throttle body

[figgie]

ummm

you guys are aware that the Throttle body of the CTS is Drive By Wire.

Yes it is metal but has electronics in it to do away with the cable. Works quite well.

[CaddiLackin]

good point

[Marlin]

The drive by wire has a motor/actuator on the throttle body. You should be able to replace it without replacing the TB.

[tommy compton]

it could be the throttle position sensor??? i by-passed the coolant line's going into the throttle body(meant to to warm the valve to prevent sticking in cold weather) well i never changed it back last winter and i would get thrown into limp mode(had to warm the car up abit and restart to clear it)
it threw up a throttle position sensor code, it would actually disable my traction control and abs system as they are all interconnected.
your problem is not mine, but i'm wondering if it is possible that the sensor in yours maybe faulty.
but yes the motor/actuator sounds like a good source too.