CAN COMMUNICATION SYSTEM (for LHD) 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 "Bus Check" screen Click here.

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


  • 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

A01FDUPE01

INSPECTION PROCEDURE

Note


  • 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 Click here.

  • 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, 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 notice before proceeding with work Click here.

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

  • 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 60 seconds.

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

Tech Tips


  • Operating the engine switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.

  • 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 WIRE (FRONT STEERING CONTROL ECU CAN BRANCH WIRE)


    1. A01FFDME01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Front Steering Control ECU)

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

    2. Disconnect the 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
      N104-3 (CNH1) - N104-9 (CNL1) Cable disconnected from negative (-) battery terminal 54 to 69 Ω

    NG
    OK
  2. CHECK HARNESS AND CONNECTOR (FRONT STEERING CONTROL ECU - BATTERY AND BODY GROUND)


    1. A01FHFAE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Front Steering Control ECU)

      Connect the cable to the negative (-) battery terminal.

      Note

      When connecting the cable, some systems need to be initialized after the cable is reconnected Click here.

    2. Disconnect the front steering control ECU connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A31-2 (PIG) - Body ground Always 11 to 14 V
      N104-7 (+BI) - Body ground Always 11 to 14 V
      N104-4 (IG) - Body ground Engine switch on (IG) 11 to 14 V
    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      A31-1 (PGND) - Body ground Always Below 1 Ω
      N104-13 (PGD2) - Body ground Always Below 1 Ω

    NG
    OK