POWER STEERING SYSTEM, Diagnostic DTC:C1551

DTC Code DTC Name
C1551 IG Power Supply Voltage Malfunction

DESCRIPTION

The power steering ECU determines whether the ignition switch status is ON or off through the IG power supply circuit.

DTC Code DTC Detection Condition Trouble Area
C1551 An IG power supply circuit malfunction inside the ECU.

  • IG power supply circuit

  • Power steering ECU assembly

WIRING DIAGRAM

A004QMVE01
*a Stop and Start System
*b Power Steering ECU

CAUTION / NOTICE / HINT

Note

If the power steering ECU assembly is replaced with a new one, perform rotation angle sensor initialization and torque sensor zero point calibration Click here.

PROCEDURE


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


    1. Turn the ignition switch off.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the ignition switch to ON.

    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
      IG Power Supply

      ECU power source voltage/

      Min.: 0.0000 V

      Max.: 20.1531 V

      		 11 to 14 V The ignition switch is ON.
      OK
      The normal condition value is displayed the intelligent tester.
      Result
      Result Proceed to
      OK for LHD A
      for RHD B
      NG C

    A

    REPLACE POWER STEERING ECU ASSEMBLY Click here

    B

    REPLACE POWER STEERING ECU ASSEMBLY Click here

    C

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


    1. A004TJJE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Power Steering ECU)

      Disconnect the A29 power steering ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A29-2 (PGND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK HARNESS AND CONNECTOR (IG POWER SUPPLY)


    1. A004RY5E02
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Power Steering ECU)

      Disconnect the D50 power steering ECU connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      D50-6 (IG) - Body ground Ignition switch ON 11 to 14 V
      Result
      Result Proceed to
      OK for LHD A
      for RHD B
      NG C

    A

    REPLACE POWER STEERING ECU ASSEMBLY Click here

    B

    REPLACE POWER STEERING ECU ASSEMBLY Click here

    C

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