
- Rear window defogger
- Outside mirror defogger (if equipped)
- Windshield wiper deicer (if equipped)
The Subaru Ascent is equipped with an integrated defogger and deicer system designed to maintain clear visibility in cold, wet, or frosty conditions. This system operates only when the ignition switch is set to the "ON" position, ensuring efficient use of vehicle power.

Defogger button
To activate the rear window defogger, outside mirror heater (if equipped), and windshield wiper deicer simultaneously in the Subaru Ascent, press the defogger button located on the climate control panel. When activated, the indicator light will illuminate, confirming system operation.
To deactivate the system, press the button again. The system will also automatically turn off when the ignition is switched to the "ACC" or "LOCK"/"OFF" position.
The Subaru Ascent defogger and deicer system is programmed to switch off automatically after approximately 15 minutes. If visibility is restored earlier, it is recommended to turn the system off manually to conserve battery power.
Additionally, the system can be configured for continuous operation via the center information display. Refer to the "Car settings" section for customization options.
CAUTION
- To avoid unnecessary battery drain in the Subaru Ascent, do not operate the defogger and deicer system longer than required.
- Do not use sharp tools or abrasive cleaners on the inside of the rear window, as they may damage the conductive elements embedded in the glass.
NOTE
- Activate the defogger and deicer system if the windshield wipers are frozen to the glass.
- Remove heavy snow accumulation from the windshield to ensure the deicer operates effectively.
- When continuous mode is enabled in the Subaru Ascent:
- If vehicle speed remains below approximately 9 mph (15 km/h) for 15 minutes, the windshield wiper deicer will automatically stop, while the rear window and mirror defoggers continue to operate.
- If the battery voltage drops below a safe threshold, the system will automatically shut down to protect electrical components.
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