Dtc P0400 Exhaust Gas Recirculation Flow

Engine. Lexus Is250, Is220D. Gse20 Ale20
2Ad-Fhv Engine Control System. Lexus Is250, Is220D. Gse20 Ale20

DESCRIPTION

MONITOR DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK OTHER DTC OUTPUT (IN ADDITION TO DTC P0400)

READ VALUE OF INTELLIGENT TESTER (EGR POSITION)

INSPECT EGR VALVE ASSEMBLY (RESISTANCE)

CHECK HARNESS AND CONNECTOR (EGR VALVE ASSEMBLY - ECM)

CHECK HARNESS AND CONNECTOR (EGR VALVE ASSEMBLY - EFI MAIN RELAY)

REPLACE EGR VALVE ASSEMBLY

CHECK IF DTC OUTPUT REOCCURS (SEE IF DTC P0400 IS OUTPUT AGAIN)

DTC P0400 Exhaust Gas Recirculation Flow


DESCRIPTION

The EGR system recirculates exhaust gases, in order to suit every driving condition. The recirculated gas mingles with the intake air, therefore the EGR system can slow combustion speed and keep the combustion temperature down. This helps reduce NOx emissions.
In order to increase EGR circulation efficiency, the ECM adjusts the lift amount of the EGR valve and intake shutter valve angle (throttle valve).

DTC No.
DTC Detection Condition
Trouble Area
P0400
Target and actual positions of the EGR valve are different
(1 trip detection logic)
  1. EGR valve stuck
  2. EGR valve does not move smoothly
  3. Open or short in EGR circuit
  4. Open or short in EGR valve position sensor circuit
  5. EGR valve position sensor
  6. ECM

MONITOR DESCRIPTION

When the target and actual positions of the EGR valve are different, the ECM interprets this as a malfunction of the EGR valve and illuminates the CHK ENG light.

Lexus Is250, Is220D. Gse20 Ale20.2Ad-Fhv Engine Control System.Ecd System. Dtc P0400 Exhaust Gas Recirculation Flow


WIRING DIAGRAM


Lexus Is250, Is220D. Gse20 Ale20.2Ad-Fhv Engine Control System.Ecd System. Dtc P0400 Exhaust Gas Recirculation Flow


INSPECTION PROCEDURE

NOTICE:
After replacing the ECM, the new ECM needs registration (Click here) and initialization (Click here).
HINT:
After warming up the engine, DTC P0400 can be set if 1 second or more passes after quickly accelerating the engine from idling.
1.CHECK OTHER DTC OUTPUT (IN ADDITION TO DTC P0400)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the engine switch ON (IG) and turn the intelligent tester ON.

  1. Enter the following menus: "Powertrain / Engine / DTC".

  1. Read DTCs.

    Result:

    Display (DTC output)
    		Proceed to
    P0400
    		A
    P0400 and P0405 and/or P0406
    		B
    HINT:
    If codes other than P0400 are output, perform troubleshooting for those DTCs first.


B
GO TO DTC CHART
A


2.READ VALUE OF INTELLIGENT TESTER (EGR POSITION)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the engine switch ON (IG) and turn the intelligent tester ON.

  1. Enter the following menus: "Powertrain / Engine / Data List / EGR Position" and read its value displayed on the intelligent tester.

    Result:

    Condition
    		Result
    		Proceed to
    After warming up the engine, quickly accelerate the engine from idle to 3,000 rpm by using the accelerator pedal
    		Constant or changes slowly
    		A
    Smooth changes from approximately 0% to approximately 50%
    		B
    HINT:
    1. EGR valve closed: EGR Position is 0%
    2. EGR valve open: EGR Position is 65%


B
CHECK FOR INTERMITTENT PROBLEMS
A


3.INSPECT EGR VALVE ASSEMBLY (RESISTANCE)


    Lexus Is250, Is220D. Gse20 Ale20.2Ad-Fhv Engine Control System.Ecd System. Dtc P0400 Exhaust Gas Recirculation Flow

  1. Disconnect the E64 EGR valve connector.

  1. Measure the resistance between the terminals of the EGR valve.

    Standard resistance:
    Tester Connection
    		Condition
    		Specified Condition
    1 - 5
    		20°C (68°F)
    		Approximately 6.5 to 7.5 Ω

  1. Reconnect the EGR valve connector.



NG
REPLACE EGR VALVE ASSEMBLY
OK


4.CHECK HARNESS AND CONNECTOR (EGR VALVE ASSEMBLY - ECM)


    Lexus Is250, Is220D. Gse20 Ale20.2Ad-Fhv Engine Control System.Ecd System. Dtc P0400 Exhaust Gas Recirculation Flow

  1. Disconnect the E64 EGR valve connector.

  1. Disconnect the E59 ECM connector.

  1. Check the resistance between the wire harness side connectors.

    Standard resistance (Check for open):
    Tester Connection
    		Specified Condition
    EGRS (E59-85) - EGR valve (E64-5)
    		Below 1 Ω
    Standard resistance (Check for short):
    Tester Connection
    		Specified Condition
    EGRS (E59-85) or EGR valve (E64-5) - Body ground
    		10 kΩ or higher

  1. Reconnect the EGR valve connector.

  1. Reconnect the ECM connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


5.CHECK HARNESS AND CONNECTOR (EGR VALVE ASSEMBLY - EFI MAIN RELAY)


    Lexus Is250, Is220D. Gse20 Ale20.2Ad-Fhv Engine Control System.Ecd System. Dtc P0400 Exhaust Gas Recirculation Flow

  1. Remove the EFI MAIN relay from the engine room R/B No. 2.

  1. Disconnect the E64 EGR valve connector.

  1. Check the resistance between the wire harness side connectors.

    Standard resistance (Check for open):
    Tester Connection
    		Specified Condition
    EFI MAIN relay (1) - EGR valve (E64-1)
    		Below 1 Ω
    Standard resistance (Check for short):
    Tester Connection
    		Specified Condition
    EFI MAIN relay (1) or EGR valve (E64-1) - Body ground
    		10 kΩ or higher

  1. Reinstall the EFI MAIN relay.

  1. Reconnect the EGR valve connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


6.REPLACE EGR VALVE ASSEMBLY

NEXT


7.CHECK IF DTC OUTPUT REOCCURS (SEE IF DTC P0400 IS OUTPUT AGAIN)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the engine switch on (IG) and turn the tester ON.

  1. Clear DTCs.

  1. Start the engine.

  1. Enter the following menus: Powertrain / Engine / DTC.

  1. Read the DTCs using the intelligent tester.

    Result:

    Display (DTC output)
    		Proceed to
    P0400
    		A
    No output
    		B


B
SYSTEM IS OK
A

REPLACE ECM