CAN COMMUNICATION SYSTEM(for RHD), Diagnostic DTC:U1110

DTC Code DTC Name
U1110 Lost Communication with Clearance Sonar Module

DESCRIPTION

DTC No. Detection Item DTC Detection Condition Trouble Area DTC Output from
U1110 Lost Communication with Clearance Sonar Module There is no communication from the clearance warning ECU assembly.

  • Power source circuit of clearance warning ECU assembly

  • Clearance warning ECU assembly ground circuit

  • Clearance warning ECU assembly CAN branch wire or connector

  • Clearance warning ECU assembly

 Network gateway ECU

For vehicles with a LEXUS parking assist-sensor system.

WIRING DIAGRAM

B0059KSE08
*1 No. 3 CAN Junction Connector
*2 ECU-IG NO.2
*3 from IG1 NO.2 Relay
*4 Clearance Warning ECU Assembly

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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  • 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.

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  • 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 21 seconds.

  • After the repair, perform the CAN bus check and check that all the ECUs and sensors connected to the CAN communication system are displayed.

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  • 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. Check for DTCs.


      Body Electrical > Gateway > Trouble Codes

      Tech Tips

      If DTC U1002 is output from the gateway of the network gateway ECU, this indicates a sub bus 2 malfunction. Troubleshoot for DTC U1002 and check for malfunctions in sub bus 2.

      Result
      Result Proceed to
      U1002 is not output from network gateway ECU A
      U1002 is output from network gateway ECU B

    B

    GO TO DIAGNOSIS PROCEDURE INDICATED BY OUTPUT DTC Click here

    A

  2. CHECK FOR OPEN IN CAN BUS WIRE (CLEARANCE WARNING ECU ASSEMBLY BRANCH WIRE)


    1. A01XP5WC03
      *a

      Rear view of wire harness connector

      (to Clearance Warning ECU Assembly)

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

    2. Disconnect the clearance warning ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I20-17 (R1) - I20-18 (R2) Cable disconnected from negative (-) battery terminal 54 to 69 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (CLEARANCE WARNING ECU ASSEMBLY)

    OK

  3. CHECK HARNESS AND CONNECTOR (CLEARANCE WARNING ECU ASSEMBLY - BATTERY AND BODY GROUND)


    1. A01XP5WC04
      *a

      Rear view of wire harness connector

      (to Clearance Warning ECU Assembly)

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

      Note

      When disconnecting the cable, some systems need to be initialized after the cable is reconnected.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      I20-12 (IG) - Body ground Engine switch on (IG) 11 to 14 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I20-27 (E) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE CLEARANCE WARNING ECU ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR