At oil temp Subaru Lights – How to Fix

Several warning lights in Subaru cars warn drivers of impending dangers so they make timely adjustments to prevent car damage. One of such warning light is the At Oil Temp light. This warning light is common in Subaru, and there is a high chance you must see it if you own one.

So it’s expedient you know what it means and how to fix it when it appears. As the illumination of this light could spell doom for your engine if not handled properly. So what does AT Oil Temp Subaru mean, and how do you fix it?

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What does “at oil temp light mean”?

Found in all vehicles with automatic transmission, AT oil temp light is the automatic transmission fluid temperature. It helps in regulating transmission oil temperature. 

This light works by alerting drivers of escalating transmission fluid temperature. It turns on when your automatic transmission fluid is extremely hot. The at oil temp light is the same across all Subaru and other car models. So, if you are asking what AT oil temp in Subaru Impreza or Forester means, you have your answers.

What does it mean when at oil temp light comes on the Subaru

The AT oil temp light coming on your Subaru dash is an indication that your automatic transmission fluid is too hot. Allowing the transmission to cool down should get rid of the light.

It’s important you let it cool, as driving with such hot fluid could result in expensive repairs. The illumination of this light passes the same message across all Subaru. So, for those asking, what does the at oil temp in Subaru Impreza or at oil temp Subaru Impreza mean? Now you know.

How many oil warning lights are in Subaru?

There are four oil warning lights in a Subaru, all of which help alert drivers of issues in the oil system. This includes the At oil temperatures light, low oil level indicator light, low oil pressure warning light, and diff temperature warning light.

At oil temperature light

This light appears as a text on your dash reading “AT oil temp light or AT oil temp light.” This is the vehicle telling you that the automatic transmission fluid is hotter than usual.

The At oil temp light may illuminate or blink for several reasons. However, light blinking immediately after starting the vehicle often points to issues with the transmission control module.

Low oil level indicator light

The low oil level indicator is an amber-colored genie-looking lamp that appears on your dash. And sometimes it looks like an oil can dripping oil. The illumination of this light is a telltale sign that your engine oil level is too low and needs topping to avoid severe engine damage.

Low oil pressure warning light

The oil pressure is a red-colored-looking genie lamp. The illumination of the light indicates that the engine oil pressure is low or the sensor is failing.

Low oil pressure means your engine parts are not getting the right amount of oil to keep them protected. As such, the engine components may rub against each other and eventually overheat. Addressing this light seriously will help prevent permanent engine damage.

Rear differential temp light

The Rear differential temp light is an amber color light and turns on when the rear differential oil is overheating. The R differential oil helps lubricate the rear differential to keep the rotating parts lubricated and protected from excess friction, wear, or tear.

When it is old or contaminated, it loses its lubricating properties. This not only harms the differential but also strains the power train, resulting in more harm. When this warning light comes on, stop your vehicle and park for a while so the differential oil cools off.

You can continue your journey when the light goes off. You should, however, check the differential oil and replace it if it has aged or is too dirty. Not tackling the cause may result in the light returning.

Some mechanic and car user discussions

Many find forum discussions useful since they get experts and general car users to answer their questions directly regarding their specific vehicles. However, these forums most times only give straight answers and don’t go in depth.

In this article, I have explained in-depth what AT Oil Temp in Subaru means and how to spot if the problem is severe. When the At Oil Temp light is steady, it tells that the ATF temperature is hot due to car running for long. This shouldn’t bother you; allowing your transmission to cool should solve the issue.

However, if the light keeps flashing, it’s a serious issue that needs to be taken seriously. Chances are some faults are in the system. These I also explained as well as ways to fix them. However, if you want to explore other causes and ways to fix AT oil temp issues related to your specific model, you may want to engage this Subaru At Oil Temp Subaru thread.

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How do you fix it if at oil temp warning light comes on Subaru?

There are a couple of things you can do depending on what triggered the light. It could be as simple as just letting the car cool or having to fix or change a few things. Here is how to fix at oil temp warning light in your Subaru.

