Try a general google search, it's more likely to bring up technical info like this with the exact, or similar application that uses the same part. Rockauto lists only the 2010-2011 GMC Terrain as using the same throttle body as the 08-11 CTS. The mismatch between the plug sockets is a strong indication that even if you get it wired correctly, it will not operate compatibly with the PCM. Sounds like you have a throttle body from a 2012+ model. The throttle valve may be a different diameter which will cause an air load mismatch with the throttle position, or the built in sensor calibration may be different, or both.