POWER STEERING SYSTEM, Diagnostic DTC:C1552, C1554

DTC Code DTC Name
C1552 PIG Power Supply Voltage Malfunction
C1554 Power Supply Relay Failure

DESCRIPTION

When a problem occurs in the power steering system, the power supply relay circuit is shut off to stop the power assist.

DTC Code DTC Detection Condition Trouble Area
C1552 A PIG power supply circuit malfunction inside the ECU.

  • EPS fuse

  • PIG power supply circuit

  • Power steering ECU assembly

  • ECU wire sub-assembly
C1554 A power supply relay circuit malfunction.

WIRING DIAGRAM

A01IQ0LE01

INSPECTION PROCEDURE

Note


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

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

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER (PIG POWER SUPPLY)


    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.

      EMPS
      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

      		 11 to 14 V The engine is running and power steering is operating.
      OK
      The normal condition value is displayed the intelligent tester.

    NG

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

    OK

    REPLACE POWER STEERING ECU ASSEMBLY Click here

  2. CHECK HARNESS AND CONNECTOR (POWER STEERING ECU - BATTERY)


    1. Turn the ignition switch off.

    2. A01ITNXE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to ECU Wire Sub-assembly)

      Disconnect the Az1 power steering ECU connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      Az1-1 - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK GROUND BOLT AND WIRE HARNESS


    1. Turn the ignition switch off.

    2. Check that the ground bolt and wire harness are installed correctly Click here.

      OK
      Ground bolt and wire harness are installed correctly.

    NG

    INSTALL GROUND BOLT AND WIRE HARNESS CORRECTLY Click here

    OK

  4. CHECK TERMINAL SCREW AND ECU WIRE SUB-ASSEMBLY


    1. Remove the power terminal cover from the power steering ECU Click here.

    2. Check that the z21 and z21 terminal screws and ECU wire sub-assembly are installed correctly Click here.

      OK
      Terminal screws and ECU wire sub-assembly are installed correctly.

    NG

    INSTALL TERMINAL SCREW AND ECU WIRE SUB-ASSEMBLY CORRECTLY Click here

    OK

  5. CHECK ECU WIRE SUB-ASSEMBLY


    1. A01IPW8E01
      Text in Illustration
      *1 ECU Wire Sub-assembly

      Remove the z21 and z22 terminal screws from the power steering ECU Click here.

    2. Disconnect the Az1 connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      z21-1 (PGND) - Body ground Always Below 1 Ω
      z22-1 (PIG) - Az1-1 Always Below 1 Ω
      z21-1 (PGND) - z22-1 (PIG) Always 10 kΩ or higher

    NG

    REPLACE ECU WIRE SUB-ASSEMBLY Click here

    OK

    REPLACE POWER STEERING ECU ASSEMBLY Click here