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 GTS 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 with motor assembly branch line or connector

  • Power source circuit of power steering ECU with motor assembly

  • Power steering ECU with motor assembly ground circuit

  • Power steering ECU with motor assembly

WIRING DIAGRAM

A01G836E06
A01G5X0E02

INSPECTION PROCEDURE

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, 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 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: Drive the vehicle at a speed of 20 km/h (12 mph) or more for 5 minutes or more.

  • 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 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 WITH MOTOR ASSEMBLY BRANCH LINE)


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

    2. A01G45OE04
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Power Steering ECU with Motor Assembly)

      Disconnect the c1 power steering ECU with motor assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      c1-7 (CANH) - c1-8 (CANL) Cable disconnected from negative (-) battery terminal 54 to 69 Ω
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Power Steering ECU with Motor Assembly)

    NG

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

    OK

  2. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)


    1. A01G7ABE13
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Power Steering ECU with Motor Assembly)

      Disconnect the c2 power steering ECU with motor assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      c2-2 (PGND) - Body ground Cable disconnected from negative (-) battery terminal Below 1 Ω

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

    4. A01G45OE05
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Power Steering ECU with Motor Assembly)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      c1-1 (IG) - Body ground Engine switch on (IG) 11 to 14 V
      Result
      Result Proceed to
      OK (for Power Tilt and Power Telescopic Steering Column) A
      OK (for Manual Tilt and Manual Telescopic Steering Column) B
      NG C

    B

    REPLACE POWER STEERING ECU WITH MOTOR ASSEMBLY Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

    A

    REPLACE POWER STEERING ECU WITH MOTOR ASSEMBLY Click here