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 in the ON position

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

  • Open or short in turbo actuator circuit

  • Turbocharger sub-assembly

  • ECM

WIRING DIAGRAM

Refer to DTC P0045 Click here.

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK WHETHER DTC OUTPUT RECURS (U1123)


    1. Clear the DTCs Click here.

    2. Turn the ignition switch off.

    3. Turn the ignition switch to the ON position.

    4. Turn the tester on.

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

    6. Read the DTCs.

      Result
      Result Proceed to
      DTC U1123 is output A
      No DTC output B

    B

    CHECK FOR INTERMITTENT PROBLEMS

    A

  2. CHECK HARNESS AND CONNECTOR (CAN BUS LINE)


    1. A01CHPOE07

      Disconnect the turbocharger connector.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      X19-1 (CANH) - X19-4 (CANL) Always 105 to 135 Ω

    3. Reconnect the turbocharger connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (CAN BUS LINE)

    OK

  3. CHECK TURBOCHARGER SUB-ASSEMBLY (POWER SOURCE)


    1. A01CHPOE08

      Disconnect the turbocharger connector.

    2. Turn the ignition switch to the ON position.

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

      Standard voltage
      Tester Connection Condition Specified Condition
      X19-3 (+B) - X19-6 (GND) Ignition switch on 11 to 14 V

    4. Reconnect the turbocharger connector.


    NG

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

    OK

    REPLACE TURBOCHARGER SUB-ASSEMBLY

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


    1. A01CHPOE09

      Disconnect the turbocharger connector.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      X19-6 (GND) - Body ground Always Below 1 Ω

    3. Reconnect the turbocharger connector.


    NG

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

    OK

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