02 Avalanche (ABS)

For some reason the there is a constant buzzing from the Electro-Hydraulic Control Unit (EHCU). My OBD II Scanner pulled two codes: C0265 EBCM relay circuit - open and C0267 Pump motor circuit - open or shorted circuit. Could the EHCU be faulty?

You need to get and go threw the repair flow charts for you codes.
A good factory repair manual or.
http://www.alldata.com/products/diy/index.html
And remember always clear codes and see whatcomes back.

Common problem. My coworker needed an abs module because the built in internal relay was stuck and the pump continued to run.

Don't forget to check fuse's & relays!

A blown fuse = open circuit

Thanks for all the responses. I'll let you know what happens.