The TCA is snapped to the surface of the evaporator box, facing the rear of the car. The sensor for the unit is at the end of a 12 inch lead, passing through an opening in the seam of the two piece evaporator box shell, attached to a plastic clip embedded into the downstream face of the evaporaor.
Search my posting. There are several pictures.
PS I thought the TCA was an r134a item that replaced the TSV (throttle suction valve). I may be wrong.