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HOMESERVICE MANUALSFORD2004RANGER 2D PICKUP, 3.0 U, 4WD, AUTOMATICREPAIR AND DIAGNOSISENGINE PERFORMANCETESTING & DIAGNOSISENGINE CONTROLS - PINPOINT TEST KE: IDLE AIR CONTROL (IAC) VALVE THROUGH PINPOINT TEST QA: UNABLE TO ACTIVATE SELF-TEST/NETWORK COMMUNICATION ERROR/DTC P1001 - CNG, FLEX-FUEL & GASOLINEPINPOINT TEST KF: FAN CONTROL RELAYSTEST PROCEDURE
2004 Ford Ranger 2D Pickup, 3.0 U, 4WD, Automatic

Test Procedure

2004 Ford Ranger 2D Pickup, 3.0 U, 4WD, AutomaticSECTION Test Procedure
  1. KF1 KOEO AND KOER DTCS P0480 OR P1474: CHECK THE VPWR VOLTAGE TO LOW SPEED FC RELAY 
    • LFC Relay connector disconnected.
    • Key ON Engine OFF.
    • Measure the voltage between:
    ( + )LFC Relay Connector, Harness Side ( - )
    VPWR - Pin 1 Ground

    Is the voltage greater than 10.5 V? 

    Yes No
    GO to  KF2. REPAIR open circuit.
  2. KF2 CHECK FOR LFC CIRCUIT CYCLING 
    • Key ON Engine OFF.
    • Connect non-powered test lamp between:
    ( + )LFC Relay Connector, Harness Side ( - )LFC Relay Connector, Harness Side
    VPWR - Pin 1 LFC - Pin 2
    • Scan Tool Connected
    • Enter Output Test Mode. Refer to OUTPUT TEST MODE .
    • Command low speed fan ON
    • Command high speed fan ON
    • Command outputs OFF

    Does the test lamp turn on and off when either the low or high speed cooling fan output is commanded on and off? 

    Yes No
    INSTALL a new LFC relay. KEY OFF
    REMOVE the test lamp
    GO to  KF3.
  3. KF3 CHECK THE LFC CIRCUIT FOR A SHORT TO POWER IN THE HARNESS 
    • PCM connector disconnected.
    • Key ON Engine OFF.
    • Measure the voltage between:
    ( + )LFC Relay Connector, Harness Side ( - )
    LFC - Pin 2 Ground

    Is the voltage less than 1 V? 

    Yes No
    KEY OFF
    GO to  KF4.    		 REPAIR short circuit.
  4. KF4 CHECK THE LFC CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS 
    • Scan tool connector disconnected.
    • Measure the resistance between:
    ( + )LFC Relay Connector, Harness Side ( - )
    LFC - Pin 2 Ground

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  KF5. REPAIR short circuit.
  5. KF5 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 2 LFC

    Is the resistance less than 5 ohms? 

    Yes No
    INSTALL a new PCM. REPAIR open circuit.
  6. KF6 KOEO AND KOER DTCS P0482 OR P1477: CHECK THE VPWR VOLTAGE TO MEDIUM SPEED FC RELAY 
    • MFC Relay connector disconnected.
    • Key ON Engine OFF.
    • Measure the voltage between:
    ( + )MFC Relay Connector, Harness Side ( - )
    VPWR - Pin 1 Ground

    Is the voltage greater than 10.5 V? 

    Yes No
    GO to  KF7. REPAIR open circuit.
  7. KF7 CHECK FOR MFC CIRCUIT CYCLING 
    • Key ON Engine OFF.
    • Connect non-powered test lamp between:
    ( + )MFC Relay Connector, Harness Side ( - )MFC Relay Connector, Harness Side
    VPWR - Pin 1 MFC - Pin 2
    • Scan Tool Connected
    • Enter Output Test Mode. Refer to OUTPUT TEST MODE .
    • Command low speed fan ON
    • Command high speed fan ON
    • Command outputs OFF

    Does the test lamp turn on and off when either the low or high speed cooling fan output is commanded on and off? 

    Yes No
    INSTALL a new MFC relay. KEY OFF
    REMOVE the test lamp
    GO to  KF8.
  8. KF8 CHECK THE MFC CIRCUIT FOR A SHORT TO POWER IN THE HARNESS 
    • PCM connector disconnected.
    • Key ON Engine OFF.
    • Measure the voltage between:
    ( + )MFC Relay Connector, Harness Side ( - )
    MFC - Pin 2 Ground

    Is the voltage less than 1 V? 

    Yes No
    KEY OFF
    GO to  KF9.    		 REPAIR short circuit.
  9. KF9 CHECK THE MFC CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS 
    • Scan tool connector disconnected.
    • Measure the resistance between:
    ( + )MFC Relay Connector, Harness Side ( - )
    MFC - Pin 2 Ground

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  KF10. REPAIR short circuit.
  10. KF10 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 2 MFC

    Is the resistance less than 5 ohms? 

