[zroger73]

The A/T temp light came on when I put it into 4WD.

You don't "put" a Ridgeline into "4WD" - the rear wheels assist as-needed without any input from the driver. It's a fully automatic system.

Did you mean you put the Ridgeline in VTM-4 LOCK mode by shifting to R, 1, or 2 then pressing the VTM-4 LOCK button? If you did under conditions where you shouldn't have, then that likely caused your transmission to overheat and took tens of thousands of miles off the life of the clutches in the VTM-4 unit.

 

[zroger73]

VTM-4 lock has nothing to do with A/T temp lights. They are separate systems, although sorta related. I think the RL comes with a HD tranny cooler because it needs it, and not just for towing.

If the A/T overheats, the A/T light comes on. If the VTM-4 unit overheats, the VTM-4 indicator blinks.

If the OP was driving at low speeds while in "2", that could easily explain the high A/T temp.

Also, if VTM-4 lock is used on inappropriate (high friction) surfaces, more power is required to overcome the holding capacity of the clutches. This additional power requirement causes the transmission and VTM-4 unit to produce more heat and can eventually lead to an overheat condition in both components.