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Home >> Subaru >> 2004 >> Forester XT, Standard >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Diagnostic Trouble Code (DTC) Detecting Criteria (H4DOTC) >> Diagnostic Trouble Code (DTC) Detecting Criteria >> DTC P0111: Intake Air Temperature Circuit Range/Performance
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DTC P0111: Intake Air Temperature Circuit Range/Performance

  1. OUTLINE OF DIAGNOSIS 

    Detect the malfunction of intake air temperature sensor output property.

    Judge NG when the intake air temperature is not varied whereas it seemed to be varied from the viewpoint of engine condition.

  2. COMPONENT DESCRIPTION 
    Fig 1: Intake Air Temperature Circuit Range/Performance Graph
    G03320224Courtesy of SUBARU OF AMERICA, INC.
  3. ENABLE CONDITION 
    ENABLE CONDITION CHART

    Secondary Parameters Enable Conditions
    Coolant temp, before engine start < 30°C (86°F)
    Coolant temperature > 75°C (167°F)
    Battery voltage "GREATER THAN EQUAL TO" 0.9 V
    Continuous time when the vehicle speed is less than 50 km/h (31 MPH) 600 seconds or more
  4. GENERAL DRIVING CYCLE 

    Perform the diagnosis when the vehicle speed condition is completed after idling from starting the cooled engine.

  5. DIAGNOSTIC METHOD 
    • Abnormality Judgment 

      Judge NG when the continuous time of completing the malfunction criteria below becomes more than 1 second.

      Judgment Value 

      JUDGMENT VALUE CHART

      Malfunction Criteria Threshold Value
      Output voltage difference between Max. and Min. < 20 mV (It is equal to approx. 0.5°C (33°F) around 25°.)
      Exhaust temperature above 500°C (932°F) 60 seconds or more

      Time Needed for Diagnosis:  1 second

      Malfunction Indicator Light Illumination:  Illuminates when malfunction occurs in 2 continuous driving cycles.

    • Normality Judgment 

      Judge OK and clear the NG when the malfunction criteria below are completed.

      Judgment Value 

      JUDGMENT VALUE CHART

      Malfunction Criteria Threshold Value
      Output voltage difference between Max. and Min. "GREATER THAN EQUAL TO" 0 mV
  6. DTC CLEAR CONDITION 
    • When the OK idling cycle was completed 40 times in a row
    • When "Clear Memory" was performed
  7. MALFUNCTION INDICATOR LIGHT CLEAR CONDITION 
    • When the OK driving cycle was completed 3 times in a row
    • When "Clear Memory" was performed
  8. FAIL SAFE 

    Intake air temperature sensor process: Intake air temperature is fixed at 20°C (68°F).

  9. ECM OPERATING AT DTC SETTING 

    Memorize the freeze frame data. (For test mode $02)