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Diagnostic Aids

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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 DPFEGR Sensor Voltage

    his DTC indicates DPFEGR circuit input fault. Possible causes for this fault are:
    • Leaking upstream pressure hose.
    • DPFEGR circuit shorted to GND or SIG RTN circuit.
    • VREF shorted to GND or SIG RTN circuit.
    • Faulty DPFEGR sensor.
    • Faulty PCM.

    Turn ignition on. Using scan tool, select DPFEGR PID from PID/DATA monitor menu. If PID voltage is less than .2 volt, DPFEGR sensor voltage is less than minimum. Go to next step. If voltage is .2 volt or more, inspect DPFEGR sensor vacuum hoses. Repair as necessary and retest. If vacuum hoses are okay, fault is intermittent. Go to step  5).

  2. 2) Generate Opposite DPFEGR Sensor Signal

    Turn ignition off. Disconnect DPFEGR sensor connector. Connect a jumper wire between DPFEGR and VREF terminals at DPFEGR sensor wiring harness connector. See Fig 2. Turn ignition on. Using scan tool, select DPFEGR PID. If scan tool error occurs, disconnect jumper wire and go to next step. If PID voltage is not 4-6 volts, remove jumper wire and go to next step. If PID voltage is 4-6 volts, replace DPFEGR sensor.
    Fig 2: Identifying DPFEGR Sensor Wiring Harness Connector Terminals
    G99J02602Courtesy of FORD MOTOR CO.

  3. 3) Measure VREF Voltage At DPFEGR Sensor

    Measure voltage between SIG RTN terminal and VREF terminal at DPFEGR sensor wiring harness connector. If voltage is 4-6 volts, go to next step. If voltage is not 4-6 volts, go to TEST C .

  4. 4) Check DPFEGR Circuit For Short To Ground

    Turn ignition off. Disconnect PCM 104-pin connector. Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Measure resistance between PCM connector pins No. 65 and 91 (SIG RTN). Also measure resistance between PCM connector pin No. 65 and negative battery terminal. If both resistance readings are more than 10,000 ohms, replace PCM. If any resistance reading is 10,000 ohms or less, repair short to ground.

  5. 5) Wiggle Test Sensor & Harness

    Turn ignition on. Using scan tool, select DPFEGR PID. Observe DPFEGR PID voltage for indication of fault while shaking and bending DPFEGR sensor wiring harness and connector. Tap lightly on DPFEGR sensor to simulate road shock. An indication of fault is a sudden change in DPFEGR PID voltage. If fault is indicated, isolate and repair as necessary. If no fault is indicated, go to TEST Z .
    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 DPFEGR Sensor Voltage

    This DTC indicates PCM has detected DPFEGR circuit input above maximum. Possible causes for this fault are:
    • Open in DPFEGR circuit or SIG RTN circuit.
    • DPFEGR circuit shorted to VREF or PWR circuit.
    • VREF circuit shorted to PWR circuit.
    • Faulty DPFEGR sensor.
    • Faulty PCM.

    Turn ignition on. Using scan tool, select DPFEGR PID. If PID voltage is more than 4 volts, go to next step. If PID voltage is 4 volts or less, go to step  19).

  7. 11) Check DPFEGR Circuit For Short To Power

    Turn ignition off. Disconnect DPFEGR sensor connector. Turn ignition on. Measure voltage between DPFEGR terminal at DPFEGR sensor wiring harness connector and negative battery 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 For Short To Power

    Disconnect PCM 104-pin connector. Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Turn ignition on. Measure voltage between PCM connector pin No. 65 and negative battery terminal. If voltage is more than 10.5 volts, repair short to power in DPFEGR circuit. If voltage is 10.5 volts or less, replace PCM.

  9. 13) Generate Opposite DPFEGR Signal

    Turn ignition off. Connect a jumper wire between DPFEGR and SIG RTN terminals at DPFEGR sensor wiring harness connector. See Fig 2. Turn ignition on. Using scan tool, select DPFEGR PID. If scan tool error occurs, disconnect jumper wire and go to step  18). If PID voltage is .05 volt or more, disconnect jumper wire and go to step  16). If PID voltage is less than .05 volt, disconnect jumper wire and go to next step.

  10. 14) Verify VREF Is Within Range

    Turn ignition on. Measure voltage between SIG RTN terminal and VREF terminal at DPFEGR sensor wiring harness connector. If voltage is 4-6 volts, go to next step. If voltage is not 4-6 volts, go to TEST C .

  11. 15) Check DPFEGR Circuit For Short To VREF

    Turn ignition off. Disconnect PCM 104-pin connector. Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Measure voltage between PCM connector pins No. 65 and 90. If voltage is less than one volt, replace DPFEGR sensor. If voltage is one volt or more, repair short circuit.

  12. 16) Check DPFEGR For Open Circuit

    Turn ignition off. Disconnect PCM 104-pin connector. Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Ensure DPFEGR sensor is disconnected. Measure resistance between PCM connector pin No. 65 and DPFEGR terminal at DPFEGR sensor wiring harness connector. 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 For Open Circuit

    Measure resistance between PCM connector pin No. 91 and SIG RTN terminal at DPFEGR sensor wiring 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. 18) Check DPFEGR For Short To VREF

    Turn ignition off. Disconnect PCM 104-pin connector. Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Measure resistance between PCM connector pins No. 65 and 90. If resistance is more than 10,000 ohms, replace PCM. If resistance is 10,000 ohms or less, repair short between DPFEGR and VREF circuits.

  15. 19) Wiggle Test Sensor & Harness

    Turn ignition on. Using scan tool, select DPFEGR PID. Observe PID voltage for indication of fault while shaking and bending DPFEGR sensor wiring harness and connector. An indication of fault is a sudden change in DPFEGR PID voltage. Tap lightly on DPFEGR sensor to simulate road shock. If fault is indicated, isolate and repair as necessary. If no fault is indicated, go to TEST Z .

  16. 20) DTC P0402: Check EGR Flow At Idle

    This DTC indicates PCM has detected EGR flow at idle. Possible causes for this fault are:
    • EGR valve stuck open.
    • EGR Vacuum Regulator (VR) solenoid vent plugged.
    • EGRVR circuit shorted to ground.
    • EGRVR circuit shorted to VREF circuit.
    • Pinched, plugged or damaged vacuum hose.
    • Faulty EGRVR solenoid.
    • Faulty PCM.
    NOTE: If Continuous Memory DTC P1405 is present, go to step  50).

    Disconnect and plug EGR 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, go to next step.

  17. 21) Check EGR Flow

    Turn ignition off. Reconnect EGR vacuum hose. 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 for pinched vacuum hoses. Repair as necessary and retest. If vacuum hoses are okay, go to step  30).

  18. 22) Check EGR System

    A pinched or plugged EGR vacuum hose can trap vacuum between EGR vacuum regulator solenoid and EGR valve not allowing EGR valve to close. 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

    Turn ignition off. Disconnect pressure hoses at DPFEGR sensor. Connect vacuum pump to DPFEGR sensor port marked REF. Turn ignition on. Using scan tool, select DPFEGR PID from PID/DATA monitor menu. Note PID voltage. PID voltage should be .2-1.3 volts with ignition on and no vacuum applied. Using vacuum pump, apply 8-9 in. Hg. PID voltage should be more than 4 volts. When vacuum is quickly released, PID voltage should drop to less than 1.5 volts within 3 seconds. If PID voltage is not as specified, replace DPFEGR sensor. If PID voltage is as specified, go to next step.

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

    Turn ignition off. Disconnect EGR valve vacuum hose. Connect vacuum gauge to hose. Start engine and allow to idle. While observing vacuum gauge, disconnect EGRVR solenoid connector. If vacuum gauge reading stays at more than 1.6 in. Hg, go to next step. If vacuum gauge reading is 1.6 in. Hg or less, go to step  26).

  21. 25) Check EGRVR Solenoid Vent

    Turn ignition off. Disconnect EGRVR solenoid vacuum hoses. Remove EGRVR solenoid vent cap (if removable). Remove EVR filter and inspect for restriction. Plug EGRVR solenoid vacuum supply port. See Fig 3. Using a vacuum pump, apply 10-15 in. Hg to EGRVR solenoid source port. If vacuum holds or is slow to release, EGRVR solenoid is plugged or restricted. Repair or replace EGRVR solenoid as necessary. If vacuum releases (solenoid not plugged or restricted), replace EGRVR solenoid.
    Fig 3: Testing EGRVR Solenoid
    G98G00204Courtesy of FORD MOTOR CO.

  22. 26) Check EGR VR Solenoid Coil Resistance

    Turn ignition off. Disconnect EGR VR solenoid connector. 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

    Disconnect PCM 104-pin connector. Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Measure resistance between PCM connector pin No. 47 (EGRVR) and negative battery terminal. If resistance is more than 10,000 ohms, go to next step. If resistance is 10,000 ohms or less, repair short to ground in EGRVR circuit.

  24. 28) Check EGRVR Circuit For Short To VREF

    Measure resistance between PCM connector pins No. 47 and 90. If resistance is more than 10,000 ohms, replace PCM. If resistance is 10,000 ohms or less, repair short between EGRVR circuit and VREF circuit.
    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

    Turn ignition off. Disconnect pressure hoses at DPFEGR sensor. Connect vacuum pump to DPFEGR sensor downstream port marked REF. Turn ignition on. Using scan tool, select DPFEGR PID and note voltage reading. PID voltage should be .2-1.3 volts with ignition on and no vacuum applied. Using vacuum pump, apply 8-9 in. Hg. PID voltage should be more than 4 volts. When vacuum is quickly released, PID voltage should drop to less than 1.5 volts within 3 seconds. If PID voltage is not as specified, replace DPFEGR sensor. If PID voltage is as specified, go to next step.

  26. 31) Check DPFEGR Sensor Voltage

    Reconnect DPFEGR sensor connector. Turn ignition on. Using scan tool, select DPFEGR PID and note voltage reading. PID voltage should be .2-1.25 volts. Disconnect vacuum hose at EGR valve and plug hose. Connect a vacuum pump to EGR valve. Start engine and allow to idle. Observe DPFEGR PID voltage at idle and compare to PID voltage reading taken with ignition on. Apply only enough vacuum (2-3 in. Hg) to open EGR valve without stalling engine and release vacuum. Repeat several times while observing DPFEGR PID voltage on scan tool. DPFEGR PID voltage should increase as EGR valve begins to open and return to initial voltage value as vacuum is released. A slow return to voltage is an indication of a slow closing EGR valve. If DPFEGR PID voltage does not indicate a fault, go to next step. If DPFEGR PID voltage indicates a fault (an open, binding or slow closing EGR valve), service or replace EGR valve.

  27. 32) Check EGR Valve Vacuum While Wiggling EGRVR Solenoid Circuit

    Turn ignition off. Remove vacuum pump from EGR valve vacuum hose and connect a vacuum gauge to hose. Turn ignition on. Observe vacuum gauge for indication of fault while wiggling EGRVR solenoid wiring harness and connector. Fault is indicated by a sudden jump in vacuum reading. Tap lightly on EGRVR solenoid to simulate road shock. If no faults are indicated, go to next step. If fault is indicated, isolate and repair fault as necessary.

