Toyota Repair: Green ext pwr light is on, toyota 4runner, pwr

Question
I have a 1998 Toyota 4Runner and starting yesterday my green ext pwr light came on my dash.  Any ideas of what I need to do to get it turned off?

Thanks for your help!!!!  

Answer
I think you mean the ECT power light, is this correct because the term ext pwr light makes no sense to me.
There is a switch on the shift console that lets you switch between normal and ECT power transmission operation, all you have to do is press the switch to make the transmission go to normal mode.