Code No. P0403: Exhaust Gas Recirculation Control System




OPERATION



FUNCTION



TROUBLE JUDGMENT


Check Conditions
or

Judgment Criterion

PROBABLE CAUSE



DIAGNOSIS PROCEDURE

STEP 1. Connector check: B-103 EGR valve connector

Q. Is the check result normal?

Go to Step 2 .

Repair or replace.

STEP 2. Check EGR valve itself.

  • Check EGR valve itself [Refer to GROUP 17 - Emission Control System - Exhaust Gas Recirculation (EGR) System - EGR Valve (stepper motor) Check .

Q. Is the check result normal?
Go to Step 3 .
Replace EGR valve (stepper motor).

STEP 3. Perform voltage measurement at B-103 EGR valve connector.


  • Disconnect connector, and measure at harness side.
  • Ignition switch: ON
  • Voltage between terminal No. 2, No. 5 and earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 5 .

Go to Step 4 .

STEP 4. Connector check: B-15X engine control relay connector


Q. Is the check result normal?


    Check intermediate connector C-116, and repair if necessary. If intermediate connector is normal, check and repair harness between B-103 (terminal No. 2, No. 5) EGR valve connector and B-15X (terminal No. 1) engine control relay connector.

    • Check power supply line for open/short circuit.

Repair or replace.

STEP 5. Perform voltage measurement at C-110 engine-ECU <M/T> connector or engine-A/T-ECU <A/T>.


  • Disconnect connector, and measure at harness side.
  • Ignition switch: ON
  • Voltage between terminal No. 3, No. 12, No. 19, No. 26 and earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 7 .

Go to Step 6 .

STEP 6. Connector check: C-110 engine-ECU <M/T> connector or engine-A/T-ECU <A/T> connector


Q. Is the check result normal?


    Check and repair harness between B-103 EGR valve and C-110 engine-ECU <M/T> connector or engine-A/T-ECU <A/T> connector.

    1. Check harness between B-103 (terminal No. 1) EGR valve and C-110 (terminal No. 3) engine-ECU <M/T> connector or engine-A/T-ECU <A/T> connector.
    2. Check harness between B-103 (terminal No. 3) EGR valve and C-110 (terminal No. 12) engine-ECU <M/T> connector or engine-A/T-ECU <A/T> connector.
    3. Check harness between B-103 (terminal No. 4) EGR valve and C-110 (terminal No. 19) engine-ECU <M/T> connector or engine-A/T-ECU <A/T> connector.
    4. Check harness between B-103 (terminal No. 6) EGR valve and C-110 (terminal No. 26) engine-ECU <M/T> connector or engine-A/T-ECU <A/T> connector.

    • Check power supply line for open/short circuit.

Repair or replace.

STEP 7. Connector check: C-110 engine-ECU <M/T> connector or engine-A/T-ECU <A/T> connector

Q. Is the check result normal?

Go to Step 8 .

Repair or replace.

STEP 8. Check harness between B-103 EGR valve and C-110 engine-ECU <M/T> or engine-A/T-ECU <A/T>.



  1. Check harness between B-103 (terminal No. 1) EGR valve and C-110 (terminal No. 3) engine-ECU <M/T> connector or engine-A/T-ECU <A/T> connector.
  2. Check harness between B-103 (terminal No. 3) EGR valve and C-110 (terminal No. 12) engine-ECU <M/T> connector or engine-A/T-ECU <A/T> connector.
  3. Check harness between B-103 (terminal No. 4) EGR valve and C-110 (terminal No. 19) engine-ECU <M/T> connector or engine-A/T-ECU <A/T> connector.
  4. Check harness between B-103 (terminal No. 6) EGR valve and C-110 (terminal No. 26) engine-ECU <M/T> connector or engine-A/T-ECU <A/T> connector.

  • Check output line for damage.

Q. Is the check result normal?

Go to Step 9 .

Repair.

STEP 9. Check harness between B-103 (terminal No. 2, No. 5) EGR valve connector and B-15X (terminal No. 1) engine control relay connector.


note Before checking harness, check intermediate connector C-116, and repair if necessary.

  • Check power supply line for damage.

Q. Is the check result normal?

Replace engine-ECU <M/T> or engine-A/T-ECU <A/T>.

Repair.