  28. 33) Check EGRVR Solenoid For Restriction

    Turn ignition off. Remove EGRVR solenoid vent filter. Inspect for contamination or water. Remove EGR vacuum hose and inspect for restriction. Repair or replace as necessary. If no faults can be found, problem is intermittent and cannot be identified at this time. Go to TEST Z .
    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) DTC P1405: Check For Upstream Pressure Hose Connection

    Check upstream hose at DPFEGR sensor and orifice tube for clean, tight connection. See Fig 4. Repair as necessary. Perform EGR MONITOR REPAIR VERIFICATION DRIVE CYCLE. See DRIVE CYCLES  under ADDITIONAL SYSTEM FUNCTIONS. If hose is okay, go to next step.
    Fig 4: Identifying DPFEGR Sensor Vacuum Circuits
    G98H00205Courtesy of FORD MOTOR CO.

  30. 51) Inspect Upstream Pressure Hose

    Check upstream hose routing and for a clean, tight connection. Ensure hose is not plugged, pinched, wet or contaminated. Repair as necessary. Perform EGR MONITOR REPAIR VERIFICATION DRIVE CYCLE. See DRIVE CYCLES  under ADDITIONAL SYSTEM FUNCTIONS. If hose is okay, go to next step.

  31. 52) Inspect Orifice Tube Assembly & DPFEGR Sensor

    Check DPFEGR sensor port marked HI for restriction or damage. Inspect exhaust manifold side pressure pick-up tube (port) at orifice tube assembly for restriction or damage. Repair as necessary. Perform EGR MONITOR REPAIR VERIFICATION DRIVE CYCLE. See DRIVE CYCLES  under ADDITIONAL SYSTEM FUNCTIONS. If no faults are found, go to next step.

  32. 53) Check DPFEGR Sensor Output

    Disconnect pressure hoses at DPFEGR sensor. Connect vacuum pump to DPFEGR sensor port marked REF. Turn ignition on. Using scan tool, select DPFEGR PID and note voltage reading. PID voltage should be .2-1.3 volts with ignition on and no vacuum applied. Using vacuum pump, apply 8-9 in. Hg. PID voltage should be more than 4 volts. When vacuum is quickly released, PID voltage should drop to less than 1.5 volts within 3 seconds. If PID voltage is not as specified, replace DPFEGR sensor. If PID voltage is as specified, fault is intermittent and cannot be identified at this time. Go to TEST Z .
    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) DTC P1406: Check For Downstream Pressure Hose Connection

    Check downstream hose at DPFEGR sensor and office tube for clean, tight connection. See Fig 1. Repair as necessary. If hose is okay, go to next step.

  34. 61) Inspect Downstream Pressure Hose

    Check downstream hose routing and for a clean, tight connection. Ensure hose is original equipment. Ensure hose is not pinched, wet or contaminated. Repair as necessary. If hose is okay, go to next step.

  35. 62) Inspect Orifice Tube Assembly & DPFEGR Sensor

    Check DPFEGR sensor ports for restriction or damage. Inspect intake manifold side pressure pick-up tube (port) and orifice tube assembly for restriction or damage. Repair as necessary. If no faults are found, go to next step.

  36. 63) Check DPFEGR Sensor Output

    Disconnect pressure hoses at DPFEGR sensor. Connect vacuum pump to DPFEGR sensor port marked REF. Turn ignition on. Using scan tool, select DPFEGR PID and note voltage reading. PID voltage should be .2-1.3 volts with ignition on and no vacuum applied. Using vacuum pump, apply 8-9 in. Hg. PID voltage should be more than 4 volts. When vacuum is quickly released, PID voltage should drop to less than 1.5 volts within 3 seconds. If PID voltage is not as specified, replace DPFEGR sensor. If PID voltage is as specified, fault is intermittent and cannot be identified at this time. Go to TEST Z .
    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) DTC P0401

    This DTC indicates self-test has detected insufficient EGR flow. Possible causes are:
    • EGR valve stuck closed.
    • EGR valve diaphragm leak.
    • EGR flow plugged or restricted.
    • Faulty EGR hose.
    • EVR VPWR circuit open.
    • EVR VPWR circuit to PCM open or shorted to PWR.
    • DPFEGR sensor VPWR circuit open.
    • Faulty DPFEGR sensor hoses.
    • Faulty DPFEGR sensor.
    • 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) DTC P1408

