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Test He: EGR System: Testing

NOTE: Proceed to DTC testing steps listed in FAULT CODE SETTING CONDITION  table of fault code setting condition.
FAULT CODE SETTING CONDITION

Fault Code KOEO KOER Continuous Memory
P0401      HE70
P0402  HE22  HE22  HE22
P0403  HE110  HE110  HE120
P0405  HE1  HE1  HE1
P0406  HE10  HE10  HE10
P1400  HE1  HE1  HE1
P1401  HE10  HE10  HE10
P1405      HE50
P1406      HE60
P1408      HE71
P1409  HE110  HE110  HE120
(1)
For engines equipped with a "Exhaust Gas Recirculation System Module (ESM)" see FAULT CODE SETTING CONDITION .
(2)
For engines equipped with "Electric Exhaust Gas Recirculation (EEGR) Assembly see FAULT CODE SETTING CONDITION .
    NOTE: For additional testing information, see DIAGNOSTIC AIDS .

  1. 1) For KOEO, KOER & Continuous Memory DTC P0405 & P1400: Determine Present DPFEGR PID Voltage
    DTC P0405 and P1400 indicates EGR MONITOR failed due to average voltage to PCM dropping below minimum calibrated limit of less than .2 volt. 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, access 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) Attempt To Induce Opposite DPFEGR Sensor Voltage

    Turn ignition switch to OFF position. Disconnect DPFEGR sensor harness connector. See Figure-Figure . Turn ignition switch to ON position. Using scan tool, access 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.

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

    Using a DVOM, measure voltage between SIG RTN and VREF circuits at DPFEGR sensor harness connector. See Figure-Figure . 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 In Harness

    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 DPFEGR circuit, and SIG RTN circuit at PCM harness connector, and negative battery terminal. See PCM CONNECTOR IDENTIFICATION and Figure-Figure . 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 in DPFEGR circuit.

  5. 5) Perform Wiggle Test On DPFEGR Sensor & Circuit While Monitoring DPFEGR PID For A Sudden Change

    Ensure ignition switch is in ON position. Using scan tool, access 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. NOTE: For additional testing information, see DIAGNOSTIC AIDS .

  6. 10) For KOEO, KOER & Continuous Memory DTC P0406 & P1401: Determine Present DPFEGR Sensor PID Voltage
    DTC P0406 and P1401 indicate EGR MONITOR failed due to average voltage to PCM exceeding maximum calibrated limit of 4.5 volts. Possible causes for this fault are:
    • Open In DPFEGR Or SIG RTN circuit.
    • VREF Or DPFEGR circuit shorted To PWR.
    • Faulty DPFEGR sensor.
    • Faulty PCM.

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

  7. 11) Check DPFEGR Circuit For Short To PWR

    Turn ignition switch to OFF position. Disconnect DPFEGR sensor connector. Turn ignition switch to ON position. Using a DVOM, measure voltage between chassis ground and DPFEGR circuit at DPFEGR sensor harness connector. 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

    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 voltage between negative battery terminal and DPFEGR circuit at PCM harness connector. See PCM CONNECTOR IDENTIFICATION and Figure-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 faulty PCM.

  9. 13) Verify Scan Tool Communication

    Connect jumper wire between DPFEGR and SIG RTN circuits at the DPFEGR sensor harness connector. See Figure-Figure . Turn ignition switch to ON position. Using scan tool, access DPFEGR PID from PID/DATA MONITOR & RECORD menu. If a scan tool communication concern appears with the jumper wire connected, immediately remove jumper wire. Go to step  19). If a scan tool communication concern does not appear with the jumper wire connected, go to next step.

  10. 14) Induce Opposite DPFEGR Sensor Voltage

    With jumper wire connected between DPFEGR and SIG RTN circuits at DPFEGR sensor harness connector, use scan tool to access DPFEGR PID from PID/DATA MONITOR & RECORD menu. If DPFEGR PID voltage reading is .05 volt or more, disconnect jumper wire and go to step  17). If DPFEGR PID voltage reading is less than .05 volt, disconnect jumper wire and go to next step.

  11. 15) Check VREF Voltage To DPFEGR Sensor

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

  12. 17) Check DPFEGR Circuit For Open In Harness

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

  13. 18) 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. If resistance is less than 5 ohms, replace PCM. If resistance is 5 ohms or more, repair open in SIG RTN circuit.

  14. 19) 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 DPFEGR and VREF circuits at PCM harness connector (both VREF circuits on 150-pin PCM). See PCM CONNECTOR IDENTIFICATION and Figure-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. 20) Perform Wiggle Test On DPFEGR Sensor & Circuit While Monitoring DPFEGR PID For A Sudden Change

    Turn ignition switch to ON position. Using scan tool, access DPFEGR PID from PID/DATA MONITOR & RECORD menu. Observe DPFEGR PID value for a sudden 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 value indicates a fault. If fault is indicated, isolate and repair as necessary. If no fault is indicated, go to TEST Z, step 1) .

  16. 21) Check For Presence Of DTC P1405 With DTC P0402

    If DTC P1405 is present with DTC P0402, go to step  50). If DTC P1405 is not present with P0402, go to next step.
    17. NOTE: For additional testing information, see DIAGNOSTIC AIDS .

  17. 22) For KOER & Continuous Memory Only DTC P0402: Check EGR Flow At Idle (Vacuum Hose Disconnected)
    DTC P0402 indicates EGR MONITOR failed due to PCM detecting EGR signal at idle is more than at KOEO by a calibrated amount of .5 volt. 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

    Disconnect and plug EGR valve vacuum hose. Perform KOER ON-DEMAND SELF-TEST . If KOER DTC P0402 is present, KOER self-test is unable to be performed, 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.

  18. 23) Check For EGR Flow At Idle With Vacuum Hose Connected

    Ensure EGR valve vacuum hose is reconnected. Perform KOER ON-DEMAND SELF-TEST . If DTC P0402 is present, engine stalls or will not start, there may be EGR flow at idle. 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  31).
    19. NOTE: 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.

  19. 24) Check EGR System Vacuum Hoses For Integrity & Proper Connection
    Using vehicle's vacuum diagram label, check EGR system vacuum hoses for damage, tight connections and correct routing. Repair as necessary. If hoses are okay, go to next step.

  20. 25) Check DPFEGR Sensor Output By Applying Vacuum With Hand Pump

    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 downstream connection at DPFEGR sensor (intake manifold side or smaller diameter port). See Figure. Using scan tool, access DPFEGR PID from PID/DATA MONITOR & RECORD menu. Read the following DPFEGR PID values with ignition switch in ON position:
    • DO NOT apply vacuum to sensor. Record DPFEGR PID value. DPFEGR PID value should be .2-1.3 volts.
    • Using vacuum pump, apply 8-9 in. Hg (27-30 kPa) for a few seconds. DPFEGR PID value should increase to more than 4 volts.
    • Quickly release vacuum. DPFEGR PID value should drop to less than 1.5 volts within 3 seconds of releasing vacuum.

    If any DPFEGR PID values are not as specified, replace DPFEGR sensor. If all DPFEGR PID values are as specified, reconnect DPFEGR sensor and go to next step.

    21. NOTE: EGR valve requires more than 1.6 in. Hg (5.4 kPa) of vacuum to begin to open. If vacuum reading stays at more than 1.6 in. Hg (5.4 kPa) after EGRVR solenoid connector is disconnected, this indicates a mechanical fault in EGRVR solenoid.

  21. 26) Check For EGR Flow At Idle With EGRVR Solenoid Disconnected
    Disconnect EGR valve vacuum hose and 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 (5.4 kPa), go to next step. If vacuum gauge measurement is 1.6 in. Hg (5.4 kPa) or less, go to step  28).
    22. NOTE: A plugged EGRVR solenoid vent will not allow EGR vacuum to vent to atmosphere.
    Fig 1: Testing EGRVR Solenoid
    G98G00204Courtesy of FORD MOTOR CO.

