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

  • ECU wire sub-assembly

  • Power steering ECU assembly

  • Engine stop and start ECU*

WIRING DIAGRAM

A01ITMGE02

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. A01IRTBE04
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Power Steering ECU Assembly)

      Disconnect the 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 HARNESS AND CONNECTOR (ECU WIRE SUB-ASSEMBLY - BATTERY)


    1. A01ITNXE03
      Text in Illustration
      *a

      Front view of wire harness connector

      (to 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 ECU wire sub-assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      Az1-1 (PIG) - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. 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 HARNESS CORRECTLY Click here

    OK

  6. 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

  7. CHECK ECU WIRE SUB-ASSEMBLY


    1. A01IPW8E03

      Remove the z21 and z22 terminal screws from the power steering ECU assembly Click here.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      z21-1 (PGND) - Body ground Always Below 1 Ω
      z22-1 (PIG) - Az1-1 Always Below 1 Ω
      z22-1 (PIG) or Az1-1 - Body ground Always 10 kΩ or higher

    NG

    REPLACE ECU WIRE SUB-ASSEMBLY Click here

    OK

  8. CHECK HARNESS AND CONNECTOR (POWER STEERING ECU ASSEMBLY - BATTERY)


    1. A01IRTBE05
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Power Steering ECU Assembly)

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      H49-5 (IG) - Body ground Ignition switch ON 11 to 14 V
      Result
      Result Proceed to
      OK A
      NG (w/o Stop and Start System) B
      NG (w/ Stop and Start System) C

    B

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    C

    CHECK HARNESS AND CONNECTOR (POWER STEERING ECU ASSEMBLY - ENGINE STOP AND START ECU) Click here

    A

    REPLACE POWER STEERING ECU ASSEMBLY Click here

  9. CHECK HARNESS AND CONNECTOR (POWER STEERING ECU ASSEMBLY - ENGINE STOP AND START ECU)


    1. Disconnect the H121 engine stop and start ECU connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      H49-5 (IG) - H121-12 (IGO1) Always Below 1 Ω
      H49-5 (IG) or H121-12 (IGO1) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE ENGINE STOP AND START ECU Click here