new to the landyzone question on tc

After receiving help on the traction control issue, i have a manual that i downloaded. It explained that the light tc on the dash means that it has taken the traction control off line and will not work. Just as well, i say, but i would like to find out the cause. The traction control uses the rear brakes and the slip sensors from the abs system to apply the rear brake on the spinning wheel. What should i look for?? Loses abs gear, bad sensor, ??

Thanks again for the help

Harold Calvert
Chicago, IL, USA