POWER STEERING SYSTEM, Diagnostic DTC:C1551/25

DTC Code DTC Name
C1551/25 IG Power Supply Voltage Malfunction

DESCRIPTION

The power steering ECU assembly distinguishes the ignition switch status as ON or off through the IG power source circuit.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Warning Indicate

Return-to-normal Condition

C1551/25

IG Power Supply Voltage Malfunction

IG power source circuit malfunction inside ECU

  • EPS-IG fuse (w/o Stop and start system)

  • IG power source circuit

  • ECU wire sub-assembly

  • Power steering ECU assembly

On

Ignition switch ON again

WIRING DIAGRAM

C277338E01

CAUTION / NOTICE / HINT

Note:

  • If the power steering ECU assembly has been replaced, perform assist map writing (Click here).

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

PROCEDURE

  1. CHECK CONNECTOR CONNECTION CONDITION AND GROUND WIRE

    1. Check the connection condition of the ECU wire sub-assembly and power steering ECU assembly connectors.

      OK

      The ECU wire sub-assembly and 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

    Click here

    OK

  2. READ VALUE USING GTS (IG POWER SUPPLY)

    1. Turn the ignition switch off.

    2. Connect the GTS to the DLC3.

    3. Turn the ignition switch to ON.

    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

      Ignition switch ON: 11 to 14 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
    OK

    CHECK INTERMITTENT PROBLEMS

    Click hereClick here

    NG

  3. CHECK HARNESS AND CONNECTOR (IG POWER SUPPLY)

    1. C278679C01

      *a

      Front view of wire harness connector

      (to ECU Wire Sub-assembly)

      Disconnect the hG1 ECU wire sub-assembly connector.

    2. Turn the ignition switch to ON.

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

      Standard Voltage

      Tester Connection

      Switch Condition

      Specified Condition

      hG1-5 (IG) - Body ground

      Ignition switch ON

      11 to 14 V

    Result

    Proceed to

    OK

    NG (w/o Stop and Start System)

    NG (w/ Stop and Start System)
    NG (w/o Stop and Start System)

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    NG (w/ Stop and Start System)

    GO TO STOP AND START SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING)

    for 2WW:Click here

    for 3ZR-FAE:Click here

    OK

  4. CHECK ECU WIRE SUB-ASSEMBLY

    1. C240351C03

      *a

      Front view of wire harness connector

      (to Power Steering ECU Assembly)

      Connect the hG1 connector to the ECU wire sub-assembly.

    2. Disconnect the h1 and h2 power steering ECU assembly connectors.

    3. Turn the ignition switch to ON.

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

      Standard Voltage

      Tester Connection

      Switch Condition

      Specified Condition

      h1-1 (IG) - Body ground

      Ignition switch ON

      11 to 14 V

    5. Turn the ignition switch off.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      h2-2 (PGND) - Body ground

      Always

      Below 1 Ω

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE POWER STEERING ECU ASSEMBLY

    Click here

    NG

    REPAIR OR REPLACE ECU WIRE SUB-ASSEMBLY

    Click here