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 Note
C1552 PIG Power Supply Voltage PIG power source circuit malfunction

  • EPS fuse

  • EPS-B fuse

  • EPS relay (Electric power steering relay)

  • PIG power source circuit

  • Power steering ECU assembly

 EPS warning light: Comes on -
C1554 Power Supply Relay Failure Power source relay circuit malfunction

  • EPS fuse

  • EPS-B fuse

  • EPS relay (Electric power steering relay)

  • PIG power source circuit

  • Power steering ECU assembly

 EPS warning light: Comes on -

WIRING DIAGRAM

B003Y9HE04
*a from Auxiliary Battery
*b Power Steering ECU Assembly

CAUTION / NOTICE / HINT

Note

If the power steering ECU assembly has been replaced, perform assist map writing, rotation angle sensor initialization and torque sensor zero point calibration.

Click here

Tech Tips

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

PROCEDURE


  1. CHECK CONNECTORS


    1. Check the connection of the power steering ECU assembly connector.

    2. Visually inspect the terminals of the power steering ECU assembly connector.

      Result
      Result Proceed to
      Normal A
      Connectors not properly connected B
      Power steering ECU assembly connector terminals abnormal C

    B

    CONNECT CONNECTORS PROPERLY

    C

    REPLACE POWER STEERING ECU ASSEMBLY for LHD: Click here
    REPLACE POWER STEERING ECU ASSEMBLY for RHD: Click here

    A

  2. CHECK HARNESS AND CONNECTOR (AUXILIARY BATTERY - NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY)


    1. Remove the EPS relay (electric power steering relay) from the No. 1 engine room relay block and No. 1 junction block assembly.

    2. B003XWLC01
      *a

      Component without EPS relay (electric power steering relay) connected

      (No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly)
      *b

      Component without EPS relay (electric power steering relay) connected

      (EPS Relay (electric power steering relay) connection area)

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

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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT EPS RELAY (ELECTRIC POWER STEERING RELAY)


    1. B003Y4ZC02
      *a EPS Relay (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 not applied between terminals 1 and 2 10 kΩ or higher
      5 - 3 Voltage applied between terminals 1 and 2 Below 1 Ω
      1 - 3 Voltage not applied between terminals 1 and 2 10 kΩ or higher
      2 - 5 Voltage not applied between terminals 1 and 2 10 kΩ or higher
      1 - 2 Voltage not applied between terminals 1 and 2 180 to 220 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE EPS RELAY (ELECTRIC POWER STEERING RELAY)

    OK

  4. CHECK HARNESS AND CONNECTOR (POWER STEERING ECU ASSEMBLY - NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY)


    1. Disconnect the A19 power steering ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A19-10 (PIG) - 3 (No. 1 engine room relay block and No. 1 junction block assembly) Always Below 1 Ω
      A19-12 (RLY) - 2 (No. 1 engine room relay block and No. 1 junction block assembly) Always Below 1 Ω
      A19-10 (PIG) or 3 (No. 1 engine room relay block and No. 1 junction block assembly) - Body ground Always 10 kΩ or higher
      A19-12 (RLY) or 2 (No. 1 engine room relay block and No. 1 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. B003XR2C21
      *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
      A19-9 (PGND) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE POWER STEERING ECU ASSEMBLY for LHD: Click here
    REPLACE POWER STEERING ECU ASSEMBLY for RHD: Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR