POWER STEERING SYSTEM, Diagnostic DTC:C1552, C1554

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

DESCRIPTION

When a problem occurs in the system, the power source relay circuit and the motor relay circuit are shut off to stop the power assist. The ECU must be replaced when there is a problem with the relays because the relays are built into the ECU.

DTC No. Detection Item DTC Detection Condition Trouble Area Warning Indicate Return-to-normal Condition Note
C1552 PIG Power Supply Voltage PIG power source circuit malfunction

  • EPS fuse

  • Electric power steering relay

  • PIG power source circuit

  • Power steering ECU assembly

 EPS Warning Light: Comes on Ignition switch ON again -
C1554 Power Supply Relay Failure Power source relay circuit malfunction

  • EPS fuse

  • Electric power steering relay

  • PIG power source circuit

  • Power steering ECU assembly

 EPS Warning Light: Comes on Ignition switch ON again -

WIRING DIAGRAM

A00Y8AFE01

CAUTION / NOTICE / HINT

Note

If the power steering ECU assembly has been replaced with a new one, perform assist map writing and torque sensor zero point calibration.

Click here

Tech Tips


  • If DTC C1551 is output together with DTC C1552 and/or C1554, perform troubleshooting for DTC C1551 first.

    Click here

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

PROCEDURE


  1. READ VALUE USING GTS


    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 "PIG 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
      PIG Power Supply Power source voltage to active motor

      Min.: 0.0000 V

      Max.: 20.1531 V

      		 9 to 16 V Ignition switch ON

      Chassis > EMPS > Data List
      Tester Display
      PIG Power Supply
      OK
      The normal condition value is displayed on the GTS.
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE POWER STEERING ECU ASSEMBLY Click here

    NG

  2. CHECK HARNESS AND CONNECTOR (BATTERY - ENGINE ROOM RELAY BLOCK AND JUNCTION BLOCK ASSEMBLY)


    1. A00Y4ZDC06
      *a Engine Room Relay Block and Junction Block Assembly
      *b Electric Power Steering Relay

      Remove the electric power steering relay.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      5 - Body ground Always 9 to 16 V
      1 - Body ground Always 9 to 16 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT ELECTRIC POWER STEERING RELAY


    1. A00YA3QC07
      *a Electric Power Steering Relay

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      5 - 3 Voltage is not applied between terminals 1 and 2 10 kΩ or higher
      5 - 3 Voltage is applied between terminals 1 and 2 Below 1 Ω
      1 - 3 Voltage is not applied between terminals 1 and 2 10 kΩ or higher
      2 - 5 Voltage is not applied between terminals 1 and 2 10 kΩ or higher
      1 - 2 Voltage is not applied between terminals 1 and 2 100 to 300 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE ELECTRIC POWER STEERING RELAY

    OK

  4. CHECK HARNESS AND CONNECTOR (POWER STEERING ECU ASSEMBLY - ENGINE ROOM RELAY BLOCK AND JUNCTION BLOCK ASSEMBLY)


    1. Disconnect the E30 and A53 power steering ECU assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E30-4 (RLY) - 2 (Engine room relay block and junction block assembly) Always Below 1 Ω
      E30-4 (RLY) or 2 (Engine room relay block and junction block assembly) - Body ground Always 10 kΩ or higher
      A53-2 (PIG) - 3 (Engine room relay block and junction block assembly) Always Below 1 Ω
      A53-2 (PIG) or 3 (Engine room relay block and junction block assembly) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. A00Y675C02
      *a

      Front view of wire harness connector

      (to Power Steering ECU Assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A53-1 (PGND) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE POWER STEERING ECU ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR