If you had it put on and you feel it's not working properly, take it back and have them fix it. (this is assuming you had it put on recently).
If not, towing packages unless used very often tend to have the wires corrode, break away, lose what were nice connections, etc. Look at the wires as stated above and make sure all the connections are clean and not eroding away.
07' Chevy Cobalt SS - GMPP SRI INTAKE / JET PERFORMANCE MODULE