ECD SYSTEM, Diagnostic DTC:U1123

DTC Code DTC Name
U1123 Lost Communication with Variable Nozzle Type Turbo Charger Module

DESCRIPTION

The CAN (Controller Area Network) is a serial data communication system for real time application. It is a multiplex communication system designed for on-vehicle use that provides a superior communication speed of 500 kbps and a capability to detect malfunctions. Through the combination of the CANH and CANL bus lines, the CAN is able to maintain communication based on differential voltage.

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.

DTC No. DTC Detection Condition Trouble Area
U1123

Both of the following conditions are met:

(a) Ignition switch ON

(b) No communication between ECM and turbocharger actuator for 0.7 seconds

  • Open or short in turbo actuator circuit

  • Turbocharger sub-assembly

  • CAN communication system

  • ECM

WIRING DIAGRAM

Refer to DTC P0045 Click here.

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK WHETHER DTC OUTPUT RECURS (U1123)


    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. Clear the DTCs Click here.

    6. Turn the ignition switch off.

    7. Turn the ignition switch to ON.

    8. Turn the tester on.

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

    10. Read the DTCs.

      Result
      Result Proceed to
      DTC U1123 is output A
      DTC is not output B

    B

    CHECK FOR INTERMITTENT PROBLEMS Click here

    A

  2. CHECK HARNESS AND CONNECTOR (CAN BUS LINE)


    1. A01CHPOE18
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Turbocharger Actuator)

      Disconnect the turbocharger actuator connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      T8-1 (CANH) - T8-4 (CANL) Always 105 to 135 Ω

    3. Reconnect the turbocharger actuator connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (CAN BUS LINE)

    OK

  3. CHECK TURBOCHARGER SUB-ASSEMBLY (POWER SOURCE)


    1. A01CHPOE19
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Turbocharger Actuator)

      Disconnect the turbocharger actuator 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 Switch Condition Specified Condition
      T8-3 (+B) - T8-6 (GND) Ignition switch ON 11 to 14 V

    4. Reconnect the turbocharger actuator connector.


    NG

    CHECK HARNESS AND CONNECTOR (TURBOCHARGER ACTUATOR - BODY GROUND) Click here

    OK

    REPLACE TURBOCHARGER SUB-ASSEMBLY Click here

  4. CHECK HARNESS AND CONNECTOR (TURBOCHARGER ACTUATOR - BODY GROUND)


    1. Disconnect the turbocharger actuator connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      T8-6 (GND) - Body ground Always Below 1 Ω

    3. Reconnect the turbocharger actuator connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (TURBOCHARGER ACTUATOR - BODY GROUND)

    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR (TURBOCHARGER ACTUATOR - ENG-3 RELAY)