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Home >> Lincoln >> 2009 >> MKZ AWD >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Controls - Pinpoint Test A: No Start Through Pinpoint Test DK: Accelerator Pedal Position (App) Sensor - (Except Diesel & Hybrid) >> Pinpoint Test DK: Accelerator Pedal Position (App) Sensor >> Test Procedure
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Test Procedure

  1. DK1 CHECK FOR DIAGNOSTIC TROUBLE CODES (DTCS) 

    Are DTCs P1575, P2104, P2121, P2122, P2123, P2126, P2127, P2128, P2131, P2132, P2133, or P2138 present? 

    Yes No
    For DTC P1575, GO to  DK2.
    For all others, GO to  DK4.    		 For a lack/loss of power, GO to  DK3.
    For all others, GO to DTC LIST .
  2. DK2 DTC P1575: REPEAT THE KOEO SELF-TEST 
    NOTE: Make sure the accelerator pedal is not applied during the KOEO self-test.
    • Ignition ON, engine OFF.
    • Carry out the KOEO self-test.

    Are any DTCs present other than P1575? 

    Yes No
    DISREGARD the current diagnostic trouble code (DTC) at this time. DIAGNOSE the next DTC. GO to DTC LIST . GO to  DK3.
  3. DK3 CHECK THE ACCELERATOR PEDAL FOR OBSTRUCTION 
    • Ignition ON, engine OFF.
    • Press the accelerator pedal fully to the floor and release.

    Does the pedal move freely to the floor and back? 

    Yes No
    GO to  DK4. ISOLATE and REPAIR the obstruction.
    CLEAR the DTCs. REPEAT the self-test.
  4. DK4 CHECK THE APP SENSOR SIGNAL VOLTAGE RANGES FOR THE ACCELERATOR PEDAL FULLY APPLIED AND RELEASED POSITIONS 
    • Access the PCM and monitor the APP1, APP2 and APP3 PIDs.
    • Press the accelerator pedal fully to the floor and release.
      ACCELERATOR PEDAL FULLY APPLIED VOLTAGE VALUES

      Vehicle APP1 APP2 APP3
      Crown Victoria, Grand Marquis, Town Car 0.35 - 1.83 3.06 - 4.48 2.51 - 3.93
      E-Series 4.6L, E-Series 5.4L, Escape/Mariner, Expedition, F-150, Focus, Navigator 3.59 - 4.60 1.72 - 2.40 -
      Explorer, Explorer Sport Trac, Mountaineer 0.60 - 1.57 3.07 - 4.50 2.57 - 3.89
      F-Super Duty 0.28 - 0.97 3.45 - 4.71 2.95 - 4.10
      Fusion, Milan, MKZ 1.20 - 2.50 2.50 - 3.94 2.00 - 3.33
      All others 0.48 - 1.76 2.95 - 4.62 2.43 - 4.02
      ACCELERATOR PEDAL FULLY RELEASED VOLTAGE VALUES

      Vehicle APP1 APP2 APP3
      E-Series 4.6L, E-Series 5.4L, Escape/Mariner, Expedition, F-150, Focus, Navigator 0.64 - 0.96 0.27 - 0.53 -
      All others 3.43 - 4.69 1.13 - 1.88 0.64 - 1.28

    Are all APP signals out of range for the pedal fully applied and released positions? 

    Yes No
    GO to  DK5. For continuous memory DTCs P2121 and P2126 with P2131, GO to  DK22.
    For all others, GO to  DK5.
  5. DK5 CHECK THE VREF VOLTAGE TO APP SENSOR 
    • Ignition OFF.
    • APP Sensor connector disconnected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) APP Sensor Connector, Harness Side (-) APP Sensor Connector, Harness Side
      ETCREF ETCRTN
      ETCREF2 ETCRTN2
      ETCREF3 ETCRTN3

    Are the voltages between 4 - 6 V? 

