AT Oil Temp Subaru: Meaning, Causes, Symptoms, & Fixes

The AT Oil Temp Subaru, or Automatic Transmission Oil Temperature, is a warning light that illuminates when the transmission oil temperature is too high. This can be caused by several things, including low transmission fluid, clogged AT oil filter, towing a heavy load, or driving in hot weather.

If the oil warning light comes on, it’s vital to take action to cool down the transmission to prevent damage whether you are driving a Subaru Forester, Subaru Outback, Subaru Impreza, or any other Subaru model. Pull over to the side and idle the car to let the transmission cool itself down.

The AT oil temp Subaru light is an essential indicator of the health of your car’s automatic transmission. This article will discuss what it means when the AT oil temp Subaru light comes on, what might be causing it, and how to fix it.

Why Is the AT Oil Temp Subaru Light Flashing?

The AT Oil Temp light on your Subaru will flash when the transmission oil temperature is too high.

This can be caused by several things, such as a clogged AT oil filter, driving in stop-and-go traffic, or towing a heavy load.

If the AT Oil Temp light is flashing, it’s vital to take action immediately to avoid damaging your transmission.

What to Do When AT Oil Temp Subaru Light Flashes?

You can do several things to fix an oil temp light flashing.

First, try to idle your car for a while to allow the transmission to cool down. If that doesn’t work, you may need to add transmission fluid if the levels are low, or have your transmission serviced.

If the AT oil temp light comes on, it’s essential to take action immediately. Overheating can damage your transmission and lead to costly repairs.

By troubleshooting the problem and taking care of it quickly, you can avoid major issues down the road.

In some cases, you may need to replace your transmission altogether. If you’re not sure what to do, it’s best to take your car to a mechanic for repair.

Related: Car Won’t Move in Any Gear Automatic Transmission

AT Oil Temp Subaru Causes

If the AT oil temp light illuminates your dashboard, there are some potential causes.

One probable cause is that the transmission is overheating.

This can be caused by various factors, such as a malfunctioning thermostat or low fluid levels.

If the oil light comes on while driving, pull over and shut off your car immediately. Continuing to drive could damage your transmission.

Here are a few causes to AT oil temp light illuminating:

Low Transmission Fluid

One common cause of an illuminated oil light is low fluid levels. When the AT oil level is too low, it can’t properly cool the transmission.

Dirty AT Oil Filter

A dirty AT oil filter can restrict AT oil flow, which will increase the AT oil temperature.

Another common cause is a clogged transmission cooler. This can occur if the AT oil filter is not replaced regularly.

Bad Transmission Fluid Usage

The manufacturer of your Subaru vehicle recommends the use of Subaru ATF hp “Dexron iii” transmission fluid.

While using another type of transmission fluid can seem to work fine, it can cause problems in the future.

Lubrication Issue

Another potential cause of the AT oil temp light is a problem with the transmission’s lubrication system.

When this happens, the transmission won’t be able to cool down properly and will overheat.

One common symptom of a lubrication system issue is gear slippage.

If you notice your car slipping gears or shaking when you accelerate, it could be a sign that you need to have your transmission serviced.

AT Oil Temp Subaru Symptoms

Some potential symptoms of this problem include the car hesitating when shifting gears or the transmission slipping.

In severe cases, the transmission can overheat and fail completely.

If you notice any of these issues, have your car checked by a mechanic as soon as possible.

Constant flashing warning light

Symptoms of a high transmission oil temperature include the AT oil temp light constant flashing, and this warning light is an indicator that the automatic transmission is too hot.

Related: P0420 Code – Meaning, Causes, Symptoms, & Fixes

This can happen due to a number of reasons, such as a malfunctioning thermostat or low transmission fluid levels.

If this light comes on, you should pull over and stop the car as soon as possible to prevent further damage.

Transmission failure

Automatic transmissions depend on transmission fluid to keep them cool and functioning properly.

When the automatic transmission oil temperature becomes too high, it can cause transmission failure.

There are several factors that can contribute to high AT oil temp light, such as driving habits, type of transmission fluid used, and terrain.

How to Fix AT Oil Temp Subaru

There are several things you can do to fix this problem, including adding more transmission fluid, driving in a lower gear, or pulling over and letting the car cool down.

With a little bit of knowledge and preventive care, you can keep your oil temperature light from illuminating and causing problems to your vehicle.

Stop and Allow the Engine to Idle

When you see the AT oil temp light on your Subaru, find a safe place to park.

Let the engine idle, or turn the ignition switch to off, so the transmission can cool down on its own while not being under a heavy load.

After a while, the warning signal will go off on its own, but your transmission will probably overheat again as you carry on your trip.

Inspect Transmission Fluid Level

The most obvious solution is to add more AT oil if you see the oil temp warning light. This will help to cool the transmission and prevent it from overheating.

If the AT oil level is acceptable, then you may need to replace the automatic transmission fluid filter.

A clogged AT oil filter can be cleaned with a solvent such as a carburetor cleaner. If the AT oil filter is damaged, it will need to be replaced.

If your automatic transmission fluid temperature is still too high after doing these steps, you may need to take your vehicle to a mechanic.

The transmission may need to be flushed or replaced.

This is a costly repair, so it’s important to address the problem as soon as possible.

How Much Does It Cost to Repair Subaru Transmission?

The cost of a fluid transmission change is around $200, but this is just one potential repair expense. In order to determine the actual cost of repairs, you need to know what’s wrong with the vehicle; however, most repairs will start at $1,000, with an average cost of around $2,000. A complete transmission refurbishment or replacement is likely to cost as much as $3,500.

Subaru vehicles are not cheap to maintain, especially when it comes to the powertrain.

My advice would be to have the vehicle inspected, and the transmission oil changed.

If this does not solve the problem, you need to weigh the current value of the vehicle against the cost of several thousand dollars in repairs.

If the math does not add up, sell the car instead of repairing it and use the money to buy another vehicle.


There are a few things that can cause a transmission failure. One of the most common reasons is when the transmission fluid is low or dirty.

This can cause the system to overheat, leading to failure.

Symptoms of a transmission failure include shuddering, jerking, and a loss of power.

If you experience any of these symptoms, it’s important to take your car to a mechanic as soon as possible.

There are a few things that you can do to prevent a transmission failure, such as making sure the fluid is clean and at the correct level and avoiding driving in extreme temperatures.

If you experience a transmission failure, there are a few repair options available. However, the best way to avoid this issue is to take preventative measures.

Although it is possible to fix this problem at home, it is highly recommended that you let certified mechanics diagnose and repair your transmission.

We hope this article was helpful in understanding oil temp warning flashing and its causes, symptoms, and fixes.

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Robin Söder

Robin has always been passionate about cars ever since young age. Over the years, Robin has worked on thousands of cars and gained invaluable experience in the process. He is considered an expert in his field and is often consulted by other mechanics for advice.

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