What Does That “AT Oil Temp” Light Mean?
The "AT Oil Temp" light on your car's dashboard tells you that the automatic transmission fluid temperature is too high. The transmission will enter a failsafe mode and won't shift until the fluid has cooled down. This is a safety feature to prevent damage to the transmission.
If this light comes on, pull over and turn off the engine as soon as possible. You should let the transmission cool down for a few minutes before checking the fluid level. If it's low, add more fluid. If the level is fine, check the transmission for leaks.
It's best to scan your vehicle's computer for codes to get a more accurate idea of what's going on. You can usually do this for free at your local auto parts store. Once you have the codes, you can look them up to see what they mean and what needs to be done to fix the problem.