Posted in MMC L200

P0403 – EGR Valve (DC Motor) Malfunction MMC L200 IV

 Posted by  Posted on September 28, 2020

OPERATION

  • The electric current from the engine-ECU (terminal No. 130 and No. 115) to the EGR valve (DC motor) (terminal No. 4 and No. 6).

    • FUNCTION

  • The engine-ECU performs duty control over the EGR valve (DC motor).
  • The engine-ECU performs feedback control over the EGR valve based on the signals from the EGR position sensor.

    • TROUBLE JUDGMENT

  • Ignition switch is in “ON” position
  • An overcurrent cut-off signal from the EGR valve drive control integrated circuit (IC) is detected for 0.5 second.

    • PROBABLE CAUSES

  • Failed EGR valve
  • Open/short circuit or harness damage in EGR valve circuit or loose connector contact
  • Failed engine-ECU

    • DIAGNOSIS PROCEDURE

    STEP 1. Connector check: A-45 EGR valve assembly connector

    Q. Is the check result normal?

    STEP 2. Check EGR valve itself

    Q. Is the check result normal?

    STEP 3. Connector check: C-103 engine-ECU connector

    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 open/short circuit and 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 connector.

  • Check output line for open/short circuit and damage.

    • Q. Is the check result normal?

    STEP 6. M.U.T.-III diagnosis code

  • After clearing the diagnosis code through M.U.T.-III, start the engine and confirm whether the diagnosis code is set.

    • Q. Is the diagnosis code set?

    Author: admin