Transmission Temperature Light on a Subaru Forester
Have this checked promptly. It is not an immediate stop, but do not ignore it for long.
What the Transmission Temperature Light Means on a Subaru Forester
On the Subaru Forester, this red light means automatic transmission fluid temperature has climbed too high — often from towing, heavy loads, or low/old fluid. Continuing risks expensive gearbox harm.
How Urgent Is the Transmission Temperature Light?
Urgency level for this indicator on the Subaru Forester: high. Reading the colour is the fastest gut-check — a red symbol asks you to stop and investigate quickly, while amber or yellow means schedule a check soon rather than immediately. Green and blue symbols are simply telling you a system is active. Whatever the colour, the safest habit is to note when the Transmission Temperature Light appeared, how the Subaru Forester is behaving, and whether the light is steady or flashing, because a flashing warning almost always means act now.
Common Symptoms Alongside the Transmission Temperature Light
The Transmission Temperature Light on your Subaru Forester is one data point, and the symptoms around it are the rest of the story. Perhaps the engine feels different, a gauge reads unusually, or the car behaves normally but the symbol simply will not clear. Note everything you observe, because the pattern of symptoms on the Subaru Forester is exactly what turns a vague warning into a specific, fixable diagnosis.
- Transmission temp warning lit
- Delayed or harsh shifts
- Burning smell
- Transmission slipping under load
- Often appears when towing or climbing hills
What Causes the Transmission Temperature Light to Come On?
Why did the Transmission Temperature Light come on in your Subaru Forester? The honest answer is 'it depends', but the possibilities cluster into a recognisable set of causes. Knowing them in advance means you will not be caught off guard by a diagnosis, and it lets you sanity-check any repair quote against what commonly goes wrong on the Subaru Forester.
- Heavy towing or load
- Low transmission fluid level
- Old, degraded fluid
- Blocked transmission cooler
- Stuck thermostat or failing pump
How to Fix the Transmission Temperature Light on a Subaru Forester
The right way to clear the Transmission Temperature Light on a Subaru Forester is to fix the underlying cause, not just reset the symbol. Work through the steps below in order — they move from the simplest checks any driver can do to the diagnostic work best left to a scan tool. Following this sequence prevents the classic mistake of replacing expensive parts before ruling out the cheap, common problems first.
- Pull over safely and let the transmission cool with the engine idling in park
- Reduce load and avoid stop-start driving until cool
- Check transmission fluid level and condition
- Have the cooler and fluid inspected
- Service the fluid or repair the cooling circuit as diagnosed
Is It Safe to Drive With the Transmission Temperature Light On?
Whether it is safe to keep driving your Subaru Forester with the Transmission Temperature Light on comes down to urgency (high) and behaviour. As a rule, if the light is red or flashing, or the Subaru Forester is running poorly, stop somewhere safe and arrange help rather than pushing on. If the light is amber and the car drives normally, you generally have time to reach a workshop — but 'have time' is not the same as 'ignore it', so book a check promptly.
Diagnostic Trouble Codes Linked to the Transmission Temperature Light
If you scan a Subaru Forester showing this light, these are the OBD-II trouble codes most commonly associated with it. The code you actually retrieve is what pinpoints the repair.
| Code | Meaning |
|---|---|
P0700 |
Transmission Control System Malfunction A general request from the transmission control module indicating a stored transmission fault. |
P0740 |
Torque Converter Clutch Circuit Malfunction The torque converter lock-up clutch circuit is not responding correctly, affecting shifting and economy. |
Professional Mechanic Tips
Burnt-smelling, dark transmission fluid is overdue for a change — old fluid is a leading cause of overheating.
If this light appears while towing with a Subaru Forester, pulling over and idling in park (not off) lets the fluid circulate and cool fastest.
Frequently Asked Questions
Why is the Transmission Temperature Light on in my Subaru Forester?
On a Subaru Forester, the Transmission Temperature Light comes on because a monitored value crossed a threshold the car considers abnormal. It could be a simple, inexpensive cause or a genuine fault — the only way to be sure is to scan the vehicle and interpret the codes rather than guess from the symbol alone.
Can I keep driving with the Transmission Temperature Light on?
Short answer: sometimes, but not indefinitely. Given this indicator's high priority, respect the warning colour and the car's behaviour. When in doubt with your Subaru Forester, the safe choice is to stop and have it checked rather than risk further damage.
How much does it cost to fix the Transmission Temperature Light on a Subaru Forester?
Cost varies widely because the Transmission Temperature Light can stem from several causes on a Subaru Forester. Some fixes are almost free — tightening a cap or a connector — while others involve a sensor or component and its labour. Getting the specific trouble code first is what lets a shop quote accurately instead of estimating blind.
Will the Transmission Temperature Light reset itself on a Subaru Forester?
Sometimes the Transmission Temperature Light on a Subaru Forester clears on its own once the condition that triggered it no longer exists — for example after several good drive cycles. More often, though, the light stays on until the underlying fault is repaired and the code is cleared, so treat a self-clearing light as a reason to still investigate.