Posted in MMC L200

P0402 – EGR Flow Excessive MMC L200 IV

 Posted by  Posted on September 28, 2020

FUNCTION

  • The engine-ECU monitors the EGR flow rate.

    • TROUBLE JUDGEMENT

  • Engine is running
  • Battery positive voltage is 8 – 16 V.
  • Vehicle is stopped (transmission: Neutral <M/T>, P range <A/T>)
  • The EGR flow rate is smaller than target EGR flow rate by the rate that is more than the specified value.

    • PROBABLE CAUSES

  • Failed EGR passage (air suction)
  • Harness damage in EGR valve circuit or loose connector contact
  • Failed EGR valve operation
  • Harness damage in air flow sensor circuit or loose connector contact
  • Failed air flow sensor (abnormal output characteristics)
  • Failed engine-ECU

    • DIAGNOSIS PROCEDURE

    STEP 1. M.U.T.-III diagnosis code

    Q. Is diagnosis code P0403 or P2413 stored?

    STEP 2. Connector check: A-45 EGR valve assembly connector

    Q. Is the check result normal?

    STEP 3. Connector check: C-103 and C-105 engine-ECU connectors

    Q. Is the check result normal?

    STEP 4. Check harness between C-103 (terminal No. 115) engine-ECU connector and A-45 (terminal No. 6) EGR valve assembly connector.

  • Check output line for damage.

    • Q. Is the check result normal?

    STEP 5. Check harness between C-103 (terminal No. 130) engine-ECU connector and A-45 (terminal No. 4) EGR valve assembly connector.

  • Check output line for damage.

    • Q. Is the check result normal?

    STEP 6. Check harness between C-105 (terminal No. 81) engine-ECU connector and A-45 (terminal No. 2) EGR valve assembly connector.

  • Check earthing line for damage.

    • Q. Is the check result normal?

    STEP 7. Check harness between C-105 (terminal No. 71) engine-ECU connector and A-45 (terminal No. 3) EGR valve assembly connector.

  • Check power supply line for damage.

    • Q. Is the check result normal?

    STEP 8. Check harness between C-105 (terminal No. 57) engine-ECU connector and A-45 (terminal No. 1) EGR valve assembly connector.

  • Check output line for damage.

    • Q. Is the check result normal?

    STEP 9. Check EGR valve itself.

    Q. Is the check result normal?

    STEP 10. Check EGR passage for air suction.

  • Check the EGR valve, the EGR pipe and the EGR cooler for the air suction.

    • Q. Is the check result normal?

    STEP 11. Connector check: A-135 air flow sensor connector

    Q. Is the check result normal?

    STEP 12. Check harness between A-135 (terminal No. 4) air flow sensor connector and C-103 (terminal No. 155) engine-ECU connector.

  • Check earthing line for damage.

    • Q. Is the check result normal?

    STEP 13. Check harness between A-135 (terminal No. 3) air flow sensor connector and C-103 (terminal No. 140) engine-ECU connector.

  • Check output line for damage.

    • Q. Is the check result normal?

    STEP 14. Replace the air flow sensor.

  • After replacing the air flow sensor, re-check the trouble symptoms.

    • Q. Is the check result normal?

    Author: admin