POWER STEERING SYSTEM (for 2AR-FSE) Power Steering Warning Light Circuit

DESCRIPTION

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


WIRING DIAGRAM

A01FRUSE03

INSPECTION PROCEDURE

Note


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

  • If the power steering ECU assembly is replaced with a new one, perform assist map writing, clear the motor rotation angle sensor calibration value, initialize the motor rotation angle sensor value and calibrate the torque sensor zero point Click here.

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR


    1. Turn the power switch on (READY).

    2. Check the indication condition of the power steering warning light by wiggling the power steering ECU assembly connector and wire harness up, down, right and left.

      OK
      The power steering warning light indication condition does not change.

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. CHECK CAN COMMUNICATION SYSTEM


    1. Check for DTCs Click here.

      Result
      Result Proceed to
      DTC is not output A
      DTC is output for LHD B
      for RHD C

    B

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

    C

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

    A

  3. CHECK TERMINAL VOLTAGE (IG)


    1. Disconnect the power steering ECU assembly connector.

    2. A01FUH4E02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Power Steering ECU Assembly)

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A29-14 (IG) - Body ground Power 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
      A29-9 (PGND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK EPS RELAY (ELECTRIC POWER STEERING RELAY)


    1. A01FQXPE03
      Text in Illustration
      *1 EPS Relay (Electric Power Steering Relay)

      Remove the EPS relay (electric power steering relay) from the No. 1 engine room relay block and junction block assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1 - 2 20°C (68°F) 180 to 220 Ω
      3 - 5 Auxiliary battery voltage not applied to terminals 1 and 2 10 kΩ or higher
      Auxiliary battery voltage applied to terminals 1 and 2 Below 1 Ω

    NG

    REPLACE EPS RELAY (ELECTRIC POWER STEERING RELAY)

    OK

  5. CHECK TERMINAL VOLTAGE (EPS RELAY [ELECTRIC POWER STEERING RELAY])


    1. A01FTX6E01
      Text in Illustration
      *a

      Component without EPS Relay (Electric Power Steering Relay)

      (No. 1 Engine Room Relay Block and Junction Block Assembly)
      *b

      Component without EPS Relay (Electric Power Steering Relay)

      EPS Relay (Electric Power Steering Relay) Connection Area

      Remove the EPS relay (electric power steering relay) from the No. 1 engine room relay block and junction block assembly.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      1 - Body ground Always 11 to 14 V
      5 - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. CHECK HARNESS AND CONNECTOR (NO. 1 ENGINE ROOM RELAY BLOCK AND JUNCTION BLOCK ASSEMBLY - POWER STEERING ECU ASSEMBLY)


    1. Remove the EPS relay (electric power steering relay) from the No. 1 engine room relay block and junction block assembly.

    2. Disconnect the A29 power steering ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A29-12 (RLY) - 2 Always Below 1 Ω
      A29-10 (PIG) - 3 Always Below 1 Ω
      A29-12 (RLY) - A29-10 (PIG) Always 10 kΩ or higher
      A29-10 (PIG) or 3 - Body ground Always 10 kΩ or higher
      A29-12 (RLY) or 2 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. REPLACE POWER STEERING ECU ASSEMBLY


    1. Replace the power steering ECU assembly Click here.

    2. Perform assist map writing, clear the motor rotation angle sensor calibration value, initialize the motor rotation angle sensor value and calibrate the torque sensor zero point Click here.

    3. Check the illumination condition of the power steering warning light.

      OK
      The power steering warning light illuminates with the power switch on (IG) and turns off after the power switch is turned from on (IG) to on (READY).

    NG

    REPLACE COMBINATION METER ASSEMBLY Click here

    OK

    END