ECD SYSTEM EGR Control Circuit

DESCRIPTION


  1. DESCRIPTION


    1. The EGR system recirculates exhaust gas, which is controlled to the proper quantity to suit the driving conditions into the intake air mixture to slow down combustion, reduce the combustion temperature and reduce NOx emissions,

      The lift amount of EGR valve is controlled by the vacuum which is regulated by the E-VRV operated by the ECM.

      If even one of the following conditions is fulfilled, the VSV is turned ON by a signal from the ECM. This results in atmospheric air acting on the EGR valve, closing the EGR valve and shutting off the exhaust gas (EGR cut-off).

    2. Under the following conditions, EGR is cut to maintain driveability.


      • Before the engine is warmed up

      • Engine speed over 4,000 rpm

WIRING DIAGRAM

A01KGB0E01

INSPECTION PROCEDURE

When not using the intelligent tester go to step 8.

PROCEDURE


  1. CHECK THE CONNECTION OF VACUUM HOSE


    NG

    REPAIR OR REPLACE VACUUM HOSE

    OK

  2. CHECK VACUUM


    1. A01KG29E01
      Text in Illustration
      *1 Vacuum Gage

      Using a 3-way connector, connect a vacuum gauge to the hose between the VSV and EGR valve.

    2. Warm up the engine to above 80°C (176°F).

    3. Check the vacuum at 1,500 rpm.

      Result
      Type Vacuum
      1 0 kPa (0 mmHg, 0 in. Hg)
      2 Above 28 kPa (210 mmHg, 8.3 in. Hg)

    TYPE1

    REPAIR OR REPLACE VACUUM HOSE

    TYPE2

    CHECK ECM (CHECK VOLTAGE) Click here

  3. CHECK ECM (CHECK VOLTAGE)


    1. A01KGH8E01

      Connect the oscilloscope between terminals EGR and E1 of the ECM (E7) connector.

    2. Turn the ignition switch ON.

    3. Reference:

      Inspection using the oscilloscope.

      During EGR system is ON (engine speed 1,500 rpm), check the waveform between terminals EGR and E1 of ECM (E7) connector.

      Tech Tips

      The correct waveform is as shown.


    NG

    CHECK AND REPLACE ECM Click here

    OK

  4. PERFORM ACTIVE TEST BY INTELLIGENT TESTER (CHECK ELECTRIC EGR CONTROL VALVE ASSEMBLY (E-VRV))


    1. A01KGQDE01
      Text in Illustration
      *1 Air Filter
      *a Air
      *b E-VRV: ON
      *c E-VRV: OFF

      Disconnect the vacuum hoses from the E-VRV.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the ignition switch ON and the push intelligent tester main switch ON.

    4. Select the ACTIVE TEST mode on the intelligent tester.

    5. Check the operation of the E-VRV when it is operated by the intelligent tester.

      Result
      E-VRV is ON
      Air from port E flows out through port F.
      E-VRV is OFF
      Air from port E flows out through air filter.

    OK

    REPLACE ELECTRIC EGR CONTROL VALVE ASSEMBLY

    NG

  5. CHECK ELECTRIC EGR CONTROL VALVE ASSEMBLY (E-VRV)


    1. A01KFOGE01
      Text in Illustration
      *1 Ohmmeter

      Inspect the E-VRV for open circuit.


      1. Using an ohmmeter, measure the resistance between terminals as shown.

        Resistance
        11 - 13 Ω at 20°C (68°F)
    2. A01KGG5E01
      Text in Illustration
      *1 Ohmmeter
      *a No Continuity

      Inspect the E-VRV for ground.


      1. Using an ohmmeter, check that there is no continuity between terminals and E-VRV body.

    3. A01KEMPE01
      Text in Illustration
      *a Vacuum

      Inspect the E-VRV for air tightness.


      1. Check that when vacuum is applied to the vacuum outlet port shown, the needle of vacuum pump indicates an increase of 66.7 kPa (500 mmHg, 19.7 in. Hg) or more.

    4. A01KHPWE01
      Text in Illustration
      *a 6 V
      *b Vacuum

      Inspect the E-VRV operation.


      1. Apply about 6 V of DC power to the terminals.

      2. Check that when vacuum is applied to the vacuum outlet port shown, the need does not move.


    NG

    REPLACE ELECTRIC EGR CONTROL VALVE ASSEMBLY

    OK

  6. CHECK WIRE HARNESS (ECM - E-VRV) (a) (E-VRV - EFI MAIN RELAY (MARKING: EFI)) (b)


    1. A01KIJCE01

      Check for open and short in harness and connector between ECM and E-VRV.


      1. Disconnect the E-VRV connector.

      2. Disconnect the ECM (E7) connector.

      3. Check the continuity between the terminals E-VRV and ECM connector as shown in the illustration and table.

        Continuity (Check for open)

        Terminal

        (E-VRV ←→ ECM)

        		 Standard
        2 ←→ EGR (E7-2) Continuity
        Continuity (Check for short)

        Terminal

        (ECM ←→ ECM(Ground))

        		 Standard
        EGR (E7-2) ←→ E1 (E7-22) No continuity
    2. A01KIOOE01

      Check for open and short in harness and connector between the E-VRV and EFI main relay.


      1. Remove the EFI main relay.

      2. Disconnect the engine E-VRV connector.

      3. Check the continuity between the terminals the E- VRV and EFI main relay of the R/B No. 2 (3) as shown in the illustration and table.

