CAN COMMUNICATION SYSTEM (for RHD), 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

A01H1GDE31

INSPECTION PROCEDURE

Note

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

Tech Tips

Operating the power 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 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.


    NEXT

  2. DISCONNECT CABLE FROM NEGATIVE AUXILIARY BATTERY TERMINAL


    1. Disconnect the cable from the negative (-) auxiliary 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 (-) auxiliary 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. A01H003E05
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Driving Support ECU Assembly)

      Disconnect the 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
      A33-40 (CA1P) - A33-39 (CA1N) Power switch off 54 to 69 Ω

    NG

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

    OK

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


    1. A01H003E01
      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 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
      A33-13 (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
      A33-25 (GND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here