POWER STEERING SYSTEM, Diagnostic DTC:C1552 and 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

C206807E03

CAUTION / NOTICE / HINT

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.

      Table 1. 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.

    REPLACE POWER STEERING ECU ASSEMBLY

    (Click here)

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

    1. Turn the ignition switch off.

    2. U123144E02

      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
      Table 2. Text in Illustration

      *1

      Front view of wire harness connector

      (to ECU Wire Sub-assembly)

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  3. CHECK GROUND BOLT AND WIRE HARNESS

    Click here

    INSTALL GROUND BOLT AND WIRE HARNESS CORRECTLY

    (Click here)

  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.

    INSTALL TERMINAL SCREW AND ECU WIRE SUB-ASSEMBLY CORRECTLY

    (Click here)

  5. CHECK ECU WIRE SUB-ASSEMBLY

    U123259E02

    1. 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
    Table 3. Text in Illustration

    *1

    ECU Wire Sub-assembly

    REPLACE POWER STEERING ECU ASSEMBLY

    (Click here)

    REPLACE ECU WIRE SUB-ASSEMBLY

    (Click here)