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Home >> Ford >> 2005 >> Freestyle SEL, FWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 1544 (Engine Controls - Pinpoint Test A: No Start Through Pinpoint Test DJ: Air Conditioning Evaporator Temperature (ACET) Sensor - (Except Diesel & Hybrid)) >> Pinpoint Test DA: Intake Air Temperature (IAT) Sensor >> Test Procedure

Test Procedure

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  1. DA1 CHECK FOR DTCS 

    Are DTCs P0112, P0113, P0114, or P1112 present? 

    Yes No
    For KOEO and KOER DTC P0112, GO to  DA6.
    For KOEO and KOER DTC P0113, GO to  DA2.
    For continuous memory DTCs P0112, P0113 or P1112, GO to  DA9.
    For DTC P0114, GO to  DA9.    		 For all others, GO to DIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS .
  2. DA2 DTC P0113: CHECK THE IAT SIGNAL CIRCUIT 
    NOTE: The DTC indicates the sensor signal is greater than the self-test maximum.
    • MAF/IAT Sensor connector disconnected.
    • Key ON, engine OFF.
    • Measure the voltage between:
      ( + ) MAF/IAT Sensor Connector, Harness Side ( - )
      IAT Ground

    Is the voltage between 4.5 - 5.5 V? 

    Yes No
    GO to  DA3. GO to  DA4.
  3. DA3 CHECK THE IAT SENSOR RESISTANCE 
    • Key in OFF position.
    • Measure the resistance between:
      ( + ) MAF/IAT Sensor Connector, Component Side ( - ) MAF/IAT Sensor Connector, Component Side
      IAT SIGRTN

    Is the resistance between 1K - 500K ohms? 

    Yes No
    GO to  DA4. INSTALL a new MAF/IAT sensor. REFER to the appropriate ELECTRONIC ENGINE CONTROLS article .
    CLEAR the DTCs. REPEAT the self-test.
  4. DA4 CHECK THE SIGNAL AND SIGRTN CIRCUITS FOR AN OPEN IN THE HARNESS 
    • PCM connector disconnected.
    • Measure the resistance between:
      ( + ) MAF/IAT Sensor Connector, Harness Side ( - ) PCM Connector, Harness Side
      IAT IAT
      SIGRTN SIGRTN

    Are the resistances less than 5 ohms? 

    Yes No
    GO to  DA5. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
  5. DA5 CHECK THE SIGNAL FOR A SHORT TO VOLTAGE IN HARNESS 
    • Key in OFF position.
    • PCM connector disconnected.
    • Key ON, engine OFF.
    • Measure the voltage between:
      ( + ) MAF/IAT Sensor Connector, Harness Side ( - )
      IAT Ground

    Is the voltage greater than 1 V? 

    Yes No
    REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test. GO to  DA12.
  6. DA6 DTC P0112: SIMULATE AN OPPOSITE SIGNAL TO THE PCM 
    NOTE: The DTC indicates the sensor signal is less than the self-test minimum.
    • MAF/IAT Sensor connector disconnected.
    • Key ON, engine OFF.
    • Access the PCM and monitor the IAT V PID.

    Is the voltage greater than 4.2 V? 

    Yes No
    INSTALL a new MAF/IAT sensor. REFER to the appropriate ELECTRONIC ENGINE CONTROLS article .
    CLEAR the DTCs. REPEAT the self-test.    		 GO to  DA7.
  7. DA7 CHECK THE IAT CIRCUIT FOR A SHORT TO MAF RTN 
    • Key in OFF position.
    • PCM connector disconnected.
    • Measure the resistance between:
      ( + ) MAF/IAT Sensor Connector, Harness Side ( - ) MAF/IAT Sensor Connector, Harness Side
      IAT MAF RTN

    Is the resistance less than 5 ohms? 

    Yes No
    REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test. GO to  DA8.
  8. DA8 CHECK THE IAT CIRCUIT FOR A SHORT TO GROUND 
    • PCM connector disconnected.
    • Measure the resistance between:
      ( + ) PCM Connector, Harness Side ( - ) PCM Connector, Harness Side
      IAT SIGRTN
    • Measure the resistance between:
      ( + ) PCM Connector, Harness Side ( - ) 12 Volt Vehicle Battery
      IAT Negative terminal

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  DA12. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.
  9. DA9 SELF-TEST DTCS P0112, P0113, P0114 OR P1112: INTERMITTENT CHECK 
    • Key ON, engine OFF.
    • Access the PCM and monitor the IAT V PID.
    • While observing the PID, carry out the following:
      • Tap on the sensor to simulate road shock
      • Wiggle the sensor connector

    Is there a large change in the voltage reading? 

    Yes No
    DISCONNECT and INSPECT the connector. If OK, INSTALL a new MAF/IAT sensor. REFER to the appropriate ELECTRONIC ENGINE CONTROLS article .
    CLEAR the DTCs. REPEAT the self-test.    		 GO to  DA10.
  10. DA10 CHECK THE ELECTRONIC ENGINE CONTROL (EEC) WIRING HARNESS 
    • Access the PCM and monitor the IAT V PID.
    • While observing the PID, wiggle, shake, and bend small sections of the wiring harness while working from the sensor to the PCM.

    Is there a large change in the voltage reading? 

    Yes No
    ISOLATE the concern. REPAIR as necessary.
    CLEAR the DTCs. REPEAT the self-test.    		 GO to  DA11.
  11. DA11 CHECK THE PCM AND VEHICLE HARNESS CONNECTORS 
    • Key in OFF position.
    • PCM connector disconnected.
    • MAF/IAT Sensor connector disconnected.

    Are the connectors and terminals OK? 

    Yes No
    The concern is not present at this time. REPAIR as necessary.
    DISREGARD the current diagnostic trouble code (DTC) at this time. DIAGNOSE the next DTC. GO to DIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS . CLEAR the DTCs. REPEAT the self-test.
  12. DA12 CHECK FOR CORRECT PCM OPERATION 
    • Disconnect all the PCM connectors.
    • Visually inspect for:
      • pushed out pins
      • corrosion
    • Connect all the PCM connectors and make sure they seat correctly.
    • Carry out the PCM self-test and verify the concern is still present.

    Is the concern still present? 

    Yes No
    INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) . The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
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