Why is my brake pedal pulsating?

Sounds like the ABS may be activating. If the pedal does not vibrate all the time when you press it then this is not a brake pulsation due to warped rotors.

If this is happening on dry roads then we need to start with scanning for ABS codes. Here is a guide that will help with this:

https://www.youtube.com/watch?v=rTtAnsOlZU4

Depending on the codes we will have a better idea but the most likely cause of this is either a speed sensor issue or an ABS module issue.

I attached the info below on this but let's start with the codes and go from there. Thanks