POWER STEERING SYSTEM EPS Warning Light Circuit

DESCRIPTION

Perform the following troubleshooting procedure when the EPS warning light remains on after the engine is started, but no DTCs are stored.

Tech Tips


  • If the power steering ECU (rack and pinion power steering gear assembly) detects a malfunction in the power source voltage input (IG) circuit, the EPS warning light illuminates.

  • If the power steering ECU (rack and pinion power steering gear assembly) detects a drop in the power voltage input (IG and PIG) circuit, the force required to turn the steering wheel may increase, the EPS warning light turns on in order to warn the driver.

WIRING DIAGRAM

B0070L0E02

CAUTION / NOTICE / HINT

Note


  • If the rack and pinion power steering gear 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 rack and pinion power steering gear 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 ignition switch is turned to ON 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.

      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 Click here

    A

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


    1. Disconnect the C71 rack and pinion power steering gear assembly connector.

      B0070QJC10
      *a

      Front view of wire harness connector

      (to Rack and Pinion Power Steering Gear Assembly)

      		 - -

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      C71-4 (IG) - Body ground Ignition switch ON 8 to 16 V
      C71-8 (PIG) - 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
      C71-7 (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 C71 rack and pinion power steering gear assembly connectors.

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


      Body Electrical > Combination Meter > Active Test
      Tester Display
      EPS Warning

    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 RACK AND PINION POWER STEERING GEAR ASSEMBLY Click here

    NG

    GO TO METER / GAUGE SYSTEM Click here