CAN COMMUNICATION SYSTEM, Diagnostic DTC:U1100

DTC Code DTC Name
U1100 Lost Communication with Seat Belt Control ECU

DESCRIPTION

DTC Code DTC Detection Condition Trouble Area
U1100 There is no communication with the seat belt control ECU.

  • Power source circuit of seat belt control ECU

  • Seat belt control ECU

  • Seat belt control ECU branch wire or connector

WIRING DIAGRAM

A006TKQE02

INSPECTION PROCEDURE

Note

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

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. DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL


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

      CAUTION:

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

      Note


      • w/ Navigation System (for HDD):

        After the ignition switch is turned off, the HDD navigation system requires approximately a minute to record various types of memory and settings. As a result, after turning the ignition switch off, wait a minute or more before disconnecting the cable from the negative (-) battery terminal.

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


    NEXT

  2. CHECK FOR SHORT IN CAN BUS WIRES (SEAT BELT CONTROL ECU BRANCH WIRE)


    1. A006USHE01
      Text in Illustration
      *1 for LHD
      *2 for RHD
      *13

      Rear view of wire harness connector

      (to Seat Belt Control ECU)

      Disconnect the A53*1 or D110*2 seat belt control ECU connector


      • *1: for LHD

      • *2: for RHD

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

      Standard Resistance
      for LHD
      Tester Connection Switch Condition Specified Condition
      A53-1 (CANH) - A53-2 (CANL) Ignition switch off 54 to 69 Ω
      for RHD
      Tester Connection Switch Condition Specified Condition
      D110-1 (CANH) - D110-2 (CA1NL) Ignition switch off 54 to 69 Ω

    NG

    REPAIR OR REPLACE SEAT BELT CONTROL ECU BRANCH WIRE OR CONNECTOR (CANH, CANL)

    OK

  3. CHECK HARNESS AND CONNECTOR (SEAT BELT CONTROL ECU - BATTERY AND BODY GROUND)


    1. 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. A006T7OE01
      Text in Illustration
      *1 for LHD
      *2 for RHD
      *13

      Rear view of wire harness connector

      (to Seat Belt Control ECU)

      Disconnect the A52 and A53*1 or D109 and D110*2 seat belt control ECU connectors.


      • *1: for LHD

      • *2: for RHD

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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      A52-8 (PGND) - Body ground Always Below 1 Ω
      for RHD
      Tester Connection Condition Specified Condition
      D109-8 (PGND) - Body ground Always Below 1 Ω

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

      Standard Voltage
      for LHD
      Tester Connection Switch Condition Specified Condition
      A52-7 (+B) - Body ground Always 11 to 14 V
      A53-8 (IG1) - Body ground Ignition switch ON 11 to 14 V
      for RHD
      Tester Connection Switch Condition Specified Condition
      D109-7 (+B) - Body ground Always 11 to 14 V
      D110-8 (IG1) - Body ground Ignition switch ON 11 to 14 V
      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

    B

    REPLACE SEAT BELT CONTROL ECU Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    A

    REPLACE SEAT BELT CONTROL ECU Click here