  22. 27) Check EGRVR Solenoid Vent For Plugging
    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. Using a hand vacuum pump, apply 10-15 in. Hg (34-51 kPa) to EGRVR solenoid source port. See Fig 1. If vacuum holds or is slow to release, EGRVR solenoid vent may be plugged or restricted. Repair EGRVR solenoid as necessary. If unable to repair EGRVR solenoid, replace EGRVR solenoid. If vacuum releases (solenoid vent not plugged or restricted), replace EGRVR solenoid.

  23. 28) Check EGRVR Solenoid Coil Resistance

    Turn ignition switch to OFF position. Ensure EGRVR solenoid is disconnected. 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.

  24. 29) 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 EGRVR circuit at PCM harness connector. See PCM CONNECTOR IDENTIFICATION and Fig 2. 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.
    Fig 2: Identifying EGRVR Solenoid Wiring Harness Connector Terminals (All Others)
    G00190960Courtesy of FORD MOTOR CO.

  25. 30) Check EGRVR Circuit For Short To VREF

    Using a DVOM, measure resistance between EGRVR and VREF circuits at PCM harness connector (both VREF circuits on 150-pin PCM). See PCM CONNECTOR IDENTIFICATION and Fig 2. 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.

  26. 31) Check DPFEGR Sensor Output By Applying Vacuum With Hand Pump

    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 downstream connection at DPFEGR sensor (intake manifold side or smaller diameter port). See Figure. Using scan tool, access DPFEGR PID from PID/DATA MONITOR & RECORD menu. Read the following DPFEGR PID values with ignition switch in ON position:
    • DO NOT apply vacuum to sensor. Record DPFEGR PID value. DPFEGR PID value should be .2-1.3 volts.
    • Using vacuum pump, apply 8-9 in. Hg (27-30 kPa) for a few seconds. DPFEGR PID value should increase to more than 4 volts.
    • Quickly release vacuum. DPFEGR PID value should drop to less than 1.5 volts within 3 seconds of releasing vacuum.

    If any DPFEGR PID values are not as specified, replace DPFEGR sensor. If all DPFEGR PID values are as specified, reconnect DPFEGR sensor and go to next step.

  27. 32) Check DPFEGR Sensor Voltage While Operating EGR Valve

    Ensure DPFEGR sensor is connected. Turn ignition switch to ON position. Using scan tool, access DPFEGR PID from PID/DATA MONITOR & RECORD menu. Record KOEO DPFEGR PID 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 KOEO reading. Apply about 2-3 in. Hg (7-10 kPa) of vacuum to open EGR valve without stalling engine, then release vacuum. Repeat several times while observing DPFEGR PID. DPFEGR PID voltage reading should increase as EGR valve begins to open, and return to initial voltage reading as vacuum is released. A higher voltage reading at idle indicates an EGR valve not seating fully. If DPFEGR PID is slow to return to initial voltage reading after releasing vacuum, EGR valve may be binding or slow closing. Service or replace EGR valve as necessary. If DPFEGR PID quickly returns to initial voltage reading after releasing vacuum, go to next step.
    28. 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.

  28. 33) Monitor EGR Valve Vacuum While Wiggling EGRVR Solenoid Circuit
    Turn ignition switch to OFF position. Remove hand vacuum pump from EGR valve vacuum hose. Connect a vacuum gauge to EGR valve vacuum 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.
    29. NOTE: In colder climates, excessive water in vent filter may freeze and plug solenoid vent.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 34) to step 50). No test procedures have been omitted.

  29. 34) Inspect EGRVR Solenoid & Vacuum Hoses For Potential Plugging
    Turn ignition switch to OFF position. Remove EGRVR solenoid vent filter. Inspect for contamination or water. Remove EGR vacuum hose and inspect for pinching or restriction. Repair or replace as necessary. If no faults are found, concern is intermittent and cannot be identified at this time. Go to TEST Z, step 1) .
    30. NOTE: For additional testing information, see DIAGNOSTIC AIDS .
    Fig 3: Identifying DPFEGR Sensor Vacuum Circuits
    G98H00205Courtesy of FORD MOTOR CO.

  30. 50) For Continuous Memory Only DTC P1405: Check Upstream Pressure Hose Connections
    DTC P1405 indicates EGR MONITOR failed while driving due to PCM detecting signal from DPFEGR sensor EGR flow 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 3. Repair as necessary. Perform DRIVE CYCLES . Ensure EGR MONITOR PROCEDURE is performed to verify repair. If upstream hose connections are okay, go to next step.

    31. NOTE: Ensure DPFEGR pressure hose is the correct repair part and not a substitute.

  31. 51) Inspect Upstream Pressure Hose For Plugging
    Check upstream hose for proper routing. Remove upstream hose and ensure it is not pinched and that hose routing does not have low spots where water could collect, freeze and plug hose in colder climates. Repair as necessary. Perform DRIVE CYCLES . Ensure EGR MONITOR PROCEDURE is performed to verify repair. If upstream hose is okay, go to next step.

  32. 52) Check Orifice Tube Assembly & DPFEGR Sensor

    Check DPFEGR sensor upstream connection on DPFEGR sensor for plugging or damage. See Fig 3. Inspect exhaust manifold side pressure pick-up tube at orifice tube assembly for plugging or damage. Repair or replace DPFEGR sensor or orifice tube as necessary. Perform DRIVE CYCLES . Ensure EGR MONITOR PROCEDURE is performed to verify repair. If no faults are found, go to next step.

  33. 53) Check DPFEGR Sensor Output By Applying Vacuum With Hand Pump

    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 downstream connection at DPFEGR sensor (intake manifold side or smaller diameter port). See Figure. Using scan tool, access DPFEGR PID from PID/DATA MONITOR & RECORD menu. Read the following DPFEGR PID values with ignition switch in ON position:
    • DO NOT apply vacuum to sensor. Record DPFEGR PID value. DPFEGR PID value should be .2-1.3 volts.
    • Using vacuum pump, apply 8-9 in. Hg (27-30 kPa) for a few seconds. DPFEGR PID value should increase to more than 4 volts.
    • Quickly release vacuum. DPFEGR PID value should drop to less than 1.5 volts within 3 seconds of releasing vacuum.

    If any DPFEGR PID values are not as specified, replace DPFEGR sensor. If all DPFEGR PID values are as specified, reconnect DPFEGR sensor. Unable to duplicate or identify fault 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.
    34. NOTE: For additional testing information, see DIAGNOSTIC AIDS .

  34. 60) For Continuous Memory Only DTC P1406: Check Downstream Pressure Hose Connections
    If DTC P1406 is currently present, DTC P1408 will be output in KOER self-test. DTC P1406 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

    Verify EGR valve is securely attached and exhaust gasses are not leaking from the sealing surface.

    Check downstream hose at DPFEGR sensor and orifice tube for clean and tight connections. See Fig 3. Repair as necessary. Perform DRIVE CYCLES . Ensure EGR MONITOR PROCEDURE is performed to verify repair. If downstream hose connections are okay, go to next step.

    35. NOTE: Ensure DPFEGR pressure hose is the correct repair part and not a substitute.

  35. 61) Inspect Downstream Pressure Hose For Plugging
    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 or replace hose as necessary. Perform DRIVE CYCLES . Ensure EGR MONITOR PROCEDURE is performed to verify repair. If downstream hose is okay, go to next step.

  36. 62) Check Orifice Tube Assembly & DPFEGR Sensor

    Inspect DPFEGR sensor downstream connection for plugging or damage. See Fig 3. Inspect intake manifold side pressure pick-up tube and orifice tube assembly for plugging, loose connection or damage. Repair or replace DPFEGR sensor or orifice tube as necessary. Perform DRIVE CYCLES . Ensure EGR MONITOR PROCEDURE is performed to verify repair. If no faults are found, go to next step.

