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Diagnostic Aids

Perform this test when instructed by QUICK TEST. This test is only intended to diagnose:

Fig 1: Identifying DPFEGR System Components
G96C29134Courtesy of FORD MOTOR CO.

  1. 1) DTC P1400: Check Present DPFEGR Sensor PID

    This DTC indicates EGR MONITOR failed due to average voltage to PCM dropping below minimum calibrated limit. Possible causes for this fault are:
    • DPFEGR Circuit Shorted To GND Or SIG RTN Circuit
    • Faulty DPFEGR Sensor
    • VREF Circuit Shorted To GND Or SIG RTN Circuit
    • Faulty PCM

    Connect scan tool to Data Link Connector (DLC). Turn ignition switch to ON position. Using scan tool, select DPFEGR PID from PID/DATA MONITOR & RECORD menu. If DPFEGR PID voltage is less than .2 volt, fault is currently present. Go to next step. If voltage is .2 volt or more, fault is intermittent. Go to step  5).

  2. 2) Simulate Opposite DPFEGR Sensor Signal

    Turn ignition switch to OFF position. Disconnect DPFEGR sensor harness connector. See Fig 2. Turn ignition switch to ON position. Using scan tool, select DPFEGR PID from PID/DATA MONITOR & RECORD menu. If PID voltage is 4-6 volts, replace DPFEGR sensor. If PID voltage is not 4-6 volts, go to next step.
    Fig 2: Identifying DPFEGR Sensor Wiring Harness Connector Terminals
    G99J02602Courtesy of FORD MOTOR CO.

  3. 3) Check VREF & SIG RTN Circuits For Open To DPFEGR Sensor

    Using a DVOM, measure voltage between DPFEGR sensor harness connector SIG RTN and VREF terminals. See Fig 2. If voltage is 4-6 volts, go to next step. If voltage is not 4-6 volts, go to TEST C, step  1).

  4. 4) Check DPFEGR Circuit For Short To Ground & SIG RTN

    Disconnect scan tool from Data Link Connector (DLC). Turn ignition switch to OFF position. Disconnect PCM connector(s). Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Using a DVOM, measure resistance between PCM harness connector DPFEGR and SIG RTN terminals. See WIRING DIAGRAMS article. See Figure. Using a DVOM, measure resistance between negative battery terminal and PCM harness connector DPFEGR terminal. If both resistance measurements are more than 10 k/ohms, replace PCM. If either resistance measurement is 10 k/ohms or less, repair short to ground or SIG RTN circuit.

  5. 5) Monitor DPFEGR PID & Perform Wiggle Test On DPFEGR Sensor & Harness

    Turn ignition switch to ON position. Using scan tool, select DPFEGR PID from PID/DATA MONITOR & RECORD menu. Observe DPFEGR PID voltage reading for change while tapping lightly on DPFEGR sensor, and shaking and bending DPFEGR sensor wiring harness and connector to simulate road shock. A sudden change in DPFEGR PID voltage reading indicates a fault. If fault is indicated, isolate and repair as necessary. If no fault is indicated, go to TEST Z, step  1).
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 5) to step 10). No test procedures have been omitted.

  6. 10) DTC P1401: Check Present DPFEGR Sensor PID

    This DTC indicates EGR MONITOR failed due to average voltage to PCM exceeding the maximum calibrated limit. Possible causes for this fault are:
    • Open In DPFEGR Circuit Or SIG RTN Circuit
    • VREF Circuit Shorted To PWR Circuit
    • Faulty DPFEGR Sensor
    • DPFEGR Circuit Shorted To VREF Or PWR Circuit
    • Faulty PCM

    Connect scan tool to Data Link Connector (DLC). Turn ignition switch to ON position. Using scan tool, select DPFEGR PID from PID/DATA MONITOR & RECORD menu. If DPFEGR PID voltage is more than 4 volts, go to next step. If DPFEGR PID voltage is 4 volts or less, go to step  19).

  7. 11) Check DPFEGR Circuit For Short To PWR

    Turn ignition switch to OFF position. Disconnect DPFEGR sensor harness connector. Turn ignition switch to ON position. Using a DVOM, measure voltage between chassis ground and DPFEGR sensor harness connector DPFEGR terminal. If voltage is more than 10.5 volts, go to next step. If voltage is 10.5 volts or less, go to step  13).

  8. 12) Check DPFEGR Circuit For Short To PWR In Harness

    Ensure ignition switch is turned to OFF position. Disconnect PCM connector(s). Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Turn ignition switch to ON position. Using a DVOM, measure voltage between negative battery terminal and PCM harness connector DPFEGR terminal. See WIRING DIAGRAMS article. See Figure. If voltage is more than 10.5 volts, repair short to PWR in DPFEGR circuit. If voltage is 10.5 volts or less, replace PCM.

