Click here

POWER STEERING SYSTEM EPS Warning Light Circuit

Click here
Click here Click here
DTC Code DTC Name
  EPS Warning Light Circuit
Click here

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.

Click here

WIRING DIAGRAM

Click here

CAUTION / NOTICE / HINT

Note:

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

    Click here

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

Click here

PROCEDURE


  1. Click here

    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.
      Tip:

      When the EPS warning light is operating properly, it comes on when the engine switch is turned on (IG) and goes off when the engine is started.

      Result
      Proceed to
      OK
      NG

    • OKClick here
    • NG

      REPAIR OR REPLACE HARNESS OR CONNECTOR

  2. Click here

    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

  3. Click here

    CHECK HARNESS AND CONNECTOR (IG POWER SUPPLY - GROUND)


    1. Disconnect the A18 power steering ECU assembly connector.

    2. B00682SC46
      *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 Condition Specified Condition
      A18-14 (IG) - Body ground Engine switch on (IG) 8 to 16 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A18-9 (PGND) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    • OKClick here
    • NG

      REPAIR OR REPLACE HARNESS OR CONNECTOR

  4. Click here

    INSPECT EPS RELAY (ELECTRIC POWER STEERING RELAY)


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

    2. B0066SEC02
      *a EPS Relay (Electric Power Steering Relay)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      5 - 3 Voltage not applied between terminals 1 and 2 10 kΩ or higher
      5 - 3 Voltage applied between terminals 1 and 2 Below 1 Ω
      1 - 3 Voltage not applied between terminals 1 and 2 10 kΩ or higher
      2 - 5 Voltage not applied between terminals 1 and 2 10 kΩ or higher
      1 - 2 Voltage not applied between terminals 1 and 2 180 to 220 Ω
      Result
      Proceed to
      OK
      NG

    • OKClick here
    • NG

      REPLACE EPS RELAY (ELECTRIC POWER STEERING RELAY)

  5. Click here

    CHECK HARNESS AND CONNECTOR (BATTERY - NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY)


    1. B00661GC01
      *A for RHD
      *a No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
      *b EPS Relay (Electric Power Steering Relay)
      B00656MC01
      *A for LHD
      *a No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
      *b EPS Relay (Electric Power Steering Relay)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      1 - Body ground Always 9 to 16 V
      5 - Body ground Always 9 to 16 V
      Result
      Proceed to
      OK
      NG

    • OKClick here
    • NG

      REPAIR OR REPLACE HARNESS OR CONNECTOR

  6. Click here

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


    1. Disconnect the A18 power steering ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A18-10 (PIG) - 3 (No. 1 engine room relay block and No. 1 junction block assembly) Always Below 1 Ω
      A18-12 (RLY) - 2 (No. 1 engine room relay block and No. 1 junction block assembly) Always Below 1 Ω
      A18-10 (PIG) or 3 (No. 1 engine room relay block and No. 1 junction block assembly) - Body ground Always 10 kΩ or higher
      A18-12 (RLY) or 2 (No. 1 engine room relay block and No. 1 junction block assembly) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    • OKClick here
    • NG

      REPAIR OR REPLACE HARNESS OR CONNECTOR

  7. Click here

    INSPECT COMBINATION METER ASSEMBLY


    1. Reconnect the A18 power steering ECU assembly connector.

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


      1. 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 for LHD:Click here

      REPLACE POWER STEERING ECU ASSEMBLY for RHD:Click here

    • NG

      GO TO METER / GAUGE SYSTEMClick here