Hidden Switch connection - Prius gen2

Check this diagram out.

Toyota Prius (XW20) (2003-2009) Fuse Diagram • FuseCheck.com

and these threads on Priuschat.

You want the "DC cut short pin" that disables the ignition and accessories that the factory uses for overseas shipping of a new vehicle.

D/C cut, short pin dome fuse | PriusChat

Prius generation matters for "short pins TS & CG" kinds of procedures! | PriusChat

 

I couldn’t recommend this modification, or indeed any changes that might cause the vehicle to stop unexpectedly in traffic, which is potentially a very serious hazard.

The IGN fuse supplies the hybrid vehicle control ECU, engine control module, battery ECU, and ID code box, and the coil of the C/OPN relay (circuit opening relay), which controls the fuel pump, so the fuse isn’t likely to blow. Adding a switch and relay to the circuit would decrease its reliability, and Toyota’s published information doesn’t tell us how these ECUs would respond if the IGN circuit were opened.

If you choose to proceed despite this warning, there are many considerations for selecting an appropriate relay, some of which are reviewed in Panasonic’s Automotive Relay Users Guide (PDF).

I couldn’t recommend this, either: it might cause the car to stall if the sensor is actuated because of a bump or an ascending or descending grade. I’m also not sure it’s of much value: if thieves are tilting the car, to load it onto a tow truck or reach the catalytic converter, they’re probably not trying to start or drive it.

Neither the Electrical Wiring Diagram (more info) for 2006 Prius cars nor the page you linked shows a D/C CUT fuse or shorting pin. On other models that do have such a fuse or pin, removing it wouldn’t prevent the car from being started or driven; it just reduces the dark current (parasitic load on the auxiliary battery) by disabling the radio and other convenience features.

 

You’re most welcome.

I agree that disabling the power switch might not be quite as risky, but it could still defeat a built-in safety feature, the ability to turn off the hybrid system while driving, as might be desirable in case of a stuck accelerator pedal or other malfunction. As Toyota writes in the Owner’s Manual (PDF) for U.S.-specification vehicles, on pages 141 and 143:

If, in an emergency, you must turn the hybrid system off while the vehicle is moving, press the “POWER” switch more than 3 seconds. At this time, the “ACC” mode and shift position “N” are automatically enabled.​

In addition, consider that there could be electromagnetic compatibility or other reasons that the power switch requires a continuous connection to body ground.

 

I'm experimenting with a modified push button start-stom switch that will light up but will not turn on the accessories or start the car. Finding the pins to clip off will be the tougest part.

Keeping the totally functioning start-stop button in a hidden place and putting in the modified dummy switch will really deter the thief. Another method might be just to put a kill switch in the wiring harness to the start function in the start-stop circuit.

It very low 5 volts, so a small micro switch will work. It could also be a hidden micro push button that needs to be held dowi with your left hand finger to complete the circuit to start the car. Because it is a momentary push button, it will automatically reset after each use.