  9. 13) Simulate Opposite DPFEGR Sensor Signal

    Turn ignition switch to OFF position. Connect a jumper wire between DPFEGR sensor harness connector DPFEGR and SIG RTN terminals. See Fig 2. Turn ignition switch to ON position. Using scan tool, select DPFEGR PID from PID/DATA MONITOR & RECORD menu. If scan tool error occurs, disconnect jumper wire and go to step  18). If DPFEGR PID voltage reading is .05 volt or more, disconnect jumper wire and go to step  16). If DPFEGR PID voltage reading is less than .05 volt, disconnect jumper wire and go to next step.

  10. 14) Check VREF Voltage To DPFEGR Sensor

    Turn ignition switch to ON position. Using a DVOM, measure voltage between DPFEGR sensor harness connector SIG RTN and VREF terminals. See Fig 2. If voltage is 4-6 volts, go to next step. If voltage is not 4-6 volts, go to TEST C, step  1).

  11. 15) Check DPFEGR Circuit For Short To VREF In Harness

    Turn ignition switch to OFF position. Disconnect PCM connector(s). Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Using a DVOM, measure resistance between PCM harness connector DPFEGR and VREF circuit terminals. See Fig 2. If resistance is more than 10 k/ohms, replace DPFEGR sensor. If resistance is 10 k/ohms or less, repair short between DPFEGR and VREF circuits.

  12. 16) Check DPFEGR Circuit For Open In Harness

    Turn ignition switch to OFF position. Disconnect PCM connector(s). Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Ensure DPFEGR sensor is disconnected. Using a DVOM, measure resistance of DPFEGR circuit between PCM harness connector and DPFEGR sensor harness connector. See Fig 2. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in DPFEGR circuit.

  13. 17) Check SIG RTN Circuit For Open In Harness

    Using a DVOM, measure resistance of SIG RTN circuit between PCM harness connector and DPFEGR sensor harness connector. See Fig 2. If resistance is less than 5 ohms, replace PCM. If resistance is 5 ohms or more, repair open in SIG RTN circuit.

  14. 18) Check DPFEGR Circuit For Short To VREF In Harness

    Turn ignition switch to OFF position. Disconnect PCM connector(s). Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Using a DVOM, measure resistance between PCM harness connector DPFEGR and VREF terminals. See WIRING DIAGRAMS article. See Figure. If resistance is more than 10 k/ohms, replace PCM. If resistance is 10 k/ohms or less, repair short between DPFEGR and VREF circuits.

  15. 19) Monitor DPFEGR PID & Perform Wiggle Test On DPFEGR Sensor & Harness

    Turn ignition switch to ON position. Using scan tool, select DPFEGR PID from PID/DATA MONITOR & RECORD menu. Observe DPFEGR PID voltage reading for change while tapping lightly on DPFEGR sensor, and shaking and bending DPFEGR sensor wiring harness and connector to simulate road shock. A sudden change in DPFEGR PID voltage reading indicates a fault. If fault is indicated, isolate and repair as necessary. If no fault is indicated, go to TEST Z, step  1).

  16. 20) KOER & Continuous Memory DTC P0402: Check EGR Flow At Idle (Vacuum Hose Disconnected)

    This DTC indicates EGR MONITOR failed due to PCM detecting EGR signal at idle is more than at KOEO by a calibrated amount. Possible causes for this fault are:
    • EGR Valve Stuck Open
    • EGR Vacuum Regulator (VR) Solenoid Vent Plugged
    • EGR Tube Plugged
    • DPFEGR Sensor Slow To Respond
    • Faulty DPFEGR Sensor
    • Pinched, Plugged, Damaged Or Improperly Connected Vacuum Hose
    • EGRVR Circuit Shorted To Ground
    • EGRVR Circuit Shorted To VREF Circuit
    • Faulty EGRVR Solenoid
    • Faulty PCM
    NOTE: If Continuous Memory DTC P1405 is present, go to step  50).

    Disconnect and plug EGR valve vacuum hose. Perform KOER ON-DEMAND SELF-TEST . If DTC P0402 is present, engine stalls or will not start, check EGR tube, EGR valve and hoses. Repair as necessary and retest. If DTC P0402 is not present, engine starts and does not stall, reconnect EGR valve vacuum hose and go to next step.

  17. 21) Check EGR Flow At Idle With Vacuum Hose Connected

    Turn ignition switch to OFF position. Ensure EGR valve vacuum hose is reconnected. Perform KOER ON-DEMAND SELF-TEST . If DTC P0402 is present, engine stalls or will not start, go to next step. If DTC P0402 is not present, engine starts and does not stall, fault is intermittent. Check vacuum hoses for pinching and icing. Repair as necessary and retest. If vacuum hoses are okay, go to step  30).

  18. 22) Check EGR System Vacuum Hoses

    A pinched or plugged EGR vacuum hose will not allow EGR valve to close if vacuum becomes trapped between EGR vacuum regulator solenoid and EGR valve. Using vehicle's vacuum diagram label, check EGR system vacuum hoses for damage, tight connections and correct routing. If hoses are okay, go to next step. If hoses are not okay, repair as necessary.

