CAN COMMUNICATION SYSTEM(for RHD 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

B002A2IE01

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 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 here

Tech Tips


  • 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

      Tech Tips

      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. B0029VWC36
      *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 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. B0029VWC35
      *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 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. B0029VWC35
      *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 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 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: GO TO STOP AND START SYSTEM Click here
    GO TO STOP AND START SYSTEM for 3ZR-FAE: GO TO STOP AND START SYSTEM Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR