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HOMESERVICE MANUALSLINCOLN2009NAVIGATOR L RWDREPAIR AND DIAGNOSIS (SINGLE PAGE)ENGINE PERFORMANCESYSTEMENGINE CONTROLS - PINPOINT TEST DZ: UNIVERSAL HEATED OXYGEN SENSOR (HO2S) THROUGH PINPOINT TEST HG: POSITIVE CRANKCASE VENTILATION (PCV) SYSTEM - (EXCEPT DIESEL & HYBRID)PINPOINT TEST HE: EXHAUST GAS RECIRCULATION (EGR) SYSTEMSTEST PROCEDURE
2009 Lincoln Navigator L RWD

Test procedure

2009 Lincoln Navigator L RWDSECTION Test procedure
  1. HE1 CHECK FOR DTCS 

    Are DTCs P0401, P0402, P0403, P0405, P0406, P1405, P1406, P1408, or P1409 present? 

    Yes No
    For DTCs P0401 and P1408, GO to  HE36.
    For DTC P0402, GO to  HE13.
    For KOEO and KOER DTCs P0403 and P1409, GO to  HE59.
    For continuous memory DTCs P0403 and P1409, GO to  HE64.
    For DTC P0405, GO to  HE2.
    For DTC P0406, GO to  HE6.
    For DTC P1405, GO to  HE27.
    For DTC P1406, GO to  HE31.    		 For symptoms without DTCs, GO to  HE57.
    For all others, GO to DTC LIST .
  2. HE2 DTC P0405: DETERMINE THE PRESENT DPFEGR PID VOLTAGE 
    NOTE: Depending on the application, verify a prior repair has not resulted in the differential pressure feedback EGR sensor being installed backwards or the vacuum hoses being installed on the opposite ports.
    • Ignition ON, engine OFF.
    • Access the PCM and monitor the DPFEGR PID.

    Is the voltage less than 0.05 V? 

    Yes No
    GO to  HE3. An intermittent concern is suspected in the EGR system.
    GO to  HE12.
  3. HE3 CHECK THE VREF AND SIGRTN CIRCUITS FOR AN OPEN IN THE HARNESS 
    • Ignition OFF.
    • Differential Pressure Feedback EGR Sensor connector disconnected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
    (+) Differential Pressure Feedback EGR Sensor Connector, Harness Side (-) Differential Pressure Feedback EGR Sensor Connector, Harness Side
    VREF - Pin 1 SIGRTN - Pin 2

    Is the voltage between 4 - 5.5 V? 

    Yes No
    GO to  HE4. GO to Pinpoint Test C .
  4. HE4 CHECK THE DPFE CIRCUIT(S) FOR A SHORT TO SIGRTN OR GND IN THE HARNESS 
    • Ignition OFF.
    • PCM connector disconnected.
    • Measure the resistance between:
    (+) PCM Connector, Harness Side (-) PCM Connector, Harness Side
    DPFE SIGRTN
    • Measure the resistance between:
    (+) PCM Connector, Harness Side (-) Vehicle Battery
    DPFE Negative terminal

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  HE5. REPAIR the short circuit. CLEAR the DTCs.
    REPEAT the self-test.
  5. HE5 INDUCE THE OPPOSITE DIFFERENTIAL PRESSURE FEEDBACK EGR SENSOR VOLTAGE 
    • PCM connector connected.
    • Ignition ON, engine OFF.
    • Access the PCM and monitor the DPFEGR PID.

    Is the voltage between 4 - 5.5 V? 

    Yes No
    INSTALL a new Differential Pressure Feedback EGR sensor.
    After installing the new differential pressure feedback EGR sensor, TURN the ignition to the ON position for approximately 5 seconds before starting. This allows the PCM to calibrate itself to the new differential pressure feedback EGR sensor. Failure to do this may result in an incorrect DTC P0402.
    CLEAR the DTCs. REPEAT the self-test.    		 GO to  HE66.
  6. HE6 DTC P0406: DETERMINE THE PRESENT DPFEGR PID VOLTAGE 
    • Ignition ON, engine OFF.
    • Access the PCM and monitor the DPFEGR PID.

    Is the voltage greater than 4 V? 

    Yes No
    GO to  HE7. An intermittent concern is suspected in the EGR system.
    GO to  HE12.
  7. HE7 CHECK THE VREF VOLTAGE TO THE DIFFERENTIAL PRESSURE FEEDBACK EGR SENSOR 
    • Ignition OFF.
    • Differential Pressure Feedback EGR Sensor connector disconnected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
    (+) Differential Pressure Feedback EGR Sensor Connector, Harness Side (-) Differential Pressure Feedback EGR Sensor Connector, Harness Side
    VREF - Pin 1 SIGRTN - Pin 2

    Is the voltage between 4 - 5.5 V? 

    Yes No
    GO to  HE8. GO to Pinpoint Test C .
  8. HE8 CHECK THE DPFE AND SIGRTN CIRCUIT(S) FOR AN OPEN IN THE HARNESS 
    • Ignition OFF.
    • PCM connector disconnected.
    • Measure the resistance between:
    (+) PCM Connector, Harness Side (-) Differential Pressure Feedback EGR Sensor Connector, Harness Side
    DPFE DPFE - Pin 3
    SIGRTN SIGRTN - Pin 2

    Are the resistances less than 5 ohms? 

    Yes No
    GO to  HE9. REPAIR the open circuit. CLEAR the DTCs.
    REPEAT the self-test.
  9. HE9 CHECK THE DPFE CIRCUIT FOR A SHORT TO VREF 
    • Measure the resistance between:
    (+) PCM Connector, Harness Side (-) PCM Connector, Harness Side
    VREF DPFE

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  HE10. REPAIR the short circuit. CLEAR the DTCs.
    REPEAT the self-test.
  10. HE10 CHECK THE DPFE CIRCUIT FOR A SHORT TO VOLTAGE 
    • Ignition ON, engine OFF.
    • Measure the voltage between:
    (+) Differential Pressure Feedback EGR Sensor Connector, Harness Side (-) Vehicle Battery
    DPFE - Pin 3 Negative terminal

    Is the voltage less than 0.2 V? 

    Yes No
    GO to  HE11. REPAIR the short circuit. CLEAR the DTCs.
    REPEAT the self-test.
  11. HE11 CHECK THE DPFEGR PID 
    • Ignition OFF.
    • PCM connector connected.
    • Connect a 5 amp fused jumper wire between the following:
    Point A Differential Pressure Feedback EGR Sensor Connector, Harness Side Point B
    DPFE - Pin 3 Ground
    • Ignition ON, engine OFF.
    • Access the PCM and monitor the DPFEGR PID.

    Is the DPFEGR PID greater than 4.5 V with the jumper wire removed and is the DPFEGR PID less than 0.1 V with the jumper wire installed? 

    Yes No
    INSTALL a new Differential Pressure Feedback EGR sensor. CLEAR the DTCs. REPEAT the self-test. GO to  HE66.
  12. HE12 CARRY OUT A THOROUGH WIGGLE TEST ON THE DIFFERENTIAL PRESSURE FEEDBACK EGR HARNESS 
    • Access the PCM and monitor the DPFEGR PID.
    • Wiggle, shake, and bend small sections of the wiring harness while working from the sensor to the PCM.

    Is there any change in the voltage reading, or is a concern present? 

    Yes No
    REPAIR as necessary.
    CLEAR the DTCs. REPEAT the self-test.    		 Unable to duplicate or identify the concern at this time.
    GO to Pinpoint Test Z .
  13. HE13 DTCS P0402 AND P1405: CHECK FOR SIMULTANEOUS PRESENCE 

    Is DTC P0402 present with DTC P1405? 

    Yes No
    GO to  HE28. GO to  HE14.
  14. HE14 DTC P0402: CHECK FOR EGR FLOW AT IDLE WITH THE EGR VACUUM HOSE DISCONNECTED 
    NOTE: A pinched or plugged EGR vacuum hose can trap vacuum between the EGR vacuum regulator solenoid and EGR valve, not allowing the EGR valve to close.
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.