300, 300C & Magnum 2006-2008, Charger 2006-2008

Intake Air Temperature Sensor

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Operation



The Intake Air Temperature (IAT) Sensor provides an input voltage to the Powertrain Control Module (PCM) indicating the density of the air entering the intake manifold based upon intake manifold temperature. At key-on, a 5-volt power circuit is supplied to the sensor from the PCM. The sensor is grounded at the PCM through a low-noise, sensor-return circuit. The resistance values of the IAT sensor are the same as for the Engine Coolant Temperature (ECT) sensor.

The PCM uses this input to calculate the following:



Injector pulse-width
 
Adjustment of spark timing (to help prevent spark knock with high intake manifold air-charge temperatures).
 

Removal & Installation



2.7L, 3.5L & 5.7L Engines
  1. Disconnect negative battery cable.
  2.  
  3. Unlock the Inlet Manifold Air Temperature (IAT) sensor electrical connector.
  4.  
  5. Remove electrical connector from sensor
  6.  
  7. Note the orientation of the sensor.
  8.  
  9. Remove the sensor from air inlet hose.
  10.  

To install:

  1. Install the IAT sensor. Rotate for proper orientation of sensor.
  2.  
  3. Install the electrical connector and lock.
  4.  
  5. Connect negative battery cable.
  6.  

Testing



2.7L, 3.5L & 5.7L Engines
  1. If possible, allow the vehicle to sit with the ignition off for more than 480 minutes in an environment where the temperature is consistent and above 19.4°F (-7°C).
  2.  
  3. With a scan tool, select View DTCs.
  4.  
  5. If an Intake Air Temperature (IAT) Sensor code is present, turn the ignition off.
  6.  
  7. Disconnect the Intake Air Temperature Sensor harness connector.
  8.  
  9. Turn the ignition on.
  10.  
  11. With a scan tool, read the IAT sensor voltage.
  12.  
  13. The sensor voltage should be approximately 5.0 volts (plus or minus .1 volt) with the connector disconnected. If not check the signal circuit for an open or high resistance.
  14.  
  15. If the sensor voltage was approximately 5.0 volts (plus or minus .1 volt), turn the ignition off.
  16.  
  17. Connect a jumper wire between the (K21) IAT Signal circuit and the (K900) Sensor Ground circuit in the Intake Air Temperature Sensor harness connector.
  18.  
  19. Turn the ignition on.
  20.  
  21. With a scan tool, read the IAT sensor voltage.
  22.  
  23. The sensor voltage should be approximately 0.0 volts (plus or minus .1 volt) with the jumper wire in place.
  24.  
  25. If the scan tool displays the voltage as described above suspect faulty IAT sensor.

    Click image to see an enlarged view

    Fig. Intake Air Temperature (IAT) Sensor harness connector

  26.  

 
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