Did you recently change your engine air filter? If so and you happened to disconnect the (Map) Sensor to remove the filter easier, it will trip these codes sometimes if not connected back correctly. The (IAT) Intake Air Temperature Sensor Wiring is connected to the (MAP) Sensor in that harness connection. Check this location
Can anyone send me a location of the IAT sensor location. I see the MAF sensor and I unplugged that and opened the air intake and pulled the filter out but I do not see any other sensors. Or would someone have a pic. Autozone shows something totally different than the gmc parts website.