Test Procedure

2007 Ford Escape Base, 2.3 Z, FWD, AutomaticSECTION Test Procedure
WARNING: This page is about a different car, the 2011 Mercury Milan, 2011 Lincoln MKZ, 2011 Ford Fusion, 2010 Mercury Milan, and 2010 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.
  1. DZ1 CHECK FOR DIAGNOSTIC TROUBLE CODES (DTCS) 

    Are any of the following DTCs present during PCM or transaxle control module (TCM) self-test: P0030, P0053, P0130, P0133, P0134, P0135, P1127, P2096, or P2097? 

    Yes No
    For DTC P0030, GO to  DZ2.
    For DTCs P0053 or P0135, GO to  DZ5.
    For DTC P0130, GO to  DZ10.
    For DTC P0133, GO to  DZ14.
    For DTC P0134, GO to  DZ17.
    For DTC P1127, GO to  DZ18.
    For DTCs P2096 or P2097, GO to  DZ19.
    For symptoms without DTCs, GO to  DZ23.
    For all others, GO to DIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS .
  2. DZ2 DTC P0030: CHECK FOR MISFIRE CONCERNS AND AFTERMARKET EQUIPMENT 
    • Ignition OFF.
    • Check for the following:
      • misfire concern
      • non-factory or aftermarket equipment that may increase the exhaust temperature
    • Universal HO2S-Front connector disconnected.
    • Check the universal HO2S connector for damage or corrosion.

    Is a concern present? 

    Yes No
    REPAIR as necessary.
    Clear the PCM DTCs. REPEAT the self-test.
    GO to  DZ3.
  3. DZ3 CHECK THE UO2SHTR CIRCUIT FOR A SHORT TO VOLTAGE 
    • PCM connector disconnected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
    VOLTAGE REFERENCE CHART

    (+) Universal HO2S-Front Connector, Harness Side (-)
    UO2SHTR - Pin 3 Ground

    Is any voltage present? 

    Yes No
    REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test. GO to  DZ4.
  4. DZ4 CHECK THE UO2S, UO2SGREF, UO2SHTR CIRCUITS FOR AN OPEN IN THE HARNESS 
    • Ignition OFF.
    • Measure the resistance between:
    RESISTANCE REFERENCE CHART

    (+) Universal HO2S-Front Connector, Harness Side (-) PCM Connector, Harness Side
    UO2S - Pin 6 UO2S - Pin E38
    UO2SGREF - Pin 2 UO2SGREF - Pin E26
    UO2SHTR - Pin 3 UO2SHTR - Pin E52

    Are the resistances less than 5 ohms? 

    Yes No
    INSTALL a new Universal HO2S. REFER to the ELECTRONIC ENGINE CONTROLS (HYBRID)
    RESET the keep alive memory (KAM). REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) .
    REPEAT the self-test.
    REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test.
  5. DZ5 DTCS P0053 AND P0135: CHECK FOR VPWR IN THE HARNESS 
    • Ignition OFF.
    • Universal HO2S-Front connector disconnected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
    VOLTAGE REFERENCE CHART

    (+) Universal HO2S-Front Connector, Harness Side (-)
    VPWR - Pin 4 Ground

    Is the voltage greater than 10 V? 

    Yes No
    GO to  DZ6. REPAIR the open circuit. CHECK the fuses.
    Clear the PCM DTCs. REPEAT the self-test.
  6. DZ6 CHECK THE UO2SHTR CIRCUIT FOR AN OPEN IN THE HARNESS 
    • Ignition OFF.
    • Universal HO2S-Front connector disconnected.
    • PCM connector disconnected.
    • Measure the resistance between:
    RESISTANCE REFERENCE CHART

    (+) Universal HO2S-Front Connector, Harness Side (-) PCM Connector, Harness Side
    UO2SHTR - Pin 3 UO2SHTR - Pin E52

    Is the resistance less than 5 ohms? 

    Yes No
    GO to  DZ7. REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test.
  7. DZ7 CHECK THE UO2SHTR CIRCUIT FOR A SHORT IN THE HARNESS 
    • Measure the resistance between:
      RESISTANCE REFERENCE CHART

      (+) Universal HO2S-Front Connector, Harness Side (-) Vehicle Battery
      UO2SHTR - Pin 3 Negative terminal
    • Measure the resistance between:
    RESISTANCE REFERENCE CHART

    (+) Universal HO2S-Front Connector, Harness Side (-) Universal HO2S-Front Connector, Harness Side
    UO2SHTR - Pin 3 UO2S - Pin 6
    UO2SHTR - Pin 3 UO2SGREF - Pin 2
    UO2SHTR - Pin 3 UO2SPC - Pin 1
    UO2SHTR - Pin 3 UO2SPCT - Pin 5
    UO2SHTR - Pin 3 VPWR - Pin 4

    Are the resistances greater than 10K ohms? 

