POWER STEERING SYSTEM Power Steering Warning Light Circuit

DTC Code DTC Name
Power Steering Warning Light Circuit

DESCRIPTION

The power steering ECU is connected to the combination meter via CAN communication. If any of the following conditions are detected, the power steering warning light remains on.

  • The circuit that supplies power source voltage to the power steering ECU assembly (terminal IG) is open.

  • The power supply voltage to the power steering ECU assembly (terminals IG and PIG) drops.

WIRING DIAGRAM

C277340E01

CAUTION / NOTICE / HINT

Note:

  • If the power steering ECU assembly has been replaced, perform assist map writing (Click here).

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

PROCEDURE

  1. CHECK CONNECTOR CONNECTION CONDITION AND GROUND WIRE

    1. Check the connection condition of the ECU wire sub-assembly and power steering ECU assembly connectors.

      OK

      The ECU wire sub-assembly and power steering ECU assembly connectors are securely connected.

    2. Check that the ground wire is securely installed with the bolt.

      Click here

      OK

      The ground wire is securely installed with the bolt.

    Result

    Proceed to

    OK

    NG
    NG

    CONNECT CONNECTOR OR INSTALL GROUND WIRE

    Click here

    OK

  2. CHECK FOR DTC (CAN COMMUNICATION SYSTEM)

    1. Check for DTCs.

      Click here

      Chassis > EMPS > Trouble Codes

      OK

      DTC is not output.

    Result

    Proceed to

    OK

    NG
    NG

    GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING)

    for LHD:Click here

    for RHD:Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (IG POWER SUPPLY)

    1. C278679C01

      *a

      Front view of wire harness connector

      (to ECU Wire Sub-assembly)

      Disconnect the hG1 ECU wire sub-assembly connector.

    2. Turn the ignition switch to ON.

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

      Standard Voltage

      Tester Connection

      Switch Condition

      Specified Condition

      hG1-5 (IG) - Body ground

      Ignition switch ON

      11 to 14 V

    Result

    Proceed to

    OK

    NG (w/o Stop and Start System)

    NG (w/ Stop and Start System)
    NG (w/o Stop and Start System)

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    NG (w/ Stop and Start System)

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

    Click here

    OK

  4. CHECK ECU WIRE SUB-ASSEMBLY

    1. C240351C03

      *a

      Front view of wire harness connector

      (to Power Steering ECU Assembly)

      Connect the hG1 connector to the ECU wire sub-assembly.

    2. Disconnect the h1 and h2 power steering ECU assembly connectors.

    3. Turn the ignition switch to ON.

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

      Standard Voltage

      Tester Connection

      Switch Condition

      Specified Condition

      h1-1 (IG) - Body ground

      Ignition switch ON

      11 to 14 V

    5. Turn the ignition switch off.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      h2-2 (PGND) - Body ground

      Always

      Below 1 Ω

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE ECU WIRE SUB-ASSEMBLY

    Click here

    OK

  5. CHECK HARNESS AND CONNECTOR (BATTERY - ECU WIRE SUB-ASSEMBLY)

    1. C277337C01

      *a

      Front view of wire harness connector

      (to ECU Wire Sub-assembly)

      Disconnect the Ah1 ECU wire sub-assembly connector.

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

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      Ah1-1 (PIG) - Body ground

      Always

      11 to 14 V

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. CHECK ECU WIRE SUB-ASSEMBLY

    1. C240344C05

      *a

      Front view of wire harness connector

      (to Power Steering ECU Assembly)

      Connect the Ah1 connector to the ECU wire sub-assembly.

    2. Disconnect the h2 power steering ECU assembly connector.

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

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      h2-1 (PIG) - Body ground

      Always

      11 to 14 V

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE ECU WIRE SUB-ASSEMBLY

    Click here

    OK

  7. INSPECT COMBINATION METER ASSEMBLY

    1. Reconnect the h1 and h2 power steering ECU assembly connectors.

    2. Perform the Active Test of the combination meter assembly using the GTS.

      Click here

      Body Electrical > Combination Meter > Active Test

      Tester Display

      Indicat. EPS

    3. Check the combination meter assembly.

      OK

      The power steering warning light turns on or off in accordance with the GTS operation.

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE POWER STEERING ECU ASSEMBLY

    Click here

    NG

    REPLACE COMBINATION METER ASSEMBLY

    Click here