Lexus ES: System Description
SYSTEM DESCRIPTION
GENERAL
(a) The rear window defogger wire (back window glass) is attached to the inside of the rear window and defogs the window surface quickly when the rear window defogger switch is pressed. The indicator light on the switch illuminates while the system is operating. This system automatically turns off after approximately 15 minutes.
NOTICE:
If the auxiliary battery voltage becomes low, auxiliary battery load control will operate in order to ensure sufficient power is supplied to the power steering system. In this case, the window defogger system may not operate.
HINT:
The window defogger system is linked with the mirror heater function.
FUNCTION OF MAIN COMPONENT
| Component | Outline |
|---|---|
| Rear Window Defogger Switch (Air Conditioning Control Assembly) | Sends signals to the air conditioning amplifier assembly to operate the window defogger system. |
| Air Conditioning Amplifier Assembly | Sends a window defogger system activation request signal to the DEF relay. |
| DEF Relay | Receives a window defogger system activation request signal from the air conditioning amplifier assembly and supplies power to the rear window defogger wire (back window glass). |
| Rear Window Defogger Wire (Back Window Glass) | Receives power from the DEF relay and heats the rear window using the rear window defogger wire (back window glass). |
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How To Proceed With Troubleshooting
CAUTION / NOTICE / HINT HINT:
Use the following procedure to troubleshoot the window defogger system.
*: Use the Techstream.
PROCEDURE 1. VEHICLE BROUGHT TO WORKSHOP
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Operation Check
OPERATION CHECK CHECK WINDOW DEFOGGER SYSTEM (a) Turn the power switch on (IG). (b) Check that the rear window defogger wire becomes warm by operating the rear window defogger switch of the air condit
Problem Symptoms Table
PROBLEM SYMPTOMS TABLE HINT:
Inspect the fuses and relays related to this system before inspecting the suspected areas below.
Use the table below to help determine the cause of problem symptoms.
SEE MORE:
Disassembly
DISASSEMBLY CAUTION / NOTICE / HINT The necessary procedures (adjustment, calibration, initialization or registration) that must be performed after parts are removed and installed, or replaced during engine unit removal/installation are shown below. Necessary Procedure After Parts Removed/Installed/
ECM Power Source Circuit
DESCRIPTION When the power switch is turned to on (IG), the auxiliary battery voltage is applied to IGSW of the ECM. When the transistor in the MREL circuit operates, current flows from the auxiliary battery to ground through the drive circuit of the EFI-MAIN NO. 1 relay, thus operating the relay wh