    Yes No
    INSTALL a new PCM. REPAIR open circuit.
  11. KF11 KOEO AND KOER DTCS P0481 OR P1479: CHECK THE VPWR VOLTAGE TO HIGH SPEED FC RELAY 
    • HFC Relay connector disconnected.
    • Key ON Engine OFF.
    • Measure the voltage between:
    ( + )HFC Relay Connector, Harness Side ( - )
    VPWR - Pin 1 Ground

    Is the voltage greater than 10.5 V? 

    Yes No
    GO to  KF12. REPAIR open circuit.
  12. KF12 CHECK FOR HFC CIRCUIT CYCLING 
    • Key ON Engine OFF.
    • Connect non-powered test lamp between:
    ( + )HFC Relay Connector, Harness Side ( - )HFC Relay Connector, Harness Side
    VPWR - Pin 1 HFC - Pin 2
    • Scan Tool Connected
    • Enter Output Test Mode. Refer to OUTPUT TEST MODE .
    • Command low speed fan ON
    • Command high speed fan ON
    • Command outputs OFF

    Does the test lamp turn on and off when either the low or high speed cooling fan output is commanded on and off? 

    Yes No
    INSTALL a new HFC relay. KEY OFF
    REMOVE the test lamp
    GO to  KF13.
  13. KF13 CHECK THE HFC CIRCUIT FOR A SHORT TO POWER IN THE HARNESS 
    • PCM connector disconnected.
    • Key ON Engine OFF.
    • Measure the voltage between:
    ( + )HFC Relay Connector, Harness Side ( - )
    HFC - Pin 2 Ground

    Is the voltage less than 1 V? 

    Yes No
    KEY OFF
    GO to  KF14    		 REPAIR short circuit.
  14. KF14 CHECK THE HFC CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS 
    • Scan tool connector disconnected.
    • Measure the resistance between:
    ( + )HFC Relay Connector, Harness Side ( - )
    HFC - Pin 2 Ground

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  KF15. REPAIR short circuit.
  15. KF15 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 2 HFC

    Is the resistance less than 5 ohms? 

    Yes No
    INSTALL a new PCM. REPAIR open circuit.
  16. KF16 KOEO AND KOER DTCS P0480 OR P1474: CHECK THE VPWR VOLTAGE TO LFC1 RLY 
    NOTE: This application has 2 relays wired to the LFC circuit. This procedure may call out LFC1 & LFC2 relays. Either of the relays may be used as the number 1, with the other relay being number 2.
    • LFC1 Relay connector disconnected.
    • Key ON Engine OFF.
    • Measure the voltage between:
    ( + )LFC1 Relay Connector, Harness Side ( - )
    VPWR Ground

    Is the voltage greater than 10.5 V? 

    Yes No
    GO to  KF17. REPAIR open circuit.
  17. KF17 CHECK FOR LFC CIRCUIT CYCLING 
    • Connect non-powered test lamp between:
    ( + )LFC1 Relay Connector, Harness Side ( - )LFC1 Relay Connector, Harness Side
    VPWR LFC
    • Scan Tool Connected
    • Enter Output Test Mode. Refer to OUTPUT TEST MODE .
    • Command low speed fan ON
    • Command high speed fan ON
    • Command outputs OFF

    Does the test lamp turn on and off when either the low or high speed cooling fan output is commanded on and off? 

    Yes No
    REPLACE the LFC1 RLY at end of diagnostics
    Leave RLY disconnected
    GO to  KF22.    		 Leave the test lamp connected
    GO to  KF18.
  18. KF18 CHECK FOR LFC CIRCUIT CYCLING WITH THE LFC2 RLY DISCONNECTED 
    • Connect non-powered test lamp between:
    ( + )LFC1 Relay Connector, Harness Side ( - )LFC1 Relay Connector, Harness Side
    VPWR LFC
    • LFC2 Relay connector disconnected.
    • Command low speed fan ON
    • Command high speed fan ON
    • Command outputs OFF

    Does the test lamp turn on and off when either the low or high speed cooling fan output is commanded on and off? 

    Yes No
    INSTALL a new LFC2 relay. GO to  KF19.
  19. KF19 CHECK THE LFC CIRCUIT FOR A SHORT TO POWER IN THE HARNESS 
    • PCM connector disconnected.
    • Key ON Engine OFF.
    • Measure the voltage between:
    ( + )LFC1 Relay Connector, Harness Side ( - )
    LFC Ground

    Is the voltage less than 1 V? 

