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Home >> Ford >> 2014 >> Fusion Energi Titanium >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Pinpoint Tests (Hybrid) >> Pinpoint Test DW: Heated Oxygen Sensor (Ho2S) >> Test Procedure
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Test Procedure

  1. DW1 CHECK FOR DIAGNOSTIC TROUBLE CODES (DTCS) 

    Are DTCs P0054, P0137, P0138, P013A, P013E or P0141 present? 

    Yes No
    GO to DW2  . RETURN to ENGINE CONTROLS - SYMPTOM CHARTS (HYBRID) for further direction.
  2. DW2 VISUALLY INSPECT THE HO2S HARNESS 
    • Ignition OFF.
    • Verify the HO2S connectors are connected to the correct engine bank.
    • Visually inspect for:
      • crossed sensor wires
      • pinched, shorted, and corroded wiring and pins
      • oil or water contamination
      • damaged HO2S

    Is a concern present? 

    Yes No
    REPAIR as necessary.
    Clear the PCM DTCs. REPEAT the self-test.    		 GO to DW3  .
  3. DW3 CHECK FOR A SOURCE OF POTENTIAL HO2S CONTAMINATION 
    • Investigate the following items as potential sources of HO2S contamination:
      • use of unapproved silicon sealers
      • fuel contaminated by silicon additives
      • excessive oil consumption
      • glycol leaking internally in the engine
      • contaminated fuel
      • short drive cycles in cold weather
      • use of unapproved cleaning agents

    Is a concern present? 

    Yes No
    REPAIR the source of the contamination.
    CHANGE the engine oil and oil filter.
    RESET the keep alive memory (KAM). REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) , Programming the VID Block for a Replacement PCM.
    REPEAT the self-test.    		 GO to DW4  .
  4. DW4 CHECK FOR UNMETERED AIR LEAKS 
    NOTE: Fuel calculations can be affected by unmetered air leaks.
    • Carefully inspect the following areas for potential air leaks:
      • hoses connecting to the mass airflow (MAF) sensor assembly
      • hoses connecting to the throttle body
      • intake manifold gasket leaks
      • positive crankcase ventilation (PCV) system
      • the vacuum lines are disconnected
      • incorrectly seated engine oil dipstick, tube or oil fill cap

    Are any air leaks present? 

    Yes No
    REPAIR the source of the air leak. RESET the keep alive memory (KAM). REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) , Programming the VID Block for a Replacement PCM.
    REPEAT the self-test.    		 GO to DW5  .
  5. DW5 CHECK FOR EXHAUST SYSTEM AND FUEL SELECTION CONCERNS 
    • Inspect the exhaust system for the following:
      • exhaust leaks at flanges and gaskets
      • exhaust leaks at the HO2S
      • aftermarket accessories and performance modifications

    Is a concern present? 

    Yes No
    REPAIR as necessary.
    Clear the PCM DTCs. REPEAT the self-test.    		 GO to DW6  .
  6. DW6 CHECK FOR VPWR 
    • HO2S connector disconnected.
    • Check the connector (both halves) for any water contamination.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) HO2S Connector, Harness Side (-)
      VPWR - Pin 1 Ground

    Is the voltage greater than 10.5 V? 

    Yes No
    GO to DW7  . REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test.
  7. DW7 CHECK THE HO2S CIRCUITS FOR AN OPEN 
    • Ignition OFF.
    • PCM connector disconnected.
    • Measure the resistance between:
      (+) HO2S Connector, Harness Side (-) PCM Connector, Harness Side
      HO2S12 - Pin 4 HO2S12 - Pin E21
      HTR12 - Pin 2 HTR12 - Pin E35
      SIGRTN - Pin 3 SIGRTN - Pin E9

    Are the resistances less than 5 ohms? 

    Yes No
    GO to DW8  . REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test.
  8. DW8 CHECK THE HO2S CIRCUITS FOR A SHORT 
    • Measure the resistance between:
      (+) HO2S Connector, Harness Side (-) HO2S Connector, Harness Side
      HO2S12 - Pin 4 SIGRTN - Pin 3
      HO2S12 - Pin 4 HTR12 - Pin 2
      HTR12 - Pin 2 SIGRTN - Pin 3
    • Measure the resistance between:
      (+) HO2S Connector, Harness Side (-)
      HO2S12 - Pin 4 Ground
      HTR12 - Pin 2 Ground

    Are the resistances greater than 10K ohms? 

    Yes No
    GO to DW9  . REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test.
  9. DW9 CHECK THE HO2S CIRCUITS FOR A SHORT TO VOLTAGE 
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) HO2S Connector, Harness Side (-)
      HO2S12 - Pin 4 Ground
      HTR12 - Pin 2 Ground
      SIGRTN - Pin 3 Ground

    Is any voltage present? 

    Yes No
    REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test. GO to DW10  .
  10. DW10 CHECK THE INTERNAL RESISTANCE OF THE HO2S HEATER 
    • Ignition OFF.
    • Measure the resistance between:
      (+) HO2S Connector, Component Side (-) HO2S Connector, Component Side
      HTR12 - Pin 2 VPWR - Pin 1

    Is the resistance between 3 - 30 ohms? 

    Yes No
    GO to DW11  . INSTALL a new HO2S. REFER to the Electronic Engine Controls article. RESET the keep alive memory (KAM). REFER to DIAGNOSTIC METHODS .
    REPEAT the self-test.
  11. DW11 CARRY OUT A THOROUGH WIGGLE TEST ON THE HO2S HARNESS 
    • Ignition OFF.
    • PCM connector connected.
    • HO2S connector connected.
    • Ignition ON, engine OFF.
    • Access the PCM and monitor the O2S12 (VOLT) PID.
    • Carry out a thorough wiggle test on the HO2S harness.

    Does the voltage change during the wiggle test? 

    Yes No
    REPAIR as necessary.
    Clear the PCM DTCs. REPEAT the self-test.    		 GO to DW12  .
  12. DW12 CHECK THE HO2S SIGNAL 
    • Ignition OFF.
    • HO2S connector disconnected.
    • Ignition ON, engine running.
    • Access the PCM and monitor the O2S12 (VOLT) PID.

    Is the voltage less than 1 V? 

    Yes No
    GO to DW13  . GO to  DW14.
  13. DW13 CHECK THE HO2S CIRCUIT CONTINUITY 
    • Ignition OFF.
    • Connect a 5 amp fused jumper wire between the following:
      Point A HO2S Connector, Harness Side Point B HO2S Connector, Harness Side
      HO2S12 - Pin 4 VPWR - Pin 1
    • Ignition ON, engine running.
    • Access the PCM and monitor the O2S12 (VOLT) PID.

    Is the voltage greater than 1 V? 

    Yes No
    INSTALL a new HO2S. REFER to the Electronic Engine Controls article.
    Clear the PCM DTCs. REPEAT the self-test.    		 GO to DW14  .
  14. DW14 CHECK FOR CORRECT PCM OPERATION 
  15. Ignition OFF. 
    • 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.
    • Verify the concern is still present.

    Is the concern still present? 

    Yes No
    INSTALL a new PCM. REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) , Programming the VID Block for a Replacement PCM. The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
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