Intake Air Temperature Sensor 1 Circuit

Intake air temperature sensor circuit malfunction. On Ford trucks, the IAT is integrated into the MAF sensor. Check the MAF/IAT connector for backed-out pins or corrosion. If the reading is erratic, replace the MAF/IAT assembly (Motorcraft). Also verify the air filter box is properly sealed -- hot engine air entering the intake causes false readings. Confirm the exact part for your year and engine with a retailer's fitment lookup or your VIN before ordering - these applications split by engine and build date.

The IAT sensor on the 5.3L is located in the intake air duct. Check the connector for corrosion from water intrusion. Test the sensor resistance -- should be approximately 2.5K ohms at 68F. If resistance is out of spec, replace with an OE-quality ACDelco unit. Also check for a damaged air intake duct allowing engine bay heat to skew readings. Confirm the exact part for your year and engine with a retailer's fitment lookup or your VIN before ordering - these applications split by engine and build date.

IAT sensor is integrated into the MAF on Nissan QR25DE. Check the connector at the MAF for moisture or corrosion. If the scan tool shows -40F or 300F readings, the sensor element has failed or there is an open/short in the circuit. Replace the MAF/IAT assembly (Hitachi). Also check for a damaged air filter housing allowing unfiltered air in. Confirm the exact part for your year and engine with a retailer's fitment lookup or your VIN before ordering - these applications split by engine and build date.