POWER STEERING SYSTEM EPS Warning Light Circuit

DESCRIPTION

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

WIRING DIAGRAM

A017BG0E02
A017G3OE02

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK FOR DTC (CAN COMMUNICATION SYSTEM)


    1. Turn the ignition switch off.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the ignition switch on (IG).

    4. Turn the intelligent tester on.

    5. Using the intelligent tester, check for DTCs and confirm that there are no problems in the CAN communication system.

      OK
      CAN DTCs are not output.

    NG

    GO TO CAN COMMUNICATION SYSTEM Click here

    OK

  2. READ VALUE USING INTELLIGENT TESTER (IG POWER SUPPLY)


    1. Enter the following menus: Chassis / EMPS / Data List.

    2. Select the item "IG Power Supply" in the Data List and read the value displayed on the intelligent tester.

      EMPS:
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      IG Power Supply

      ECU power source voltage:

      Min.: 0 V

      Max.: 20.1531 V

      		 11 to 14 V Ignition switch on (IG)

    NG

    INSPECT FUSE (ECU IG NO. 1) Click here

    OK

  3. PERFORM ACTIVE TEST BY INTELLIGENT TESTER


    1. Enter the following menus: Body / Combination meter / Active Test.

    2. According to the display on tester, perform the "Active Test".

      Combination meter:
      Tester Display Test Part Control Range Diagnostic Note
      Indicat. EPS (*1) P/S Warning Light ON or OFF Confirm that the vehicle is stopped, engine idling
      Master Warning (*2) Master Warning Light ON or OFF Confirm that the vehicle is stopped, engine idling

      *1: w/o Multi-information Display

      *2: w/ Multi-information Display

      OK
      Indicator comes on.

    NG

    REPLACE COMBINATION METER ASSEMBLY Click here

    OK

    REPLACE POWER STEERING ECU Click here

  4. INSPECT FUSE (ECU IG NO. 1)


    1. Remove the ECU IG No. 1 fuse from the instrument panel junction block.

    2. Measure the resistance of the fuse.

      OK
      Below 1 Ω

    NG

    REPLACE FUSE

    OK

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


    1. A017EPBE09

      Disconnect the connectors from the power steering ECU.

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

      Standard voltage
      Tester Connection Switch Condition Specified Condition
      D5-5 (IG) - Body ground Ignition switch on (IG) 11 to 14 V

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

      Standard resistance
      Tester Connection Condition Specified Condition
      D4-2 (PGND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. PERFORM ACTIVE TEST USING INTELLIGENT TESTER


    1. Enter the following menus: Body / Combination meter / Active Test.

    2. According to the display on the tester, perform the "Active Test".

      Combination meter:
      Tester Display Test Part Control Range Diagnostic Note
      Indicat. EPS (*1) P/S Warning Light ON or OFF Confirm that the vehicle is stopped, engine idling
      Master Warning (*2) Master Warning Light ON or OFF Confirm that the vehicle is stopped, engine idling

      *1: w/o Multi-information Display

      *2: w/ Multi-information Display

      OK
      Indicator comes on.

    NG

    REPLACE COMBINATION METER ASSEMBLY Click here

    OK

    REPLACE POWER STEERING ECU Click here