Variable Suspension	ACTIVE HEIGHT CONTROL SUSPENSION & ADAPTIVE VARIABLE SUSPENSION - DIAGNOSIS
4. ABS & Vehicle Skid Control (VSC) & Brake Assist (BA) System	ABS & VEHICLE SKID CONTROL (VSC) & BRAKE ASSIST (BA) SYSTEM - DIAGNOSIS
5. Power Tilt and Power Telescopic Steering Column	POWER TILT & TELESCOPIC STEERING COLUMN - DIAGNOSIS
6. Variable Gear Ratio Steering	VARIABLE GEAR RATIO STEERING - DIAGNOSIS
7. Supplemental Restraint System	DIAGNOSTICS
8. Power Seat Control System	POWER SEAT CONTROL SYSTEM - DIAGNOSIS
9. Wireless Door Lock Control System	WIRELESS DOOR LOCK CONTROL SYSTEM - DIAGNOSIS
10.Theft Deterrent System	THEFT DETERRENT SYSTEM - DIAGNOSIS
11 .Cruise Control System	CRUISE CONTROL SYSTEM - DIAGNOSIS
12.Engine Immobiliser System	ENGINE IMMOBILIZER SYSTEM - DIAGNOSIS
13.LEXUS Night View System	LEXUS NIGHT VIEW SYSTEM - DIAGNOSIS
14. Rain Sensor System	RAIN SENSOR SYSTEM - DIAGNOSIS
15.Sliding Roof System	SLIDING ROOF SYSTEM - DIAGNOSIS
16.Body Control System	BODY CONTROL SYSTEM - DIAGNOSIS
17.Driver Door Control System	DRIVER DOOR CONTROL SYSTEM - DIAGNOSIS
18.Multiplex Communication System	MULTIPLEX COMMUNICATION SYSTEM - DIAGNOSIS
19.LEXUS Navigation System	LEXUS NAVIGATION SYSTEM - DIAGNOSIS
20.LEXUS Link System	LEXUS LINK SYSTEM - DIAGNOSIS
21 .Air Conditioning System	AIR CONDITIONING SYSTEM - DIAGNOSIS

FOR USING OBD II SCAN TOOL OR LEXUS HAND-HELD TESTER

Before using the scan tool or tester, the scan tool's instruction book or tester's operator manual should be read thoroughly.
If the scan tool or tester cannot communicate with ECU controlled systems when you have connected the cable of the scan tool or tester to DLC3, turned the ignition switch ON and operated the scan tool, there is a problem on the vehicle side or tool side.

If communication is normal when the tool is connected to another vehicle, inspect the diagnosis data link line (Bus(c)line) or ECU power circuit of the vehicle.
If communication is still not possible when the tool is connected to another vehicle, the problem is probably in the tool itself, so perform the Self Test procedures outline in the Tester Operator's Manual.