CAN COMMUNICATION SYSTEM(for LHD with Central Gateway ECU), Diagnostic DTC:U023A

DTC Code DTC Name
U023A Lost Communication with Front Camera Module

DESCRIPTION

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

DTC Output from

U023A

Lost Communication with Front Camera Module

There is no communication from the forward recognition camera.

  • Power source or inside forward recognition camera

  • Forward recognition camera CAN main wire or connector

  • Forward recognition camera

Driving support ECU assembly

WIRING DIAGRAM

C334649E03

CAUTION / NOTICE / HINT

Note:

  • Because the order of diagnosis is important to allow correct diagnosis, make sure to begin troubleshooting using How to Proceed with Troubleshooting when CAN communication system related DTCs are output.

    Click here

  • Before measuring the resistance of the CAN bus, turn the ignition switch off and leave the vehicle for 1 minute or more without operating the key, switches or opening or closing the doors. After that, disconnect the cable from the negative (-) battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.

  • After turning the ignition switch off, waiting time may be required before disconnecting the cable from the battery terminal. Therefore, make sure to read the disconnecting the cable from the battery terminal notice before proceeding with work.

    Click hereClick here

  • Inspect the fuses for circuits related to this system before performing the following procedure.

  • After performing repairs, perform the DTC check procedure and confirm that the DTCs are not output again.

  • DTC check procedure: Turn the ignition switch to ON and wait at least 20 seconds.

  • After the repair, perform CAN Bus Check and check that all the ECUs and sensors connected to the CAN communication system are displayed.

    Click hereClick here

Tip:

  • Operating the ignition switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.

  • Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the ECUs or wire harness while performing the inspection below may help determine the cause of the malfunction.

PROCEDURE

  1. CHECK FOR DTC

    1. Check for DTCs.

      Body Electrical > Pre-Crash 2 > Trouble Codes

      Tip:

      If DTC U1002 is output from gateway of the driving support ECU assembly, this indicates a local bus malfunction. Troubleshoot for DTC U1002 and check for malfunctions in local bus.

    Result

    Result

    Proceed to

    DTC U1002 is not output from driving support ECU assembly

    A

    DTC U1002 is output from driving support ECU assembly

    B
    B

    GO TO GO TO DIAGNOSIS PROCEDURE INDICATED BY OUTPUT DTC

    Click here

    A

  2. CHECK FOR OPEN IN CAN BUS WIRE (FORWARD RECOGNITION CAMERA CAN MAIN WIRE)

    1. C268302C36

      *a

      Front view of wire harness connector

      (to Forward Recognition Camera)

      Disconnect the cable from the negative (-) battery terminal.

    2. Disconnect the forward recognition camera connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      Q17-6 (CANH) - Q17-12 (CANL)

      Cable disconnected from negative (-) battery terminal

      108 to 132 Ω

    Result

    Result

    Result

    Proceed to

    OK (w/o Stop and Start System)

    A

    OK (w/ Stop and Start System)

    B

    NG

    C
    B

    CHECK HARNESS AND CONNECTOR (FORWARD RECOGNITION CAMERA - BATTERY AND BODY GROUND)Click here

    C

    REPAIR OR REPLACE FORWARD RECOGNITION CAMERA CAN MAIN WIRE OR CONNECTOR (CANH, CANL)

    A

  3. CHECK HARNESS AND CONNECTOR (FORWARD RECOGNITION CAMERA - BATTERY AND BODY GROUND)

    1. C268302C35

      *a

      Front view of wire harness connector

      (to Forward Recognition Camera)

      Connect the cable to the negative (-) battery terminal.

      Note:

      When disconnecting the cable, some systems need to be initialized after the cable is reconnected.

      Click hereClick here

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

      Standard Voltage

      Tester Connection

      Switch Condition

      Specified Condition

      Q17-7 (IGB) - Body ground

      Ignition switch ON

      11 to 14 V

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      Q17-10 (GND) - Body ground

      Always

      Below 1 Ω

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE FORWARD RECOGNITION CAMERA

    Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  4. CHECK HARNESS AND CONNECTOR (FORWARD RECOGNITION CAMERA - BATTERY AND BODY GROUND)

    1. C268302C35

      *a

      Front view of wire harness connector

      (to Forward Recognition Camera)

      Connect the cable to the negative (-) battery terminal.

      Note:

      When disconnecting the cable, some systems need to be initialized after the cable is reconnected.

      Click hereClick here

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

      Standard Voltage

      Tester Connection

      Switch Condition

      Specified Condition

      Q17-7 (IGB) - Body ground

      Ignition switch ON

      10.5 to 16 V

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      Q17-10 (GND) - Body ground

      Always

      Below 1 Ω

    Result

    Result

    Result

    Proceed to

    OK

    A

    NG (IGB terminal)

    B

    NG (GND terminal)

    C
    A

    REPLACE FORWARD RECOGNITION CAMERA

    Click here

    B

    GO TO STOP AND START SYSTEM

    for 2WW:

    Click here

    for 3ZR-FAE:

    Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR