A pulsing brake pedal on your Canyon III almost always traces back to rotor thickness variation or uneven pad deposits, not a mysterious electronic gremlin. Here is what I check first, and how long you can safely keep driving.
What that pulsing pedal is really telling you
When you press the brake pedal on your GMC Canyon III and feel it throb or pulse in rhythm with wheel speed, you are feeling a mechanical variation in the brake rotor, not the pedal itself. As the wheel turns, the caliper piston and pads are being pushed in and out by a rotor that is no longer uniform. On these trucks, the classic story is disc thickness variation — the rotor is slightly thicker in one spot than another — and you feel one pulse per wheel revolution. It is worth saying up front that what everyone calls a 'warped rotor' is usually not a bent piece of iron. It is more often uneven pad material transfer, hot spots, or runout caused by something else, like a hub flange that was not perfectly clean when the rotor was installed. That distinction matters, because slapping on new rotors without fixing the root cause just means you will be back in the same spot in 10,000 miles.
