Circuit Description

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.

When the defogger switch is turned on, a rear defogger activation request signal is input to the A/C control assembly (A/C ECU) from the multi-display^*1 or center cluster integration panel^*2 . Then, the A/C control assembly outputs this signal to the defogger relay (Marking: DEFOG) and the rear window defogger system is activated.

HINT:

^*1: w/ LEXUS navigation system

^*2: w/ LEXUS navigation system

NOTE: The rear window defogger system is part of the large-scale body multiplex communication system. The first step in any repair is to confirm the proper operation of the communication system. Proceed with troubleshooting after the communication has been verified.