    This DTC indicates KOER self-test has detected EGR flow out of range. Possible causes are:
    • EGR valve stuck closed.
    • EGR valve diaphragm leak.
    • EGR flow plugged or restricted.
    • Faulty EGR hose.
    • EGRVR circuit to PCM open.
    • EGRVR circuit to PCM open or shorted to PWR.
    • DPFEGR sensor VPWR circuit open.
    • DPFEGR sensor hoses faulty or reversed.
    • Downstream pressure hoses plugged or removed.
    • Faulty orifice tube assembly.
    • Faulty DPFEGR sensor.
    • 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 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. During test, if EGR vacuum increased to 3 in. Hg or more, go to next step. If vacuum stays less than 3 in. Hg, vacuum is insufficient to open EGR valve. Go to step  80).

  40. 73) Inspect DPFEGR Pressure Hoses

    Check both DPFEGR sensor hoses for correct routing. See Fig 4. Ensure hoses are not restricted or plugged or leaking. 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 VREF Voltage At DPFEGR Sensor

    Disconnect pressure hoses at DPFEGR sensor. Connect vacuum pump to DPFEGR sensor port marked REF. Turn ignition on. Using scan tool, select DPFEGR PID and note voltage reading. PID voltage should be .2-1.3 volts with ignition on and no vacuum applied. Using vacuum pump, apply 8-9 in. Hg. PID voltage should be more than 4 volts. When vacuum is quickly released, PID voltage should drop to less than 1.5 volts within 3 seconds. If PID voltage is not as specified, replace DPFEGR sensor. If PID voltage is as specified, reconnect hoses and go to next step.
    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

    Turn ignition off. Disconnect and plug hose at EGR valve. Connect 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 1000 RPM. As vacuum increases, PID voltage should increase (up to 2.5 volts). When vacuum is held steady, PID voltage should also hold steady. If PID voltage is as specified, reconnect all components and go to step  85). If PID voltage is not as specified, service or replace EGR valve.
    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 EGRVR Solenoid Vacuum

    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 pump to EGRVR solenoid vacuum supply hose. Start engine and allow to idle. If vacuum gauge reading is 15 in. Hg or more, go to next step. If vacuum gauge reading is less than 15 in. Hg, isolate fault and repair as necessary.

  44. 81) Check VPWR To EGRVR Solenoid

    Turn ignition off. Disconnect EGRVR solenoid connector. Turn ignition on. Measure voltage between ground and VPWR terminal at EGRVR solenoid wiring 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) Check Resistance At EGRVR Solenoid

    Turn ignition off. 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.

  46. 83) Check EGRVR Circuit For Short To PWR

    Disconnect PCM 104-pin connector. Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Turn ignition on. Measure voltage between PCM connector pin No. 47 (EGRVR) and negative battery terminal. If voltage is less than one volt, go to next step. If voltage is more than one volt, repair short to power in EGRVR circuit.

  47. 84) Check EGRVR Circuit For Open In Harness

    Turn ignition off. Measure resistance between PCM connector pin No. 47 and EGRVR terminal at EGRVR solenoid wiring harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in EGRVR circuit.

  48. 85) Check EGRVR Solenoid Vacuum Output Capability

    Reconnect EGRVR solenoid connector. Reconnect PCM connector. Disconnect hose from EGR valve. Connect EGR vacuum hose to vacuum gauge. Start engine and allow to idle. Connect a jumper wire between PCM connector pin No. 47 and chassis ground. If vacuum gauge reading is 4 in. Hg or more, replace PCM. If vacuum gauge 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

    Turn ignition off. 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) Inspect DPFEGR Pressure Hoses

    Check both DPFEGR sensor hoses for correct routing. See Fig 4. Ensure hoses are not restricted or plugged or leaking. 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 Voltage At DPFEGR Sensor

    Disconnect pressure hoses at DPFEGR sensor. Connect vacuum pump to DPFEGR sensor port marked REF. Turn ignition on. Using scan tool, select DPFEGR PID and note voltage reading. PID voltage should be .2-1.3 volts with ignition on and no vacuum applied. Using vacuum pump, apply 8-9 in. Hg. PID voltage should be more than 4 volts. When vacuum is quickly released, PID voltage should drop to less than 1.5 volts within 3 seconds. If PID voltage is not as specified, replace DPFEGR sensor. If PID voltage is as specified, reconnect hoses and go to next step.

