ECD SYSTEM(w/ Glow Plug Controller), Diagnostic DTC:P0405 and P0406

DTC Code DTC Name
P0405 Exhaust Gas Recirculation Sensor "A" Circuit Low
P0406 Exhaust Gas Recirculation Sensor "A" Circuit High

DESCRIPTION

The EGR system is designed to reduce and control NOx formation due to a reduction of peak temperature in the engine combustion chamber, which is accomplished by introducing an inert gas into intake manifold.

Exhaust gases are redirected to the EGR valve, and when the valve opens, the gases are circulated into the intake manifold by difference in the pressure between exhaust manifold and intake manifold.

The ECM judges engine condition from engine speed (NE) and injection amount and operates the EGR valve with DC motor and the amount of EGR gas. And also, it controls diesel throttle opening position with DC motor. By sensing the engine coolant temperature sensor and atmospheric sensor, the EGR system can operate according to various driving conditions.

Adopting an exhaust gas passage in the cylinder head and a water cooling type EGR cooler makes it possible to lower the temperature of the exhaust gas and recirculate a great amount of exhaust gas.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

P0405

Exhaust Gas Recirculation Sensor "A" Circuit Low

Open or short in EGR valve position sensor circuit

(1 trip detection logic)

  • Electric EGR control valve assembly

  • Open or short in EGR valve position sensor circuit

  • ECM

Comes on

DTC stored

P0406

Exhaust Gas Recirculation Sensor "A" Circuit High

Open or short in EGR valve position sensor circuit

(1 trip detection logic)

  • Electric EGR control valve assembly

  • Open or short in EGR valve position sensor circuit

  • ECM

Comes on

DTC stored
Table 1. DTC Detection Drive Pattern

DTC No.

DTC Detection Drive Pattern

P0405

Ignition switch ON for 3 seconds

P0406

WIRING DIAGRAM

Refer to DTC P0403.

Click here

CAUTION / NOTICE / HINT

Note:

When replacing the ECM, perform ECM Initialization and Registration.

Click here

Tip:

  • When the ECM must be replaced, before replacing the ECM, perform the "Learning Values Save" function using the GTS. Then after installing a new ECM, perform all of the initialization and registration procedures for the "Learning Values Write" function by following the instructions shown on the GTS display.

  • Read freeze frame data using the GTS. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, and other data from the time the malfunction occurred.

PROCEDURE

  1. CHECK HARNESS AND CONNECTOR (ELECTRIC EGR CONTROL VALVE ASSEMBLY - ECM)

    1. Disconnect the electric EGR control valve assembly connector.

    2. Disconnect the ECM connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      B134-5 (VC) - B212-64 (VCEG)

      Always

      Below 1 Ω

      B134-4 (VTA) - B212-79 (EGLS)

      Always

      Below 1 Ω

      B134-3 (E2) - B212-111 (EEGL)

      Always

      Below 1 Ω

      B134-5 (VC) or B212-64 (VCEG) - Body ground and other terminals

      Always

      10 kΩ or higher

      B134-4 (VTA) or B212-79 (EGLS) - Body ground and other terminals

      Always

      10 kΩ or higher

      B134-3 (E2) or B212-111 (EEGL) - Body ground and other terminals

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTORClick here

    OK

  2. CHECK TERMINAL VOLTAGE (VC VOLTAGE)

    A200329C02

    *a

    Front view of wire harness connector

    (to Electric EGR Control Valve Assembly)

    1. Disconnect the electric EGR control valve assembly connector.

    2. Turn the ignition switch to ON.

    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      B134-5 (VC) - B134-3 (E2)

      Ignition switch ON

      4.5 to 5.5 V

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE ECMClick here

    OK

  3. REPLACE ELECTRIC EGR CONTROL VALVE ASSEMBLY

    1. Replace the electric EGR control valve assembly.

      Click here

    Result

    Proceed to

    NEXT
    NEXT

    CHECK WHETHER DTC OUTPUT RECURS (DTC P0405 OR P0406)Click here

  4. REPAIR OR REPLACE HARNESS OR CONNECTOR

    Result

    Proceed to

    NEXT
    NEXT

  5. CHECK WHETHER DTC OUTPUT RECURS (DTC P0405 OR P0406)

    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON and turn the GTS on.

    3. Clear the DTCs.

      Powertrain > Engine and ECT > Clear DTCs

    4. Turn the ignition switch to ON and wait for 15 seconds or more.

    5. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

    6. Read the DTCs.

      Powertrain > Engine and ECT > Trouble Codes

      Result

      Result

      Proceed to

      DTC is not output

      A

      DTC P0405 or P0406 is output

      B
    A

    END

    B

  6. REPLACE ECM

    1. Replace the ECM.

      Click here

    Result

    Proceed to

    NEXT
    NEXT

  7. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON and turn the GTS on.

    3. Clear the DTCs.

      Powertrain > Engine and ECT > Clear DTCs

    4. Turn the ignition switch to ON and wait for 15 seconds or more.

    5. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

    6. Confirm that the DTC is not output again.

      Powertrain > Engine and ECT > Trouble Codes

    Result

    Proceed to

    NEXT
    NEXT

    END