Let me take a wild stab at this problem. The job of the traction control is to sense the car is in a skid situation and cut power to the engine so that it slowes down allowing the driver to regain control on the vehicle. Along with cutting power to the engine it also applies individual brake to the fastest spinning wheel. How it decides that car is in a skid situatuin is through getting information from a combination of sensors: steering angle sensor, yaw sensor and four individual speed sensors on each of the wheels. What is happening is that one or more of these sensors is/are triggering the traction control into thinking your car is in a skid situation and cutting power to the engine.
So what to do to fix it? Connect a good scanner that can read live data. The scanner will identify the cause of triggering your car's traction control system. Check the real time output from the 4 wheel speed sensors. They must have identical ouput while driving in a straight line. Check the yaw sensor output, in a straight line drive reading should be zero. The steering angle sensor should report zero angle. You can do a bit of zig zag driving to see how these sensor readings vary. This is my take on your problem. Others with more experience can guide you better.
