[Casper]

Traction control doesnt gradually reduce power on the AU's, it just shuts it all down in a hurry.
As parawolf said, if you dont have the button, you dont have TC. All AU XR's have the spot in the dash for the light (mine does) but not too many were fitted with it. I'm betting its auto related however I dont know if its torque truncation or simply your auto overheating which can have a similar effect.