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Home >> Ford >> 2008 >> Escape Hybrid, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls (Hybrid) - Fault Code Index, Pinpoint Tests A - DL >> PINPOINT TEST DA: Intake Air Temperature (IAT) Sensor >> Test Procedure

Test Procedure

  1. DA1 CHECK FOR DIAGNOSTIC TROUBLE CODES (DTCS) 
    • Are any of the following DTCs present during PCM or transmission control module (TCM) self-test: P0112, P0113, or P0114? 
    Yes No
    For KOEO and KOER DTC P0112, GO to  DA6.
    For KOEO and KOER DTC P0113, GO to  DA2.
    For all others, GO to  DA8.    		 Unable to duplicate or identify the concern at this time.
    RETURN to the SYMPTOM CHARTS article, Symptom Charts for further direction.
  2. DA2 DTC P0113: CHECK THE IAT SIGNAL CIRCUIT 
    • 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 - Pin 1 Ground
    • Is the voltage between 4.5 - 5.5 V? 
    Yes No
    GO to  DA3. GO to  DA4.
  3. DA3 CHECK IAT SENSOR RESISTANCE 
    • Key in OFF position.
    • Measure the resistance between:
      ( + ) MAF/IAT Sensor Connector, Component Side ( - ) MAF/IAT Sensor Connector, Component Side
      IAT - Pin 1 SIGRTN - Pin 2
    • Is the resistance between 1K - 500K ohms? 
    Yes No
    GO to  DA4. INSTALL a new MAF/IAT sensor.
    REFER to the ELECTRONIC ENGINE CONTROLS - HYBRID .
    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 - Pin 1 IAT - Pin B39
      SIGRTN - Pin 2 SIGRTN - Pin B41
    • 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 - Pin 1 Ground
    • Is the voltage greater than 1 V? 
    Yes No
    REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test. GO to  DA11.
  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 PID.
    • Is the voltage greater than 4.2 V? 
    Yes No
    INSTALL a new MAF/IAT sensor.
    REFER to the ELECTRONIC ENGINE CONTROLS - HYBRID .
    CLEAR the DTCs. REPEAT the self-test.    		 Key in OFF position.
    GO to  DA7.
  7. DA7 CHECK THE SENSOR SIGNAL FOR A SHORT TO GROUND 
    • PCM connector disconnected.
    • Measure the resistance between:
      ( + ) PCM Connector, Harness Side ( - ) PCM Connector, Harness Side
      IAT - Pin B39 SIGRTN - Pin B41
    • Measure the resistance between:
      ( + ) PCM Connector, Harness Side ( - ) Vehicle Battery
      IAT - Pin B39 Negative terminal
    • Measure the resistance between:
      ( + ) PCM Connector, Harness Side ( - ) PCM Connector, Harness Side
      IAT - Pin B39 MAF RTN - Pin B43
    • Is the resistance greater than 10K ohms? 
    Yes No
    GO to  DA11. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.
  8. DA8 SELF-TEST DTCS P0112, P0113, P0114 OR P1112: INTERMITTENT CHECK 
    • Key ON, engine OFF.
    • Access the PCM and monitor the IAT 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 ELECTRONIC ENGINE CONTROLS - HYBRID for additional information.
    CLEAR the DTCs. REPEAT the self-test.    		 GO to  DA9.
  9. DA9 CHECK THE WIRING HARNESS 
    • Access the PCM and monitor the IAT PID.
    • While observing the PID, wiggle, shake, and bend small sections of the wiring harness 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  DA10.
  10. DA10 CHECK THE PCM AND VEHICLE HARNESS CONNECTORS 
    • PCM connector disconnected.
    • MAF/IAT Sensor connector disconnected.
    • Are the connectors and pins OK? 
    Yes No
    DISREGARD the current diagnostic trouble code (DTC) at this time. DIAGNOSE the next DTC. GO toDIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS . REPAIR as necessary.
    CLEAR the DTCs. REPEAT the self-test.
  11. DA11 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 toFLASH 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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