AT Oil Temperature Subaru: 2 Common Causes and Fixes 

Tim Miller
AT Oil Temp Subaru


The automatic transmission fluid is too hot. 

AT Oil Temp Subaru


  • Low Transmission Fluid
  • Bad Transmission Fluid Usage



Easy to fix


What Does AT Oil Temp Light Mean on Subaru? 

AT oil temp Subaru
The AT oil temp light indicates that your automatic transmission fluid temperature is hot. 

The AT oil temp light on your Subaru dashboard means your automatic transmission fluid temperature is too hot. 

I’d recommend you pull over your vehicle and park it immediately after the light appears. Let the engine idle as the transmission fluid cools down until the light turns off.

Once the light is off, you can continue driving, but it’s best to seek professional help if it reappears. A mechanic will help identify the reason why your transmission is overheating. 

Note, if the AT oil temp light starts flashing after you start the engine, the issue could be with the Transmission Control Module or more. It’ll behave this way until a professional mechanic addresses the issue. 

Is It Safe to Drive with an AT Oil Temp Light On? 

Yes, you can still easily drive your Subaru when the AT oil temp light is on. But this doesn’t mean that you take the issue for granted. 

Ignoring your car’s AT oil temperature for two weeks or more might lead to serious issues. In the long run, what could have cost you a few dollars to fix will cost hundreds.

You should always be on the look for any of these symptoms. 

  • Stalling 
  • Overrevving 
  • Difficulty changing gear 
  • Jumping or lurching 

The transmission will get damaged if it’s not well lubricated, so don’t take risks. It’s best to visit a transmission specialist as soon as possible to fix the issue. 

Why Does the AT Oil Temp Light Come On? 

I’ve worked with several Subaru models, including the Outback, Forester, etc. The cause of AT oil temperature light in most of these models is usually transmission-oil related. Here are some of the common causes of the warning signal. 

Low Transmission Fluid 

Low transmission fluid levels cause friction between transmission parts, thus leading to overheating. The light will come on when the transmission fluid becomes too hot. 

Solution: The low transmission fluid levels can result from a leak. You can avoid this by regularly checking and topping up the transmission fluid at intervals. Additionally, ensure that all vehicle parts are inspected and changed during service. 

Watch this video to learn how to check the transmission fluid level on a Subaru.

Bad Transmission Fluid Usage 

Every car manufacturer recommends a particular type of transmission fluid brand for their vehicle. Hundreds of fluid transmission brands are in the market but aren’t compatible with every vehicle.

The Subaru manufacturers recommend Subaru ATF hp “Dexron III” transmission fluid. However, the Subaru engine can still function with other transmission fluids, but it’ll start developing issues over time. 

Solution: It’s best to always stick to the manufacturer’s transmission fluid to avoid transmission issues. 

What to Do When the AT Oil Temp Light Comes On

How to Fix AT Oil Temp Subaru

Dealing with AT oil temp light issues is simple, and in no time, you’ll be back on the road. Here is a guide on how to quickly fix the issue. 

Step 1: Allow the engine to cool or idle 

Once the oil light comes on while driving, you should get to a safe place and turn the engine off. Alternatively, keep the engine idle and let the oil cool off. 

Note that it’s best to stop the engine because your Subaru might have run out of transmission fluid. 

This can break it down and put you at other risks. Additionally, if you risk driving the car with AT oil temp lights on, it can lead to more engine damage. 

Step 2: Check the transmission fluid level

If the issue isn’t fixed by stopping or idling the engine, then the problem might be the fluid level. But before checking the fluid level, ensure the car engine is completely off. 

You can use a clean dipstick to check; if it comes out dry or shows no oil, the issue is a low fluid level. 

Step 3: Add fluid 

Adding the transmission fluid will fix the low-level issue. You can order from a nearby store or service center if you don’t have any transmission fluid. However, only use the fluid recommended by the manufacturer. 


You now know what the AT oil temperature light means, its causes, and how to fix them. The transmission fluid is essential for the proper functioning of the transmission system. It costs little, and having the right amount will save you lots of trouble. 

In addition, always check out your transmission fluid color, thickness, and smell. If you notice anything unusual, then it’s time to replace it. 

Remember to pay attention to all car dashboard symbols, as they reveal essential information about your car’s performance. Stay informed, take appropriate action, and drive safely!

Now it’s your turn.

Have you determined why your AT oil temperature indicator light is on? Let me know by leaving a comment below.

Learn more

Lexus AFS OFF Light: A comprehensive article about why the AFS OFF Light comes on and what to do.

Share this article

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top
Information sourced from the owner's manual.