SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSMERCURY2010MARINER HYBRID, AWDREPAIR AND DIAGNOSISENGINE PERFORMANCETESTING & DIAGNOSISENGINE CONTROLS - PINPOINT TESTS - (HYBRID)PINPOINT TEST KF: FAN CONTROL (FC)TEST PROCEDURE
2010 Mercury Mariner Hybrid, AWD

Test Procedure

2010 Mercury Mariner Hybrid, AWDSECTION Test Procedure
  1. KF1 CHECK FOR DIAGNOSTIC TROUBLE CODES (DTCS) P0480, P0481 AND P0482 

    Are any of the following DTCs present during PCM self-test P0480, P0481, or P0482? 

    Yes No
    For KOEO and KOER DTC P0480, GO to  KF2.
    For KOEO and KOER DTC P0481, GO to  KF12.
    For KOEO and KOER DTC P0482, GO to  KF7.
    For continuous memory DTC P0480, GO to  KF17.
    For continuous memory DTC P0481, GO to  KF19.
    For continuous memory DTC P0482, GO to  KF21.    		 For cooling fan always runs, GO to  KF23.
    For cooling fan does not operate, GO to  KF24.
  2. KF2 KOEO AND KOER DTC P0480: CHECK THE VPWR VOLTAGE TO LOW SPEED FC RELAY 
    • LFC Relay connector disconnected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) LFC Relay Connector, Harness Side (-) Vehicle Battery
      VPWR - Pin 2 Negative terminal

    Is the voltage greater than 10.5 V? 

    Yes No
    GO to  KF3. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
  3. KF3 CHECK FOR LFC CIRCUIT CYCLING 
    NOTE: During KOEO on demand self-test, the LFC circuit will be cycled on and off.
    • Connect a non-powered test lamp between:
      Point A LFC Relay Connector, Harness Side Point B LFC Relay Connector, Harness Side
      VPWR - Pin 2 LFC - Pin 1
    • Carry out the PCM KOEO on demand self-test.

    Does the test lamp illuminate on and off during the KOEO on demand self-test? 

    Yes No
    INSTALL a new LFC relay. CLEAR the DTCs. REPEAT the self-test. REMOVE the test lamp.
    GO to  KF4.
  4. KF4 CHECK THE LFC CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS 
    • Ignition OFF.
    • PCM connector disconnected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) LFC Relay Connector, Harness Side (-) Vehicle Battery
      LFC - Pin 1 Negative terminal

    Is the voltage less than 1 V? 

    Yes No
    GO to  KF5. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.
  5. KF5 CHECK THE LFC CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS 
    • Measure the resistance between:
      (+) LFC Relay Connector, Harness Side (-) Vehicle Battery
      LFC - Pin 1 Negative terminal

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  KF6. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.
  6. KF6 CHECK THE LFC CIRCUIT FOR AN OPEN IN THE HARNESS 
    • Measure the resistance between:
      (+) LFC Relay Connector, Harness Side (-) PCM Connector, Harness Side
      LFC - Pin 1 LFC - Pin B34

    Is the resistance less than 5 ohms? 

    Yes No
    GO to  KF30. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
  7. KF7 KOEO AND KOER DTC P0482: CHECK THE VPWR VOLTAGE TO MEDIUM SPEED FC RELAY 
    • MFC Relay connector disconnected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) MFC Relay Connector, Harness Side (-)
      VPWR - Pin 2 Ground

    Is the voltage greater than 10.5 V? 

    Yes No
    GO to  KF8. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
  8. KF8 CHECK FOR MFC CIRCUIT CYCLING 
    NOTE: During KOEO on demand self-test, the MFC circuit will be cycled on and off.
    • Connect a non-powered test lamp between:
      Point A MFC Relay Connector, Harness Side Point B MFC Relay Connector, Harness Side
      VPWR - Pin 2 MFC - Pin 1
    • Carry out the PCM KOEO on demand self-test.

    Does the test lamp illuminate on and off during the KOEO on demand self-test? 

    Yes No
    INSTALL a new MFC relay. CLEAR the DTCs. REPEAT the self-test. REMOVE the test lamp.
    GO to  KF9.
  9. KF9 CHECK THE MFC CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS 
    • Ignition OFF.
    • PCM connector disconnected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) MFC Relay Connector, Harness Side (-)
      MFC - Pin 1 Ground

    Is the voltage less than 1 V? 

    Yes No
    GO to  KF10. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.
  10. KF10 CHECK THE MFC CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS 
    • Ignition OFF.
    • Measure the resistance between:
      (+) MFC Relay Connector, Harness Side (-)
      MFC - Pin 1 Ground

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  KF11. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.
  11. KF11 CHECK THE MFC CIRCUIT FOR AN OPEN IN THE HARNESS 
    • Measure the resistance between:
      (+) MFC Relay Connector, Harness Side (-) PCM Connector, Harness Side
      MFC - Pin 1 MFC - Pin B18

    Is the resistance less than 5 ohms? 

    Yes No
    GO to  KF30. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
  12. KF12 KOEO AND KOER DTC P0481: CHECK THE VPWR VOLTAGE TO THE HIGH SPEED FC RELAY 
    • HFC Relay connector disconnected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) HFC Relay Connector, Harness Side (-)
      VPWR - Pin 2 Ground

    Is the voltage greater than 10.5 V? 

    Yes No
    GO to  KF13. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
  13. KF13 CHECK FOR HFC CIRCUIT CYCLING 
    NOTE: During KOEO on demand self-test, the HFC circuit will be cycled on and off.
    • Connect a non-powered test lamp between:
      Point A HFC Relay Connector, Harness Side Point B HFC Relay Connector, Harness Side
      VPWR - Pin 2 HFC - Pin 1
    • Carry out the KOEO on demand self-test.

    Does the test lamp illuminate on and off during the KOEO on demand self-test? 

    Yes No
    INSTALL a new HFC relay. CLEAR the DTCs. REPEAT the self-test. REMOVE the test lamp.
    GO to  KF14.
  14. KF14 CHECK THE HFC CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS 
    • PCM connector disconnected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) HFC Relay Connector, Harness Side (-) Vehicle Battery
      HFC - Pin 1 Negative terminal

    Is the voltage less than 1 V? 

    Yes No
    GO to  KF15. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.
  15. KF15 CHECK THE HFC CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS 
    • Measure the resistance between:
      (+) HFC Relay Connector, Harness Side (-) Vehicle Battery
      HFC - Pin 1 Negative terminal

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  KF16. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.
  16. KF16 CHECK THE HFC CIRCUIT FOR AN OPEN IN THE HARNESS 
    • Measure the resistance between:
      (+) HFC Relay Connector, Harness Side (-) PCM Connector, Harness Side
      HFC - Pin 1 HFC - Pin B36

    Is the resistance less than 5 ohms? 

    Yes No
    GO to  KF30. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
  17. KF17 CONTINUOUS MEMORY DTC P0480: CHECK THE LFC CIRCUIT FOR AN INTERMITTENT OPEN OR SHORT TO VOLTAGE 
    • A/C and defrost off.
    • Left Fan Motor connector disconnected.
    • Right Fan Motor connector disconnected.
    • Connect a non-powered test lamp between:
      Point A Left Fan Motor Connector, Harness Side Point B Left Fan Motor Connector, Harness Side
      LSFAN PWR - Pin 1, 2 GND - Pin 3
    • Ignition ON, engine OFF.
    • Enter Output Test Mode. Refer to OUTPUT TEST MODE (OTM) .
    • Command the low speed fan ON.
    • Observe the test lamp for an indication of a concern while carrying out the following. Note that the lamp turns off when a concern is detected.
      • Shake, wiggle, and bend the LFC circuit(s).
      • Shake, wiggle, and bend the VPWR circuit to the LFC relay.
      • Lightly tap on the low speed FC relay to simulate road shock

    Is a concern present? 

