CAN COMMUNICATION SYSTEM, Diagnostic DTC:U1104

DTC Code DTC Name
U1104 Lost Communication with Driving Support ECU

DESCRIPTION

DTC Code DTC Detection Condition Trouble Area
U1104 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

WIRING DIAGRAM

A00OQYKE04

INSPECTION PROCEDURE

Note

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

Tech Tips

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

PROCEDURE


  1. PRECAUTION

    Note

    After turning the ignition switch off, waiting time may be required before disconnecting the cable from the battery terminal. Therefore, make sure to read the disconnecting the cable from the battery terminal notice before proceeding with work Click here.


    NEXT

  2. DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL


    1. Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the CAN main wire and the CAN branch wire.

      CAUTION:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

      Note

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


    NEXT

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


    1. A00OSHDE10
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Driving Support ECU Assembly)

      Disconnect the D14 driving support ECU assembly connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      D14-39 (CA2H) - D14-17 (CA2L) Ignition switch off 54 to 64 Ω

    NG

    REPAIR OR REPLACE DRIVING SUPPORT ECU CAN BRANCH WIRE OR CONNECTOR (CA2H, CA2L)

    OK

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


    1. A00OSHDE09
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Driving Support ECU Assembly)

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

      Note

      When disconnecting 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
      D14-30 (B) - Body ground Ignition switch ON 11 to 14 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D14-25 (GND) - Body ground Always Below 1 Ω
      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

    B

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    A

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here