Subaru AT Oil Temp Light Comes On? Here’s What It Means And How To Fix

Do you have a Subaru and the AT Oil Temp light comes on? Is it flashing, perhaps? Here's what it means and how to fix it.

These days, cars don’t just have warning lights. They often tell you exactly what’s wrong.

The AT Oil Temp warning light in Subarus is one such example. The automatic transmission’s oil temperature has exceeded the upper threshold. It’s too hot, in layman’s terms.

You’ll probably need a transmission rebuild.

In this guide, I will explain exactly why.

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What Is The Subaru AT Oil Temp Light?

Subaru AT Oil Temp

The AT Oil Temp warning means your automatic transmission’s oil is too hot.

  • “AT” – automatic transmission
  • “Oil Temp” – oil temperature

The oil (or transmission liquid, also known as ATF) needs to be maintained at a constant temperature. Its role is to ensure the parts stay cool.

When it gets very warm, the transmission will begin to overheat, which causes the parts and gears to expand and create significant harm to one another.

The transmission oil also can’t lubricate the parts properly if it gets too hot.

The AT Oil Temp light will flash or blink at you. It’s a warning. Your transmission isn’t working – it needs immediate attention, or it’ll break or seize!

Can You Drive With AT Oil Temp Light On A Subaru?


If you immediately stop and wait for a while, it might be possible. Might. You’ll need to drive extremely carefully and slowly, watching out for your transmission all the way.

You should leave the car to cool down for an hour or so. You could leave it idling or turn it off completely. The oil should cool enough to mean the warning light turns off.

If you notice any of the symptoms below, you should immediately stop. They mean it’s time for a breakdown company or tow truck to help.

  • Lurching or jumping
  • Difficulty changing gear
  • Overrevving
  • Stalling

The parts will get damaged if you drive without adequate lubrication in the transmission.

It’s best not to risk it. Call the tow truck immediately instead.

You’ll need to go straight to a transmission-specialist shop or a Subaru dealership.

What Causes The Subaru AT Oil Temp Warning Light?

adding transmission fluid

The warning light comes on to let you know that the transmission oil is too hot.

There are only really two possible causes here:

  1. Low transmission oil levels
  2. A mechanical problem within the transmission

Low transmission fluid levels could be caused by a leak. It should be checked and topped up at regular intervals. Check your service booklet to see when it was last inspected or changed.

A mechanical problem within an automatic transmission is a pretty serious issue. Any one of the hundreds of components could be the root cause, but it often rests with the solenoid, bands, and clutches.

How To Fix AT Oil Temp Problem On A Subaru

Car Mechanic

Unfortunately, overheating oil problem is likely to be an expensive fix. This is far too complicated to fix at home, even for mechanically-minded individuals.

If you’re lucky, all you’ll need is a transmission fluid top-up or change. A simple transmission oil change should cost around $200 – a top-up will, of course, be much less.

This isn’t recommended. It’s more likely to be $200 down the drain than an efficient fix.

There’s more to it than magical, vanishing ATF. If the oil has leaked out, where has it gone? Your topped-up transmission will simply leak again.

As such, you’ll often find that you need a complete transmission rebuild – regardless of whether the problem is mechanical or low-fluid related.

Expect to pay out somewhere between $2,000 and $3,000 for this. The cost is mainly made up of labor.

Don’t forget that, in most instances, the mechanic will need to strip the component, find the problem, mend it, and rebuild it. There’s a lot to do – hence the cost.

Is A Subaru AT Oil Temp Warning Worth Fixing?

Car and money value

As with all mechanical problems, the longer you leave it, the more damage it’ll do. The resultant bill from the mechanic will get exponentially higher with time, too.

As soon as you see the warning light, you need to go straight for professional help. You might save a small amount of money by going to a local transmission shop rather than a dealership, but expect it to be expensive either way.

What is the value of your car? Will the repairs be more expensive than its total worth? When it comes to important tasks like rebuilding the transmission, it’s worth taking a break.

If so, it might be more financially worthwhile to scrap it and use the proceeds to buy another.

The Subaru AT Oil Temp warning is perfectly fixable – but not without some serious damage to your wallet.

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Benjamin Kitchen

Ben is an IMI-qualified light vehicle technician from England with experience in a fast-fit garage. He aims to help drivers worldwide with common automotive problems. You’ll often find him working with his 1.2 Vauxhall Corsa. It may have a tiny engine, but in eight years it's never once let him down!