Code 24, Intake Air Temp Sensor CKT/Low Temp Indicated
The IAT sensor uses a thermistor to control the signal voltage at ECM. ECM applies 4-6 volts to the sensor. When air is cold, thermistor resistance is high. ECM will sense a high signal voltage. If air is warm, sensor resistance is low. ECM will sense a low voltage.
NOTE:
Test numbers refer to test numbers on diagnostic chart.
- Verifies 4-5 volts is present at IAT sensor connector.
- Checks ground side of IAT sensor circuit.
- Determines whether problem is caused by ECM or by open circuit.
- Determines whether Black wire is open, or ECM is defective.