POWER STEERING SYSTEM Power Steering Warning Light Circuit

DESCRIPTION

The power steering ECU is connected to the combination meter via CAN communication. If any of the following conditions are detected, the power steering warning light remains on.


WIRING DIAGRAM

A01MJ76E02
*a Combination Meter Assembly
*b from IG Circuit
*c Power Steering ECU Assembly
*d CAN Communication Line

CAUTION / NOTICE / HINT

Note

If the power steering ECU assembly has been replaced, perform assist map writing and torque sensor zero point calibration.

Click here

Tech Tips

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

PROCEDURE


  1. CHECK CONNECTOR CONNECTION CONDITION AND GROUND WIRE


    1. Check the connection condition of the power steering ECU assembly connectors.

      OK
      The power steering ECU assembly connectors are securely connected.

    2. Check that the ground wire is securely installed with the bolt.

      Click here

      OK
      The ground wire is securely installed with the bolt.
      Result
      Proceed to
      OK
      NG

    NG

    CONNECT CONNECTOR OR INSTALL GROUND WIRE

    OK

  2. CHECK FOR DTC (CAN COMMUNICATION SYSTEM)


    1. Check for DTCs.


      OK
      DTC is not output.
      Result
      Result Proceed to
      DTC is not output A
      DTC is output (for RHD) B
      DTC is output (for LHD) C

    B

    GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) Click here

    C

    GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) Click here

    A

  3. READ VALUE USING GTS (IG POWER SUPPLY)


    1. Turn the power switch off.

    2. Connect the GTS to the DLC3.

    3. Turn the power switch on (IG).

    4. Turn the GTS on.

    5. Enter the following menus: Chassis / EMPS / Data List.

    6. Select the item "IG power supply" in the Data List and read the value displayed on the GTS.


      Chassis > EMPS > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      IG Power Supply ECU power source voltage

      Min.: 0.0000 V

      Max.: 20.1531 V

      		 Power switch on (IG): 9 to 16 V -

      Chassis > EMPS > Data List
      Tester Display
      IG Power Supply
      OK
      The normal condition value is displayed on the GTS.
      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR Click here

    OK

  4. READ VALUE USING GTS (PIG POWER SUPPLY)


    1. Turn the power switch off.

    2. Connect the GTS to the DLC3.

    3. Turn the power switch on (IG).

    4. Turn the GTS on.

    5. Enter the following menus: Chassis / EMPS / Data List.

    6. Select the item "PIG Power Supply" in the Data List and read the value displayed on the GTS.


      Chassis > EMPS > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      PIG Power Supply Power source voltage to active motor

      Min.: 0.0000 V

      Max.: 20.1531 V

      		 Always: 9 to 16 V -

      Chassis > EMPS > Data List
      Tester Display
      PIG Power Supply
      OK
      The normal condition value is displayed on the GTS.
      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR Click here

    OK

  5. CHECK COMBINATION METER ASSEMBLY


    1. Perform the Active Test of the combination meter assembly using the GTS.

      Click here


      Body Electrical > Combination Meter > Active Test
      Tester Display
      Indicat. EPS

    2. Check the combination meter assembly.

      OK
      The power steering warning light (red) turns on or off in accordance with the GTS operation.
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE POWER STEERING ECU ASSEMBLY Click here

    NG

    GO TO METER / GAUGE SYSTEM Click here

  6. CHECK HARNESS AND CONNECTOR


    1. A01MIO7C13
      *a

      Front view of wire harness connector

      (to Power Steering ECU Assembly)

      Disconnect the power steering ECU assembly connectors.

    2. Turn the power switch on (IG).

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      G47-6 (IG) - Body ground Power switch on (IG) 9 to 16 V

    4. Turn the power switch off.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A24-2 (PGND) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE POWER STEERING ECU ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR Click here

  7. CHECK HARNESS AND CONNECTOR


    1. A01MJXJC08
      *a

      Front view of wire harness connector

      (to Power Steering ECU Assembly)

      Disconnect the power steering ECU assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A24-1 (PIG) - Body ground Always 9 to 16 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A24-2 (PGND) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE POWER STEERING ECU ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR Click here