I've read where the Avalanche is pre-wired for an electronic brake control? is this true, if so what controller would I need to purchase?

 

The wires are wrapped up under the dash, there are youtube videos that show you where the wires are and how to install it. I bought a pigtail with plug.. so the controller could be moved to another vehicle or easily replaced.. the choice of which to get is mostly between a proportional and non proportional . with proportional giving you better control. I have 2 reese controllers (plugin style) in my vehicles, purchased from amazon... The latest being a Reese Towpower 8508211 (49$).. I can't say it is the best or not, but it does the job.

 

The manufacturer of the controller should have a wiring adapter available to match your truck to the controller. No splicing required.