CAN COMMUNICATION SYSTEM(w/ Central Gateway ECU), Diagnostic DTC:U023A

DTC Code DTC Name
U023A Lost Communication with Front Camera Module

DESCRIPTION

DTC No. DTC Detection Condition Trouble Area
U023A No communication from the forward recognition camera continues.

  • Forward recognition camera branch line or connector

  • Power source circuit of forward recognition camera

  • Forward recognition camera ground circuit

  • Forward recognition camera

Tech Tips

This diagnosis procedure is for when DTC U023A is output by the driving support ECU assembly (GTS display: Pre-crash 2).

WIRING DIAGRAM

A01W2BEE02

CAUTION / NOTICE / HINT

Note


  • Before measuring the resistance of the CAN bus, turn the engine switch off and leave the vehicle for 1 minute or more without operating the key or any 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 engine switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work Click here.

  • 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.

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

  • DTC check procedure: Turn the engine switch on (IG) and wait at least 3 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.

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

Tech Tips


  • Operating the engine switch, any other switches or a door triggers related ECU and sensor communication on the CAN. This communication will cause the resistance value to change.

  • 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. RECONFIRM DTC OUTPUT


    1. Reconfirm DTCs.

      Tech Tips

      If DTC U1002 is output from Pre-Crash 2 of the driving support ECU assembly, this indicates a sub bus 13 malfunction. Troubleshoot for DTC U1002 and check for malfunctions in sub bus 13.

      Result
      Result Proceed to

      U1002 is not output from driving support ECU assembly

      (GTS display: Pre-Crash 2)

      		 A

      U1002 is output from driving support ECU assembly

      (GTS display: Pre-Crash 2)

      		 B

    B

    GO TO DIAGNOSIS PROCEDURE INDICATED BY OUTPUT DTC Click here

    A

  2. CHECK FOR OPEN IN CAN BUS LINES (FORWARD RECOGNITION CAMERA BRANCH LINE)


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

    2. A01W3QHE04
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Forward Recognition Camera)

      Disconnect the T12 forward recognition camera connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      T12-6 (CANH) - T12-12 (CANL) Cable disconnected from negative (-) battery terminal 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN BRANCH LINE OR CONNECTOR (FORWARD RECOGNITION CAMERA)

    OK

  3. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)


    1. A01W1DHE04
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Forward Recognition Camera)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      T12-10 (GND) - Body ground Cable disconnected from negative (-) battery terminal Below 1 Ω

    2. Reconnect the cable to the negative (-) battery terminal.

    3. A01W1VME02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Forward Recognition Camera)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      T12-7 (IGB) - Body ground Engine switch on (IG) 11 to 14 V
      Result
      Result Proceed to
      OK A
      NG (except 6AR-FSE) B
      NG (for 6AR-FSE) C

    A

    REPLACE FORWARD RECOGNITION CAMERA Click here

    B

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

    C

    CHECK FOR BACKUP BOOST CONVERTER CIRCUIT Click here