    Yes No
    KEY OFF
    GO to  KF20.    		 REPAIR short circuit.
  20. KF20 CHECK THE LFC CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS 
    • Scan tool connector disconnected.
    • Measure the resistance between:
    ( + )LFC1 Relay Connector, Harness Side ( - )
    LFC Ground

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  KF21. REPAIR short circuit.
  21. KF21 CHECK THE LFC CIRCUIT FOR AN OPEN IN THE HARNESS 
    • Measure the resistance between:
    ( + )LFC1 Relay Connector, Harness Side ( - )PCM Connector, Harness Side
    LFC LFC

    Is the resistance less than 5 ohms? 

    Yes No
    INSTALL a new PCM. REPAIR open circuit.
  22. KF22 VERIFY THERE IS NOT AN OPEN IN THE CIRCUIT SPECIFIC TO THE LFC2 RELAY 
    • Access the PCM -LFCF PID.
    • Command high speed fan ON
    • Command outputs OFF
    • Command low speed fan ON
    • Command outputs OFF

    Does the PID indicate a fault (yes) when either the high or low speed Cooling fan output is commanded on and off? 

    Yes No
    GO to  KF23. INSTALL a new LFC1 relay.
  23. KF23 CHECK THE VPWR VOLTAGE TO LFC2 RLY 
    • LFC2 Relay connector disconnected.
    • Key ON Engine OFF.
    • Measure the voltage between:
    ( + )LFC2 Relay Connector, Harness Side ( - )
    VPWR Ground

    Is the voltage greater than 10.5 V? 

    Yes No
    KEY OFF
    GO to  KF24.    		 REPAIR open circuit.
  24. KF24 CHECK THE LFC CIRCUIT BETWEEN THE LOW SPEED FC RELAY(S) 
    • Measure the resistance between:
    ( + )LFC1 Relay Connector, Harness Side ( - )LFC2 Relay Connector, Harness Side
    LFC LFC

    Is the resistance less than 5 ohms? 

    Yes No
    INSTALL a new LFC relay
    REPLACE both LFC relays    		 REPAIR open circuit.
  25. KF25 KOEO AND KOER DTCS P0482 OR P1477: CHECK THE VPWR VOLTAGE TO MFC1 RLY 
    NOTE: This application has 2 relays wired to the MFC circuit. This procedure may call out MFC1 & MFC2 relays. Either of the relays may be used as the number 1, with the other relay being number 2.
    • MFC1 Relay connector disconnected.
    • Key ON Engine OFF.
    • Measure the voltage between:
    ( + )MFC1 Relay Connector, Harness Side ( - )
    VPWR Ground

    Is the voltage greater than 10.5 V? 

    Yes No
    GO to  KF26. REPAIR open circuit.
  26. KF26 CHECK FOR MFC CIRCUIT CYCLING 
    • Connect non-powered test lamp between:
    ( + )MFC1 Relay Connector, Harness Side ( - )MFC1 Relay Connector, Harness Side
    VPWR MFC
    • Scan Tool Connected
    • Enter Output Test Mode. Refer to OUTPUT TEST MODE .
    • Command low speed fan ON
    • Command high speed fan ON
    • Command outputs OFF

    Does the test lamp turn on and off when either the low or high speed cooling fan output is commanded on and off? 

    Yes No
    REPLACE the MFC1 RLY at end of diagnostics
    Leave RLY disconnected
    GO to  KF31.    		 Leave the test lamp connected
    GO to  KF27.
  27. KF27 CHECK FOR MFC CIRCUIT CYCLING WITH THE MFC2 RLY DISCONNECTED 
    • Connect non-powered test lamp between:
    ( + )MFC1 Relay Connector, Harness Side ( - )MFC1 Relay Connector, Harness Side
    VPWR MFC
    • MFC2 Relay connector disconnected.
    • Command low speed fan ON
    • Command high speed fan ON
    • Command outputs OFF

    Does the test lamp turn on and off when either the low or high speed cooling fan output is commanded on and off? 

    Yes No
    INSTALL a new MFC2 relay. GO to  KF28.
  28. KF28 CHECK THE MFC CIRCUIT FOR A SHORT TO POWER IN THE HARNESS 
    • PCM connector disconnected.
    • Key ON Engine OFF.
    • Measure the voltage between:
    ( + )MFC1 Relay Connector, Harness Side ( - )
    MFC Ground

    Is the voltage less than 1 V? 

    Yes No
    KEY OFF
    GO to  KF29.    		 REPAIR short circuit.
  29. KF29 CHECK THE MFC CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS 
    • Scan tool connector disconnected.
    • Measure the resistance between:
    ( + )MFC1 Relay Connector, Harness Side ( - )
    MFC Ground

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  KF30. REPAIR short circuit.
  30. KF30 CHECK THE MFC CIRCUIT FOR AN OPEN IN THE HARNESS 
    • Measure the resistance between:
    ( + )MFC1 Relay Connector, Harness Side ( - )PCM Connector, Harness Side
    MFC MFC

    Is the resistance less than 5 ohms? 

