2025+ (6th Gen) Toyota 4Runner AC System Behavior: Why the Green Light Doesn’t Stay On

[Trail4R]

If you’ve recently picked up a 6th Gen 4Runner and noticed the A/C system doesn’t retain the compressor “ON” state after restarting the vehicle, you’re not alone, and you're not crazy. Here’s a breakdown of what’s going on and what to expect.

What’s Happening?​

• When you power off the vehicle with the A/C on (green light illuminated), it does not stay on when you restart.
• Even if the temperature is set low (e.g. 60°F), the system will blow warm or ambient air unless the A/C button is pressed again.
• This behavior occurs whether or not the system is in AUTO mode.

Key Points​

• Green light = compressor active.
• No green light = compressor not active - If it’s off, the blower is running but not cooling.
• You must manually press the A/C button every time you restart the vehicle... if you want cold air.
• Lowering the temp does not automatically re-enable the compressor.
• A few dealers have acknowledged it and mentioned a possible future software update from Toyota — but nothing official has been confirmed yet.

Is It Normal?​

It appears to be standard behavior for now. It may be a design choice by Toyota, possibly for efficiency or emissions compliance, but it’s something to be aware of.

A/C OFF

A/C ON

A/C Mode with AUTO toggle on/off​

You can access this setting through Vehicle Customize -> Climate -> A/C Mode with AUTO

In the 2025 Toyota 4Runner, the "A/C" button on the climate control panel allows you to manually control the air conditioning compressor. Here's how it functions:

• AUTO Mode with A/C ON: When you press the "AUTO" button, the system automatically regulates fan speed, air distribution, and activates the A/C compressor as needed to maintain the set temperature.
• AUTO Mode with A/C OFF: If you press the "A/C" button to turn it off while in AUTO mode, the system will continue to control fan speed and air distribution automatically but will not engage the A/C compressor. This means it won't dehumidify the air, which can be less effective for defogging windows or cooling in humid conditions.
• Manual Mode: You can also manually control the fan speed, air distribution, and A/C compressor by adjusting the respective controls, bypassing the automatic settings.

Understanding the A/C Compressor Behavior in AUTO Mode​

• A/C Compressor Activation: In AUTO mode, the system uses sensors to monitor cabin and ambient temperatures. If cooling or dehumidification is required to achieve the set temperature, the system will engage the A/C compressor automatically, regardless of the A/C button's indicator light status.
• Indicator Light: The green light on the A/C button typically indicates manual activation of the A/C compressor. However, in AUTO mode, the system can control the compressor independently, so the light may remain off even when the compressor is active.

Ultimately, here is the takeaway:

When the climate control system is set to "AUTO" mode, it automatically manages various components—including the A/C compressor—to maintain the desired cabin temperature. This means the system may activate the A/C compressor as needed, even if the green indicator light on the A/C button is not illuminated.

How to Enable Auto Mode?​

Press the big button that say's "Auto" and you will have enabled Auto Mode.

After you enable Auto Mode, an indicator will appear on the screen.

 

[ClarkeBar]

Thanks for that info I've seen this and was wondering WTH was going on. I'm in FL where my AC is on almost all year so for me its quite a dumb choice by Toyota.

 

[stellarbuilt]

Good to know, thanks for sharing.