    Yes No
    ISOLATE the concern and REPAIR as necessary. GO to  KF18.
  18. KF18 CHECK THE LFC CIRCUIT FOR AN INTERMITTENT SHORT TO GROUND 
    • Ignition ON, engine OFF.
    • Command the outputs OFF
    • Observe the test lamp for an indication of a concern while completing the following. Note that the lamp turns on when a concern is detected.
      • Shake, wiggle, and bend the LFC circuit(s).
      • Lightly tap on the LFC relay to simulate road shock

    Is a concern present? 

    Yes No
    ISOLATE the concern and REPAIR as necessary. Unable to duplicate or identify the concern at this time.
    GO to PINPOINT TEST Z .
  19. KF19 CONTINUOUS MEMORY DTC P0481: CHECK THE HFC CIRCUIT FOR AN INTERMITTENT OPEN OR SHORT TO VOLTAGE 
    • A/C and defrost off.
    • Left Fan Motor connector disconnected.
    • Right Fan Motor connector disconnected.
    • Connect a non-powered test lamp between:
      Point A Right Fan Motor Connector, Harness Side Point B Right Fan Motor Connector, Harness Side
      HSFAN PWR - Pin 2 GND - Pin 1
    • Ignition ON, engine OFF.
    • Enter Output Test Mode. Refer to OUTPUT TEST MODE (OTM) .
    • Command the high speed fan ON.
    • Observe the test lamp for an indication of a concern while completing the following. Note that the lamp turns on when a concern is detected.
      • Shake, wiggle, and bend the HFC circuit(s).
      • Shake, wiggle, and bend the VPWR circuit to the HFC relay.
      • Lightly tap on the high speed FC relay to simulate road shock

    Is a concern present? 

    Yes No
    ISOLATE the concern and REPAIR as necessary. GO to  KF20.
  20. KF20 CHECK THE HFC CIRCUIT FOR AN INTERMITTENT SHORT TO GROUND 
    • Ignition ON, engine OFF.
    • Command the outputs OFF
    • Observe the test lamp for an indication of a concern while completing the following. Note that the lamp turns on when a concern is detected.
    • Shake, wiggle, and bend the HFC circuit(s).

    Is a concern present? 

    Yes No
    ISOLATE the concern and REPAIR as necessary. Unable to duplicate or identify the concern at this time.
    GO to PINPOINT TEST Z .
  21. KF21 CONTINUOUS MEMORY DTC P0482: CHECK THE MFC CIRCUIT FOR AN INTERMITTENT OPEN OR SHORT TO VOLTAGE 
    • A/C and defrost off.
    • Left Fan Motor connector disconnected.
    • Right Fan Motor connector disconnected.
    • Connect a non-powered test lamp between:
      Point A Right Fan Motor Connector, Harness Side Point B Right Fan Motor Connector, Harness Side
      MSFAN PWR - Pin 2 GND - Pin 1
    • Ignition ON, engine OFF.
    • Enter Output Test Mode. Refer to OUTPUT TEST MODE (OTM) .
    • Command the low speed fan ON.
    • Observe the test lamp for an indication of a concern while carrying out the following. Note that the lamp turns off when a concern is detected.
      • Shake, wiggle, and bend the MFC circuit(s).
      • Shake, wiggle, and bend the VPWR circuit to the MFC relay.
      • Medium speed FC relay low speed FC relay

    Is a concern present? 

    Yes No
    ISOLATE the concern and REPAIR as necessary. GO to  KF22.
  22. KF22 CHECK THE MFC CIRCUIT FOR AN INTERMITTENT SHORT TO GROUND 
    • Ignition ON, engine OFF.
    • Command the outputs OFF
    • Observe the test lamp for an indication of a concern while completing the following. Note that the lamp turns off when a concern is detected.
    • Shake, wiggle, and bend the MFC circuit(s).

    Is a concern present? 

