POWER STEERING SYSTEM, Diagnostic DTC:C1555

DTC Code DTC Name
C1555 Motor Relay Welding Failure

DESCRIPTION

The power steering ECU supplies current to the power steering motor.

DTC Code DTC Detection Condition Trouble Area
C1555 Motor relay malfunction is detected.

  • Wire harness

  • Power steering motor (built into power steering link assembly)

  • Power steering ECU

Tech Tips

If there are any tears or holes in the rack boots, water or other foreign material may enter the interior of the power steering link assembly and cause a malfunction.

WIRING DIAGRAM

A0019S4E15
for LHD
*a Shielded
*b Power Steering Motor
*c Power Steering ECU
A0019S4E16
for RHD
*a Shielded
*b Power Steering Motor
*c Power Steering ECU

PROCEDURE


  1. CHECK CONNECTORS


    1. Check the connection of the power steering ECU and power steering link assembly connectors.

    2. Visually inspect the terminals of the power steering ECU and power steering link assembly connectors.

      Result
      Result Proceed to
      Normal A
      Connectors not properly connected B
      Power steering ECU connector terminals abnormal C
      Power steering link assembly connector terminals abnormal (w/ VGRS) D
      Power steering link assembly connector terminals abnormal (w/o VGRS) E

      Note


      • If replacing the power steering link assembly, clear the rotation angle sensor value calibration value, initialize the rotation angle sensor value, and calibrate the torque sensor zero point Click here.

      • If replacing the power steering ECU, initialize the rotation angle sensor value and calibrate the torque sensor zero point Click here.


    B

    CONNECT CONNECTORS CORRECTLY

    C

    REPLACE POWER STEERING ECU Click here

    D

    REPLACE POWER STEERING LINK ASSEMBLY (w/ VGRS) Click here

    E

    REPLACE POWER STEERING LINK ASSEMBLY (w/o VGRS) Click here

    A

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


    1. Disconnect the C1 ECU connector.

      A0019W5E01
      *1 for LHD:
      *2 for RHD:
      *3 Front view of wire harness connector: (to Power Steering Motor)
      *4 (to Power Steering ECU)

    2. Disconnect the C3 motor connector.

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

      Standard resistance (for LHD)
      Tester Connection Condition Specified Condition
      C1-1 (V) - C3-1 (W) Always Below 1 Ω
      C1-2 (U) - C3-3 (U) Always Below 1 Ω
      C1-3 (W) - C3-2 (V) Always Below 1 Ω
      C1-1 (V) - Body ground Always 10 kΩ or higher
      C1-2 (U) - Body ground Always 10 kΩ or higher
      C1-3 (W) - Body ground Always 10 kΩ or higher
      Standard resistance (for RHD)
      Tester Connection Condition Specified Condition
      C1-1 (V) - C3-3 (U) Always Below 1 Ω
      C1-2 (U) - C3-2 (W) Always Below 1 Ω
      C1-3 (W) - C3-1 (V) Always Below 1 Ω
      C1-1 (V) - Body ground Always 10 kΩ or higher
      C1-2 (U) - Body ground Always 10 kΩ or higher
      C1-3 (W) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT POWER STEERING LINK ASSEMBLY (POWER STEERING MOTOR)

    A001DR4E05

    1. Disconnect the C3 motor connector.

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

      Standard resistance (for LHD)
      Tester Connection Condition Specified Condition
      3 (U) - 2 (V) Always 0.07 to 10 Ω
      2 (V) - 1 (W) Always 0.07 to 10 Ω
      1 (W) - 3 (U) Always 0.07 to 10 Ω
      3 (U) - Body ground* Always 100 kΩ or higher
      2 (V) - Body ground* Always 100 kΩ or higher
      1 (W) - Body ground* Always 100 kΩ or higher
      Standard resistance (for RHD)
      Tester Connection Condition Specified Condition
      3 (U) - 2 (W) Always 0.07 to 10 Ω
      2 (W) - 1 (V) Always 0.07 to 10 Ω
      1 (V) - 3 (U) Always 0.07 to 10 Ω
      3 (U) - Body ground* Always 100 kΩ or higher
      2 (W) - Body ground* Always 100 kΩ or higher
      1 (V) - Body ground* Always 100 kΩ or higher

      *: Touch the negative probe to the power steering link assembly housing at the position shown in the illustration to perform the measurement.

      Note


      • If replacing the power steering link assembly, clear the rotation angle sensor value calibration value, initialize the rotation angle sensor value, and calibrate the torque sensor zero point Click here.

      • If replacing the power steering ECU, initialize the rotation angle sensor value and calibrate the torque sensor zero point Click here.

      Result
      Result Proceed to
      OK A
      NG (w/ VGRS) B
      NG (w/o VGRS) C

    B

    REPLACE POWER STEERING LINK ASSEMBLY (w/ VGRS) Click here

    C

    REPLACE POWER STEERING LINK ASSEMBLY (w/o VGRS) Click here

    A

  4. CHECK POWER STEERING LINK ASSEMBLY (CHECK RACK BOOTS FOR LEAK)


    1. Remove the power steering link assembly.


    2. Clean off any dirt or foreign matter attached to the rack boots.

    3. Rotate the pinion shaft all the way to the end, and with the rack boot extended, check to make sure there are no holes. Use this procedure to check both the LH and RH boots.

      OK
      There are no tears or holes.

      Note


      • If replacing the power steering link assembly, clear the rotation angle sensor value calibration value, initialize the rotation angle sensor value, and calibrate the torque sensor zero point Click here.

      • If replacing the power steering ECU, initialize the rotation angle sensor value and calibrate the torque sensor zero point Click here.

      Result
      Result Proceed to
      OK A
      NG (w/ VGRS) B
      NG (w/o VGRS) C

    A

    REPLACE POWER STEERING ECU Click here

    B

    REPLACE POWER STEERING LINK ASSEMBLY (w/ VGRS) Click here

    C

    REPLACE POWER STEERING LINK ASSEMBLY (w/o VGRS) Click here