ELECTRONIC POWER STEERING SYSTEM, Diagnostic DTC:C1552/52, C1554/54

DTC Code DTC Name
C1552/52 PIG Power Source Circuit
C1554/54 EPS Relay Circuit

DESCRIPTION

If a malfunction occurs in the system, the system prohibits the steering assist by interrupting the circuit of the EPS relay and the motor relay (built into the power steering ECU assembly).

DTC No. DTC Detecting Conditions Trouble Areas
C1552/52 Unusual motor power source voltage value which not within specification input to PIG terminal of power steering ECU assembly

  • EMPS fuse

  • PIG power source circuit

  • Power steering ECU assembly
C1554/54 Open or short circuit of EPS relay circuit detected

WIRING DIAGRAM

A0137EQE01
A0138LXE01

INSPECTION PROCEDURE

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER

    Check that PIG POWER SUPPLY in the DATA LIST is between 10 V and 16 V.


    OK

    INSPECT FOR SHORT CIRCUIT IN HARNESSES AND ALL COMPONENTS CONNECTED TO EMPS FUSE

    NG

  2. INSPECT FUSE (EMPS)


    1. A0137U8E01

      Remove the EMPS fuse from the engine room R/B No.1 and J/B No.1.

    2. Check the resistance of the EMPS fuse.

      Standard Resistance
      Below 1 Ω

    3. Reinstall the EMPS fuse.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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

    A0135ZNE02

    1. Disconnect the C24 connector from the power steering ECU assembly.

    2. Measure the resistance between terminal PGND of the C24 connector and body ground.

      Standard Resistance
      1 Ω or less

    3. Reconnect the connector.


    NG

    CHECK FOR INTERMITTENT PROBLEMS

    OK

  4. INSPECT FUSE (ECU-IG)

    A01391UE02

    1. Remove the ECU-IG fuse from the instrument panel J/B.

    2. Check the resistance of the ECU-IG fuse.

      Standard Resistance
      Below 1 Ω

    3. Reinstall the ECU-IG fuse.


    NG

    INSPECT FOR SHORT CIRCUIT IN ALL HARNESS AND COMPONENTS CONNECTED TO ECU - IG FUSE

    OK

  5. CHECK HARNESS AND CONNECTOR (POWER STEERING ECU ASSEMBLY - INSTRUMENT PANEL J/B)

    A01370WE01

    1. Disconnect the C23 and C24 connectors from the power steering ECU assembly.

    2. Turn the ignition switch ON.

    3. Measure the voltage between terminals IG and PGND of the C23 and C24 connectors.

      Standard Voltage
      10 to 16 V

    4. Reconnect the connectors.


    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR

    OK

    REPLACE POWER STEERING ECU ASSEMBLY