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HOMESERVICE MANUALSMERCURY2010MARINER HYBRID, AWDREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 1377 (ENGINE CONTROLS - PINPOINT TESTS (HYBRID))PINPOINT TEST DC: MASS AIR FLOW (MAF) SENSORTEST PROCEDURE
2010 Mercury Mariner Hybrid, AWD

Test Procedure

2010 Mercury Mariner Hybrid, AWDSECTION 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. DC1 CHECK FOR DIAGNOSTIC TROUBLE CODES (DTCS) 

    Are any of the following DTCs present during the PCM self-test: P0102, P0103, P0104, or P1101? 

    Yes No
    For DTC P0102, GO to  DC3.
    For DTC P0103, GO to  DC19.
    For DTC P0104, GO to  DC23.
    For KOEO DTC P1101, GO to  DC7.
    For KOER DTC P1101, GO to  DC2.    		 GO to  DC25.
  2. DC2 DTC P1101: CHECK FOR MAF SENSOR CONTINUOUS MEMORY DTCS 
    • Retrieve any continuous memory DTCs.

    Is a continuous memory MAF sensor DTC present with the KOER DTC P1101? 

    Yes No
    GO to  DC3. GO to  DC5.
  3. DC3 VERIFY THE CONTINUOUS MEMORY DTC P0102 

    Is a continuous memory DTC P0102 present with the KOER DTC P1101? 

    Yes No
    GO to  DC5. GO to  DC4.
  4. DC4 VERIFY THE CONTINUOUS MEMORY DTC P0103 

    Is a continuous memory DTC P0103 present with the KOER DTC P1101? 

    Yes No
    GO to  DC19. DISREGARD the current diagnostic trouble code (DTC) at this time. DIAGNOSE the next DTC. GO to DIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS .
  5. DC5 KOER AND CONTINUOUS MEMORY DTCS P0102, P0104 OR P1101: CHECK THE INTAKE AIR SYSTEM FOR LEAKS, OBSTRUCTIONS, AND DAMAGE 
    • Check the intake air system (air cleaner, housing, ductwork) for obstructions or blockage.
    • Check for broken/loose air outlet tube clamps (throttle body and air cleaner assembly ends), cracks/holes in the air outlet tube, and worn gaskets between the MAF/IAT sensor and the air cleaner assembly. Verify the MAF/IAT sensor is connected. Repair as necessary.

    Were any concerns found during the visual inspection? 

    Yes No
    REPAIR as necessary.
    Clear the PCM DTCs. REPEAT the self-test.    		 GO to  DC6.
  6. DC6 CHECK THE MAF PID 
    • Start the engine using the engine running diagnostic mode. Refer to DIAGNOSTIC MODES .
    • Run the engine up to 1,500 RPM for 5 seconds, then bring it back to idle.
    • Access the PCM and monitor the RPM (RPM) PID.
    • Access the PCM and monitor the MAF (VOLT) PID.

    Is the voltage less than 0.23 V? 

    Yes No
    GO to  DC9. GO to  DC7.
  7. DC7 CHECK THE MAF SIGNAL 
    NOTE: DTC P1101 can be generated by a low charged 12 volt battery or the garage exhaust ventilation system. Repair the 12 volt battery as necessary, then remove the ventilation system and properly vent to the outside atmosphere. Check the intake air system (air cleaner, housing, ductwork) for obstructions or blockage. Repeat the KOEO self-test.
    • Ignition ON, engine OFF.
    • Access the PCM and monitor the MAF (VOLT) PID.

    Is the voltage less than 0.2 V? 

    Yes No
    GO to  DC8. GO to  DC9.
  8. DC8 CHECK THE MAF SIGNAL SENT TO THE PCM 
    • Ignition ON, engine running.
    • Access the PCM and monitor the MAF (VOLT) PID.

    Is the voltage between 0.46 - 2.44 V? 

