CAN COMMUNICATION SYSTEM (for LHD), Diagnostic DTC:U0104, U1104

DTC Code DTC Name
U0104 Lost Communication with Driving Support ECU
U1104 Lost Communication with Driving Support ECU

DESCRIPTION

DTC Code DTC Detection Condition Trouble Area
U0104 There is no communication from the driving support ECU assembly.

  • Power source or inside of driving support ECU assembly

  • Driving support ECU assembly CAN branch wire or connector

  • Driving support ECU assembly
U1104

WIRING DIAGRAM

A01FUUZE05

INSPECTION PROCEDURE

Note


  • 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.

  • 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, 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 auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the auxiliary battery terminal notice before proceeding with work Click here.

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

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

  • DTC check procedure: Allow the radar cruise control system (vehicle control mode) to operate for 0.19 seconds or more.

  • 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.

Tech Tips


  • Operating the power switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.

  • 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: w/o Dynamic Rear Steering System

    • *2: w/ Dynamic Rear Steering System


    1. Reconfirm DTCs.

      Tech Tips

      If DTC U1002 is output from Gateway of the network gateway ECU, this indicates a sub bus 2*1 or sub bus 18*2 and sub bus 19*2 malfunction. Troubleshoot for DTC U1002 and check for malfunctions in sub bus 2*1 or sub bus 18*2 and sub bus 19*2.

      Result
      Result Proceed to
      DTC U1002 is not output from network gateway ECU. A
      DTC U1002 is output from network gateway ECU (Sub Bus 2*1 or Sub Bus 18*2). B
      DTC U1002 is output from network gateway ECU (Sub Bus 19). C

    B

    GO TO DIAGNOSIS PROCEDURE INDICATED BY OUTPUT DTC Click here

    C

    GO TO DIAGNOSIS PROCEDURE INDICATED BY OUTPUT DTC Click here

    A

  2. RECONFIRM DTC OUTPUT


    1. Reconfirm DTCs.

      Tech Tips

      If DTC U1002 is output from Gateway 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
      DTC U1002 is not output from driving support ECU assembly. A
      DTC U1002 is output from driving support ECU assembly. B

    B

    GO TO DIAGNOSIS PROCEDURE INDICATED BY OUTPUT DTC Click here

    A

  3. CHECK FOR OPEN IN CAN BUS WIRE (DRIVING SUPPORT ECU ASSEMBLY CAN BRANCH WIRE)


    1. w/o Dynamic Rear Steering System:


      1. A01FSJEE02
        Text in Illustration
        *A Sub Bus 2
        *B Sub Bus 13
        *a

        Rear view of wire harness connector

        (to Driving Support ECU Assembly)

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

      2. Disconnect the driving support ECU assembly connector.

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

        Standard Resistance
        Sub Bus 2
        Tester Connection Condition Specified Condition
        N5-39 (CA2H) - N5-17 (CA2L) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω
        Sub Bus 13
        Tester Connection Condition Specified Condition
        N5-40 (CA1P) - N5-18 (CA1N) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω

    2. w/ Dynamic Rear Steering System:


      1. A01FSJEE03
        Text in Illustration
        *A Sub Bus 18
        *B Sub Bus 19
        *C Sub Bus 13
        *a

        Rear view of wire harness connector

        (to Driving Support ECU Assembly)

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

      2. Disconnect the driving support ECU assembly connector.

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

        Standard Resistance
        Sub Bus 18
        Tester Connection Condition Specified Condition
        N5-39 (CA2H) - N5-17 (CA2L) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω
        Sub Bus 19
        Tester Connection Condition Specified Condition
        N5-2 (CA3H) - N5-20 (CA3L) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω
        Sub Bus 13
        Tester Connection Condition Specified Condition
        N5-40 (CA1P) - N5-18 (CA1N) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω

    NG

    REPAIR OR REPLACE DRIVING SUPPORT ECU ASSEMBLY CAN BRANCH WIRE OR CONNECTOR (CA1P, CA1N, CA2H, CA2L, CA3H, CA3L)

    OK

  4. CHECK HARNESS AND CONNECTOR (DRIVING SUPPORT ECU ASSEMBLY - BATTERY AND BODY GROUND)


    1. A01FSJEE01
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Driving Support ECU Assembly)

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

      Note

      When connecting the cable, some systems need to be initialized after the cable is reconnected Click here.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      N5-30 (B) - Body ground Power 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
      N5-25 (GND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here