POWER STEERING SYSTEM EPS Warning Light Circuit

DESCRIPTION

If the power steering ECU assembly detects a malfunction, the power steering ECU assembly stores a DTC and illuminates the EPS warning light.

WIRING DIAGRAM

A01UCOHE02

CAUTION / NOTICE / HINT

Note


  • If the power steering ECU assembly has been replaced, perform assist map writing and torque sensor zero point calibration.

    Click here

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

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR


    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.

      Tech Tips

      When the EPS warning light is operating properly, it illuminates when the engine switch is turned on (IG) and turns 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.

      for LHD: Click here

      for RHD: Click here

      Result
      Result Proceed to
      CAN communication system DTCs are not output. A
      CAN communication system DTCs are output. B

    B

    GO TO CAN COMMUNICATION SYSTEM for LHD: Click here
    GO TO CAN COMMUNICATION SYSTEM for RHD: Click here

    A

  3. CHECK HARNESS AND CONNECTOR (IG POWER SUPPLY - GROUND)


    1. Disconnect the G53 and G20 power steering ECU assembly connectors.

      A01UEBNC03
      *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
      G20-1 (IG) - Body ground Engine switch on (IG) 8 to 16 V
      G53-1 (PIG) - Body ground Engine switch on (IG) 9 to 16 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G53-2 (PGND) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. INSPECT COMBINATION METER ASSEMBLY


    1. Connect the G53 and G20 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