  19. 23) Check DPFEGR Sensor Output While Applying Vacuum

    Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Disconnect pressure hoses at DPFEGR sensor. Connect hand vacuum pump to DPFEGR sensor intake manifold (smaller diameter) port. DO NOT apply vacuum to sensor. See Fig 1. Turn ignition switch to ON position. Using scan tool, select DPFEGR PID from PID/DATA MONITOR & RECORD menu. Record DPFEGR PID voltage reading without vacuum applied.

    DPFEGR PID voltage reading should be .2-1.3 volts with ignition switch turned to ON position and no vacuum applied. Using vacuum pump, apply 8-9 in. Hg. DPFEGR PID voltage reading should increase to more than 4 volts with vacuum applied. Quickly release vacuum. DPFEGR PID voltage reading should drop to less than 1.5 volts within 3 seconds of releasing vacuum. If DPFEGR PID voltage reading does not operate as specified, replace DPFEGR sensor. If DPFEGR PID voltage reading operates as specified, reconnect DPFEGR sensor and go to next step.

  20. 24) Check For EGR Flow At Idle With EGRVR Solenoid Disconnected

    Turn ignition switch to OFF position. Disconnect EGR valve vacuum hose. Connect vacuum gauge to hose. Start engine and allow to idle. While observing vacuum gauge, disconnect EGRVR solenoid harness connector. If vacuum gauge measurement stays at more than 1.6 in. Hg, go to next step. If vacuum gauge measurement is 1.6 in. Hg or less, go to step  26).
    21. NOTE: A plugged EGRVR solenoid vent will not allow EGR vacuum to vent to atmosphere.
    Fig 3: Testing EGRVR Solenoid
    G98G00204Courtesy of FORD MOTOR CO.

  21. 25) Check EGRVR Solenoid Vent
    Turn ignition switch to OFF position. Disconnect EGRVR solenoid vacuum hoses. Remove EGRVR solenoid vent cap (if removable). Remove EGRVR solenoid filter and check for blockage or icing. Plug EGRVR solenoid vacuum supply port to EGR. See Fig 3. Using a hand vacuum pump, apply 10-15 in. Hg to EGRVR solenoid source port. If vacuum holds or is slow to release, EGRVR solenoid may be plugged or restricted. Repair EGRVR solenoid as necessary. If unable to repair EGRVR solenoid, replace EGRVR solenoid. If vacuum releases (solenoid not plugged or restricted), replace EGRVR solenoid.

  22. 26) Check EGRVR Solenoid Coil Resistance

    Turn ignition switch to OFF position. Disconnect EGRVR solenoid connector. Using a DVOM, measure resistance between EGRVR solenoid terminals. If resistance is 26-40 ohms, go to next step. If resistance is not 26-40 ohms, replace EGRVR solenoid.

  23. 27) Check EGRVR Circuit For Short To Ground In Harness

    Disconnect scan tool from DLC. Disconnect PCM connector(s). Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Using a DVOM, measure resistance between negative battery terminal and PCM harness connector EGRVR circuit terminal. See WIRING DIAGRAMS article. See Figure. If resistance is more than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, repair short to ground in EGRVR circuit.

  24. 28) Check EGRVR Circuit For Short To VREF

    Using a DVOM, measure resistance between PCM harness connector EGRVR and VREF circuit terminals. See WIRING DIAGRAMS article. See Figure. If resistance is more than 10 k/ohms, replace PCM. If resistance is 10 k/ohms or less, repair short between EGRVR and VREF circuits.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 28) to step 30). No test procedures have been omitted.

  25. 30) Check DPFEGR Sensor Output While Applying Vacuum

    Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Disconnect pressure hoses at DPFEGR sensor. Connect hand vacuum pump to DPFEGR sensor downstream intake manifold (smaller diameter) port. DO NOT apply vacuum to sensor. See Fig 3. Turn ignition switch to ON position. Using scan tool, select DPFEGR PID from PID/DATA MONITOR & RECORD menu. Record DPFEGR PID voltage reading without vacuum applied. DPFEGR PID voltage reading should be .2-1.3 volts with ignition switch turned to ON position and no vacuum applied. Using vacuum pump, apply 8-9 in. Hg. DPFEGR PID voltage reading should increase to more than 4 volts with vacuum applied. Quickly release vacuum. DPFEGR PID voltage reading should drop to less than 1.5 volts within 3 seconds of releasing vacuum. If DPFEGR PID voltage reading does not operate as specified, replace DPFEGR sensor. If DPFEGR PID voltage reading operates as specified, reconnect DPFEGR sensor and go to next step.
    26. NOTE: A higher voltage reading with engine idling could be due to an EGR valve not seating fully.