    Yes No
    Unable to identify the concern at this time.
    GO to PINPOINT TEST Z .    		 GO to  DC9.
  9. DC9 CHECK THE VPWR TO THE MAF SENSOR 
    • MAF/IAT Sensor connector disconnected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
    VOLTAGE REFERENCE CHART

    (+) MAF/IAT Sensor Connector, Harness Side (-) Vehicle Battery
    VPWR - Pin 6 Negative terminal

    Is the voltage greater than 10.5 V? 

    Yes No
    GO to  DC10. REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test.
  10. DC10 CHECK THE PWRGND CIRCUIT TO THE MAF SENSOR 
    • Measure the voltage between:
    VOLTAGE REFERENCE CHART

    (+) Vehicle Battery (-) MAF/IAT Sensor Connector, Harness Side
    Positive terminal PWRGND - Pin 5

    Is the voltage greater than 10.5 V? 

    Yes No
    GO to  DC11. REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test.
  11. DC11 CHECK FOR SHORTS BETWEEN CIRCUITS IN THE MAF HARNESS 
    • PCM connector disconnected.
    • MAF Sensor connector disconnected.
    • Measure the resistance between:
    RESISTANCE REFERENCE CHART

    (+) MAF/IAT Sensor Connector, Harness Side (-) MAF/IAT Sensor Connector, Harness Side
    MAF - Pin 3 PWRGND - Pin 5
    MAF - Pin 3 MAF RTN - Pin 4
    MAF - Pin 3 SIGRTN - Pin 2
    MAF - Pin 3 IAT - Pin 1

    Are the resistances greater than 10K ohms? 

    Yes No
    GO to  DC12. REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test.
  12. DC12 CHECK THE MAF RTN CIRCUIT FOR AN OPEN IN THE HARNESS 
    • Measure the resistance between:
    RESISTANCE REFERENCE CHART

    (+) PCM Connector, Harness Side (-) MAF/IAT Sensor Connector, Harness Side
    MAF RTN - Pin B41 MAF RTN - Pin 4

    Is the resistance less than 5 ohms? 

    Yes No
    GO to  DC13. REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test.
  13. DC13 CHECK THE MAF RTN CIRCUIT FOR A SHORT TO PWRGND IN THE HARNESS 
    • Measure the resistance between:
    RESISTANCE REFERENCE CHART

    (+) MAF/IAT Sensor Connector, Harness Side (-) MAF/IAT Sensor Connector, Harness Side
    MAF RTN - Pin 4 PWRGND - Pin 5

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  DC14. REPAIR the short circuit to GND. Clear the PCM DTCs. REPEAT the self-test.
  14. DC14 CHECK THE MAF CIRCUIT FOR A SHORT TO PWRGND IN THE PCM 
    • PCM connector connected.
    • Measure the resistance between:
    RESISTANCE REFERENCE CHART

    (+) MAF/IAT Sensor Connector, Harness Side (-) MAF/IAT Sensor Connector, Harness Side
    MAF - Pin 3 PWRGND - Pin 5

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  DC15. GO to  DC29.
  15. DC15 CHECK THE MAF CIRCUIT VOLTAGE CYCLING INTEGRITY 
    • Ignition ON, engine OFF.
    • Access the MAF V PID.
    • Connect a 5 amp fused jumper wire between the following:
      CONNECTOR PINS REFERENCE CHART

      Point A MAF/IAT Sensor Connector, Harness Side Point B MAF/IAT Sensor Connector, Harness Side
      MAF RTN - Pin 4 PWRGND - Pin 5
      MAF - Pin 3 VPWR - Pin 6
    • Record the PID reading while both jumpers are installed.
    • Remove the VPWR jumper while monitoring the MAF V PID.

    Does the MAF PID change from greater than 4.50 volts to less than 0.20 volt when the VPWR jumper is removed? 