    Yes No
    INSTALL a new PCM. REPAIR open circuit.
  31. KF31 VERIFY THERE IS NOT AN OPEN IN THE CIRCUIT SPECIFIC TO THE MFC2 RELAY 
    • Access the PCM -MFCF PID.
    • Command high speed fan ON
    • Command outputs OFF
    • Command low speed fan ON
    • Command outputs OFF

    Does the PID indicate a fault (yes) when either the high or low speed Cooling fan output is commanded on and off? 

    Yes No
    GO to  KF32. INSTALL a new MFC relay.
  32. KF32 CHECK THE VPWR VOLTAGE TO MFC2 RLY 
    • MFC2 Relay connector disconnected.
    • Key ON Engine OFF.
    • Measure the voltage between:
    ( + )MFC2 Relay Connector, Harness Side ( - )
    VPWR Ground

    Is the voltage greater than 10.5 V? 

    Yes No
    KEY OFF
    GO to  KF33.    		 REPAIR open circuit.
  33. KF33 CHECK THE MFC CIRCUIT BETWEEN THE MEDIUM SPEED FC RELAY(S) 
    • Measure the resistance between:
    ( + )MFC1 Relay Connector, Harness Side ( - )MFC2 Relay Connector, Harness Side
    MFC MFC

    Is the resistance less than 5 ohms? 

    Yes No
    INSTALL a new HFC relay.
    (REPLACE both HFC relays)    		 REPAIR open circuit.
  34. KF34 KOEO AND KOER DTCS P0481 OR P1479: CHECK THE VPWR VOLTAGE TO HFC1 RLY 
    NOTE: This application has 2 relays wired to the HFC circuit. This procedure may call out HFC1 & HFC2 relays. Either of the relays may be used as the number 1, with the other relay being number 2.
    • HFC1 Relay connector disconnected.
    • Key ON Engine OFF.
    • Measure the voltage between:
    ( + )HFC1 Relay Connector, Harness Side ( - )
    VPWR Ground

    Is the voltage greater than 10.5 V? 

    Yes No
    GO to  KF35. REPAIR open circuit.
  35. KF35 CHECK FOR HFC CIRCUIT CYCLING 
    • Connect non-powered test lamp between:
    ( + )HFC1 Relay Connector, Harness Side ( - )HFC1 Relay Connector, Harness Side
    VPWR HFC
    • Scan Tool Connected
    • Enter Output Test Mode. Refer to OUTPUT TEST MODE .
    • Command low speed fan ON
    • Command high speed fan ON
    • Command outputs OFF

    Does the test lamp turn on and off when either the low or high speed cooling fan output is commanded on and off? 

    Yes No
    REPLACE the HFC1 RLY at end of diagnostics
    Leave RLY disconnected
    GO to  KF40.    		 Leave the test lamp connected
    GO to  KF36.
  36. KF36 CHECK FOR HFC CIRCUIT CYCLING WITH THE HFC2 RLY DISCONNECTED 
    • Connect non-powered test lamp between:
    ( + )HFC1 Relay Connector, Harness Side ( - )HFC1 Relay Connector, Harness Side
    VPWR HFC
    • HFC2 Relay connector disconnected.
    • Command low speed fan ON
    • Command high speed fan ON
    • Command outputs OFF

    Does the test lamp turn on and off when either the low or high speed cooling fan output is commanded on and off? 

    Yes No
    INSTALL a new HFC2 relay. GO to  KF37.
  37. KF37 CHECK THE HFC CIRCUIT FOR A SHORT TO POWER IN THE HARNESS 
    • PCM connector disconnected.
    • Key ON Engine OFF.
    • Measure the voltage between:
    ( + )HFC1 Relay Connector, Harness Side ( - )
    HFC Ground

    Is the voltage less than 1 V? 

    Yes No
    KEY OFF
    GO to  KF38.    		 REPAIR short circuit.
  38. KF38 CHECK THE HFC CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS 
    • Scan tool connector disconnected.
    • Measure the resistance between:
    ( + )HFC1 Relay Connector, Harness Side ( - )
    HFC Ground

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  KF39. REPAIR short circuit.
  39. KF39 CHECK THE HFC CIRCUIT FOR AN OPEN IN THE HARNESS 
    • Measure the resistance between:
    ( + )HFC1 Relay Connector, Harness Side ( - )PCM Connector, Harness Side
    HFC HFC

    Is the resistance less than 5 ohms? 