  26. 31) Check DPFEGR Sensor Voltage While Operating EGR Valve
    Reconnect DPFEGR sensor harness connector. Turn ignition switch to ON position. Using scan tool, select DPFEGR PID and record voltage reading. DPFEGR PID voltage reading should be .2-1.3 volts with no EGR flow. Disconnect and plug vacuum hose at EGR valve. Connect a hand vacuum pump to EGR valve. Start engine and allow to idle. Observe DPFEGR PID voltage reading at idle and compare to DPFEGR PID voltage reading taken with ignition switch turned to ON position, with engine off. Apply only enough vacuum (2-3 in. Hg) to open EGR valve without stalling engine, then release vacuum. Repeat several times while observing DPFEGR PID voltage reading on scan tool. DPFEGR PID voltage reading should increase as EGR valve begins to open and return to initial voltage reading as vacuum is released. If DPFEGR PID voltage reading is slow to return to initial voltage reading after releasing vacuum, EGR valve may be stuck open, binding or slow closing. Service or replace EGR valve. If DPFEGR PID voltage reading quickly returns to initial voltage reading after releasing vacuum, go to next step.
    27. NOTE: An intermittent short to GND in EGRVR circuit may cause higher than normal vacuum to be applied to EGR valve. Normal vacuum to EGR valve at idle should be less than one in. Hg. EGR valve normally begins to open when applied vacuum is more than 1.6 in. Hg.

  27. 32) Monitor EGR Valve Vacuum While Wiggling EGRVR Solenoid Circuit
    Turn ignition switch to OFF position. Remove hand vacuum pump from EGR valve vacuum hose and connect a vacuum gauge to hose. Start engine and allow to idle. Observe vacuum gauge for indication of fault while tapping lightly on EGRVR solenoid and wiggling EGRVR solenoid connector and wiring harness between PCM and solenoid to simulate road shock. Fault is indicated by a sudden jump in vacuum gauge reading. If no fault is indicated, reconnect vacuum hose to EGR valve and go to next step. If a fault is indicated, isolate and repair fault as necessary.

  28. 33) Check EGRVR Solenoid & Vacuum Hoses For Restriction

    Turn ignition switch to OFF position. Remove EGRVR solenoid vent filter. Inspect for contamination or water. In colder climates, excessive water in vent filter may freeze and plug solenoid vent. Remove EGR vacuum hose and inspect for pinching or restriction. Repair or replace as necessary. If no faults are found, problem is intermittent and cannot be identified at this time. Go to TEST Z, step  1).
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 33) to step 50). No test procedures have been omitted.

  29. 50) Continuous Memory DTC P1405: Check Upstream Pressure Hose Connections

    This DTC indicates EGR MONITOR failed while driving due to PCM detecting DPFEGR sensor signal is in the negative direction. Possible causes for this fault are:
    • Upstream Hose Is Disconnected
    • Upstream Hose Is Plugged (Ice)
    • Plugged Or Damaged EGR Tube

    Check upstream hose at DPFEGR sensor and orifice tube for clean and tight connections. See Fig 4. Repair as necessary. Perform DRIVE CYCLE PROCEDURES  under ADDITIONAL SYSTEM FUNCTIONS. Ensure EGR MONITOR PROCEDURE is performed to verify repair. If upstream hose connections are okay, go to next step.

    Fig 4: Identifying DPFEGR Sensor Vacuum Circuits
    G98H00205Courtesy of FORD MOTOR CO.

  30. 51) Check Upstream Pressure Hose For Restriction

    Check upstream hose for proper routing. Ensure upstream hose is not pinched and that hose routing does not have low spots where water may collect, freeze and plug hose in colder climates. Repair as necessary. Perform DRIVE CYCLE PROCEDURES  under ADDITIONAL SYSTEM FUNCTIONS. Ensure EGR MONITOR PROCEDURE is performed to verify repair. If upstream hose is okay, go to next step.

  31. 52) Check Orifice Tube Assembly & DPFEGR Sensor

    Check DPFEGR sensor downstream (smaller diameter) port for restriction or damage. See Fig 4. Inspect exhaust manifold side pressure pick-up tube (port) and orifice tube assembly for restriction or damage. If DPFEGR sensor or orifice tube assembly is restricted or damaged, repair or replace DPFEGR sensor or orifice tube as necessary. Perform DRIVE CYCLE PROCEDURES  under ADDITIONAL SYSTEM FUNCTIONS. Ensure EGR MONITOR PROCEDURE is performed to verify repair. If no faults are found, go to next step.

  32. 53) Check DPFEGR Sensor Output While Applying Vacuum

    Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Disconnect pressure hoses at DPFEGR sensor. Connect hand vacuum pump to DPFEGR sensor downstream intake manifold (smaller diameter) port. DO NOT apply vacuum to sensor. See Fig 4. Turn ignition switch to ON position. Using scan tool, select DPFEGR PID from PID/DATA MONITOR & RECORD menu. Record DPFEGR PID voltage reading without vacuum applied. DPFEGR PID voltage reading should be .2-1.3 volts with ignition switch turned to ON position and no vacuum applied. Using vacuum pump, apply 8-9 in. Hg. DPFEGR PID voltage reading should increase to more than 4 volts with vacuum applied. Quickly release vacuum. DPFEGR PID voltage reading should drop to less than 1.5 volts within 3 seconds of releasing vacuum. If DPFEGR PID voltage reading does not operate as specified, replace DPFEGR sensor. Perform DRIVE CYCLE PROCEDURES  under ADDITIONAL SYSTEM FUNCTIONS. Ensure EGR MONITOR PROCEDURE is performed to verify repair. If DPFEGR PID voltage reading operates as specified, fault is unable to be duplicated at this time. Go to TEST Z, step  1).
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 53) to step 60). No test procedures have been omitted.

