2007 Lucerne, 3.8L. Basically have replaced every component on the brake system at this point with the exception of the front calipers, brake booster, ABS pump and ABS controller. It has all new brake lines and brake fluid, and new pads and rotors all around. I've replaced the master cylinder and both rear wheel hubs with the speed sensor have been replaced as well. It has been bled multiple times using the Autel computer bleed procedure I borrowed from a friend. I'm not getting any ABS related codes when I scan it.

My problem is that the ABS is activating at low speed, when coming to a stop. The brakes feel fine, and the car still stops, but just before it stops the pedal vibrates while the ABS activates, and the pedal drops a little faster than it probably should. It happens very regularly, almost every time you stop. When the roads were still icy, I tested it at higher speed and the ABS performed as expected. This is happening on dry roads, at a speed when I wouldn't think the ABS would even activate. Without a specific code, I'm trying to figure out where to look next? ABS controller? ABS pump? I'm also wondering if it could be a speed sensor/wheel hub but figured I would get a code if those were bad? Any help would be greatly appreciated. Thank you.