Hello and welcome to Just answer.com, Super mechanic here. About your vehicle.
You will want to have it scanned for any trouble codes to see what area the problem may be in. Just let us know what the code(s) are and we can go from there.
The only thing that I can figure is that it may be that the ABS is activating at low speeds, as there is a bulletin that mentions that with no trouble codes. Wheel speed sensors, dirty.
Bulletin No.: 02-05-25-006B
Date: January 05, 2006
This bulletin is being revised to update the correction and warranty information. Please discard Corporate Bulletin Number 02-05-25-006A (Section 05 - Brakes).
Some customers may comment on ABS activation at low speeds, usually below 8 km/h (5 mph). Upon investigation, the technician will find no DTCs set.
The cause of this condition may be an increased air gap between the wheel speed sensor and the hub reluctor ring due to rust and debris built up on the sensor mounting surface.
Measure AC voltage and clean wheel speed sensor mounting surfaces.