    Yes No
    INSTALL a new MAF/IAT sensor.
    REFER to the ELECTRONIC ENGINE CONTROLS (HYBRID)
    RESET the keep alive memory (KAM).
    REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) .
    Clear the PCM DTCs. REPEAT the self-test.    		 GO to  DC16.
  16. DC16 CHECK THE MAF CIRCUIT FOR AN OPEN IN THE HARNESS 
    • Ignition OFF.
    • PCM connector disconnected.
    • Measure the resistance between:
    RESISTANCE REFERENCE CHART

    (+) PCM Connector, Harness Side (-) MAF/IAT Sensor Connector, Harness Side
    MAF - Pin B40 MAF - Pin 3

    Is the resistance less than 5 ohms? 

    Yes No
    GO to  DC17. REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test.
  17. DC17 CHECK THE PWRGND CIRCUIT FOR AN OPEN IN THE HARNESS 
    • Measure the resistance between:
    RESISTANCE REFERENCE CHART

    (+) MAF/IAT Sensor Connector, Harness Side (-) Vehicle Battery
    PWRGND - Pin 5 Negative terminal

    Is the resistance less than 5 ohms? 

    Yes No
    GO to  DC18. REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test.
  18. DC18 CHECK THE MAF RTN CIRCUIT FOR AN OPEN IN THE HARNESS 
    • Measure the resistance between:
    RESISTANCE REFERENCE CHART

    (+) PCM Connector, Harness Side (-) MAF/IAT Sensor Connector, Harness Side
    MAF RTN - Pin B41 MAF RTN - Pin 4

    Is the resistance less than 5 ohms? 

    Yes No
    GO to  DC29. REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test.
  19. DC19 DTC P0103: CHECK THE MAF SENSOR FOR CONTAMINATION 
    NOTE: DTC P0103 can be generated by foreign material blocking the MAF sensor, causing an air flow restriction.
    • Check the MAF sensor for contamination or blockage.
    • Check the air cleaner element and air tubes for proper installation and sealing.

    Are any concerns present? 

    Yes No
    REPAIR as necessary.
    Clear the PCM DTCs. REPEAT the self-test.    		 GO to  DC20.
  20. DC20 DTC P0103: CHECK THE MAF SENSOR SIGNAL HIGH INPUT TO THE PCM 
    • Ignition ON, engine OFF.
    • Access the PCM and monitor the MAF (VOLT) PID.

    Is the voltage greater than 2.44 V? 

    Yes No
    GO to  DC21. GO to  DC23.
  21. DC21 CHECK THE MAF SENSOR SIGNAL SENT TO THE PCM 
    • Ignition OFF.
    • MAF/IAT Sensor connector disconnected.
    • Connect a 5 amp fused jumper wire between the following:
      CONNECTOR PINS REFERENCE CHART

      Point A MAF/IAT Sensor Connector, Harness Side Point B MAF/IAT Sensor Connector, Harness Side
      MAF RTN - Pin 4 PWRGND - Pin 5
    • Ignition ON, engine OFF.
    • Access the PCM and monitor the MAF (VOLT) PID.

    Is the voltage less than 0.1 V? 

    Yes No
    REMOVE the jumper wire(s).
    CHECK the MAF/IAT sensor electrical connector for damage, corrosion, and water intrusion.
    If OK, INSTALL a new MAF/IAT sensor.
    REFER to the ELECTRONIC ENGINE CONTROLS (HYBRID)
    RESET the keep alive memory (KAM).
    REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) .
    Clear the PCM DTCs. REPEAT the self-test.    		 GO to  DC22.
  22. DC22 CHECK THE MAF CIRCUIT FOR A SHORT TO VOLTAGE 
    • Ignition OFF.
    • PCM connector disconnected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
    VOLTAGE REFERENCE CHART

    (+) PCM Connector, Harness Side (-)
    MAF - Pin B40 Ground

    Is the voltage less than 1 V? 