  52. 93) Check EGR Valve Operation

    Disconnect and plug hose at EGR valve. Connect 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 avoid stalling. When vacuum increases, PID voltage should increase as EGR valve opens. EGR operation should be smooth with no binding. If EGR valve opens smoothly and holds vacuum, go to next step. If EGR valve is not as specified, service or replace EGR valve as necessary.
    NOTE: In cold climate, EGR valve may freeze shut and thaw when engine warms, causing intermittent DTC to be set in PCM memory.

  53. 94) Check Vacuum Signal For Intermittent Fault

    Connect vacuum pump to EGR valve vacuum supply hose. Start engine and allow to idle. Connect a jumper wire between PCM connector pin No. 47 and chassis ground to turn EGRVR solenoid on. Vacuum gauge reading should be more than 4 in. Hg. Observe vacuum gauge for fault while tapping lightly on EGRVR solenoid. Fault will be indicated by a sudden drop of vacuum. Wiggle EGRVR solenoid vacuum hoses, wiring harness and connector. 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 .
    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) Check For EGR Flow

    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. Turn ignition on. Using scan tool, select DPFEGR PID and note voltage reading. Start engine and allow to idle. Again, note PID voltage reading. Compare PID voltage readings. An increase in PID voltage at idle indicates DPFEGR sensor is sensing EGR flow. If PID voltage increased about .15 volt or more at idle, service or replace EGR valve. If PID voltage did not increase, inspect EGRVR solenoid vent and vent filter for restriction. If no faults 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) DTC P1409

    This DTC indicates self-test has detected electrical malfunction in EGRVR circuit. Possible causes are:
    • EGRVR circuit open or shorted.
    • Faulty EGRVR solenoid.
    • Faulty PCM.

    Turn ignition off. Disconnect EGRVR solenoid connector. Measure resistance between EGRVR solenoid terminals. If resistance is 26-40 ohms, go to next step. If resistance is not 26-40 ohms, replace EGR VR solenoid.

  56. 111) Check VPWR To EGRVR Solenoid

    Turn ignition on. Measure voltage between VPWR terminal at EGRVR solenoid wiring harness connector and chassis ground. 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 Continuity

    Turn ignition off. Disconnect PCM 104-pin connector. Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Measure resistance between PCM connector pin No. 47 and EGRVR terminal at EGRVR solenoid wiring harness connector. 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 For Short To PWR

    Turn ignition on. Measure voltage between PCM connector pin No. 47 and negative battery terminal. If voltage is less than one volt, go to next step. If voltage is one volt or more, repair short to power in EGRVR circuit.

  59. 114) Check EGRVR For Short To PWR GND

    Turn ignition off. Measure resistance between PCM connector pins No. 47 and 103 (PWR GND). If resistance is less than 10,000 ohms, repair short circuit. If resistance is 10,000 ohms or more, 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

    This DTC indicates self-test has detected electrical malfunction in EGRVR circuit. Possible causes are:
    • EGRVR circuit open or shorted.
    • Faulty EGRVR solenoid.
    • Faulty PCM.

    Turn ignition off. Disconnect PCM 104-pin connector. Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Turn ignition on. Measure voltage between PCM connector pins No. 47 and 103 (PWR GND). Voltage should be more than 10.5 volts. Observe DVOM for indication of fault while wiggling EGRVR solenoid wiring harness and connector. Fault is indicated by a sudden drop in voltage reading. Tap lightly on EGRVR solenoid to simulate road shock. 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 .

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