Code No. P0406: Exhaust Gas Recirculation Valve Position Sensor Circuit High Input <Euro3, Euro4>








OPERATION



  • A power voltage of 5 V is applied to the exhaust gas recirculation valve assembly power terminal (terminal No. 3) from the engine-ECU (terminal No. 71) and earthed to the engine-ECU (terminal No. 81) from the exhaust gas recirculation valve assembly (terminal No. 2).
  • The sensor signal is inputted to the engine-ECU (terminal No. 57) from the exhaust gas recirculation valve assembly output terminal (terminal No. 1).

FUNCTION



  • The exhaust gas recirculation valve assembly detects the position of the exhaust gas recirculation valve and sends the signal to the engine-ECU.
  • Based on the signal, the engine-ECU performs the feedback control of the exhaust gas recirculation valve.

TROUBLE JUDGMENT


Check Conditions
  • Battery positive voltage is 8 - 16 V
  • 2 seconds later after the ignition switch has been in "ON" position or the engine has started up.
Judgment Criterion
  • The exhaust gas recirculation valve position sensor output voltage is 4.80 V or more.

PROBABLE CAUSES



  • Failed exhaust gas recirculation valve position sensor
  • Open circuit or harness damage in exhaust gas recirculation valve position sensor circuit or loose connector contact
  • Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III data list

  • Refer to Data List Reference Table .

  1. Item 16: Exhaust gas recirculation valve position sensor

Q. Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
Go to Step 2 .

STEP 2. Connector check: B-02 exhaust gas recirculation valve assembly connector

Q. Is the check result normal?
Go to Step 3 .
Repair or replace the connector.

STEP 3. Perform resistance measurement at B-02 exhaust gas recirculation valve assembly connector.

  • Disconnect connector, and measure at harness side.
  • Ignition switch: ON
  • Resistance between terminal No. 2 and earth.
OK: Continuity (2 Ω or less)

Q. Is the check result normal?
Go to Step 7 .
Go to Step 4 .

STEP 4. Connector check: D-213 engine-ECU connector

Q. Is the check result normal?
Go to Step 5 .
Repair or replace the connector.

STEP 5. Check harness between B-02 (terminal No. 2) exhaust gas recirculation valve assembly connector and D-213 (terminal No. 81) engine-ECU connector.

  • Check earthing line for open circuit and damage.

Q. Is the check result normal?
Go to Step 6 .
Repair the damaged harness wire.

STEP 6. M.U.T.-III data list

  • Refer to Data List Reference Table .

  1. Item 16: Exhaust gas recirculation valve position sensor

Q. Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
Replace the engine-ECU. When the engine-ECU is replaced, write the chassis number (Refer to GROUP 00 - Precautions Before Service - How to Perform Chassis Number Writing ). After replacing the engine-ECU, register the injector identification code and learn fuel injection (Refer to GROUP 00 - Precautions Before Service - What The Common Rail Engine Learns ).

STEP 7. M.U.T.-III data list

  • Refer to Data List Reference Table .

  1. Item 16: Exhaust gas recirculation valve position sensor

Q. Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
Replace the exhaust gas recirculation valve assembly.