POWER STEERING SYSTEM EPS Warning Light Circuit

DTC Code DTC Name
EPS Warning Light Circuit

DESCRIPTION

If the power steering ECU assembly detects a malfunction, the EPS warning light comes on. At this time, the power steering ECU assembly stores a DTC in its memory.

WIRING DIAGRAM

C273890E04

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:

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

PROCEDURE

  1. CHECK CONNECTOR CONNECTION CONDITION

    1. Jiggle the power steering ECU assembly connectors and wire harness up and down, and left and right to check the illumination condition of the EPS warning light in the combination meter assembly.

      OK

      The EPS warning light illumination condition does not change.

      Tip:

      When the EPS warning light is operating properly, it comes on when the ignition switch is turned to ON and goes off when the engine is started.

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. CHECK CAN COMMUNICATION SYSTEM

    1. Check for DTCs.

      Click hereClick hereClick hereClick here

      OK

      DTCs are not output.

    Result

    Proceed to

    OK

    NG
    NG

    GO TO CAN COMMUNICATION SYSTEM

    Click here

    OK

  3. 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 "IG 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

      IG Power Supply

      IG power source voltage

      Min.: 0.0000 V

      Max.: 20.1531 V

      8 to 16 V

      Ignition switch ON

      Chassis > EMPS > Data List

      Tester Display

      IG Power Supply

      OK

      The normal condition value is displayed on the GTS.

    Result

    Proceed to

    OK

    NG
    NG

    CHECK HARNESS AND CONNECTOR (BATTERY - POWER STEERING ECU ASSEMBLY)Click here

    OK

  4. INSPECT COMBINATION METER ASSEMBLY

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

      Body Electrical > Combination Meter > Active Test

      Tester Display

      Indicat. EPS

    2. Check the combination meter assembly.

      OK

      The EPS 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

    GO TO METER / GAUGE SYSTEM

    Click here

  5. CHECK HARNESS AND CONNECTOR (BATTERY - POWER STEERING ECU ASSEMBLY)

    1. Disconnect the E30 and A53 power steering ECU assembly connectors.

      C273483C01

      *a

      Front view of wire harness connector

      (to Power Steering ECU Assembly)

      -

      -

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

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      E30-1(IG) - Body ground

      Ignition switch ON

      9 to 16 V

    3. 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
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. INSPECT COMBINATION METER ASSEMBLY

    1. Reconnect the E30 and A53 power steering ECU assembly connectors.

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

      Body Electrical > Combination Meter > Active Test

      Tester Display

      Indicat. EPS

    3. Check the combination meter assembly.

      OK

      The EPS 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

    GO TO METER / GAUGE SYSTEM

    Click here