General Information
There are many ECU controlled systems used in LEXUS GX470. In general, ECU controlled system are considered to be very intricate and require a high level of technical knowledge and expert skill to troubleshoot. The fact is, however, that if you proceed by inspecting the circuits one by one, troubleshooting of these systems is not complex. If you have adequate understanding of the system and basic knowledge of electricity, the problem can be accurately diagnosed and fixed. This information is designed based on the above principle to help service technicians perform accurate and effective troubleshooting, and is compiled for the following major ECU controlled systems:
The troubleshooting procedures are described on the following pages.
| System | Section |
|---|---|
| 1. SFI System (2UZ-FE) | SYSTEM & COMPONENT TESTING |
| 2. Electronic Modulated Suspension & Rear Air Suspension System | ELECTRONIC MODULATED SUSPENSION & REAR AIR SUSPENSION SYSTEM |
| 3. Kinetic Dynamic Suspension System | KINETIC DYNAMIC SUSPENSION SYSTEM - DIAGNOSIS |
| 4. Tire Pressure Warning System | TIRE PRESSURE WARNING SYSTEM - DIAGNOSIS |
| 5. ABS with EBD & BA & TRAC & VSC System | ABS WITH EBD & BA & TRAC & VSC SYSTEM - DIAGNOSIS |
| 6. Electronically Controlled Automatic Transmission [ECT] | ELECTRONIC CONTROLLED AUTOMATIC TRANSMISSION (ECT) - DIAGNOSIS |
| 7. Power Tilt and Power Telescopic Steering Column | POWER TILT AND POWER TELESCOPING STEERING COLUMN - DIAGNOSIS |
| 8. Air Conditioning System | AIR CONDITIONING SYSTEM - DIAGNOSIS |
| 9. Supplemental Restraint System | AIR BAG RESTRAINT SYSTEMS |
| 10.Lighting System | LIGHTING SYSTEM - DIAGNOSIS |
| 11.Wiper and Washer System | WIPER AND WASHER SYSTEM - DIAGNOSIS |
| 12. Audio System | AUDIO SYSTEM - DIAGNOSIS |
| 13. LEXUS Navigation System | LEXUS NAVIGATION SYSTEM - DIAGNOSIS |
| 14. Rear Seat Audio System | REAR SEAT AUDIO SYSTEM - DIAGNOSIS |
| 15. Rear Seat Entertainment System | REAR SEAT ENTERTAINMENT SYSTEM - DIAGNOSIS |
| 16. LEXUS Link System | LEXUS LINK SYSTEM - DIAGNOSIS |
| 17. Back Monitor System | BACK MONITOR SYSTEM - DIAGNOSIS |
| 18. Combination Meter | COMBINATION METER - DIAGNOSIS |
| 19. Power Window Control System | POWER WINDOW CONTROL SYSTEM - DIAGNOSIS |
| 20. Power Mirror Control System (w/ memory) | POWER MIRROR CONTROL SYSTEM (W/MEMORY) - DIAGNOSIS |
| 21. Front Power Seat Control System (w/ memory) | FRONT POWER SEAT CONTROL SYSTEM (W/MEMORY) - DIAGNOSIS |
| 22. Power Door Lock Control System | POWER DOOR LOCK CONTROL SYSTEM - DIAGNOSIS |
| 23. Wireless Door Lock Control System | WIRELESS DOOR LOCK CONTROL SYSTEM - DIAGNOSIS |
| 24. Key Reminder Warning System | KEY REMINDER WARNING SYSTEM - DIAGNOSIS |
| 25. Engine Immobiliser System | ENGINE IMMOBILIZER SYSTEM - DIAGNOSIS |
| 26. Theft Deterrent System | THEFT DETERRENT SYSTEM - DIAGNOSIS |
| 27. Multiplex Communication System | MULTIPLEX COMMUNICATION SYSTEM - DIAGNOSIS |
| 28. Cruise Control System | CRUISE CONTROL SYSTEM - DIAGNOSIS |
FOR USING OBDH SCAN TOOL OR 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 the ECU controlled systems when you have connected the cable of the tester to the DLC3 with the ignition switch and tester turned ON, there is a problem on the vehicle side or tester side.
- If the communication is normal when the tester is connected to another vehicle, inspect the diagnosis data link line (Bus(+)line) or ECU power circuit of the vehicle.
- If the communication is still impossible when the tester is connected to another vehicle, the problem is probably in the tester itself, so perform the Self Test procedures outlined in the Tester Operator's Manual.