When I turn on the right turn signal of my 04 Avalanche my emergency falshers come on. Is this is flasher unit issue?

I've never seen a flasher cause this. Are you sure the flashers are actually comming on and it's not the parking lights on one side flashing with the flashers on the other side? I have seen bulbs short internally and cause the parking lights to flash in conjunction with a flasher or brake light. I have also seen an incorrect bulb and crossed wiring cause this, but this usually happens just after a bulb is replaced or wiring is repair/modified.

I was a trim electrical tech at a gm dealership. 9 ou t0f 10 times this was caused by a shorted flasher unit. ive done quite a few of those. I'd be willing to bet its a flasher issue

i would say flasher to i had that problem on a park avenue and put new flasher in and it cured it.