    Yes No
    INSTALL a new PCM. REPAIR open circuit.
  40. KF40 VERIFY THERE IS NOT AN OPEN IN THE CIRCUIT SPECIFIC TO THE HFC2 RELAY 
    • Access the PCM -HFCF PID.
    • Command high speed fan ON
    • Command outputs OFF
    • Command low speed fan ON
    • Command outputs OFF

    Does the PID indicate a fault (yes) when either the high or low speed Cooling fan output is commanded on and off? 

    Yes No
    GO to  KF41. INSTALL a new HFC1 relay.
  41. KF41 CHECK THE VPWR VOLTAGE TO HFC2 RLY 
    • HFC2 Relay connector disconnected.
    • Key ON Engine OFF.
    • Measure the voltage between:
    ( + )HFC2 Relay Connector, Harness Side ( - )
    VPWR Ground

    Is the voltage greater than 10.5 V? 

    Yes No
    KEY OFF
    GO to  KF42.    		 REPAIR open circuit.
  42. KF42 CHECK THE HFC CIRCUIT BETWEEN THE HIGH SPEED FC RELAY(S) 
    • Measure the resistance between:
    ( + )HFC1 Relay Connector, Harness Side ( - )HFC2 Relay Connector, Harness Side
    HFC HFC

    Is the resistance less than 5 ohms? 

    Yes No
    INSTALL a new HFC relay.
    (REPLACE both HFC relays)    		 REPAIR open circuit.
  43. KF43 CONTINUOUS MEMORY DTCS P0480 OR P1474: CHECK THE LFC CIRCUIT FOR AN INTERMITTENT OPEN OR SHORT TO POWER 
    • A/C and defrost off.
    • L Fan Motor connector disconnected.
    • R Fan Motor connector disconnected.
    • LFC Relay connector disconnected.
    • Connect non-powered test lamp between:
    ( + )LFC Relay Connector, Harness Side ( - )LFC Relay Connector, Harness Side
    VPWR - Pin 1 LFC - Pin 2
    • Key ON Engine OFF.
    • Scan Tool Connected
    • Enter Output Test Mode. Refer to OUTPUT TEST MODE .
    • Command low speed fan ON
    NOTE: If the test lamp does not turn on, Command high speed fan ON.
    • Observe the test lamp for an indication of a fault while completing the following. Note that the lamp turns Off when a fault is detected.
    • Shake, wiggle, and bend the LFC circuit(s).
    • Shake, wiggle, and bend the VPWR circuit to the LFC relay.
    • INSPECT the LFC RLY component for signs of damage.

    Is a fault indicated? 

    Yes No
    ISOLATE the fault and REPAIR as necessary. GO to  KF44.
  44. KF44 CHECK THE LFC CIRCUIT FOR AN INTERMITTENT SHORT TO GROUND 
    • Key ON Engine OFF.
    • Command outputs OFF
    • Observe the test lamp for an indication of a fault while completing the following. Note that the lamp turns on when a fault is detected.
    • Shake, wiggle, and bend the LFC circuit(s).
    • Lightly tap on the LFC RLY to simulate road shock.

    Is a fault indicated? 

    Yes No
    ISOLATE the fault and REPAIR as necessary. KEY OFF
    Unable to duplicate or identify the fault at this time
    GO to PINPOINT TEST Z step 1 .
  45. KF45 CONTINUOUS MEMORY DTCS P0481 OR P1479: CHECK THE HFC CIRCUIT FOR AN INTERMITTENT OPEN OR SHORT TO POWER 
    • A/C and defrost off.
    • L Fan Motor connector disconnected.
    • R Fan Motor connector disconnected.
    • HFC Relay connector disconnected.
    • Connect non-powered test lamp between:
    ( + )HFC Relay Connector, Harness Side ( - )HFC Relay Connector, Harness Side
    VPWR - Pin 1 HFC - Pin 2
    • Key ON Engine OFF.
    • Scan Tool Connected
    • Enter Output Test Mode. Refer to OUTPUT TEST MODE .
    • Command high speed fan ON
    NOTE: If the test lamp does not turn on, Command low speed fan ON.
    • Observe the test lamp for an indication of a fault while completing the following. Note that the lamp turns Off when a fault 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 HFC RLY to simulate road shock.

    Is a fault indicated? 

    Yes No
    ISOLATE the fault and REPAIR as necessary. GO to  KF46.
  46. KF46 CHECK THE HFC CIRCUIT FOR AN INTERMITTENT SHORT TO GROUND 
    • Key ON Engine OFF.
    • Command outputs OFF
    • Observe the test lamp for an indication of a fault while completing the following. Note that the lamp turns on when a fault is detected.
    • Shake, wiggle, and bend the HFC circuit(s).

    Is a fault indicated? 