  37. 63) Check DPFEGR Sensor Output By Applying Vacuum With Hand Pump

    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 downstream connection at DPFEGR sensor (intake manifold side or smaller diameter port). See Figure. Using scan tool, access DPFEGR PID from PID/DATA MONITOR & RECORD menu. Read the following DPFEGR PID values with ignition switch in ON position:
    • DO NOT apply vacuum to sensor. Record DPFEGR PID value. DPFEGR PID value should be .2-1.3 volts.
    • Using vacuum pump, apply 8-9 in. Hg (27-30 kPa) for 5 seconds. DPFEGR PID value should increase to more than 4 volts.
    • Quickly release vacuum. DPFEGR PID value should drop to less than 1.5 volts within 3 seconds of releasing vacuum.

    If any DPFEGR PID values are not as specified, replace DPFEGR sensor. If all DPFEGR PID values are as specified, reconnect DPFEGR sensor. Unable to duplicate or identify fault 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.
    38. NOTE: For additional testing information, see DIAGNOSTIC AIDS .

  38. 70) For Continuous Memory Only DTC P0401: Perform KOER Self-Test
    DTC P0401 indicates EGR MONITOR failed due to PCM detecting EGR flow is less than desired minimum while driving. 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 Sensor
    • 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).

    39. NOTE: For additional testing information, see DIAGNOSTIC AIDS .
    NOTE: If any DTC other than DTC P1406 is present, service those DTCs after completing this test. See DIAGNOSTIC TROUBLE CODE DEFINITIONS .

  39. 71) For KOER Only DTC P1408: Retrieve Continuous Memory DTCs
    DTC P1408 indicates KOER 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 Sensor
    • 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 all Continuous Memory DTCs. If DTC P1406 is present, go to step  60). If DTC P1406 is not present, go to next step.

  40. 72) Perform KOER Self-Test While Monitoring EGR Vacuum

    Disconnect vacuum hose from EGR valve and connect hose to vacuum gauge. Since EGR vacuum hose is disconnected, disregard any DTCs during this KOER self-test. Perform KOER ON-DEMAND SELF-TEST while monitoring gauge. About 30 seconds into KOER 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. Fault is likely to be in EGR vacuum control system. Turn ignition switch to OFF position and 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).

  41. 73) Inspect DPFEGR Sensor Pressure Hoses

    Check both DPFEGR sensor hoses for correct routing. See Fig 3. 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). Repair as necessary. If no faults are found, go to next step.

  42. 74) Check DPFEGR Sensor Output By Applying Vacuum With Hand Pump

    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 downstream connection at DPFEGR sensor (intake manifold side or smaller diameter port). See Figure. Using scan tool, access DPFEGR PID from PID/DATA MONITOR & RECORD menu. Read the following DPFEGR PID values with ignition switch in ON position:
    • DO NOT apply vacuum to sensor. Record DPFEGR PID value. DPFEGR PID value should be .2-1.3 volts.
    • Using vacuum pump, apply 8-9 in. Hg (27-30 kPa) for a few seconds. DPFEGR PID value should increase to more than 4 volts.
    • Quickly release vacuum. DPFEGR PID value should drop to less than 1.5 volts within 3 seconds of releasing vacuum.

    If any DPFEGR PID values are not as specified, replace DPFEGR sensor. If all DPFEGR PID values are as specified, reconnect DPFEGR sensor 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.

  43. 76) Check EGR Valve Function By Applying Vacuum With Hand Pump

    Turn ignition switch to OFF position. Disconnect and plug vacuum hose at EGR valve. Ensure a hand vacuum pump is connected to EGR valve. Start engine and allow to idle. Using scan tool, access DPFEGR and RPM PIDs from PID/DATA MONITOR & RECORD menu. Slowly apply 8-10 in. Hg (27-34 kPa) to EGR valve and hold for 10 seconds. It may be necessary to increase engine speed to obtain 1000 RPM. DPFEGR PID values should read as follows:
    • EGR valve should start opening at about 1.6 in Hg (5.4 kPa) vacuum as indicated by increasing DPFEGR PID value.
    • As vacuum increases, DPFEGR PID voltage reading should increase. DPFEGR PID must read 2.5 volts or more 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 voltage drops within a few seconds, EGR valve or vacuum source may be leaking.

