CAN COMMUNICATION SYSTEM Power Steering ECU Communication Stop Mode

DESCRIPTION

Detection Item Symptom Trouble Area
Power Steering ECU Communication Stop Mode

Either condition is met:


  • "Power Steering (EPS)" is not displayed on "Bus Check".

  • "Power Steering ECU Communication Stop Mode" in "DTC Combination Table" applies.

  • Power source or inside power steering ECU assembly

  • Power steering ECU assembly CAN branch wire or connector

  • Power steering ECU assembly

WIRING DIAGRAM

A01IO53E03

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. 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 CAN branch wire.

      CAUTION:

      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 (POWER STEERING ECU ASSEMBLY CAN BRANCH WIRE)


    1. A01IRTBE03
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Power Steering ECU Assembly)

      Disconnect the H49 power steering ECU assembly connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      H49-2 (CANH) - H49-8 (CANL) Ignition switch off 54 to 69 Ω

    NG

    REPAIR OR REPLACE POWER STEERING ECU CAN BRANCH WIRE OR CONNECTOR (CANH, CANL)

    OK

  4. CHECK GROUND BOLT AND WIRE HARNESS


    1. Check that the ground bolt and wire harness are installed correctly Click here.

      OK
      Ground bolt and wire harness are installed correctly

    NG

    INSTALL GROUND AND WIRE HANRESS CORRECTLY Click here

    OK

  5. CHECK TERMINAL SCREW AND ECU WIRE SUB-ASSEMBLY


    1. Remove the power terminal cover from the power steering ECU assembly Click here.

    2. Check that the z21 terminal screw and ECU wire sub-assembly are installed correctly Click here.

      OK
      Terminal screw and ECU wire sub-assembly are installed correctly.

    NG

    INSTALL TERMINAL SCREW AND ECU WIRE SUB-ASSEMBLY Click here

    OK

  6. CHECK HARNESS AND CONNECTOR (POWER STEERING ECU ASSEMBLY - BATTERY AND BODY GROUND)


    1. A01ITY4E01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Power Steering ECU Assembly)
      *2 ECU Wire Sub-assembly

      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 Az1 power steering ECU assembly connector.

    3. Remove the z1 terminal screw from the power steering ECU assembly Click here.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      z1-1 (PGND) - Body ground Always Below 1 Ω

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      Az1-1 (PIG) - Body ground Always 11 to 14 V
      H49-5 (IG) - Body ground Ignition switch ON 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE POWER STEERING ECU ASSEMBLY Click here