Steve (chestr) is correct. What makes the Prius EV mode operate is the computer's (ECU) programming along with a momentary switch (not available in US/Canadian units) to enable the function. Unfortunately, that programing function was not written for the '07 TCH, so just adding a switch won't give us EV capability.

John


2007 TCH -- Desert Sand, Bisque -- Original Equip: Leather Seats; NAV; Moonroof; Heated Seats
Completed Mods: Moved the side "HYBRID" emblem/badge to trunk lid; Mud Guards (Colored); Back-up Sensors; Door sill protector; ScanGauge II; Front Bra (Clear LLumar); Window Tinting (40 % Charcoal LLumar); Rear Deck Lid Spoiler
Mods in progress: None
Future mods: Rear bumper appliqué, Sliding Center Armrest