Diagnostic Aids

WARNING: This page is about a different variant/trim than selected.

With the ignition ON, when the engine is OFF and cold, properly functioning IAT sensors 1 and 2 will gradually increase the scan tool IAT Sensor 1 and 2 parameters. This is due to the heat that is generated by the multifunction intake air sensor internal 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: 10Hz; -40°C (-40°F), and there are also Humidity Sensor DTCs, check for a circuit problem.