PRE-CRASH SAFETY 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 engine 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

B002CY1E06
*1 from LH-ECU-IG NO. 1 Relay
*2 No. 6 CAN Junction Connector
*3 Forward Recognition Camera

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.

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

  • 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 Learning.

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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. CHECK FOR DTCs (PRE-CRASH SAFETY SYSTEM)


    1. Clear the DTCs.

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      Body Electrical > Pre-Crash 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 engine switch on (IG) and wait 1 second or more.

    3. Check for DTCs.

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      Body Electrical > Pre-Crash 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

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


    1. B002DM9C74
      *a

      Front view of wire harness connector

      (to Forward Recognition Camera)

      Disconnect the forward recognition camera connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      W6-6 (CANH) - W6-12 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω

    3. Connect the forward recognition camera connector.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE CAN BUS MAIN LINE OR CONNECTOR (NO. 1 CAN JUNCTION CONNECTOR - FORWARD RECOGNITION CAMERA)

    OK

  3. CHECK HARNESS AND CONNECTOR (POWER SOURCE VOLTAGE)


    1. B002DM9C75
      *a

      Front view of wire harness connector

      (to Forward Recognition Camera)

      Disconnect the forward recognition camera connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      W6-10 (GND) - Body ground Always Below 1 Ω

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

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      W6-7 (IGB) - Body ground Engine switch on (IG) 11 to 14 V
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE FORWARD RECOGNITION CAMERA Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)