PRE-COLLISION SYSTEM, Diagnostic DTC:U023A

DTC Code DTC Name
U023A Lost Communication with Front Camera Module

DESCRIPTION

DTC No. Detection Item DTC Detection Condition Trouble Area
U023A Lost Communication with Front Camera Module When the power switch is on (IG), a communication error between the forward recognition camera and driving support ECU is detected for approximately 2 seconds.

  • Forward recognition camera branch line or connector

  • Forward recognition camera power source circuit

  • Forward recognition camera

WIRING DIAGRAM

B003YQLE49
*1 No. 21 CAN Junction Connector
*2 from IG1 NO. 3 Relay
*3 IG1 NO. 3
*4 Forward Recognition Camera

CAUTION / NOTICE / HINT

Note


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

  • Before measuring the resistance of the CAN bus, turn the power 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 (-) auxiliary battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.

  • After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work.

    Click here

  • When replacing the forward recognition camera, always replace it with a new one. If a forward recognition camera which was installed to another vehicle is used, the information stored in the forward recognition camera will not match the information from the vehicle. As a result, a DTC may be stored.

  • If the forward recognition camera has been replaced with a new one, be sure to perform forward recognition camera adjustment.

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Tech Tips


  • Operating the power 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 connectors of ECUs or wire harnesses while performing the inspection below may help determine the cause of the malfunction.

PROCEDURE


  1. READ VALUE USING GTS (CAN BUS CHECK)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch to ON.

    3. Turn the GTS on.

    4. Enter the following menus: System Select / Can Bus Check.

      Click here


      CAN Bus Check
      Result
      Result Proceed to
      All of the ECUs and sensors that are currently connected to the CAN communication system are displayed A
      None of the ECUs and sensors that are currently connected to the CAN communication system are displayed, or some of them are not displayed B

    B

    GO TO CAN COMMUNICATION SYSTEM Click here

    A

  2. CHECK FOR DTCs (PRE-COLLISION SYSTEM)


    1. Clear the DTCs.

      Click here


      Body Electrical > Pre-Collision 2 > Clear DTCs

    2. Perform the following procedure.

      Tech Tips

      If the following procedure is not performed, the previously output DTC cannot be detected.


      1. Turn the power switch on (IG) and wait 2 seconds or more.

    3. Check for DTCs.

      Click here


      Body Electrical > Pre-Collision 2 > Trouble Codes
      Result
      Result Proceed to
      DTC U1002 is not output A
      DTC U1002 is output B

    B

    GO TO DTC CHART (U1002) Click here

    A

  3. CHECK FOR OPEN IN CAN BUS MAIN LINES (FORWARD RECOGNITION CAMERA)


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

    2. B003XQ4C39
      *a

      Front view of wire harness connector

      (to Forward Recognition Camera)

      Disconnect the S18 forward recognition camera connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      S18-6 (CANH) - S18-12 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω

    4. Connect the S18 forward recognition camera connector.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE CAN BUS MAIN LINE OR CONNECTOR (NO. 21 CAN JUNCTION CONNECTOR - FORWARD RECOGNITION CAMERA)

    OK

  4. CHECK HARNESS AND CONNECTOR (POWER SOURCE VOLTAGE)


    1. B003XQ4C42
      *a

      Front view of wire harness connector

      (to Forward Recognition Camera)

      Disconnect the S18 forward recognition camera connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      S18-10 (GND) - Body ground Always Below 1 Ω

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

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      S18-7 (IGB) - Body ground Power switch on (IG) 11 to 14 V

    5. Connect the S18 forward recognition camera connector.

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE FORWARD RECOGNITION CAMERA Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)