CAN COMMUNICATION SYSTEM(for RHD) Power Steering ECU Communication Stop Mode

DESCRIPTION

Detection Item Symptom Trouble Area
Power Steering ECU Communication Stop Mode

Either condition is met:


  • Communication stop for "Power Steering (EPS)" is indicated on the "Communication Bus Check" screen of the GTS.

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  • Communication system DTCs (DTCs that start with U) that correspond to "Power Steering ECU Communication Stop Mode" in "DTC Combination Table" are output.

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  • Power steering ECU assembly branch line or connector

  • Power source circuit of power steering ECU assembly

  • Power steering ECU assembly ground circuit

  • Power steering ECU assembly

WIRING DIAGRAM

B006PK0E03
*a No. 4 CAN Junction Connector
*b from Engine Stop and Start ECU
*c Power Steering ECU Assembly

CAUTION / NOTICE / HINT

CAUTION:

When performing the confirmation driving pattern, obey all speed limits and traffic laws.

Note


  • Before measuring the resistance of the CAN bus, turn the engine switch off and leave the vehicle for 1 minute or more without operating the key or any switches, or opening or closing the doors. After that, disconnect the cable from the negative (-) battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.

  • After turning the engine switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work.

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  • Because the order of diagnosis is important to allow correct diagnosis, make sure to begin troubleshooting using How to Proceed with Troubleshooting when CAN communication system related DTCs are output.

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  • After performing repairs, perform the DTC check procedure and confirm that the DTCs are not output again.

    DTC check procedure: Turn the engine switch on (IG) and wait for 1 minute or more. Then operate the suspected malfunctioning system and drive the vehicle at 60 km/h (37 mph) or more for 5 minutes or more.

  • After the repair, perform the CAN bus check and check that all the ECUs and sensors connected to the CAN communication system are displayed.

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Tech Tips


  • Operating the engine switch, any other switches or a door triggers related ECU and sensor communication on the CAN. This communication will cause the resistance value to change.

  • Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the ECUs or wire harness while performing the inspection below may help determine the cause of the malfunction.

PROCEDURE


  1. CHECK FOR OPEN IN CAN BUS LINES (POWER STEERING ECU ASSEMBLY BRANCH LINE)


    1. Disconnect the cable from the negative (-) battery terminal.

    2. Disconnect the G20 power steering ECU assembly connector.

    3. B006P8PC34
      *a

      Front view of wire harness connector

      (to Power Steering ECU Assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G20-7 (CANH) - G20-8 (CANL) Cable disconnected from negative (-) battery terminal 54 to 69 Ω
      Result
      Result
      OK
      NG

    NG

    REPAIR OR REPLACE CAN BRANCH LINES OR CONNECTOR (POWER STEERING ECU ASSEMBLY)

    OK

  2. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)


    1. Disconnect the G53 power steering ECU assembly connector.

    2. B006Q4SC04
      *a

      Front view of wire harness connector

      (to Power Steering ECU Assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G53-2 (PGND) - Body ground Cable disconnected from negative (-) battery terminal Below 1 Ω

    3. Reconnect the cable to the negative (-) battery terminal.

    4. B006P8PC35
      *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 Condition Specified Condition
      G20-1 (IG)- Body ground Engine switch on (IG) 11 to 14 V
      Result
      Result Proceed to
      OK A
      NG (for PGND signal circuit) B
      NG (for IG signal circuit) C

    A

    REPLACE POWER STEERING ECU ASSEMBLY Click here

    B

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

    C

    GO TO STOP AND START SYSTEM (FOR BACKUP BOOST CONVERTER CIRCUIT) for 2AR-FE: Click here
    GO TO STOP AND START SYSTEM (FOR BACKUP BOOST CONVERTER CIRCUIT) for 2GR-FKS: Click here