Front end vibrates when braking at high speeds. Does not vibrate at low speed.

What is your question?

We have replaced/inspected brakes, different parts in the front end, etc. Husband knows all about cars/builds them. Called the Chevy dealer and they did not know what it was about and had an Equinox in the shop with the same problem. No codes. No lights. 210K miles on the car. I am wondering if the ABS needs to be reset/replaced because one time when braking it bounced back like the ABS was active and the shaking was a lot less and now it is back to shaking a lot.