CAN COMMUNICATION SYSTEM Steering Control ECU Communication Stop Mode

DESCRIPTION

Detection Item Symptom Trouble Area
Steering Control ECU Communication Stop Mode

Either condition is met:


  • "Steering Control (VGRS)" is not displayed on the CAN Bus Check screen of the GTS

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

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  • Front steering control ECU branch line or connector

  • Power source circuit of front steering control ECU

  • Front steering control ECU ground circuit

  • Front steering control ECU

WIRING DIAGRAM

A01VRAUE10
A01VRAUE11

CAUTION / NOTICE / HINT

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 at least 14 seconds.

  • 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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  • Inspect the fuses for circuits related to this system before performing the following procedure.

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 (FRONT STEERING CONTROL ECU BRANCH LINE)


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

    2. B0076Q3C29
      *a

      Front view of wire harness connector

      (to Front Steering Control ECU)

      Disconnect the O16 front steering control ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      O16-3 (CNH1) - O16-9 (CNL1) Cable disconnected from negative (-) battery terminal 54 to 69 Ω
      Result
      Result
      OK
      NG

    NG

    REPAIR OR REPLACE CAN BRANCH LINES OR CONNECTOR (FRONT STEERING CONTROL ECU)

    OK

  2. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)


    1. A01VRMPC21
      *a

      Front view of wire harness connector

      (to Front Steering Control ECU)

      Disconnect the A56 front steering control ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A56-1 (PGND) - Body ground Cable disconnected from negative (-) battery terminal Below 1 Ω
      O16-13 (PGD2) - Body ground Cable disconnected from negative (-) battery terminal Below 1 Ω

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

    4. A01VRMPC22
      *a

      Front view of wire harness connector

      (to Front Steering Control ECU)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A56-2 (PIG) - Body ground Always 11 to 14 V
      O16-4 (IG) - Body ground Engine switch on (IG) 11 to 14 V
      O16-7 (+BI) - Body ground Always 11 to 14 V
      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

    A

    REPLACE FRONT STEERING CONTROL ECU Click here

    B

    REPLACE FRONT STEERING CONTROL ECU Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)