There are a few different reasons why the traction control system might tell you to check it. Some of the most common causes include:
* A problem with the traction control sensor. The traction control sensor monitors the speed of the wheels and the amount of slip. If the sensor is not working properly, it can send incorrect information to the traction control system, which can cause it to malfunction.
* A problem with the traction control module. The traction control module controls the traction control system. If the module is not working properly, it can cause the system to malfunction.
* A problem with the wiring. If the wiring to the traction control system is damaged or loose, it can cause the system to malfunction.
If you see the "check traction control" light come on in your 2004 Ford Freestar, you should take the vehicle to a qualified mechanic to have the system checked out.