Aspirated TAT probes are an option.
Ohh, and i just checked the AMM and origin IGO A/Cs have no aspirated TAT probes.
But even when you have a airplane with this option you find no hint in the FCOM.
You have the option installed when (on ground) the TAT indication change after you put the APU bleed in on.
(source of the air is the x-bleed duct muscle pressure line to the Trim Air Pressure Regulating Valve)