    Yes No
    For E-Series 6.8L, Explorer, Explorer Sport Trac, F-Super Duty with an adjustable accelerator pedal, and Mountaineer, GO to  DK6.
    For Fusion, Milan, and MKZ, GO to  DK7.
    For E-Series 4.6L, E-Series 5.4L, Escape/Mariner, or Focus with DTC P2122, P2123, or P2138, GO to  DK10.
    For E-Series 4.6L, E-Series 5.4L, Escape/Mariner or Focus with DTC P2127 or P2128, GO to  DK14.
    For Expedition, F-150, or Navigator, GO to  DK8.
    For all others, GO to  DK9.    		 GO to Pinpoint Test C .
  6. DK6 E-SERIES 6.8L, EXPLORER, EXPLORER SPORT TRAC, F-SUPER DUTY WITH AN ADJUSTABLE ACCELERATOR PEDAL, MOUNTAINEER: CHECK THE APP SENSOR FOR THE CORRECT RESISTANCE 
    NOTE: Make sure the accelerator pedal is fully released when taking the resistance measurements.
    • Ignition OFF.
    • APP Sensor connector disconnected.
    • Measure the resistance between:
      NOTE: APP SENSOR - RESISTANCE SPECIFICATIONS  applies to E-Series 6.8L, Explorer, Explorer Sport Trac, F-Super Duty With An Adjustable Accelerator Pedal, Mountaineer.
      APP SENSOR - RESISTANCE SPECIFICATIONS

      (+) APP Sensor Connector, Component Side (-) APP Sensor Connector, Component Side Minimum Resistance (ohms) Maximum Resistance (ohms) APP1 ETCREF 550 1,390
      APP1 ETCRTN 1,030 2,590
      APP1 APP2 2,125 5,335
      APP1 APP3 1,930 4,845
      APP2 ETCREF 1,785 4,480
      APP2 ETCRTN 1,475 3,705
      APP2 APP3 2,520 6,330
      APP3 ETCREF 1,620 4,070
      APP3 ETCRTN 1,135 2,860
      ETCREF ETCRTN 780 1,955
      ETCREF ETCREF 0 10
      ETCRTN ETCRTN 0 10

    Are all the resistances within specifications? 

    Yes No
    For DTCs P2121, P2122 or P2123 alone or in combination, GO to  DK10.
    For DTCs P2126, P2127 or P2128 alone or in combination, GO to  DK14.
    For DTCs P2131, P2132 or P2133 alone or in combination, GO to  DK18.
    For DTC P2104 alone, GO to  DK28.
    For a lack/loss of power, the concern is elsewhere. RETURN to SYMPTOM CHARTS - GASOLINE MODELS article for further direction.
    For all others, GO to  DK22.    		 INSTALL a new APP sensor. REFER to the appropriate Acceleration Control article to INSTALL a new accelerator pedal.
    CLEAR the DTCs. REPEAT the self-test.
  7. DK7 FUSION, MILAN, MKZ: CHECK THE APP SENSOR FOR THE CORRECT RESISTANCE 
    NOTE: Make sure the accelerator pedal is fully released when taking the resistance measurements.
    • Ignition OFF.
    • APP Sensor connector disconnected.
    • Measure the resistance between:
      RESISTANCE SPECIFICATIONS

      (+) APP Sensor Connector, Component Side (-) APP Sensor Connector, Component Side Minimum Resistance (ohms) Maximum Resistance (ohms)
      APP1 ETCREF 650 1,340
      APP1 ETCRTN 1,210 2,470
      APP1 APP2 2,430 4,960
      APP1 APP3 2,390 4,880
      APP2 ETCREF 2,020 4,120
      APP2 ETCRTN 1,650 3,380
      APP2 APP3 3,000 6,130
      APP3 ETCREF 2,010 4,110
      APP3 ETCRTN 1,450 2,970
      ETCREF ETCRTN 900 1,840
      ETCREF ETCREF 0 10
      ETCRTN ETCRTN 0 10

    Are all the resistances within specifications? 

    Yes No
    For DTCs P2121, P2122 or P2123 alone or in combination, GO to  DK10.
    For DTCs P2126, P2127 or P2128 alone or in combination, GO to  DK14.
    For DTCs P2131, P2132 or P2133 alone or in combination, GO to  DK18.
    For DTC P2104 alone, GO to  DK28.
    For a lack/loss of power, the concern is elsewhere. RETURN to SYMPTOM CHARTS - GASOLINE MODELS article for further direction.
    For all others, GO to  DK22.    		 INSTALL a new APP sensor. REFER to the appropriate Acceleration Control article to INSTALL a new accelerator pedal.
    CLEAR the DTCs. REPEAT the self-test.
  8. DK8 EXPEDITION, F-150, NAVIGATOR: CHECK THE APP SENSOR FOR THE CORRECT RESISTANCE 
    NOTE: Make sure the accelerator pedal is fully released when taking the resistance measurements.
    • Ignition OFF.
    • APP Sensor connector disconnected.
    • Measure the resistance between:
      RESISTANCE SPECIFICATIONS

      (+) APP Sensor Connector, Component Side (-) APP Sensor, Connector Side Minimum Resistance (ohms) Maximum Resistance (ohms)
      APP1 ETCREF1 1,550 2,700
      APP1 ETCRTN1 850 1,550
      ETCREF1 ETCRTN1 950 1,700
      APP2 ETCREF2 2,200 4,000
      APP2 ETCRTN2 850 1,500
      ETCREF2 ETCRTN2 1,600 2,800
      ETCREF1 ETCREF2 10,000 -

    Are all the resistances within specifications? 

    Yes No
    For DTCs P2121, P2122 or P2123 alone or in combination, GO to  DK10.
    For DTCs P2126, P2127 or P2128 alone or in combination, GO to  DK14.
    For DTCs P2131, P2132 or P2133 alone or in combination, GO to  DK18.
    For DTC P2104 alone, GO to  DK28.
    For a lack/loss of power, the concern is elsewhere. RETURN to SYMPTOM CHARTS - GASOLINE MODELS article for further direction.
    For all others, GO to  DK22.    		 INSTALL a new APP sensor. REFER to the appropriate Acceleration Control article to INSTALL a new accelerator pedal.
    CLEAR the DTCs. REPEAT the self-test.
  9. DK9 ALL OTHERS: CHECK THE APP SENSOR FOR THE CORRECT RESISTANCE 
    NOTE: Make sure the accelerator pedal is fully released when taking the resistance measurements.
    • Ignition OFF.
    • APP Sensor connector disconnected.
    • Measure the resistance between:
      RESISTANCE SPECIFICATIONS

      (+) APP Sensor Connector, Component Side (-) APP Sensor Connector, Component Side Minimum Resistance (ohms) Maximum Resistance (ohms)
      APP1 ETCREF 600 1,370
      APP1 ETCRTN 720 1,660
      APP1 APP2 1,300 2,960
      APP1 APP3 1,250 2,860
      APP2 ETCREF 750 1,720
      APP2 ETCRTN 660 1,520
      APP2 APP3 1,230 2,810
      APP3 ETCREF 710 1,640
      APP3 ETCRTN 580 1,340
      ETCREF ETCRTN 200 470
      ETCREF ETCREF 0 10
      ETCRTN ETCRTN 0 10

    Are all the resistances within specifications? 

    Yes No
    For DTCs P2121, P2122 or P2123 alone or in combination, GO to  DK10.
    For DTCs P2126, P2127 or P2128 alone or in combination, GO to  DK14.
    For DTCs P2131, P2132 or P2133 alone or in combination, GO to  DK18.
    For DTC P2104 alone, GO to  DK28.
    For a lack/loss of power, the concern is elsewhere. RETURN to SYMPTOM CHARTS - GASOLINE MODELS article for further direction.
    For all others, GO to  DK22.    		 INSTALL a new APP sensor. REFER to the appropriate Acceleration Control to INSTALL a new accelerator pedal.
    CLEAR the DTCs. REPEAT the self-test.
  10. DK10 CHECK THE APP1 CIRCUIT FOR AN OPEN CIRCUIT IN THE HARNESS 
    • Ignition OFF.
    • APP Sensor connector disconnected.
    • PCM connector disconnected.
    • Measure the resistance between:
      (+) APP Sensor Connector, Harness Side (-) PCM Connector, Harness Side
      APP1 APP1

    Is the resistance less than 5 ohms? 

    Yes No
    GO to  DK11. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
  11. DK11 CHECK THE APP1 CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS 
    • Measure the resistance between:
      (+) APP Sensor Connector, Harness Side (-) Vehicle Battery
      APP1 Negative terminal

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  DK12. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.
  12. DK12 CHECK THE APP1 CIRCUIT FOR A SHORT IN THE HARNESS 
    • Measure the resistance between:
      (+) APP Sensor Connector, Harness Side (-) APP Sensor Connector, Harness Side
      APP1 ETCRTN
      APP1 ETCRTN2
      APP1 ETCREF
      APP1 ETCREF2

    Are the resistances greater than 10K ohms? 

    Yes No
    GO to  DK13. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.
  13. DK13 CHECK THE APP1 CIRCUIT FOR A SHORT TO POWER IN THE HARNESS 
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) APP Sensor Connector, Harness Side (-) Vehicle Battery
      APP1 Negative terminal

    Is any voltage present? 

    Yes No
    REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test. GO to  DK22.
  14. DK14 CHECK THE APP2 CIRCUIT FOR AN OPEN CIRCUIT IN THE HARNESS 
    • Ignition OFF.
    • APP Sensor connector disconnected.
    • PCM connector disconnected.
    • Measure the resistance between:
      (+) APP Sensor Connector, Harness Side (-) PCM Connector, Harness Side
      APP2 APP2

    Is the resistance less than 5 ohms? 

    Yes No
    GO to  DK15. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
  15. DK15 CHECK THE APP2 CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS 
    • Measure the resistance between:
      (+) PCM Connector, Harness Side (-) Vehicle Battery
      APP2 Negative terminal

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  DK16. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.
  16. DK16 CHECK THE APP2 CIRCUIT FOR A SHORT IN THE HARNESS 
    • Measure the resistance between:
      (+) APP Sensor Connector, Harness Side (-) APP Sensor Connector, Harness Side
      APP2 ETCRTN
      APP2 ETCRTN3
      APP2 ETCREF
      APP2 ETCREF3

    Are the resistances greater than 10K ohms? 

    Yes No
    GO to  DK17. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.
  17. DK17 CHECK THE APP2 CIRCUIT FOR A SHORT TO POWER IN THE HARNESS 
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) PCM Connector, Harness Side (-) Vehicle Battery
      APP2 Negative terminal

    Is any voltage present? 

    Yes No
    REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test. GO to  DK23.
  18. DK18 CHECK THE APP3 CIRCUIT FOR AN OPEN CIRCUIT IN THE HARNESS 
    • PCM connector disconnected.
    • Measure the resistance between:
      (+) APP Sensor Connector, Harness Side (-) PCM Connector, Harness Side
      APP3 APP3

    Is the resistance less than 5 ohms? 

    Yes No
    GO to  DK19. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
  19. DK19 CHECK THE APP3 CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS 
    • Measure the resistance between:
      (+) PCM Connector, Harness Side (-) Vehicle Battery
      APP3 Negative terminal

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  DK20. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.
  20. DK20 CHECK THE APP3 CIRCUIT FOR A SHORT IN THE HARNESS 
    • Measure the resistance between:
      (+) APP Sensor Connector, Harness Side (-) APP Sensor Connector, Harness Side
      APP3 ETCRTN
      APP3 ETCREF

    Are the resistances greater than 10K ohms? 