1. Allow the transmission to cool

When you see the warning light, park your car and let it idle while the transmission cools. The light should go after the transmission cools down. Only continue after the light goes off. However, afterward, have your vehicle serviced immediately.

Sometimes, allowing the transmission to cool may be a temporary fix if other factors are responsible. So, how do you tell if cooling the car would solve the issue? Look at the AT oil temp light on your dash. If it appears steady, the ATF is likely hot because you’ve been driving for a while.

So, letting the transmission cool should help. Here, you will not see any code when you check with an OBD II scanner. However, if the light is flashing, there are other things responsible for the transmission overheating. In this case, you may need to fix via other methods below.

2. Change or top transmission fluid

If you are dealing with AT oil temp in Subaru Outback 2013 or AT oil temp Subaru Forester 2014, or any other model, try checking the ATF. Old or contaminated transmission oil can no longer cool down transmission, hence overheating.

Low transmission fluid levels can also result in parts not getting lubricated enough. This leads to increased friction and, eventually, overheating causing the light to illuminate. Replace with fresh transmission fluid or top if the fluid looks okay but low.

While some cars require changing or topping transmission fluid every 30k-60k miles, others may run up to 100k miles before needing a top-up. Note that low fluid level can also stem from a leak, so while topping, find and fix the cause of a leak.

3. Use the correct automatic transmission oil

The AT oil temp light flashing in Subaru forester or any other model may be due to the wrong transmission fluid. Subaru works well with certain kinds of oil. While some utilize synthetic blend oils, others use full synthetic oil. Using the wrong oil can cause wear and tear among transmission parts.

Damaged transmission parts often lead to transmission overheating, prompting the warning light to turn on. Switch to the transmission fluid and brand compatible with your Subaru. If you are unsure which transmission oil type and brand best suits your model, consult your owner’s manual.

4. Fix faulty transmission

When transmission parts wear out, they cause overheating in the transmission, triggering the warning light to pop. The only way to permanently put off the light will be to repair or change the faulty transmission. You can, however, prevent transmission failure by carrying out routine servicing —checking fluid level, using correct fluid, etc.

5. Replace dirty or wrong transmission oil filter

As the oil moves through the system, it collects dirt and other impurities, which get trapped in the oil filter. Over time, the filter can get clogged, preventing oil from entering the transmission. This often results in oil shortage in transmission and eventually overheating, triggering the warning light.

Not using the correct filter can also result in similar issues. Wrong filters often result in leaks from the transmission, causing low oil levels leading to overheating.

Change dirty transmission oil filter or switch to the correct transmitter filter.

Most manufacturers recommend changing transmission filters every 30k miles or two years. So if your at oil temp in Subaru Outback keeps popping, try checking and replacing the transmission fluid filter.

6. Properly gauge oil level

Excess oil in the transmission prevents lubrication and rotation of the crankshaft, as well as causing high oil pressure. So, ensure you keep the oil level at the recommended line. When replacing or topping oil, add a little at a time to prevent too much oil in the transmission. Other issues you may have to tackle are faulty solenoids, transmission modules, etc.

Final Words

The At Oil Temp Subaru refers to the ATF fluid temperature in your Subaru and should appear when the transmission fluid temperature is high. AT oil temp Subaru fix could be as simple as allowing your car to cool. You only need to park and let your car idle while the transmission cools itself.

However, while cooling the transmission would turn off the light, get your car serviced immediately afterward. Chances are the light will return if there are underlying issues, putting your engine in harm.

Osuagwu Solomon

Osuagwu Solomon is a certified mechanic with over a decade of experience in the mechanic garage, and he has over five years of experience in the writing industry. He started writing automotive articles to share his garage experience with car enthusiasts and armature mechanics. If he is not in the garage fixing challenging mechanical problems, he is writing automotive repair guides, buyer’s guides, and car and tools comparisons.

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