    Yes No
    GO to  DZ8. REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test.
  8. DZ8 CHECK THE INTERNAL RESISTANCE OF THE UNIVERSAL HO2S HEATER 
    • Measure the resistance between:
    RESISTANCE REFERENCE CHART

    (+) Universal HO2S-Front Connector, Component Side (-) Universal HO2S-Front Connector, Component Side
    VPWR - Pin 4 UO2SHTR - Pin 3

    Is the resistance between 1.8 - 9 ohms? 

    Yes No
    GO to  DZ9. INSTALL a new Universal HO2S. REFER to the ELECTRONIC ENGINE CONTROLS (HYBRID)
    RESET the keep alive memory (KAM). REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) .
    REPEAT the self-test.
  9. DZ9 CHECK THE UO2SHTR CIRCUIT FOR AN INTERNAL SHORT TO GROUND 
    • Measure the resistance between:
    RESISTANCE REFERENCE CHART

    (+) Universal HO2S-Front Connector, Component Side (-)
    UO2SHTR - Pin 3 Ground

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  DZ25. INSTALL a new Universal HO2S. REFER to the ELECTRONIC ENGINE CONTROLS (HYBRID)
    RESET the keep alive memory (KAM). REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) .
    REPEAT the self-test.
  10. DZ10 DTC P0130: CHECK THE UO2S AND UO2SGREF CIRCUITS FOR AN OPEN IN THE HARNESS 
    • Ignition OFF.
    • Universal HO2S-Front connector disconnected.
    • PCM connector disconnected.
    • Measure the resistance between:
    RESISTANCE REFERENCE CHART

    (+) Universal HO2S-Front Connector, Harness Side (-) PCM Connector, Harness Side
    UO2S - Pin 6 UO2S - Pin E38
    UO2SGREF - Pin 2 UO2SGREF - Pin E26

    Are the resistances less than 5 ohms? 

    Yes No
    GO to  DZ11. REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test.
  11. DZ11 CHECK THE UO2S, UO2SGREF, UO2SPC, AND UO2SPCT CIRCUITS FOR A SHORT TO GROUND IN THE HARNESS 
    • Measure the resistance between:
    RESISTANCE REFERENCE CHART

    (+) Universal HO2S-Front Connector, Harness Side (-)
    UO2S - Pin 6 Ground
    UO2SGREF - Pin 2 Ground
    UO2SPC - Pin 1 Ground
    UO2SPCT - Pin 5 Ground

    Are the resistances greater than 10K ohms? 

    Yes No
    GO to  DZ12. REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test.
  12. DZ12 CHECK THE UO2S, UO2SGREF, UO2SPC, AND UO2SPCT CIRCUITS FOR A SHORT TO VOLTAGE IN THE HARNESS 
    • Ignition ON, engine OFF.
    • Measure the voltage between:
    VOLTAGE REFERENCE CHART

    (+) Universal HO2S-Front Connector, Harness Side (-)
    UO2S - Pin 6 Ground
    UO2SGREF - Pin 2 Ground
    UO2SPC - Pin 1 Ground
    UO2SPCT - Pin 5 Ground

    Is any voltage present? 

    Yes No
    REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test. GO to  DZ13.
  13. DZ13 CHECK THE UO2SGREF CIRCUIT FOR VOLTAGE 
    • Ignition OFF.
    • PCM connector connected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
    VOLTAGE REFERENCE CHART

    (+) Universal HO2S-Front Connector, Harness Side (-)
    UO2SGREF - Pin 2 Ground

    Is the voltage between 2.4 - 2.6 V? 

    Yes No
    INSTALL a new Universal HO2S. REFER to the ELECTRONIC ENGINE CONTROLS (HYBRID)
    RESET the keep alive memory (KAM). REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) .
    REPEAT the self-test.
    GO to  DZ25.
  14. DZ14 DTC P0133: CARRY OUT THE KOER SELF-TEST 
    • Engine at normal operating temperature.
    • Carry out the PCM KOER self-test.

    Are any DTCs present other than P0133? 

    Yes No
    DISREGARD the current diagnostic trouble code (DTC) at this time. DIAGNOSE the next DTC. GO to DIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS . GO to  DZ15.
  15. DZ15 CHECK FOR A SOURCE OF POTENTIAL CONTAMINATION 
    • Investigate the following items as potential sources of universal HO2S contamination:
    • use of unapproved silicon sealers
    • fuel contaminated by silicon additives
    • excessive oil consumption
    • glycol leaking internally in the engine
    • lead-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) .
    REPEAT the self-test.
    GO to  DZ16.
  16. DZ16 CHECK THE UNIVERSAL HO2S RESPONSE TEST RESULTS 
    • Ignition ON, engine OFF.
    • Access the diagnostic monitoring test results for the HO2S11.

    Is the indicated value greater than the minimum threshold? 

