· Premium Member
Probably because it comes with the power rear slider. You can only get rear defroster on solid rear window trucks, as in previous years.
Can you see the heating element wires on your back window? I have the same button, but all it does is heat my mirrors.The button operates the heated mirrors ( if equipped) and rear defroster
the following is afrom my 2009 owners manual pg. 172:
Rear Window Features-
The rear window defroster button is located on the climate control panel. Press this button to turn on the rear window defroster and the heated outside mirrors ( if equipped). An indicator in the button will illiminate when the rear window defroster is on....