    Yes No
    ISOLATE the fault and REPAIR as necessary. KEY OFF
    Unable to duplicate or identify the fault at this time
    GO to PINPOINT TEST Z step 1 .
  47. KF47 CONTINUOUS MEMORY DTCS P0482 OR P1477: CHECK THE MFC CIRCUIT FOR AN INTERMITTENT OPEN OR SHORT TO POWER 
    • A/C and defrost off.
    • L Fan Motor connector disconnected.
    • R Fan Motor connector disconnected.
    • MFC Relay connector disconnected.
    • Connect non-powered test lamp between:
    ( + )MFC Relay Connector, Harness Side ( - )MFC Relay Connector, Harness Side
    VPWR - Pin 1 MFC - Pin 2
    • Key ON Engine OFF.
    • Scan Tool Connected
    • Enter Output Test Mode. Refer to OUTPUT TEST MODE .
    • Command low speed fan ON
    NOTE: If the test lamp does not turn on, Command high speed fan ON.
    • Observe the test lamp for an indication of a fault while completing the following. Note that the lamp turns Off when a fault is detected.
    • Shake, wiggle, and bend the MFC circuit(s).
    • Shake, wiggle, and bend the VPWR circuit to the MFC relay.
    • INSPECT the MFC RLY component for signs of damage.

    Is a fault indicated? 

    Yes No
    ISOLATE the fault and REPAIR as necessary. GO to  KF48.
  48. KF48 CHECK THE MFC CIRCUIT FOR AN INTERMITTENT SHORT TO GROUND 
    • Key ON Engine OFF.
    • Command outputs OFF
    • Observe the test lamp for an indication of a fault while completing the following. Note that the lamp turns Off when a fault is detected.
    • Shake, wiggle, and bend the MFC circuit(s).

    Is a fault indicated? 

    Yes No
    ISOLATE the fault and REPAIR as necessary. KEY OFF
    Unable to duplicate or identify the fault at this time
    GO to PINPOINT TEST Z step 1 .
  49. KF49 CONTINUOUS MEMORY DTCS P0480 OR P1474: CHECK THE LFC CIRCUIT FOR AN INTERMITTENT OPEN OR SHORT TO POWER 
    NOTE: This application has 2 relays wired to the LFC circuit. This procedure may call out LFC1 & LFC2 relays. Either of the relays may be used as the number 1, with the other relay being number 2.
    • AC and defroster OFF.
    • L Fan Motor connector disconnected.
    • R Fan Motor connector disconnected.
    • LFC1 Relay connector disconnected.
    • Connect non-powered test lamp between:
      ( + )LFC1 Relay Connector, Harness Side ( - )LFC1 Relay Connector, Harness Side
      VPWR LFC
    • Key ON Engine OFF.
    • Scan Tool Connected
    • Enter Output Test Mode. Refer to OUTPUT TEST MODE .
    • Command low speed fan ON
      NOTE: If the test lamp does not turn on, Command high speed fan ON.
    • Observe the test lamp for an indication of a fault while completing the following. Note that the lamp turns OFF when a fault is detected.
      • Shake, wiggle, and bend the LFC circuit between the PCM and both low speed FC relays.
      • Shake, wiggle, and bend the VPWR circuit to both low speed FC relays.
      • Lightly tap on the Low Speed FC relay that is still connected to simulate road shock.

    Is a fault indicated? 

    Yes No
    ISOLATE the fault and REPAIR as necessary. GO to  KF50.
  50. KF50 CHECK THE LFC CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS 
    • Key ON Engine OFF.
    • Command outputs OFF
    • Exit Output Test Mode
    • Observe the test lamp for an indication of a fault while completing the following. Note that the lamp turns ON when a fault is detected.
      • Shake, wiggle, and bend the LFC circuit between the PCM and both low speed FC relays.
    • INSPECT Low Speed FC Relay that is disconnected for intermittent concerns.

    Is a fault indicated? 

    Yes No
    ISOLATE the fault and REPAIR as necessary. KEY OFF
    GO to PINPOINT TEST Z step 1 .
  51. KF51 CONTINUOUS MEMORY DTCS P0482 OR P1477: CHECK THE MFC CIRCUIT FOR AN INTERMITTENT OPEN OR SHORT TO POWER 
    NOTE: This application has 2 relays wired to the MFC circuit. This procedure may call out MFC1 & MFC2 relays. Either of the relays may be used as the number 1, with the other relay being number 2.
    • AC and defroster OFF.
    • L Fan Motor connector disconnected.
    • R Fan Motor connector disconnected.
    • MFC1 Relay connector disconnected.
    • Connect non-powered test lamp between:
      ( + )MFC1 Relay Connector, Harness Side ( - )MFC1 Relay Connector, Harness Side
      VPWR MFC
    • Key ON Engine OFF.
    • Scan Tool Connected
    • Enter Output Test Mode. Refer to OUTPUT TEST MODE .
    • Command low speed fan ON
      NOTE: If the test lamp does not turn on, Command high speed fan ON.
    • Observe the test lamp for an indication of a fault while completing the following. Note that the lamp turns OFF when a fault is detected.
      • Shake, wiggle, and bend the MFC circuit between the PCM and both medium speed FC relays.
      • Shake, wiggle, and bend the VPWR circuit to both medium speed FC relays.
      • Lightly tap on the Medium Speed FC relay that is still connected to simulate road shock.