    Yes No
    ISOLATE the concern and REPAIR as necessary. Unable to duplicate or identify the concern at this time.
    GO to PINPOINT TEST Z .
  23. KF23 COOLING FAN ALWAYS RUNS (NO DTCS): VERIFY THE FAN IS NOT ON BECAUSE OF A/C PRESSURE SWITCH (A/CP) INPUT TO THE PCM 
    NOTE: The cooling fans can run when high engine cooling system temperature are present.
    • Air conditioning or defrost off.
    • Ignition ON, engine running.
    • Access the PCM and monitor the AC_REQ PID.

    Is the PID state no? 

    Yes No
    GO to  KF24. REFER to the DIAGNOSIS AND TESTING , to DIAGNOSE the air conditioning is always on.
    CLEAR the DTCs. REPEAT the self-test.
  24. KF24 CHECK THE VPWR VOLTAGE TO LOW SPEED FC RELAY 
    • LFC Relay connector disconnected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) LFC Relay Connector, Harness Side (-) Vehicle Battery
      VPWR - Pin 2 Negative terminal

    Is the voltage greater than 10.5 V? 

    Yes No
    GO to  KF25. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
  25. KF25 CHECK FOR LFC CIRCUIT CYCLING 
    NOTE: During KOEO on demand self-test, the LFC circuit will be cycled on and off.
    • Connect a non-powered test lamp between:
      Point A LFC Relay Connector, Harness Side Point B LFC Relay Connector, Harness Side
      VPWR - Pin 2 LFC - Pin 1
    • Carry out the PCM KOEO on demand self-test.

    Does the test lamp illuminate on and off during the KOEO on demand self-test? 

    Yes No
    GO to  KF26. REMOVE the test lamp.
    GO to  KF4.
  26. KF26 CHECK THE VPWR VOLTAGE TO MEDIUM SPEED FC RELAY 
    • Ignition OFF.
    • MFC Relay connector disconnected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) MFC Relay Connector, Harness Side (-)
      VPWR - Pin 2 Ground

    Is the voltage greater than 10.5 V? 

    Yes No
    GO to  KF27. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
  27. KF27 CHECK FOR MFC CIRCUIT CYCLING 
    NOTE: During KOEO on demand self-test, the MFC circuit will be cycled on and off.
    • Connect a non-powered test lamp between:
      Point A MFC Relay Connector, Harness Side Point B MFC Relay Connector, Harness Side
      VPWR - Pin 2 MFC - Pin 1
    • Carry out the PCM KOEO on demand self-test.

    Does the test lamp illuminate on and off during the KOEO on demand self-test? 

    Yes No
    GO to  KF28. REMOVE the test lamp.
    GO to  KF9.
  28. KF28 CHECK THE VPWR VOLTAGE TO HIGH SPEED FC RELAY 
    • Ignition OFF.
    • HFC Relay connector disconnected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) HFC Relay Connector, Harness Side (-)
      VPWR - Pin 2 Ground

    Is the voltage greater than 10.5 V? 

    Yes No
    GO to  KF29. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
  29. KF29 CHECK FOR HFC CIRCUIT CYCLING 
    NOTE: During KOEO on demand self-test, the HFC circuit will be cycled on and off.
    • Connect a non-powered test lamp between:
      Point A HFC Relay Connector, Harness Side Point B HFC Relay Connector, Harness Side
      VPWR - Pin 2 HFC - Pin 1
    • Carry out the KOEO on demand self-test.

    Does the test lamp illuminate on and off during the KOEO on demand self-test? 

    Yes No
    The PCM primary FC circuits are OK.
    REFER to the appropriate SYSTEM WIRING DIAGRAMS article to check the relay(s).
    INSTALL a new FC relay if necessary.
    To check the secondary FC circuits,
    REFER to the DIAGNOSIS AND TESTING .    		 REMOVE the test lamp.
    GO to  KF14.
  30. KF30 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 and 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.
RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

Shop Manual-Ready ToolsFree Quote CheckQuote Shield Pro

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.