        Standard (Check for open)

        Terminal

        (EFI main relay of R/B No. 2 ←→ E-VRV)

        		 Standard
        3 ←→ 1 Continuity

      4. Check the continuity between the terminals of the E-VRV and body ground as shown in the illustration and table.

        Standard (Check for short)

        Terminal

        (E-VRV ←→ ECM(Ground))

        		 Standard
        1 ←→ Body ground No continuity

    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR

    OK

  7. CHECK ELECTRIC EGR CONTROL VALVE ASSEMBLY

    Click here


    NG

    REPLACE ELECTRIC EGR CONTROL VALVE ASSEMBLY

    OK

    CHECK AND REPLACE ECM Click here

  8. REPAIR OR REPLACE VACUUM HOSE


    NG

    REPAIR OR REPLACE VACUUM HOSE

    OK

  9. CHECK VACUUM


    1. A01KG29E01
      Text in Illustration
      *1 Vacuum Gage

      Using a 3-way connector, connect a vacuum gauge to the hose between the VSV and EGR valve.

    2. Warm up the engine to above 80°C (176°F).

    3. Check the vacuum at 1,500 rpm.

      Result
      Type Vacuum
      1 0 kPa (0 mmHg, 0 in. Hg)
      2 Above 28 kPa (210 mmHg, 8.3 in. Hg)

    TYPE1

    REPAIR OR REPLACE VACUUM HOSE

    TYPE2

    CHECK ELECTRIC EGR CONTROL VALVE ASSEMBLY (E-VRV) (CHECK FUNCTION) Click here

  10. CHECK ELECTRIC EGR CONTROL VALVE ASSEMBLY (E-VRV) (CHECK FUNCTION)


    1. A01KEFTE01

      Disconnect the ECM (E7) connector from the ECM.

    2. Turn the ignition switch ON.

    3. Check the E-VRV operation.


      1. Connect between terminal EGR and E1 of the ECM (E7) connector (ON).

      2. Disconnect between terminal EGR and E1 of the ECM (E7) connector (OFF).

        E-VRV ON
        Air from port E flows out through port F.
        E-VRV OFF
        Air from port E flows out through air filter.

    OK

    CHECK AND REPLACE ECM Click here

    NG

  11. CHECK ELECTRIC EGR CONTROL VALVE ASSEMBLY (E-VRV)


    1. A01KFOGE01
      Text in Illustration
      *1 Ohmmeter

      Inspect the E-VRV for open circuit.


      1. Using an ohmmeter, measure the resistance between terminals as shown.

        Resistance
        11 - 13 Ω at 20°C (68°F)
    2. A01KGG5E01
      Text in Illustration
      *1 Ohmmeter
      *a No Continuity

      Inspect the E-VRV for ground.


      1. Using an ohmmeter, check that there is no continuity between terminals and E-VRV body.

    3. A01KEMPE01
      Text in Illustration
      *a Vacuum

      Inspect the E-VRV for air tightness.


      1. Check that when vacuum is applied to the vacuum outlet port shown, the needle of vacuum pump indicates an increase of 66.7 kPa (500 mmHg, 19.7 in. Hg) or more.

    4. A01KHPWE01
      Text in Illustration
      *a Vacuum
      *b 6 V

      Inspect the E-VRV operation.


      1. Apply about 6 V of DC power to the terminals.

      2. Check that when vacuum is applied to the vacuum outlet port shown, the need does not move.


    NG

    REPLACE ELECTRIC EGR CONTROL VALVE ASSEMBLY

    OK

  12. CHECK WIRE HARNESS (ECM - E-VRV) (a) (E-VRV - EFI MAIN RELAY (MARKING EFI)) (b)


    1. A01KIJCE01

      Check for open and short in harness and connector between ECM and E-VRV.


      1. Disconnect the E-VRV connector.

      2. Disconnect the ECM (E7) connector.

      3. Check the continuity between the terminals of the E-VRV and ECM connector as shown in the illustration and table.

        Continuity (Check for open)

        Terminal

        (E-VRV ←→ ECM)

        		 Standard
        2 ←→ EGR (E7-2) Continuity
        Continuity (Check for short)

        Terminal

        (ECM ←→ ECM(Ground))

        		 Standard
        EGR (E7-2) ←→ E1 (E7-22) No continuity
    2. A01KIOOE01

      Check for open and short in harness and connector between the E-VRV and EFI main relay.


      1. Remove the EFI main relay.

      2. Disconnect the engine E-VRV connector.

      3. Check the continuity between the terminals of the E-VRV and EFI main relay of the R/B No. 2 (3) as shown in the illustration and table.

        Standard (Check for open)

        Terminal

        (EFI main relay of R/B No. 2 ←→ E-VRV)

        		 Standard
        3 ←→ 1 Continuity

      4. Check the continuity between the terminals of the E-VRV and body ground as shown in the illustration and table.

        Standard (Check for short)

        Terminal

        (E-VRV ←→ Ground)

        		 Standard
        1 ←→ Body ground No continuity

    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR

    OK

  13. CHECK ELECTRIC EGR CONTROL VALVE ASSEMBLY

    Click here


    NG

    REPLACE ELECTRIC EGR CONTROL VALVE ASSEMBLY

    OK

    CHECK AND REPLACE ECM Click here