POWER STEERING SYSTEM, Diagnostic DTC:C1524, C1555

DTC Code DTC Name
C1524 Motor Circuit Malfunction
C1555 Motor Relay Welding Failure

DESCRIPTION

The power steering ECU supplies the current to the power steering motor through the motor circuit.

DTC Code DTC Detection Condition Trouble Area
C1524 A short or open in the motor circuit or abnormal voltage or current in the motor circuit.

  • Steering column assembly

  • Power steering ECU assembly
C1555 A motor relay malfunction.

WIRING DIAGRAM

A01IU02E01

INSPECTION PROCEDURE

Note

If the power steering ECU assembly is replaced, perform the assist map writing Click here.

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER (MOTOR VOLTAGE)


    1. Turn the ignition switch off.

    2. Connect the intelligent tester to the DLC3.

    3. Start the engine.

    4. Turn the intelligent tester on.

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

    6. Select the items "Motor Terminal Volt (U)", "Motor Terminal Volt (V)" and "Motor Terminal Volt (W)" in the Data List and read the value displayed on the intelligent tester.

      EMPS
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Motor Terminal Volt (U)

      Motor terminal voltage (U phase)/

      Min.: 0.000 V

      Max.: 98.000 V

      		 Voltage between 1 V and approximately 1 V below battery voltage displayed The engine is running and the steering wheel is being turned.
      Motor Terminal Volt (V)

      Motor terminal voltage (V phase)/

      Min.: 0.000 V

      Max.: 98.000 V

      		 Voltage between 1 V and approximately 1 V below battery voltage displayed The engine is running and the steering wheel is being turned.
      Motor Terminal Volt (W)

      Motor terminal voltage (W phase)/

      Min.: 0.000 V

      Max.: 98.000 V

      		 Voltage between 1 V and approximately 1 V below battery voltage displayed The engine is running and the steering wheel is being turned.
      Result
      Result Proceed to
      When the steering wheel is turned, a voltage between 1 V and approximately 1 V below the battery voltage is displayed. A
      When the steering wheel is turned, a value other than the above is displayed. B

    B

    REPLACE POWER STEERING ECU ASSEMBLY Click here

    A

  2. CHECK CONNECTOR CONNECTION CONDITION (POWER STEERING MOTOR - POWER STEERING ECU)


    1. Turn the ignition switch off.

    2. Remove bus bar cover from the steering column assembly Click here.

    3. Check that the metal contacts of the power steering ECU connector are securely connected to the metal contacts of the power steering motor, and that the screws are properly installed Click here.

      OK
      The metal contacts of the power steering ECU connector are securely connected to the metal contacts of the power steering motor, and the screws are properly installed.

    NG

    SECURELY CONNECT POWER STEERING ECU TO POWER STEERING MOTOR Click here

    OK

  3. CHECK STEERING COLUMN ASSEMBLY


    1. Remove the steering column assembly from the power steering ECU Click here.

    2. A01ISVKE01
      Text in Illustration
      *1

      Component without power steering ECU

      (Power Steering Motor)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1 - 2 Always Below 1 Ω
      1 - 3 Always Below 1 Ω
      2 - 3 Always Below 1 Ω
      1 - Body ground Always 10 kΩ or higher
      2 - Body ground Always 10 kΩ or higher
      3 - Body ground Always 10 kΩ or higher

    NG

    REPLACE STEERING COLUMN ASSEMBLY Click here

    OK

    REPLACE POWER STEERING ECU ASSEMBLY Click here