DTC 47, IAT Sensor Circuit Low (High Temperature Indicated): Notes

Intake Air Temperature (IAT) sensor is a thermistor that controls signal voltage to PCM. When air is cold, sensor resistance is high, and PCM will sense a high signal voltage. As air warms, sensor resistance becomes less and voltage drops. DTC 47 will set when:

Engine coolant temperature is less than 100°F (38°C).
Intake air temperature is greater than 205°F (96°C) for 2 seconds.

PCM will default to poor engine performance during cold operation.

NOTE: Test numbers refer to numbers on diagnostic chart.

This step determines if DTC 47 is result of a hard failure or an intermittent condition.
This step determines if IAT signal circuit is shorted to ground.