    Is a fault indicated? 

    Yes No
    ISOLATE the fault and REPAIR as necessary. GO to  KF52.
  52. KF52 CHECK THE MFC CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS 
    • Key ON Engine OFF.
    • Command outputs OFF
    • Exit Output Test Mode
    • Observe the test lamp for an indication of a fault while completing the following. Note that the lamp turns ON when a fault is detected.
      • Shake, wiggle, and bend the MFC circuit between the PCM and both medium speed FC relays.
    • INSPECT Medium Speed FC relay that is disconnected for intermittent concerns.

    Is a fault indicated? 

    Yes No
    ISOLATE the fault and REPAIR as necessary. KEY OFF
    GO to PINPOINT TEST Z step 1 .
  53. KF53 CONTINUOUS MEMORY DTCS P0481 OR P1479: CHECK THE HFC CIRCUIT FOR AN INTERMITTENT OPEN OR SHORT TO POWER 
    NOTE: This application has 2 relays wired to the HFC circuit. This procedure may call out HFC1 & HFC2 relays. Either of the relays may be used as the number 1, with the other relay being number 2.
    • AC and defroster OFF.
    • L Fan Motor connector disconnected.
    • R Fan Motor connector disconnected.
    • HFC1 Relay connector disconnected.
    • Connect non-powered test lamp between:
      ( + )HFC1 Relay Connector, Harness Side ( - )HFC1 Relay Connector, Harness Side
      VPWR HFC
    • Key ON Engine OFF.
    • Scan Tool Connected
    • Enter Output Test Mode. Refer to OUTPUT TEST MODE .
    • Command low speed fan ON
      NOTE: If the test lamp does not turn on, Command high speed fan ON.
    • Observe the test lamp for an indication of a fault while completing the following. Note that the lamp turns OFF when a fault is detected.
      • Shake, wiggle, and bend the HFC circuit between the PCM and both High Speed FC relays.
      • Shake, wiggle, and bend the VPWR circuit to both high speed FC relays.
      • Lightly tap on the High Speed FC relay that is still connected to simulate road shock.

    Is a fault indicated? 

    Yes No
    ISOLATE the fault and REPAIR as necessary. GO to  KF54.
  54. KF54 CHECK THE HFC CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS 
    • Key ON Engine OFF.
    • Command outputs OFF
    • Exit Output Test Mode
    • Observe the test lamp for an indication of a fault while completing the following. Note that the lamp turns ON when a fault is detected.
      • Shake, wiggle, and bend the HFC circuit between the PCM and both High Speed FC relays.
    • INSPECT High Speed FC Relay that is disconnected for intermittent concerns.

    Is a fault indicated? 

    Yes No
    ISOLATE the fault and REPAIR as necessary. KEY OFF
    GO to PINPOINT TEST Z step 1 .
  55. KF55 COOLING FAN ALWAYS RUNS (NO DTCS): VERIFY HE FAN IS NOT ON BECAUSE OF A/C HIGH PRESSURE SWITCH INPUT TO THE PCM 
    • Key ON Engine RUN.
    • Access the PCM -ACP PID.

    Is the PID state CLOSED? 

    Yes No
    KEY OFF
    The PCM will turn the fan on when the medium pressure, normally open contacts of the A/CHPSW are closed
    GO to  KF66.    		 KEY OFF
    Input OK
    GO to  KF56.
  56. KF56 COOLING FAN CONCERN (NO DTCS): CHECK THE FAN CONTROL PRIMARY CIRCUITS 
    • Verify that AC is OFF.
    • Verify engine temperature is below the temperature where the Cooling fan would come on.
    • Key ON Engine OFF.
      NOTE: Chose the PIDs below as appropriate, according to which circuits the vehicle has.
    • Access the PCM -LFCF, PCM-MFCF and PCM-HFCF PIDs.

    Does either PID indicate a fault? 

    Yes No
    Primary circuit(s) Fault found
    GO to  KF57.    		 For all except Ranger: PCM Primary circuit(s) is OK
    REFER to the appropriate ENGINE COOLING article to check the secondary wiring to the cooling fan.
    For Ranger: GO to  KF59.
  57. KF57 DID THE LFCF PID INDICATE A FAULT? 

    Did the LFCF PID indicate a fault? 

    Yes No
    Low Fan Control (LFC) Primary Circuit Failure
    For Freestar/Monterey 
    GO to  KF16
    For All Others 
    GO to  KF1.    		 GO to  KF58.
  58. KF58 DID THE MFCF PID INDICATE A FAULT? 