  33. 60) Continuous Memory DTC P1406: Check Downstream Pressure Hose Connections

    This DTC indicates EGR MONITOR failed while driving when DPFEGR sensor continues to indicate EGR flow after EGR valve is commanded closed. Possible causes for this fault are:
    • Downstream Hose Is Disconnected
    • Downstream Hose Is Plugged (Ice)
    • Plugged Or Damaged EGR Tube

    Check downstream hose at DPFEGR sensor and orifice tube for clean and tight connections. See Fig 4. Repair as necessary. Perform DRIVE CYCLE PROCEDURES  under ADDITIONAL SYSTEM FUNCTIONS. Ensure EGR MONITOR PROCEDURE is performed to verify repair. If downstream hose connections are okay, go to next step.

  34. 61) Inspect Downstream Pressure Hose For Restriction

    Check downstream hose for proper routing. Ensure downstream hose is not pinched and that hose routing does not have low spots where water may collect, freeze and plug hose in colder climates. Repair as necessary. Perform DRIVE CYCLE PROCEDURES  under ADDITIONAL SYSTEM FUNCTIONS. Ensure EGR MONITOR PROCEDURE is performed to verify repair. If downstream hose is okay, go to next step.

  35. 62) Inspect Orifice Tube Assembly & DPFEGR Sensor

    Check DPFEGR sensor downstream (smaller diameter) port for restriction or damage. See Fig 4. Inspect intake manifold side pressure pick-up tube (port) and orifice tube assembly for restriction or damage. If DPFEGR sensor or orifice tube assembly is restricted or damaged, repair or replace DPFEGR sensor or orifice tube as necessary. Perform DRIVE CYCLE PROCEDURES  under ADDITIONAL SYSTEM FUNCTIONS. Ensure EGR MONITOR PROCEDURE is performed to verify repair. If no faults are found, go to next step.

  36. 63) Check DPFEGR Sensor Output While Applying Vacuum

    Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Disconnect pressure hoses at DPFEGR sensor. Connect hand vacuum pump to DPFEGR sensor downstream intake manifold (smaller diameter) port. DO NOT apply vacuum to sensor. See Fig 4. Turn ignition switch to ON position. Using scan tool, select DPFEGR PID from PID/DATA MONITOR & RECORD menu. Record DPFEGR PID voltage reading without vacuum applied. DPFEGR PID voltage reading should be .2-1.3 volts with ignition switch turned to ON position and no vacuum applied. Using vacuum pump, apply 8-9 in. Hg. DPFEGR PID voltage reading should increase to more than 4 volts with vacuum applied. Quickly release vacuum. DPFEGR PID voltage reading should drop to less than 1.5 volts within 3 seconds of releasing vacuum. If DPFEGR PID voltage reading does not operate as specified, replace DPFEGR sensor. Perform DRIVE CYCLE PROCEDURES  under ADDITIONAL SYSTEM FUNCTIONS. Ensure EGR MONITOR PROCEDURE is performed to verify repair. If DPFEGR PID voltage reading operates as specified, fault is unable to be duplicated at this time. Go to TEST Z, step  1).
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 63) to step 70). No test procedures have been omitted.

  37. 70) Continuous Memory DTC P0401: Perform KOER Self-Test

    This DTC indicates EGR MONITOR failed due to PCM detecting EGR flow while driving is less than desired minimum. Possible causes for this fault are:
    • Vacuum Supply
    • EGR Valve Stuck Closed
    • EGR Valve Leaks Vacuum
    • EGR Flow Path Restricted
    • EGRVR Circuit Shorted To PWR
    • VREF Circuit Open To DPFEGR Sesnor
    • DPFEGR Sensor Downstream Or Upstream Hoses Disconnected, Reversed Or Restricted
    • VPWR Circuit Open To EGRVR Solenoid
    • Damaged EGR Orifice Tube
    • Faulty EGRVR Solenoid
    • Faulty PCM

    If fault is currently present, KOER DTC P1408 should be present. Perform KOER ON-DEMAND SELF-TEST . If DTC P1408 is present, go to next step. If DTC P1408 is not present, go to step  90).

  38. 71) KOER DTC P1408: Retrieve Continuous Memory DTCs

    This DTC indicates KOER ON-DEMAND SELF-TEST failed due to measured EGR flow falling below or exceeding required calibration. Possible causes are:
    • Vacuum Supply
    • EGR Valve Stuck Closed
    • EGR Valve Leaks Vacuum
    • EGR Flow Path Restricted
    • EGRVR Circuit Shorted To PWR
    • VREF Circuit Open To DPFEGR Sesnor
    • DPFEGR Sensor Downstream Or Upstream Hoses Disconnected, Reversed Or Restricted
    • VPWR Circuit Open To EGRVR Solenoid
    • Damaged EGR Orifice Tube
    • Faulty EGRVR Solenoid
    • Faulty PCM

    Retrieve Continuous Memory DTCs. If DTC P1406 is present, go to step  60). If DTC P1406 is not present, go to next step. If any other DTCs are present, record DTCs and service after completing this test.

