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Home >> Lexus >> 2002 >> SC 430 >> Repair and Diagnosis >> External Pages >> Different car >> Section 307 (Defogger System - Diagnosis) >> Rear Window Defogger Does Not Operate >> Circuit Description

Circuit Description

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

The signal via the rear defogger switch is transmitted to the luggage room J/B from the air conditioning amplifier. Then the luggage room J/B outputs it to the defogger relay.

NOTE: The rear window defogger system has a function with large-scale body multiplex communication. First of all, inspect the communication function according to HOW TO PROCEED WITH TROUBLESHOOTING, and check that no malfunction exists in the communication system. Then proceed with the troubleshooting. 
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