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 the "CAN Bus Check" screen of the Techstream Click here

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

  • 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

A011X0AE01

INSPECTION PROCEDURE

Note

  • Before measuring the resistance of the CAN bus, turn the power 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 (-) auxiliary battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.

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

  • 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.

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

  • DTC check procedure: Turn the power switch on (IG), turn the blind spot monitor main switch on and wait at least 60 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 Click here.

Tech Tips

  • Operating the power 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 (-) auxiliary battery terminal.

    2. Disconnect the power steering ECU assembly connector.

      A011X0RE03

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      j3-4 (CANH) - j3-8 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Power Steering ECU Assembly)
    NG

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

    OK

  2. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)

    1. Disconnect the power steering ECU assembly connector.

      A011XC4E05

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      j2-2 (PGND) - Body ground Cable disconnected from negative (-) auxiliary battery terminal Below 1 Ω
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Power Steering ECU Assembly)

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

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

      A011X0RE04
      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      j3-1 (IG) - Body ground Power switch on (IG) 11 to 14 V
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Power Steering ECU Assembly)
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

    OK

    REPLACE POWER STEERING ECU ASSEMBLY Click here