5DII Flash Setting

[lennon33x]

So, I use a Yongnuo YN 560III/IV as a bounce for weddings. I recently switched to this system because I love the idea of adjusting my flash power remotely/firing remotely. However, the YN560 III and IV only have a single firing pin in the shoe. Therefore, when it makes contact with the hotshoe of my 5D Mark II, it doesn't register that a flash is present (I imagine I would have to use a TTL flash to make that happen). Does anyone know any way to over ride this feature? I prefer to shoot in Av with a bounce flash, but if I need to I can stay in manual.

 

[FotosbyMike]

You are correct to control a flash from your camera you need to have a TTL enable flash connected, I.E. YN-568EXII, YN-565 EX, YN560, Canon 430EXII, 580EXII, 600...etc.
So you will not be able to adjust the power output of the flashes from the camera, the only way to get the correct exposure from the flash is to adjust the aperture. I would stay in manual so you can control your shutter speed(ambient light), aperture(flash) and ISO(both) when needed.