ECD SYSTEM, Diagnostic DTC:U1122

DTC Code DTC Name
U1122 Lost Communication with EGR Valve

DESCRIPTION

Tech Tips


  • Malfunctions in the CAN bus (communication line) can be checked from the DLC3. (Except when the sub bus line of the DLC3 is open.)

  • Diagnostic codes (DTCs) related to CAN communication can be checked by using the intelligent tester.

  • The DLC3 is connected to the CAN communication line, but the CAN communication line cannot detect malfunctions in the DLC3 sub bus line.

U1122
DTC Detection Drive Pattern DTC Detection Condition Trouble Area
-

Both of the following conditions are met:

(a) Ignition switch ON

(b) No communication between ECM and EGR valve assembly for 0.68 seconds

  • Open or short in EGR valve assembly circuit

  • EGR valve assembly

  • CAN communication system

  • ECM

INSPECTION PROCEDURE

PROCEDURE


  1. READ OUTPUT DTC (RECORD STORED DTC AND FREEZE FRAME DATA)


    1. Replace the normal DLC3 cable (12 V specification) for the intelligent tester with the 24 V DLC3 cable.

      Note

      Be sure to use the 24 V DLC3 cable when connecting the intelligent tester to the DLC3. Using the normal DLC3 cable (12 V specification) will cause damage to the tester.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the ignition switch to ON.

    4. Turn the tester on.

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

    6. Record the stored DTC and freeze frame data.

      Tech Tips

      This freeze frame data shows the actual engine conditions when engine stall trouble occurred.

    7. Clear the DTCs Click here.


    NEXT

  2. PERFORM DRIVING TEST


    1. Perform a driving test.


    NEXT

  3. CHECK DTC OUTPUT


    1. Replace the normal DLC3 cable (12 V specification) for the intelligent tester with the 24 V DLC3 cable.

      Note

      Be sure to use the 24 V DLC3 cable when connecting the intelligent tester to the DLC3. Using the normal DLC3 cable (12 V specification) will cause damage to the tester.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the ignition switch to ON.

    4. Turn the tester on.

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

    6. Read the DTCs.

      Result
      Result Proceed to
      DTC U1122 is output A
      DTC is not output B

    B

    CHECK FOR INTERMITTENT PROBLEMS Click here

    A

    GO TO CAN COMMUNICATION SYSTEM Click here