How To Proceed With Troubleshooting
WARNING: This page is about a different car, the 2005 Lexus GS 430 and 2005 Lexus GS 300. However, it is still accessible from the selected car via links, so may be relevant.
HINT:
This ECU is connected to the multiplex communication system. Therefore, be sure to check that there is no troubles in the multiplex communication system before performing the troubleshooting.
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002