Transmission Temperature Light: What It Means and What to Do
The Transmission Temperature Light means the transmission fluid is too hot, which can quickly break down the fluid and damage clutches, bands, and seals.
- What it looks like
- A gear with a thermometer inside it, or a text message such as AT OIL TEMP.
- Color
- Red or amber/yellow depending on the vehicle; often accompanied by a 'Transmission Hot' or 'AT Oil Temp' message.
Also called: transmission overheat light, AT oil temp light, transmission fluid temperature warning, gear with thermometer light
Updated 2026-11-07 · By CarWhere Research
Why the transmission temperature light comes on
A temperature sensor in the transmission reports fluid temperature to the transmission control module. Heat builds when the torque converter slips, when towing or climbing grades, or when fluid is low or old. Above a set limit the light comes on, and some vehicles change shift patterns or limit power to protect the transmission.
Common causes
- Towing a heavy load or climbing long grades
- Low or degraded transmission fluid
- Restricted transmission cooler or cooler lines
- Stop-and-go driving in hot weather, or rocking a stuck vehicle
- Torque converter slipping
- Internal slipping from worn clutches
- Faulty fluid temperature sensor
What to do when the transmission temperature light comes on
- Reduce speed and load right away.
- Pull over safely, shift to Park, and let the engine idle so fluid circulates, or follow the owner's manual procedure.
- Wait until the light goes out before continuing.
- Check the transmission fluid level and condition if your vehicle has a dipstick; dark or burnt-smelling fluid is a warning sign.
- Avoid towing until the cause is found, and consider an auxiliary cooler if you tow often.
- Have the transmission codes read if the light returns under normal driving.
Symbols and colors vary by manufacturer; your owner’s manual has the exact meaning for your vehicle.
Related OBD-II codes
P0218 — Transmission Fluid Over Temperature Condition
P0710 — Transmission Fluid Temperature Sensor "A" Circuit
P0711 — Transmission Fluid Temperature Sensor "A" Circuit Range/Performance
P0712 — Transmission Fluid Temperature Sensor "A" Circuit Low
P0713 — Transmission Fluid Temperature Sensor "A" Circuit High
P0868 — Transmission Fluid Pressure Low
P0894 — Transmission Component Slipping
P0740 — Torque Converter Clutch Solenoid Circuit/Open
Transmission Temperature Light FAQ
What does the transmission temperature light mean?
The Transmission Temperature Light means the transmission fluid is too hot, which can quickly break down the fluid and damage clutches, bands, and seals.
Can I keep driving with the transmission temperature light on?
Pull over as soon as it is safe and let the transmission cool; on most automatics, leave the engine idling in Park so the fluid can circulate through the cooler unless the manual says otherwise. Do not continue towing or climbing until the light goes out, and have the cause found.
What causes a transmission to overheat?
Heavy towing, long climbs, hot weather traffic, low or old fluid, and internal slipping are the usual causes. Each generates heat faster than the cooler can remove it.
Should I turn the engine off when the transmission temperature light comes on?
On many automatics, idling in Park cools the fluid faster because the pump keeps it moving through the cooler. If the engine is also overheating, shut it off instead.
Can overheating damage my transmission?
Yes. High heat breaks down fluid and hardens seals, which leads to slipping and further heat. Repeated overheating shortens transmission life.
Other dashboard warning lights
Sources
- 49 CFR 571.101 (FMVSS No. 101) — Controls and displays: telltale symbols and colors
- NHTSA — Check for open safety recalls by VIN
General information written by CarWhere Research, not a diagnosis of your vehicle. When in doubt, stop in a safe place and follow your owner’s manual.