LEMON Manuals: Even more car manuals for everyone
Home >> Ford >> 2022 >> Transit Connect Titanium, Gas/Ethanol >> Repair and Diagnosis >> External Pages >> Different car >> Section 503 (Engine Controls - Pinpoint Tests (Except Diesel & Hybrid) (A To H)) >> Pinpoint Tests Fa: Ambient Air Temperature (AAT) Sensor >> Test Procedure

Test Procedure

WARNING: This page does not describe the selected car, but rather 27 other vehicles, including the 2021 Lincoln Navigator, 2021 Lincoln Nautilus, 2021 Lincoln Corsair, 2021 Lincoln Aviator, and 2021 Ford Transit-350 HD. However, it is still accessible from the selected car via links, so may be relevant.
  1. FA1 CHECK FOR DTCS 

    Are DTCs P0071, P0072, P0073 or P0074 present? 

    Yes No
    GO to  FA2 RETURN to Symptom Charts for further direction.
  2. FA2 CHECK FOR AN OPEN 
    • Ignition OFF.
    • AAT Sensor connector disconnected.
    • PCM connector disconnected.
    • Measure the resistance between:
      (+) AAT Sensor Connector, Harness Side (-) PCM Connector, Harness Side
      AAT AAT
      SIGRTN SIGRTN

    Are the resistances less than 5 ohms? 

    Yes No
    GO to  FA3 REPAIR the open circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  3. FA3 CHECK FOR A SHORT 
    • Measure the resistance between:
      (+) AAT Sensor Connector, Harness Side (-)
      AAT Ground
    • Measure the resistance between:
      (+) AAT Sensor Connector, Harness Side (-) AAT Sensor Connector, Harness Side
      AAT SIGRTN

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  FA4 REPAIR the short circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  4. FA4 CHECK FOR A SHORT TO VOLTAGE 
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) AAT Sensor Connector, Harness Side (-)
      AAT Ground
      SIGRTN Ground

    Is any voltage present? 

    Yes No
    REPAIR the short circuit. Clear the PCM DTCs.
    REPEAT the self-test.    		 GO to  FA5
  5. FA5 INTERMITTENT CHECK 
    • Ignition OFF.
    • PCM connector connected.
    • AAT Sensor connector connected.
    • Ignition ON, engine OFF.
    • Access the PCM and monitor the AAT_V (VOLT) PID.
    • While observing the PID, carry out the following:
      • Wiggle the harness from the sensor to the module.
      • Wiggle the connectors and make sure they seat correctly.
      • Look for sudden changes in the PID value when the harness and connector are wiggled.

    Is a concern present? 

    Yes No
    REPAIR as necessary.
    Clear the PCM DTCs. REPEAT the self-test.    		 GO to  FA6
  6. FA6 CHECK THE RESISTANCE OF THE AAT SENSOR 
    NOTE: Verify the external temperature of the sensor is at ambient temperature. Refer to the Ambient Air Temperature (AAT) Sensor  Expected Values chart for the temperature and resistance values.
    • Ignition OFF.
    • AAT Sensor connector disconnected.
    • Measure the resistance between:
      (+) AAT Sensor Connector, Component Side (-) AAT Sensor Connector, Component Side
      AAT SIGRTN

    Is the resistance within specification? 

    Yes No
    The system is operating correctly at this time.
    The concern may have been caused by a loose or corroded connector.    		 INSTALL a new AAT sensor. REFER to the appropriate Service Information article.
    RESET the keep alive memory (KAM). Refer to Resetting The Keep Alive Memory (KAM).
    Clear the PCM DTCs. REPEAT the self-test.
scientia non olet · About LEMON Manuals