Diagnostic Aids

WARNING: This page is about a different car, the 2016 GMC Acadia, 2016 Chevrolet Traverse, and 2016 Buick Enclave. However, it is still accessible from the selected car via links, so may be relevant.

The IAT Sensor 1 and IAT Sensor 2 are integrated with the multifunction intake air sensor. With RPO LF3, this 8-pin sensor is in the intake air duct nearest to the front of the vehicle; for rear wheel drive vehicles it is on the driver's side.
With the ignition ON, the engine OFF and the engine is cold, a properly functioning IAT sensor 2 will gradually increase the scan tool IAT Sensor 2 parameter. This is due to the heat that is generated by the multifunction intake air sensor heating elements.
The humidity sensor and the IAT sensor 2 signals are sent to the ECM on the same circuit. If the IAT Sensor 2 parameter displays the values: 10 Hz; -40°C (-40°F), and there are Humidity Sensor DTCs, check for a circuit problem.