Came across an interesting service bulletin. I can't recall anyone ever posting about this, but I don't read all the forums regularly.

Service bulletin NTB10-079:

If you have a check engine light on with code P0128 (thermostat) and you have an aftermarket remote start system installed, disconnect the remote start system and see if the code goes away.

This bulletin applies to 2002 and newer Maximas. There is no solution given.