  39. 72) Perform KOER ON-DEMAND SELF-TEST While Monitoring EGR Vacuum

    Disconnect vacuum hose from EGR valve and connect hose to vacuum gauge. Perform KOER ON-DEMAND SELF-TEST  while monitoring gauge. Disregard any DTCs set during this test. About 30 seconds into performing KOER ON-DEMAND SELF-TEST, EGR flow will be requested for a few seconds. Vacuum reading on vacuum gauge should increase to more than 1.6 in. Hg. If vacuum reading increases to 3.0 in. Hg or more, vacuum is sufficient to open EGR valve. Go to next step. If vacuum reading stays less than 3 in. Hg, vacuum is insufficient to open EGR valve. Turn ignition switch to OFF position and go to step  80).

  40. 73) Check DPFEGR Sensor Pressure Hoses

    Check both DPFEGR sensor hoses for correct routing. See Fig 4. Ensure downstream and upstream hoses are not pinched and that hose routing does not have low spots where water may collect, freeze and plug hose in colder climates. Inspect DPFE sensor and orifice tube assembly for restriction or damage at pick-up tubes (ports). If no faults are found, go to next step. If faults are found, repair as necessary.

  41. 74) Check DPFEGR Sensor Output While Applying Vacuum

    Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Disconnect pressure hoses at DPFEGR sensor. Connect hand vacuum pump to DPFEGR sensor downstream intake manifold (smaller diameter) port. DO NOT apply vacuum to sensor. See Fig 4. Turn ignition switch to ON position. Using scan tool, select DPFEGR PID from PID/DATA MONITOR & RECORD menu. Record DPFEGR PID voltage reading without vacuum applied. DPFEGR PID voltage reading should be .2-1.3 volts with ignition switch turned to ON position and no vacuum applied. Using vacuum pump, apply 8-9 in. Hg. DPFEGR PID voltage reading should increase to more than 4 volts with vacuum applied. Quickly release vacuum. DPFEGR PID voltage reading should drop to less than 1.5 volts within 3 seconds of releasing vacuum. If DPFEGR PID voltage reading does not operate as specified, replace DPFEGR sensor. Perform DRIVE CYCLE PROCEDURES  under ADDITIONAL SYSTEM FUNCTIONS. Ensure EGR MONITOR PROCEDURE is performed to verify repair. If DPFEGR PID voltage reading operates as specified, reconnect pressure hoses and go to step  76).
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 74) to step 76). No test procedures have been omitted.

  42. 76) Check EGR Valve Function By Applying Vacuum

    Turn ignition switch to OFF position. Disconnect and plug vacuum hose at EGR valve. Connect hand vacuum pump to EGR valve. Start engine and allow to idle. Using scan tool, select DPFEGR and RPM PIDs. Slowly apply 8-10 in. Hg to EGR valve and hold for 10 seconds. It may be necessary to increase engine speed to obtain 1000 RPM. Check for the following:
    • EGR valve should start opening at about 1.6 in Hg.
    • As vacuum increases, DPFEGR PID voltage reading should increase (up to 2.5 volts with full vacuum applied). As DPFEGR voltage reading increases, EGR valve should open fully.
    • When vacuum is held steady, DPFEGR PID voltage reading should also hold steady.

    If DPFEGR PID voltage reading operates as specified, reconnect all components and go to step  85). If DPFEGR PID voltage reading does not operate as specified, remove EGR valve and check for contamination, wear, carbon deposits, binding, leaking diaphragm or other damage. If EGR valve is okay, check for obstructed EGR port in intake manifold or restricted orifice tube assembly. Repair as necessary.

    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 76) to step 80). No test procedures have been omitted.

  43. 80) Check Vacuum Source & Hoses To & From EGRVR Solenoid

    Inspect vacuum hoses between EGRVR solenoid and EGR valve for leaks, restrictions, damage or incorrect routing. Repair as necessary. If hoses are okay, disconnect vacuum hoses at EGRVR solenoid. Connect vacuum gauge to EGRVR solenoid vacuum supply hose. Start engine and allow to idle. If vacuum gauge measurement is 15 in. Hg or more, go to next step. If vacuum gauge measurement is less than 15 in. Hg, isolate fault and repair as necessary.

  44. 81) Check VPWR Voltage To EGRVR Solenoid

    Turn ignition switch to OFF position. Disconnect EGRVR solenoid harness connector. Turn ignition switch to ON position. Using a DVOM, measure voltage of VPWR circuit between negative battery terminal and EGRVR solenoid harness connector. See Fig 5. If voltage is more than 10.5 volts, go to next step. If voltage is 10.5 volts or less, repair open in VPWR circuit.
    Fig 5: Identifying EGRVR Solenoid Wiring Harness Connector Terminals
    G99D02604Courtesy of FORD MOTOR CO.

  45. 82) Measure Resistance At EGRVR Solenoid

    Turn ignition switch to OFF position. Using a DVOM, measure resistance between EGRVR solenoid connector terminals. If EGRVR solenoid resistance is 26-40 ohms, go to next step. If EGRVR solenoid resistance is not 26-40 ohms, replace EGRVR solenoid.

  46. 83) Check EGRVR Circuit For Short To PWR In Harness

    Ensure ignition switch is turned to OFF position. Disconnect PCM connector(s). Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Turn ignition switch to ON position. Using a DVOM, measure voltage between negative battery terminal and appropriate PCM harness connector EGRVR terminal. See Fig 5. If voltage is one volt or less, go to next step. If voltage is more than one volt, repair short to PWR in EGRVR circuit.

  47. 84) Check EGRVR Circuit For Open In Harness

    Turn ignition switch to OFF position. Using a DVOM, measure resistance of EGRVR circuit between PCM harness connector and EGRVR solenoid harness connector. See Fig 5. If resistance is less than 5 ohms, reconnect EGRVR solenoid and PCM harness connectors and go to next step. If resistance is 5 ohms or more, repair open in EGRVR circuit.

  48. 85) Check EGRVR Solenoid Vacuum Output Capability By Grounding EGRVR Circuit

    Disconnect hose from EGR valve and connect vacuum gauge to EGR vacuum hose. Start engine and allow to idle. Backprobe PCM harness connector to connect a jumper wire between chassis ground and PCM harness connector EGRVR circuit terminal. See Fig 5. If vacuum gauge reading is 4 in. Hg or more, replace PCM. If vacuum gauge reading is less than 4 in. Hg, replace EGRVR solenoid.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 85) to step 90). No test procedures have been omitted.

  49. 90) Check EGR System For Intermttent Fault

    Turn ignition switch to OFF position. Check entire EGR system for deterioration or signs of intermittent failure. Repair as necessary. If no faults are found, go to next step.

  50. 91) Check DPFEGR Sensor Pressure Hoses

    Check both DPFEGR sensor hoses for correct routing. See Fig 4. Ensure downstream and upstream hoses are not pinched and that hose routing does not have low spots where water may collect, freeze and plug hose in colder climates. Inspect DPFE sensor and orifice tube assembly for restriction or damage at pick-up tubes (ports). If no faults are found, go to next step. If faults are found, repair as necessary.

  51. 92) Check DPFEGR Sensor Output While Applying Vacuum

    Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Disconnect pressure hoses at DPFEGR sensor. Connect hand vacuum pump to DPFEGR sensor downstream intake manifold (smaller diameter) port. DO NOT apply vacuum to sensor. See Fig 4. Turn ignition switch to ON position. Using scan tool, select DPFEGR PID from PID/DATA MONITOR & RECORD menu. Record DPFEGR PID voltage reading without vacuum applied.

    DPFEGR PID voltage reading should be .2-1.3 volts with ignition switch turned to ON position and no vacuum applied. Using vacuum pump, apply 8-9 in. Hg. DPFEGR PID voltage reading should increase to more than 4 volts with vacuum applied. Quickly release vacuum. DPFEGR PID voltage reading should drop to less than 1.5 volts within 3 seconds of releasing vacuum. If DPFEGR PID voltage reading does not operate as specified, replace DPFEGR sensor. Perform DRIVE CYCLE PROCEDURES  under ADDITIONAL SYSTEM FUNCTIONS. Ensure EGR MONITOR PROCEDURE is performed to verify repair. If DPFEGR PID voltage reading operates as specified, reconnect pressure hoses and go to next step.

  52. 93) Check EGR Valve Operation

    Turn ignition switch to OFF position. Disconnect and plug vacuum hose at EGR valve. Connect hand vacuum pump to EGR valve. Start engine and allow to idle. Using scan tool, select DPFEGR and RPM PIDs. Slowly apply 5-10 in. Hg to EGR valve and hold for 10 seconds. It may be necessary to increase engine speed to obtain 800 RPM. Check for the following:
    • EGR valve should start opening at about 1.6 in Hg., which is indicated by DPFEGR PID voltage reading increasing.
    • As vacuum increases, DPFEGR PID voltage reading should increase (up to 2.5 volts with full vacuum applied). As DPFEGR voltage reading increases, EGR valve should open fully.
    • When vacuum is held steady, DPFEGR PID voltage reading should also hold steady.

    If DPFEGR PID voltage reading operates as specified, reconnect all components and go to next step. If DPFEGR PID voltage reading does not operate as specified, remove EGR valve and check for contamination, wear, carbon deposits, binding, leaking diaphragm or other damage. If EGR valve is okay, check for obstructed EGR port in intake manifold. Repair as necessary.

    NOTE: In colder climates, EGR valve may freeze shut and then thaw when engine warms causing an intermittent DTC to be set in PCM memory.

  53. 94) Check EGR Vacuum Signal Supply For Intermittent Fault

    Connect vacuum gauge to EGR valve vacuum supply hose. Start engine and allow to idle. Backprobe PCM harness connector and connect a jumper wire between chassis ground and PCM harness connector EGRVR terminal to turn EGRVR solenoid on. At idle, vacuum gauge reading should be more than 4 in. Hg. Observe vacuum gauge for fault while tapping lightly on EGRVR solenoid and wiggling EGRVR solenoid vacuum hoses, wiring harness and connector. Fault will be indicated by a sudden drop in vacuum reading. If fault is indicated, isolate and repair as necessary. If no faults are indicated, symptom cannot be identified at this time. Go to TEST Z, step  1).
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 94) to step 100). No test procedures have been omitted.

