CAN COMMUNICATION SYSTEM, 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 lane departure warning camera continues.

  • Lane departure warning camera branch line or connector

  • Power source circuit of lane departure warning camera

  • Lane departure warning camera ground circuit

  • Lane departure warning camera

Tech Tips

This diagnosis procedure is for when DTC U023A is output by the power management control ECU (Techstream display: PM1 Gateway).

WIRING DIAGRAM

A01I5YOE02

INSPECTION PROCEDURE

Note


  • 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.

  • 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 power switch on (IG), wait at least 21 seconds and then drive the vehicle at a speed of 36 km/h (22 mph) or more for 5.24 seconds or more.

  • After the repair, perform the 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 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 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 PM1 Gateway of the power management control ECU, this indicates a sub bus 11 malfunction. Troubleshoot for DTC U1002 and check for malfunctions in sub bus 11.

      Result
      Result Proceed to

      DTC U1002 is not output from the power management control ECU.

      (Techstream display: PM1 Gateway)

      		 A

      DTC U1002 is output from the power management control ECU.

      (Techstream display: PM1 Gateway)

      		 B

    B

    GO TO DIAGNOSIS PROCEDURE INDICATED BY OUTPUT DTC Click here

    A

  2. CHECK FOR OPEN IN SUB BUS 11 LINES (LANE DEPARTURE WARNING CAMERA BRANCH LINE)


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

    2. A01I4AME29
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Lane Departure Warning Camera)

      Disconnect the S20 lane departure warning camera connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      S20-6 (CA1P) - S20-12 (CA1N) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN BRANCH LINES OR CONNECTOR (LANE DEPARTURE WARNING CAMERA)

    OK

  3. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)


    1. A01I4AME30
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Lane Departure Warning Camera)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      S20-11 (GND) - Body ground Cable disconnected from negative (-) auxiliary battery terminal Below 1 Ω

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

    3. A01I4AME31
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Lane Departure Warning Camera)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      S20-7 (IGB) - Body ground Power switch on (IG) 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

    OK

    REPLACE LANE DEPARTURE WARNING CAMERA Click here