    Yes No
    Unable to duplicate or identify the concern at this time.
    Clear the PCM DTCs. REPEAT the self-test.
    INSTALL a new Universal HO2S. REFER to the ELECTRONIC ENGINE CONTROLS (HYBRID)
    RESET the keep alive memory (KAM). REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) .
    REPEAT the self-test.
  17. DZ17 DTC P0134: CHECK THE UO2SPC CIRCUIT FOR AN OPEN IN THE HARNESS 
    • Ignition OFF.
    • Universal HO2S-Front connector disconnected.
    • PCM connector disconnected.
    • Measure the resistance between:
    RESISTANCE REFERENCE CHART

    (+) Universal HO2S-Front Connector, Harness Side (-) PCM Connector, Harness Side
    UO2SPC - Pin 1 UO2SPC - Pin E23

    Is the resistance less than 5 ohms? 

    Yes No
    INSTALL a new Universal HO2S. REFER to the ELECTRONIC ENGINE CONTROLS (HYBRID)
    RESET the keep alive memory (KAM). REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) .
    REPEAT the self-test.
    REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test.
  18. DZ18 KOER DTC P1127: EXHAUST TEMPERATURE OUT OF RANGE 
    NOTE: Address all other DTCs before proceeding.
    • Ignition ON, engine running.
    • Engine at normal operating temperature.
    • Access the PCM and monitor the HTR11 (MODE) PID.

    Is the PID state ON? 

    Yes No
    CARRY OUT the KOER self-test. RUN the engine until the PID indicates ON.
    CARRY OUT the KOER self-test.
  19. DZ19 DTCS P2096 OR P2097: CARRY OUT THE KOER SELF-TEST 
    • Engine at normal operating temperature.
    • Carry out the PCM KOER self-test.

    Are any DTCs present other than P2096 or P2097? 

    Yes No
    DISREGARD the current diagnostic trouble code (DTC) at this time. DIAGNOSE the next DTC. GO to DIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS . GO to  DZ20.
  20. DZ20 VISUALLY INSPECT THE UPSTREAM AND DOWNSTREAM HO2S CONNECTORS 
    • Ignition OFF.
    • HO2S connector disconnected.
    • Universal HO2S-Front connector disconnected.
    • Check for an incorrect connection, and damaged or corroded terminals.

    Is a concern present? 

    Yes No
    REPAIR as necessary. RESET the keep alive memory (KAM). REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) .
    REPEAT the self-test.
    GO to  DZ21.
  21. DZ21 CHECK FOR LEAKS IN THE EXHAUST SYSTEM 
    • Visually inspect the exhaust system for the following:
    • exhaust leaks at flanges and gaskets
    • HO2Ss not tightened to specification
    • physical exhaust system concerns
    • aftermarket exhaust
    • punctures or cracks in the catalytic converter

    Is a concern present? 

    Yes No
    REPAIR as necessary. RESET the keep alive memory (KAM). REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) .
    REPEAT the self-test.
    GO to  DZ22.
  22. DZ22 CHECK FOR POTENTIAL SENSOR CONTAMINATION CONCERNS 
    • Investigate the following items as potential sources of universal HO2S contamination:
    • use of unapproved silicon sealers
    • fuel contaminated by silicon additives
    • excessive oil consumption
    • glycol leaking internally in the engine
    • lead-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.
    INSTALL a new Universal HO2S sensor. REFER to the ELECTRONIC ENGINE CONTROLS (HYBRID)
    CHANGE the engine oil and oil filter.
    RESET the keep alive memory (KAM). REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) .
    REPEAT the self-test.
    INSTALL a new Universal HO2S sensor. REFER to the ELECTRONIC ENGINE CONTROLS (HYBRID)
    RESET the keep alive memory (KAM). REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) .
    REPEAT the self-test.
  23. DZ23 CHECK THE UO2SPCT CIRCUIT FOR AN OPEN CIRCUIT IN THE HARNESS 
    • Ignition OFF.
    • Universal HO2S-Front connector disconnected.
    • PCM connector disconnected.
    • Measure the resistance between:
    RESISTANCE REFERENCE CHART

    (+) Universal HO2S-Front Connector, Harness Side (-) PCM Connector, Harness Side
    UO2SPCT - Pin 5 UO2SPCT - Pin E11

    Is the resistance less than 5 ohms? 

    Yes No
    GO to  DZ24. REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test.
  24. DZ24 CHECK THE RESISTANCE OF THE CURRENT TRIM RESISTOR IN THE UNIVERSAL HO2S 
    • Measure the resistance between:
    RESISTANCE REFERENCE CHART

    (+) Universal HO2S-Front Connector, Component Side (-) Universal HO2S-Front Connector, Component Side
    UO2SPCT - Pin 5 UO2SPC - Pin 1

    Is the resistance between 25 - 330 ohms? 

    Yes No
    The concern is elsewhere. RETURN to NO DIAGNOSTIC TROUBLE CODES (DTCS) PRESENT SYMPTOM CHART INDEX for further direction. INSTALL a new Universal HO2S. REFER to the ELECTRONIC ENGINE CONTROLS (HYBRID)
    RESET the keep alive memory (KAM). REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) .
    REPEAT the self-test.
  25. DZ25 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.
    • 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) , 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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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.