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*1*3

  • Power source circuit of power steering ECU assembly*1*3

  • Power steering ECU assembly ground circuit*1*3

  • Power steering ECU assembly*1*3

  • Power steering ECU with motor assembly branch line or connector*2

  • Power source circuit of power steering ECU with motor assembly*2

  • Power steering ECU with motor assembly ground circuit*2

  • Power steering ECU with motor assembly*2

*1: for 2GR-FE

*2: for 2AR w/ wireless door lock system

*3: for 2AR w/o wireless door lock system

WIRING DIAGRAM

A01HO0UE09
A01HO0UE07
A01HO0UE08

INSPECTION PROCEDURE

Note


  • Before measuring the resistance of the CAN bus, turn the ignition 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 ignition 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: Turn the ignition switch to ON, wait at least 10 seconds and then drive the vehicle at a speed of 20 km/h (12 mph) or more for 5 minutes or more. Check that the warning light remains off after turning off following the initial light check.

  • 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 ignition 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 VEHICLE TYPE


    1. Check for vehicle type.

      Result
      Result Proceed to

      • for 2GR-FE

      • for 2AR w/o wireless door lock system

      		 A
      for 2AR w/ wireless door lock system B

    B

    CHECK FOR OPEN IN CAN BUS LINES (POWER STEERING ECU WITH MOTOR ASSEMBLY BRANCH LINE) Click here

    A

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


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

    2. A01HMDRE06
      Text in Illustration
      *1 for 2AR w/o Wireless Door Lock System
      *2 for 2GR-FE
      *a

      Front view of wire harness connector

      (to Power Steering ECU Assembly)

      Disconnect the power steering ECU assembly connector.

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

      Standard Resistance (for 2AR w/o Wireless Door Lock System)
      Tester Connection Condition Specified Condition
      j1-7 (CANH) - j1-8 (CANL) Cable disconnected from negative (-) battery terminal 54 to 69 Ω
      Standard Resistance (for 2GR-FE)
      Tester Connection Condition Specified Condition
      j3-4 (CANH) - j3-8 (CANL) Cable disconnected from negative (-) battery terminal 54 to 69 Ω

    NG

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

    OK

  3. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)


    1. A01HMCTE07
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Power Steering ECU Assembly)

      Disconnect the power steering ECU assembly connector.

    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 (-) battery terminal Below 1 Ω

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

    4. A01HMDRE07
      Text in Illustration
      *1 for 2AR w/o Wireless Door Lock System
      *2 for 2GR-FE
      *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 (for 2AR w/o Wireless Door Lock System)
      Tester Connection Switch Condition Specified Condition
      j1-1 (IG) - Body ground Ignition switch ON 11 to 14 V
      Standard Voltage (for 2GR-FE)
      Tester Connection Switch Condition Specified Condition
      j3-1 (IG) - Body ground Ignition switch ON 11 to 14 V
      Result
      Result Proceed to
      OK (for 2GR-FE) A
      OK (for 2AR w/o wireless door lock system) B
      NG C

    B

    REPLACE POWER STEERING ECU ASSEMBLY Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

    A

    REPLACE POWER STEERING ECU ASSEMBLY Click here

  4. 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. A01HQUSE03
      Text in Illustration
      *1 for 2AR w/ Wireless Door Lock System
      *a

      Front view of wire harness connector

      (to Power Steering ECU with motor Assembly)

      Disconnect the power steering ECU with motor assembly connector.

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

      Standard Resistance (for 2AR w/ Wireless Door Lock System)
      Tester Connection Condition Specified Condition
      j1-7 (CANH) - j1-8 (CANL) Cable disconnected from negative (-) battery terminal 54 to 69 Ω

    NG

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

    OK

  5. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)


    1. A01HMCTE08
      Text in Illustration
      *1 for 2AR w/ Wireless Door Lock System
      *a

      Front view of wire harness connector

      (to Power Steering ECU with Motor Assembly)

      Disconnect the power steering ECU with motor assembly connector.

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

      Standard Resistance (for 2AR w/ Wireless Door Lock System)
      Tester Connection Condition Specified Condition
      j2-2 (PGND) - Body ground Cable disconnected from negative (-) battery terminal Below 1 Ω

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

    4. A01HQUSE04
      Text in Illustration
      *1 for 2AR w/ Wireless Door Lock System
      *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 (for 2AR w/ Wireless Door Lock System)
      Tester Connection Switch Condition Specified Condition
      j1-1 (IG) - Body ground Ignition switch ON 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

    OK

    REPLACE POWER STEERING ECU WITH MOTOR ASSEMBLY Click here