CAN COMMUNICATION SYSTEM(for LHD), 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 from the seat belt control ECU.

  • Power source circuit of seat belt control ECU

  • Seat belt control ECU CAN branch wire or connector

  • Seat belt control ECU

WIRING DIAGRAM

A01X7Y3E14

CAUTION / NOTICE / HINT

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. 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:

      For vehicles with an SRS system:

      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 (SEAT BELT CONTROL ECU CAN BRANCH WIRE)


    1. A01X7RPE01
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Seat Belt Control ECU)

      Disconnect the E42 seat belt control ECU connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      E42-1 (CANH) - E42-2 (CANL) Ignition switch off 54 to 69 Ω

    NG

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

    OK

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


    1. A01XB9XE01
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Seat Belt Control ECU)

      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. Disconnect the E41 seat belt control ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E41-8 (PGND) - Body ground Always Below 1 Ω

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      E41-7 (+B) - Body ground Always 11 to 14 V
      E42-8 (IG1) - Body ground Ignition switch ON 11 to 14 V

    OK

    REPLACE SEAT BELT CONTROL ECU Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR