POWER STEERING SYSTEM PS Warning Light Remains ON

DESCRIPTION

If the power steering ECU detects a malfunction, the P/S warning light comes on. At this time, the power steering ECU stores a DTC in its memory.

WIRING DIAGRAM

A01NHQZE01

INSPECTION PROCEDURE

Note

If the power steering ECU has been replaced with a new one, perform the rotation angle sensor initialization and torque sensor zero point calibration Click here.

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR


    1. Turn the power switch on (IG).

    2. Check the indication condition of the P/S warning light by wiggling the power steering ECU connector and wire harness up and down, and right and left.

      OK
      P/S warning light indication condition does not change.

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. CHECK FOR DTC (CAN COMMUNICATION SYSTEM)


    1. Check for DTCs Click here.

      Result
      Result Proceed to
      DTC is not output. A
      DTC is output. B

    B

    GO TO CAN COMMUNICATION SYSTEM Click here

    A

  3. READ VALUE USING INTELLIGENT TESTER (IG POWER SUPPLY)


    1. Turn the power switch off.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the power switch on (IG).

    4. Turn the intelligent tester 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 intelligent tester.

      EMPS
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      IG Power Supply

      ECU power source voltage/

      Min.: 0 V

      Max.: 20.1531 V

      		 11 to 14 V Power switch on (IG)
      OK
      The normal condition value is displayed on the intelligent tester.

    NG

    CHECK HARNESS AND CONNECTOR (POWER STEERING ECU - BODY GROUND) Click here

    OK

    REPLACE POWER STEERING ECU Click here

  4. CHECK HARNESS AND CONNECTOR (POWER STEERING ECU - BODY GROUND)


    1. A01NF09E22
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Power Steering ECU)

      Disconnect the connectors from the power steering ECU.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      F9-6 (IG) - Body ground Power switch on (IG) 11 to 14 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F10-2 (PGND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (COMBINATION METER)


    1. Turn the power switch off.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the power switch on (IG).

    4. Turn the intelligent tester on.

    5. Enter the following menus: Body Electrical / Combination Meter / Active Test.

    6. Perform the Active Test of the combination meter using the intelligent tester.

      Combination Meter
      Tester Display Test Part Control Range Diagnostic Note
      Indicat. EPS EPS warning light OFF or ON Confirm that the vehicle is stopped with the power switch on (READY)

    7. Check that the P/S warning light operates in accordance with the Active Test.

      OK
      The P/S warning light turns on or off in accordance with the intelligent tester operation.

    NG

    REPLACE COMBINATION METER ASSEMBLY Click here

    OK

    REPLACE POWER STEERING ECU Click here