CAN COMMUNICATION SYSTEM (for LHD), Diagnostic DTC:U1113

DTC Code DTC Name
U1113 Lost Communication with Steering Pad ECU

DESCRIPTION

DTC Code DTC Detection Condition Trouble Area
U1113 There is no communication from the steering pad switch assembly (steering pad ECU).

  • Power source or inside of steering pad switch assembly (steering pad ECU)

  • Steering pad switch assembly (steering pad ECU) CAN branch wire or connector

  • Spiral cable sub-assembly

  • Steering pad switch assembly (steering pad ECU)

WIRING DIAGRAM

A01GYRGE01

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 (STEERING PAD ECU CAN BRANCH WIRE)


    1. A01GXUBE03
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Spiral Cable Sub-assembly)

      Disconnect the spiral cable sub-assembly connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      L126-10 (CANP) - L126-9 (CANN) Power switch off 54 to 69 Ω

    NG

    REPAIR OR REPLACE STEERING PAD ECU CAN BRANCH WIRE OR CONNECTOR (CANP, CANN)

    OK

  4. INSPECT SPIRAL CABLE SUB-ASSEMBLY


    1. A01GZPSE02

      Remove the spiral cable sub-assembly Click here.

    2. Set the spiral cable sub-assembly to the center position Click here.

    3. Measure the resistance between each terminal of the spiral cable sub-assembly according to the table below.

    4. After steering the spiral cable sub-assembly to the center position, rotate the spiral cable sub-assembly 2.5 times clockwise, and measure the resistance as shown. Then rotate the spiral cable sub-assembly 5 times counterclockwise, and measure the resistance as shown.

      Standard Resistance
      Tester Connection Condition Specified Condition
      A-10 (CANP) - B-2 (CANP) Always Below 3 Ω
      A-9 (CANN) - B-1 (CANN) Always Below 3 Ω
      A-7 (+B) - B-12 (+B) Always Below 3 Ω
      A-3 (NOSB) - B-8 (NOSB) Always Below 3 Ω

    5. After steering the spiral cable sub-assembly to the center position, rotate the spiral cable sub-assembly 2.5 times clockwise, and measure the resistance as shown. Then while rotating the spiral cable sub-assembly 5 times counterclockwise, and measure the resistance as shown.

      Standard Resistance
      Tester Connection Condition Specified Condition
      A-10 (CANP) - B-2 (CANP) Always Below 3 Ω
      A-9 (CANN) - B-1 (CANN) Always Below 3 Ω
      A-7 (+B) - B-12 (+B) Always Below 3 Ω
      A-3 (NOSB) - B-8 (NOSB) Always Below 3 Ω

    NG

    REPLACE SPIRAL CABLE SUB-ASSEMBLY Click here

    OK

  5. CHECK HARNESS AND CONNECTOR (SPIRAL CABLE SUB-ASSEMBLY - BATTERY AND BODY GROUND)


    1. A01GXUBE04
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Spiral Cable Sub-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 Condition Specified Condition
      L126-7 (+B) - Body ground Always 11 to 14 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L126-3 (NOSB) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE STEERING PAD SWITCH ASSEMBLY (STEERING PAD ECU) Click here