    If DPFEGR PID voltage reading operates as specified, reconnect all components and go to step  82). 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.

  44. 80) Check Vacuum Source & Vacuum 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, go to next step.

  45. 81) Check Engine Vacuum

    Disconnect EVR vacuum hose at vacuum source. Connect vacuum gauge to vacuum source. Start engine. With engine warm and at idle, monitor vacuum gauge. If the vacuum gauge is steadily reading a minimum of 15 in. Hg (51 kPa), go to next step. If the vacuum gauge is not steadily reading a minimum of 15 in. Hg (51 kPa), isolate possible base engine concern and repair as necessary.

  46. 82) Check VPWR Voltage To EGRVR Solenoid

    Turn ignition switch to OFF position. Disconnect EGRVR solenoid. Turn ignition switch to ON position. Using a DVOM, measure voltage between negative battery terminal and VPWR circuit at EGRVR solenoid harness connector. See Fig 2. 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.

  47. 83) Measure EGRVR Solenoid Resistance

    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.

  48. 84) Check EGRVR Circuit For Short To PWR In Harness

    Ensure ignition switch is in 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 EGRVR circuit at PCM harness connector. See Fig 2. 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.

  49. 85) 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 2. 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.

  50. 86) Check EGRVR Solenoid Vacuum Output Capability By Grounding EGRVR Circuit

    Disconnect hose from EGR valve. Connect vacuum gauge to EGR vacuum hose. Start engine and allow to idle. Backprobe PCM harness connector and connect a jumper wire between EGRVR circuit at PCM and chassis ground. See Fig 2. If vacuum gauge reading is 4 in. Hg (13.5 kPa) or more within 2 seconds, replace PCM. If vacuum gauge reading is less than 4 in. Hg (13.5 kPa) within 2 seconds, 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.

  51. 90) Inspect EGR System For An Intermittent Fault

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

  52. 91) Inspect DPFEGR Sensor Pressure Hoses

    Visually inspect both DPFEGR sensor hoses for proper connections and correct routing. See Fig 3. 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). Repair as necessary. If no faults are found, go to next step.

  53. 92) Check DPFEGR Sensor Output By Applying Vacuum With Hand Pump

    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 downstream connection at DPFEGR sensor (intake manifold side or smaller diameter port). See Figure. Using scan tool, access DPFEGR PID from PID/DATA MONITOR & RECORD menu. Read the following DPFEGR PID values with ignition switch in ON position:
    • DO NOT apply vacuum to sensor. Record DPFEGR PID value. DPFEGR PID value should be .2-1.3 volts.
    • Using vacuum pump, apply 8-9 in. Hg (27-30 kPa) for a few seconds. DPFEGR PID value should increase to more than 4 volts.
    • Quickly release vacuum. DPFEGR PID value should drop to less than 1.5 volts within 3 seconds of releasing vacuum.

    If any DPFEGR PID values are not as specified, replace DPFEGR sensor. If all DPFEGR PID values are as specified, reconnect DPFEGR sensor and go to next step.

  54. 93) Check EGR Valve Function By Applying Vacuum With Hand Pump

    Turn ignition switch to OFF position. Disconnect and plug vacuum hose at EGR valve. Ensure a hand vacuum pump is connected to EGR valve. Start engine and allow to idle. Using scan tool, access DPFEGR and RPM PIDs from PID/DATA MONITOR & RECORD menu. Slowly apply 5-10 in. Hg (17-34 kPa) to EGR valve and hold for 10 seconds. It may be necessary to increase engine speed to maintain 800 RPM. DPFEGR PID values should read as follows:
    • EGR valve should start opening at about 1.6 in. Hg (5.4 kPa) vacuum as indicated by increasing DPFEGR PID value.
    • As vacuum increases, DPFEGR PID voltage reading should increase. DPFEGR PID must read 2.5 volts or more 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 voltage drops within 5 seconds, EGR valve or vacuum source may be leaking.

    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 or restricted orifice tube assembly. Repair as necessary.

    55. 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.
    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.

  55. 94) Check EGR Vacuum Signal Supply For Intermittent Fault
    Connect vacuum gauge to disconnected EGR valve vacuum supply hose. Start engine and allow to idle. Backprobe PCM harness connector and connect a jumper wire between chassis ground and EGRVR circuit at PCM harness connector to turn EGRVR solenoid on. At idle, vacuum gauge reading should be more than 4 in. Hg (13.5 kPa). Observe vacuum gauge for fault while tapping lightly on EGRVR solenoid and wiggling EGRVR solenoid vacuum hoses, connector and wiring harness between PCM and EGRVR solenoid. 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. In cold climates, the EGR valve may temporarily freeze shut and thaw when the engine warms up causing the intermittent DTC. Go to TEST Z, step 1) .
    56. NOTE: Diagnostic step  100) is performed when directed here from POOR FUEL ECONOMY symptom under SYMPTOMS in TROUBLE SHOOTING - NO CODES - CNG, FLEX-FUEL & GASOLINE article.
    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.

  56. 100) EGR Diagnosis By Symptom: Check For EGR Flow With EGR Vacuum Hose Disconnected & Plugged
    A POOR FUEL ECONOMY symptom has indicated possible EGR flow at idle with no EGR DTCs stored. 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, access DPFEGR PID and record voltage reading (KOEO). Start engine, allow to idle and record DPFEGR PID voltage reading (KOER). Compare KOER DPFEGR PID voltage reading to KOEO DPFEGR PID voltage reading. An increase in voltage at idle indicates that DPFEGR sensor is sensing EGR flow. If KOER DPFEGR PID voltage reading is .15 volt or more than that of KOEO reading, DPFEGR sensor is sensing EGR flow and most likely cause is EGR valve. Remove and 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, this indicates a fault in EGR valve vacuum supply. Check EGR valve vacuum supply hoses, EGRVR solenoid vent and vent filter for restriction. If vacuum supply hoses, EGRVR solenoid vent and vent filter are okay, replace EGRVR solenoid.

    57. NOTE: For additional testing information, see DIAGNOSTIC AIDS .

  57. 110) For KOEO & KOER Only DTC P0403 & P1409: Check EGRVR Solenoid Resistance
    DTC P0403 and P1409 indicate self-test failed due to EGRVR circuit voltage reading too high or too low when compared to expected voltage range. EGR system must be enabled for test to be completed. 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 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.

  58. 111) Check VPWR Voltage To EGRVR Solenoid

    Turn ignition switch to ON position. Using a DVOM, measure voltage between VPWR circuit at EGRVR solenoid harness connector and negative battery terminal. See Fig 2. 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.

  59. 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 PCM CONNECTOR IDENTIFICATION and Fig 2. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in EGRVR circuit.

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

    Turn ignition switch to ON position. Using a DVOM, measure voltage between EGRVR circuit at PCM harness connector and negative battery terminal. See PCM CONNECTOR IDENTIFICATION and Fig 2. 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.

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

    Turn ignition switch to OFF position. Using a DVOM, measure resistance between EGRVR and PWR GND circuits at PCM harness connector. See PCM PWR GND, SIG RTN & VREF TERMINAL IDENTIFICATION table. See PCM CONNECTOR IDENTIFICATION and Fig 2. 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.
    62. NOTE: For additional testing information, see DIAGNOSTIC AIDS .

  62. 120) For Continuous Memory Only DTC P0403 & P1409: Wiggle EGRVR Solenoid While Monitoring VPWR
    If DTC P1409 was output during KOEO or KOER self-test, go directly to step  110) to diagnose present fault. DTC P1409 indicates self-test failed due to EGRVR circuit voltage reading 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 voltage between PCM harness connector EGRVR and PWR GND terminals. See PCM PWR GND, SIG RTN & VREF TERMINAL IDENTIFICATION table. See PCM CONNECTOR IDENTIFICATION and Fig 2. 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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