    Yes No
    GO to  DK21. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.
  21. DK21 CHECK THE APP3 CIRCUIT FOR A SHORT TO POWER IN THE HARNESS 
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) PCM Connector, Harness Side (-) Vehicle Battery
      APP3 Negative terminal

    Is any voltage present? 

    Yes No
    REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test. GO to  DK24.
  22. DK22 CHECK FOR THE APP1 CIRCUIT SHORTED TO SIGNALS IN THE SAME HARNESS 
    • Ignition OFF.
    • PCM connector disconnected.
    • APP Sensor connector disconnected.
    • Measure the resistance between:
      (+) APP Sensor Connector, Harness Side (-) APP Sensor Connector, Harness Side
      APP1 APP2
      APP1 APP3
      APP1 ETCREF
      APP1 ETCREF2
      APP1 ETCRTN
      APP1 ETCRTN2

    Are the resistances greater than 10K ohms? 

    Yes No
    GO to  DK25. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.
  23. DK23 CHECK FOR THE APP2 CIRCUIT SHORTED TO SIGNALS IN THE SAME HARNESS 
    • Ignition OFF.
    • Measure the resistance between:
      (+) APP Sensor Connector, Harness Side (-) APP Sensor Connector, Harness Side
      APP2 APP1
      APP2 APP3
      APP2 ETCREF
      APP2 ETCREF3
      APP2 ETCRTN
      APP2 ETCRTN3

    Are the resistances greater than 10K ohms? 

    Yes No
    GO to  DK25. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.
  24. DK24 CHECK FOR THE APP3 CIRCUIT SHORTED TO SIGNALS IN THE SAME HARNESS 
    • Ignition OFF.
    • Measure the resistance between:
      (+) APP Sensor Connector, Harness Side (-) APP Sensor Connector, Harness Side
      APP3 APP1
      APP3 APP2
      APP3 ETCREF
      APP3 ETCRTN

    Are the resistances greater than 10K ohms? 

    Yes No
    GO to  DK25. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.
  25. DK25 CHECK THE APP SENSOR CIRCUITS FOR AN INTERMITTENT CONCERN 
    • Wiggle, shake, and bend small sections of the wiring harness while working from the sensor to the PCM.
    • Measure the resistance between:
      (+) APP Sensor Connector, Harness Side (-) PCM Connector, Harness Side
      APP1 APP1
      APP2 APP2
      APP3 APP3

    Are the resistances less than 5 ohms? 

    Yes No
    For E-Series 4.6L,
    E-Series 5.4L,
    Escape/Mariner, and
    Focus, GO to  DK26.
    For all others, GO to  DK28.    		 ISOLATE the concern and REPAIR as necessary.
    CLEAR the DTCs. REPEAT the self-test.
  26. DK26 CHECK FOR DTCS 
    • PCM connector connected.
    • Ignition ON, engine OFF.
    • Carry out the KOEO self-test.

    Are DTCs P2122 and P2127 present? 

    Yes No
    GO to  DK27. GO to  DK28.
  27. DK27 SIMULATE THE OPPOSITE SIGNAL 
    • Ignition OFF.
    • Connect a 5 amp fused jumper wire between the following:
      Point A APP Sensor Connector, Harness Side Point B APP Sensor Connector, Harness Side
      ETCREF2 APP1
      ETCREF3 APP2
    • Ignition ON, engine OFF.
    • Access the PCM and monitor the APP1 and APP2 PIDs.

    Are the voltages greater than 4.5 V? 

    Yes No
    INSTALL a new APP sensor.
    REFER to the appropriate Acceleration Control article to INSTALL a new accelerator pedal.
    CLEAR the DTCs. REPEAT the self-test.    		 GO to  DK28.
  28. DK28 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) , 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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