CAN COMMUNICATION SYSTEM (for RHD), 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 or inside of seat belt control ECU

  • Seat belt control ECU CAN branch wire or connector

  • Seat belt control ECU

WIRING DIAGRAM

A01H1TPE07

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 (SEAT BELT CONTROL ECU CAN BRANCH WIRE)


    1. A01GZNEE03
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Seat Belt Control ECU)

      Disconnect the 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
      S47-1 (CANH) - S47-2 (CANL) Power 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. A01GWONE04
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Seat Belt Control ECU)

      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. Disconnect the seat belt control ECU connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      S45-7 (+B) - Body ground Always 11 to 14 V
      S47-8 (IG1) - Body ground Power switch on (IG) 11 to 14 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      S45-8 (PGND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE SEAT BELT CONTROL ECU Click here