Connecting an EcoRoute HD to 2011 Prius (classic)

I have been trying to connect an EcoRoute to my car without success. I have ruled out the device being defective by trying a second one.

I get the standard "Cannot connect to your vehicle. Turn off your vehicle, check the accessory connection, and then try again" message on my GPS. The device is rarely described on the forums, but when it is no one else mentions difficulty connecting. I cannot find people having difficulty elsewhere on the worldwide web either.

For anyone who utilizes the EcoRoute HD, what order do you use to connect the device? I have tried the following:

--Turning car fully on by pressing the break pedal and power button, connecting the EcoRoute to the Garmin (successful) then afterward being told it cannot connect to the car.

--Turning car on by pressing the power button only (does not work)
--Pressing power button twice without depressing gas pedal (does not work)

I used the EcoRoute in another vehicle and it was finicky. Any assistance would be HUGELY appreciated.