I was driving up a sustained uphill, maybe 20min drive, gaining about 500m. The road was rough'ish, but nothing hard. Was shifted into 4Low. The 'A/T temp' light came on. I stopped let the engine run for 5min, then turned off the car and turned it on again - light was gone. Is this normal? Should my transmission be overheating? I wasn't hammering the gas or anything, just steady climb up. This happened earlier this summer when it was 30c degrees. But now it's below freezing and still happened again! The engine temp (i.e. coolant temp) was normal during the climb - just above the mid-point. Radiator is clean, not caked up with mud or anything. The truck is a 04 Xterra Supercharged. Running a lift with 32s (BFG KO2s), aftermarket bumpers and winch, but the truck itself was empty, so not very loaded down or anything! I had a shop replace the transmission oil about 6 months ago as well, when I got the new truck. I know that on longer climbs shifting down into 4Low is recommended to ensure the transmission gearing stays high so the oil circulates. I did that, maybe I should have shifted down into 1st or 2nd gear as well??