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Home >> Subaru >> 2004 >> Forester X, Automatic >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Diagnostic Trouble Code (DTC) Detecting Criteria (H4SO) >> Diagnostic Trouble Code (DTC) Detecting Criteria >> DTC P0691: Cooling Fan 1 Control Circuit Low
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DTC P0691: Cooling Fan 1 Control Circuit Low

  1. OUTLINE OF DIAGNOSIS 
    • Detect the open/short circuit of radiator fan circuit.
    • Judge NG when the ECM output level and the actual terminal level are different.
  2. ENABLE CONDITION 
    ENABLE CONDITION

    Secondary Parameters Enable Conditions
    Engine speed "GREATER THAN EQUAL TO" 500 rpm
    Battery voltage "GREATER THAN EQUAL TO" 8V
    After engine starting 1 second or more
    Ignition switch ON
  3. GENERAL DRIVING CYCLE 

    Always perform the diagnosis continuously after starting the engine.

  4. DIAGNOSTIC METHOD 

    Judge NG when the continuous time until completing the malfunction criteria below becomes more than the time (2.5 seconds) needed for diagnosis, and also judge OK when the malfunction criteria below is not completed. And then clear NG.

    Judgment Value 

    JUDGMENT VALUE

    Malfunction Criteria Threshold Value
    Terminal voltage level when ECM transmits OFF signal Low level

    Time Needed for Diagnosis:  2.5 seconds

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

  5. DTC CLEAR CONDITION 
    • When the OK idling cycle was completed 40 times in a row
    • When "Clear Memory" was performed
  6. MALFUNCTION INDICATOR LIGHT CLEAR CONDITION 
    • When the OK driving cycle was completed 3 times in a row
    • When "Clear Memory" was performed
  7. FAIL SAFE 

    None

  8. ECM OPERATION AT DTC SETTING 

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