  54. 100) EGR Diagnosis By Symptom: Check For EGR Flow With EGR Vacuum Hose Disconnected & Plugged

    If directed to this test step for a poor fuel economy symptom and no DTCs are pressent, possible causes are:
    • EGR Valve Not Fully Seated
    • EGRVR Solenoid Vent Restricted
    • Faulty EGRVR Solenoid

    Perform KOER ON-DEMAND SELF-TEST  and service any other DTCs that are present. If no other DTCs are present, disconnect and plug EGR valve vacuum supply hose. Leave scan tool connected to Data Link Connector (DLC). Turn ignition switch to ON position. Using scan tool, select DPFEGR PID and record voltage reading. Start engine and allow to idle. Observe and record DPFEGR PID voltage reading. Compare DPFEGR PID voltage readings. If DPFEGR PID voltage reading at idle is more than .15 volt of KOEO reading, DPFEGR sensor is sensing EGR flow and most likely cause is EGR valve. Check EGR valve for contamination, wear, carbon deposits, binding or damage. Repair as necessary. If DPFEGR PID voltage reading at idle is within .15 volt of KOEO reading, check EGR valve vacuum supply, EGRVR solenoid vent and vent filter for restriction. If no restrictions are found, replace EGRVR solenoid.

    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 100) to step 110). No test procedures have been omitted.

  55. 110) KOEO Or KOER DTC P1409: Check EGRVR Solenoid Resistance

    This DTC indicates self-test failed due to EGRVR circuit voltage reads too high or too low when compared to expected voltage range. Possible causes are:
    • EGRVR Circuit Open Or Shorted To VPWR Or GND
    • VPWR Circuit Open To EGRVR Solenoid
    • Faulty EGRVR Solenoid
    • Faulty PCM

    Turn ignition switch to OFF position. Disconnect EGRVR solenoid harness connector. Using a DVOM, measure resistance between EGRVR solenoid terminals. If resistance is 26-40 ohms, go to next step. If resistance is not 26-40 ohms, replace EGRVR solenoid.

  56. 111) Check VPWR Voltage To EGRVR Solenoid

    Turn ignition switch to ON position. Using a DVOM, measure voltage between VPWR terminal at EGRVR solenoid harness connector and negative battery terminal. See Fig 5. If voltage is more than 10.5 volts, go to next step. If voltage is 10.5 volts or less, repair open in VPWR circuit.

  57. 112) Check EGRVR Circuit For Open In Harness

    Turn ignition switch to OFF position. Disconnect PCM connector(s). Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Using a DVOM, measure resistance of EGRVR circuit between PCM harness connector and EGRVR solenoid harness connector. See WIRING DIAGRAMS article. See Figure or Fig 5 . If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in EGRVR circuit.

  58. 113) Check EGRVR Circuit For Short To PWR In Harness

    Turn ignition switch to ON position. Using a DVOM, measure voltage between PCM harness connector EGRVR circuit terminal and negative battery terminal. See Figure or Fig 5 . If voltage is less than one volt, go to next step. If voltage is one volt or more, repair short to PWR in EGRVR circuit.

  59. 114) Check EGRVR Circuit For Short To GND In Harness

    Turn ignition switch to OFF position. Using a DVOM, measure resistance between PCM harness connector EGRVR and PWR GND terminals. See PCM PWR GND, SIG RTN & VREF TERMINAL IDENTIFICATION  table. See Figure. If resistance is 10 k/ohms or less, repair short between circuits. If resistance is more than 10 k/ohms, replace PCM.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 114) to step 120). No test procedures have been omitted.

  60. 120) Continuous Memory DTC P1409: Wiggle EGRVR Solenoid While Monitoring VPWR

    This DTC indicates self-test failed due to EGRVR circuit voltage reads too high or too low when compared to expected voltage range. Possible causes are:
    • EGRVR Circuit Open Or Shorted To VPWR Or GND
    • VPWR Circuit Open To EGRVR Solenoid
    • Faulty EGRVR Solenoid
    • Faulty PCM

    Turn ignition switch to OFF position. Disconnect PCM connector(s). Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Turn ignition switch to ON position. Using a DVOM, measure resistance between PCM harness connector EGRVR and PWR GND terminals. See PCM PWR GND, SIG RTN & VREF TERMINAL IDENTIFICATION  table. See Figure or Fig 5 . Voltage should be more than 10.5 volts. Observe DVOM for indication of fault while tapping lightly on EGRVR solenoid, and wiggling EGRVR solenoid wiring harness and connector to simulate road shock. Fault is indicated by a sudden drop in voltage reading. If fault is indicated, isolate and repair as necessary. If no faults are indicated, unable to duplicate or identify fault at this time. Go to TEST Z, step  1).

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