    Did the MFCF PID indicate a fault? 

    Yes No
    Medium Fan Control (MFC) Primary Circuit Failure
    For Freestar/Monterey 
    GO to  KF25
    For All Others 
    GO to  KF6.    		 High Fan Control (HFC) Primary Circuit Failure
    For Taurus, 
    Sable, 
    Escape 3.0L, and 
    Focus 2.0L 
    GO to  KF34
    For All Others 
    GO to  KF11.
  59. KF59 IS THE SYMPTOM: COOLING FAN ALWAYS RUNS? 

    Is the symptom: cooling fan always runs? 

    Yes No
    GO to  KF65. GO to  KF60.
  60. KF60 ELECTRIC COOLING FAN CONCERN (WITH NO DTCS): ELECTRIC COOLING FAN FUNCTIONAL CHECK 
    • Key ON Engine OFF.
    • Scan Tool Connected
    • Enter Output Test Mode. Refer to OUTPUT TEST MODE .
    • Command low speed fan ON

    Does the fan operate? 

    Yes No
    KEY OFF
    All Cooling fan circuit checks are OK
    RETURN to SYMPTOM CHARTS - CNG, FLEX-FUEL & GASOLINE .    		 GO to  KF61.
  61. KF61 FAN INOPERATIVE: COMMAND THE LOW SPEED FAN ON AND CHECK FOR VOLTAGE TO THE CF 
    • Key OFF.
    • CF Motor connector disconnected.
    • Key ON Engine OFF.
    • Scan Tool Connected
    • Enter Output Test Mode. Refer to OUTPUT TEST MODE .
    • Command low speed fan ON
    • Measure the voltage between:
    ( + )CF Motor Connector, Harness Side ( - )
    FAN PWR Ground

    Is the voltage greater than 10.5 V? 

    Yes No
    KEY OFF
    GO to  KF62.    		 KEY OFF
    GO to  KF63.
  62. KF62 CHECK THE GROUND CIRCUIT TO COOLING FAN 
    • Measure the resistance between:
    ( + )CF Motor Connector, Harness Side ( - )
    GND Ground

    Is the resistance less than 5 ohms? 

    Yes No
    INSTALL a new CF motor. REPAIR open circuit.
  63. KF63 CHECK THE B+ VOLTAGE TO FC RLY 
    • FC Relay connector disconnected.
    • Measure the voltage between:
    ( + )FC Relay Connector, Harness Side ( - )
    B+ Ground

    Is the voltage greater than 10.5 V? 

    Yes No
    GO to  KF64. REPAIR open circuit
    B+ circuit fault. CHECK the condition of the related fuse/fuse links. If OK, REPAIR the open circuit. If the fuse/fuse link is damaged, CHECK the circuit for short to ground before replacing.
  64. KF64 CHECK THE FAN PWR CIRCUIT FOR AN OPEN IN THE HARNESS 
    • Measure the resistance between:
    ( + )FC Relay Connector, Harness Side ( - )CF Motor Connector, Harness Side
    FAN PWR FAN PWR

    Is the resistance less than 5 ohms? 

    Yes No
    INSTALL a new FC relay. REPAIR open circuit.
  65. KF65 CHECK FOR FC RLY CONTACTS ALWAYS CLOSED 
    NOTE: Verify the A/C and defrost are off.
    • FC Relay connector disconnected.
    • Key ON Engine OFF.

    Does the fan run with the key in the ON position? 

    Yes No
    REPAIR short circuit to PWR.
    (FAN PWR ckt)    		 INSTALL a new FC relay.
  66. KF66 CHECK THE A/CHPSW (MEDIUM PRESSURE, NORMALLY OPEN CONTACTS) 
    • A/CHPSW connector disconnected.
    • Key ON Engine OFF.
    • Access the PCM -ACP PID.

    Is the PID state CLOSED? 

    Yes No
    KEY OFF
    GO to  KF67.    		 KEY OFF
    Reconnect A/CHPSW
    REFER to the appropriate CLIMATE CONTROL SYSTEM article to the diagnose symptom.
    (Check the over-pressurized AC system) If OK, REPLACE A/CHPSW.
  67. KF67 CHECK THE A/CPSW CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS 
    • PCM connector disconnected.
    • Measure the resistance between:
    ( + )A/CHPSW Connector, Harness Side ( - )
    A/CPSW Ground

    Is the resistance greater than 10K ohms? 

    Yes No
    Verify the results of the previous test steps
    Return to SYMPTOM CHARTS - CNG, FLEX-FUEL & GASOLINE to continue diagnosis
    If OK, REPLACE PCM.    		 REPAIR short circuit to GND.
RENDER: 1.0x

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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.