Rear Window Defogger System Does Not Operate

REAR WINDOW DEFOGGER SYSTEM DOES NOT OPERATE

CIRCUIT DESCRIPTION

When the defogger switch is turned on, a rear defogger activation request signal is input to the A/C control (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/o 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.

Wiring Diagram:

INSPECTION PROCEDURE

Step 1-3:

Step 4-5:

Step 6-7: