Speedometer

Has the Check Engine Light /Service Engine Soon light come on and or the traction control light and cruise control stopped working if so the Vehicle Speed Sensor VSS has most likely failed, if no other symptoms are present the problem may be the instrument cluster itself.

This is very common on the 03-06 GMs. The cause is the motors behind the gauges are failing, they all go out eventually. You can get it repaired here - www.drspeedometer.com and there's a DIY guide here - www.howtorepairmyinstrumentcluster.com