2004 silverado 1500.
abs pump making loud buzzing noise. abs pump has constant power to it. vehicle doesnt have to be running. ignition doesnt even have to be on. just keeps buzzing had to unplug fuse to get it to stop. one day it was sitting in my driveway and it started to make the noise. it almost sounds like the abs pulsating sound but I cant feel it in the brake pedal. Ive had problems with the abs sensors and had to replace the wheel bearing hub assemblys. but this is weird. can anyone help? will my vehical pass inspection with the abs light on?

 

pass somg? it will pass smog with the abs light on but i have no idea what is wrong with it but it sounds like a electrical problem

 

Have you got it scanned? If you do and you get a code CO265. It indicates the electronic brake control module motor. My 03 chev had that, and turned out to be the grounds under the driver's side door on the body mount. I cleaned those write out and cured the ABS light. This is a common problem with GM trucks.