    Yes No
    GO to  DC24. REPAIR the short circuit to PWR. Clear the PCM DTCs. REPEAT the self-test.
  23. DC23 CHECK THE MAF SENSOR SIGNAL SENT TO THE PCM 
    • Start the engine using the engine running diagnostic mode. Refer to DIAGNOSTIC MODES .
    • Access the PCM and monitor the MAF (VOLT) PID.
    • Monitor the MAF signal voltage while increasing the engine RPM from idle to approximately 2,500 RPM, then back to idle.

    Is the voltage between 0.23 - 4.6 V? 

    Yes No
    The concern is intermittent.
    GO to PINPOINT TEST Z .    		 GO to  DC21.
  24. DC24 VERIFY THE IDLE CONCERN 
    • Start the engine using the engine running diagnostic mode. Refer to DIAGNOSTIC MODES .
    • PCM connector connected.
    • MAF/IAT sensor connector connected.

    Is there an idle concern present? 

    Yes No
    DISREGARD DTC P0103 at this time.
    RETURN to SYMPTOM CHARTS , for further direction.    		 GO to  DC29.
  25. DC25 SYMPTOMS WITHOUT DTCS: CHECK THE CONDITIONS RELATED TO THE MAF SENSOR 
    • Check the intake air system (air cleaner, housing, ductwork) for obstructions or blockage.
    • Check for broken/loose air outlet tube clamps (throttle body and air cleaner assembly ends), cracks/holes in the air outlet tube, and worn gaskets between the MAF/IAT sensor and the air cleaner assembly. Verify the MAF/IAT sensor is connected.

    Is a concern present? 

    Yes No
    REPAIR as necessary.
    RESET the keep alive memory (KAM).
    REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) .
    Clear the PCM DTCs. REPEAT the self-test.    		 GO to  DC26.
  26. DC26 DTCS P0171, P0172, P2195 OR P2196: CHECK THE FUNCTIONALITY OF THE MAF SENSOR 
    NOTE: A MAF PID value of less than 0.35 volt may indicate an incorrectly installed air cleaner or a leak in the air inlet system.
    • Start the engine using the engine running diagnostic mode. Refer to DIAGNOSTIC MODES .
    • Allow the engine to stabilize at the correct operating temperature.
    • Access the PCM and monitor the MAF (VOLT) PID.

    Is the MAF PID at idle and NEUTRAL between 0.35 volt and 1.3 volts? 

    Yes No
    GO to  DC28. GO to  DC27.
  27. DC27 CHECK TO ISOLATE THE MAF SENSOR FROM A LEAN DRIVEABILITY OCCURRENCE 
    NOTE: Due to increasingly stringent emission/OBD requirements, a fuel system DTC on some vehicles can be generated without a noticeable driveability concern with or without the MAF/IAT sensor disconnected. Under these conditions, if the MAF PID indicates a MAF/IAT sensor concern, install a new MAF/IAT sensor.
    • Ignition OFF.
    • MAF/IAT Sensor connector disconnected.
    • Ignition ON, engine running.
    • Road test the vehicle.

    Is the lean driveability symptom (lack of power, spark knock/detonation, buck/jerk or hesitation/surge on acceleration) gone? 

    Yes No
    INSTALL a new MAF/IAT sensor.
    REFER to the ELECTRONIC ENGINE CONTROLS (HYBRID)
    RESET the keep alive memory (KAM).
    REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) .
    Clear the PCM DTCs. REPEAT the self-test.    		 GO to  DC28.
  28. DC28 VERIFY THE DTC 

    Are any of the following DTCs present: P0171, P0172, P2195, P2196? 

    Yes No
    Unable to duplicate or identify the concern at this time.
    GO to PINPOINT TEST Z .    		 RETURN to SYMPTOM CHARTS for further direction.
  29. DC29 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) .    		 The system is operating correctly at this time.
    The concern may have been caused by a loose or corroded connector.
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Stop DIY work and contact a certified mechanic immediately if any of the following apply:

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