CAN COMMUNICATION SYSTEM Power Steering ECU Communication Stop Mode

DESCRIPTION

Detection Item Symptom Trouble Area
Power Steering ECU Communication Stop Mode

  • "EPS" is not displayed on the "Communication Bus Check" screen of the intelligent tester.

  • Applies to Power Steering ECU Communication Stop Mode in DTC Combination Table.

  • Power steering ECU assembly branch line or connector

  • Power source circuit of power steering ECU assembly

  • Power steering ECU assembly

WIRING DIAGRAM

A003WKJE01

INSPECTION PROCEDURE

Note


  • Turn the power switch off before measuring the resistances between CAN main bus lines and between CAN branch lines.

  • Turn the power switch off before inspecting CAN bus lines for a ground short.

  • After the power switch is turned off, check that the key reminder warning system and light reminder warning system are not operating.

  • Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the power switch, any other switches or the doors. If any doors need to be opened in order to check connectors, open the doors and leave them open.

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 CAN BUS LINE FOR DISCONNECTION (POWER STEERING ECU ASSEMBLY BRANCH LINE)


    1. Turn the power switch off.

    2. A003V5LE34
      Text in Illustration
      *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
      Tester Connection Switch Condition Specified Condition
      H25-1 (CANH) - H25-7 (CANL) Power switch off 54 to 69 Ω

    NG

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

    OK

  2. CHECK HARNESS AND CONNECTOR (POWER SOURCE TERMINAL)


    1. Disconnect the power steering ECU assembly connector.

    2. A003VN7E02
      Text in Illustration
      *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
      Tester Connection Switch Condition Specified Condition
      A26-1 (PIG) - Body ground Power switch off 11 to 14 V
      H25-6 (IG) - Body ground Power switch on (IG) 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

    OK

  3. CHECK HARNESS AND CONNECTOR (GROUND TERMINAL)


    1. A003VD2E17
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Power Steering ECU Assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A26-2 (PGND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (GROUND CIRCUIT)

    OK

    REPLACE POWER STEERING ECU ASSEMBLY Click here