POWER STEERING SYSTEM, Diagnostic DTC:C1552 and 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

C280406E01

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

Tip:

  • 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. C273886C06

      *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. C223718C07

      *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. C272070C02

      *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