Ford Excursion, Expedition, Lincoln Navigator 2000-2005

Intake Air Temperature (IAT) Sensor



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Fig. The tip of the IAT sensor has an exposed thermistor that changes the resistance of the sensor based upon the force of the air rushing past it

The Intake Air Temperature (IAT) sensor determines the air temperature inside the intake manifold. Resistance changes in response to the ambient air temperature. The sensor has a negative temperature coefficient. As the temperature of the sensor rises the resistance across the sensor decreases. This provides a signal to the PCM indicating the temperature of the incoming air charge. This sensor helps the PCM to determine spark timing and air/fuel ratio. Information from this sensor is added to the pressure sensor information to calculate the air mass being sent to the cylinders. The IAT is a two wire sensor, a 5-volt reference signal is sent to the sensor and the signal return is based upon the change in the measured resistance due to temperature.

Removal & Installation

6.0L Diesel Engine

Make sure the ignition switch is in the OFF position prior to working on the electronic engine controls.

  1. Turn the ignition switch to the OFF position.
  3. Disconnect the intake air temperature 2 (IAT2) electrical connector and wiring harness retainer.
  5. Remove the IAT2 sensor.

To install:

  1. To install, reverse the removal procedure and note the following:
    1. Tighten air intake temperature sensor to 13 ft. lbs. (18 Nm).



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Fig. The IAT sensor can be monitored with an appropriate and Data-stream capable scan tool

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Fig. Measure the resistance of the IAT sensor across the two sensor pins

  1. Turn the ignition switch OFF.
  3. Disconnect the wiring harness from the IAT sensor.
  5. Measure the resistance between the sensor terminals.
  7. Compare the resistance reading with the accompanying chart.
  9. If the resistance is not within specification, the IAT may be faulty.
  11. Connect the wiring harness to the sensor.