LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2017 >> LS 460 Base, AWD >> Repair and Diagnosis >> Steering >> Steering Column >> Steering Lock System - Diagnostic Codes & Circuit Tests >> Circuit Tests >> Unable to Unlock Steering Wheel [09/2015 - ] >> Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Unable to Unlock Steering Wheel [09/2015 - ]: Procedure

  1. CHECK ENGINE SWITCH 
    1. Check the power source mode change.
      1. When the key is inside the vehicle and the shift lever is in P, check that pressing the engine switch causes the power source mode to change as follows:

        OK

        off → on(ACC) → on(IG) → off

    Result:  NG

    NG 

    GO TO SMART ACCESS SYSTEM WITH PUSH-BUTTON START (POWER SOURCE MODE DOES NOT CHANGE) 

    (Refer to Power Source Mode does not Change [09/2015 - ] )

    Result:  OK

    OK 

    See step  2

  2. CHECK FOR DTC (MAIN BODY ECU) 
    1. Check the DTCs of the main body ECU by following the prompts displayed on the Techstream screen (Refer to DTC CHECK / CLEAR [09/2015 - ] ).

      OK

      No DTCs related to main body ECU are output.

    Result:  NG

    NG 

    GO TO RELEVANT DTC 

    (Refer to DIAGNOSTIC TROUBLE CODE CHART [09/2015 - ] )

    Result:  OK

    OK 

    See step  3

  3. CHECK FOR DTC (CERTIFICATION ECU) 
    1. Check the DTCs of the certification ECU by following the prompts displayed on the Techstream screen (Refer to DTC CHECK / CLEAR [09/2015 - ] ).

      OK

      No DTCs related to certification ECU are output.

    Result:  NG

    NG 

    GO TO RELEVANT DTC 

    (Refer to DIAGNOSTIC TROUBLE CODE CHART [09/2015 - ] )

    Result:  OK

    OK 

    See step  4

  4. READ VALUE USING TECHSTREAM (LOCK/UNLOCK RECEIVE) 
    1. Within 10 seconds of the engine switch being turned on (IG), check the Data List and read the value displayed on the Techstream screen.
      SMART ACCESS

      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Lock/Unlock Receive Steering lock command reception record/ Yes or No Yes: Steering lock/unlock signal received
      No: Steering lock/unlock signal not received
      -

      OK

      YES is displayed on the Techstream screen.

    Result:  NG

    NG 

    See step  7

    Result:  OK

    OK 

    See step  5

  5. CHECK HARNESS AND CONNECTOR (STEERING LOCK ECU - BODY GROUND) 
    1. Disconnect the L33 steering lock ECU connector.
    2. Measure the resistance and voltage according to the value(s) in the table below.
      GTY623891Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Voltage

      Tester Connection Condition Specified Condition
      L33-7 (B) - L33-1 (GND) Always 11 to 14 V
      L33-7 (B) - L33-2 (SGND) Always 11 to 14 V

      Standard Resistance

      Tester Connection Condition Specified Condition
      L33-1 (GND) - Body ground Always Below 1 Ω
      L33-2 (SGND) - Body ground Always Below 1 Ω

    Result:  NG

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result:  OK

    OK 

    See step  6

  6. CHECK STEERING LOCK ECU 
    1. Move the shift lever to P.
    2. Immediately after turning the engine switch on (IG), inspect the voltage between terminals 3 (IGE) and 2 (SGND) of the steering lock ECU.
      GTY641851Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      RESULT

      Result Proceed to
      Measurement is 11 to 14 V, and measurement never becomes 1 V or less A
      Immediately after turning engine switch on (IG), measurement is 1 V or less (w/ VGRS) B
      Immediately after turning engine switch on (IG), measurement is 1 V or less (w/o VGRS) C

    Result:  A

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result:  B

    REPLACE STEERING LOCK ACTUATOR ASSEMBLY (STEERING LOCK ECU) 

    (Refer to REMOVAL [09/2015 - ] )

    Result:  C

    REPLACE STEERING LOCK ACTUATOR ASSEMBLY (STEERING LOCK ECU) 

    (Refer to REMOVAL [09/2015 - ] )

  7. READ VALUE USING TECHSTREAM (S CODE CHECK) 
    1. Use the Data List to check if the S code certification is functioning properly.
      SMART ACCESS

      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      S Code Check S code match record/ NG or OK NG: S code not matched
      OK: S code matched
      -

      OK

      OK is displayed on the Techstream.

    Result:  NG

    NG 

    See step  11

    Result:  OK

    OK 

    See step  8

  8. READ VALUE USING TECHSTREAM (L CODE CHECK) 
    1. Use the Data List to check if the L code certification is functioning properly.
      SMART ACCESS

      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      L Code Check L code match record/ NG or OK NG: L code not matched
      OK: L code matched
      -

      OK

      OK is displayed on the Techstream.

    Result:  NG

    NG 

    See step  13

    Result:  OK

    OK 

    See step  9

  9. REPLACE STEERING LOCK ACTUATOR ASSEMBLY (STEERING LOCK ECU) 
    1. Replace the steering lock actuator assembly (steering lock ECU) (w/ VGRS: Refer to REMOVAL [09/2015 - ] , w/o VGRS: Refer to REMOVAL [09/2015 - ] ).

    Result:  NEXT

    NEXT 

    See step  10

  10. CHECK STEERING LOCK RELEASE OPERATION 
    1. Turn the engine switch on (IG).
    2. Operate the steering wheel and check the steering lock condition.

      OK

      Steering lock is released.

    Result:  OK

    OK 

    END (STEERING LOCK ECU IS DEFECTIVE) 

    Result:  NG

    NG 

    REPLACE CERTIFICATION ECU 

  11. REPLACE ID CODE BOX 
    1. Replace the ID code box.

    Result:  NEXT

    NEXT 

    See step  12

  12. READ VALUE USING TECHSTREAM (S CODE CHECK) 
    1. Use the Data List to check if the S code certification is functioning properly.
      SMART ACCESS

      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      S Code Check S code match record/ NG or OK NG: S code not matched
      OK: S code matched
      -

      OK

      OK is displayed on the Techstream.

    Result:  OK

    OK 

    END (ID CODE BOX IS DEFECTIVE) 

    Result:  NG

    NG 

    REPLACE CERTIFICATION ECU 

  13. REPLACE ID CODE BOX 
    1. Replace the ID code box.

    Result:  NEXT

    NEXT 

    See step  14

  14. READ VALUE USING TECHSTREAM (L CODE CHECK) 
    1. Use the Data List to check if the L code certification is functioning properly.
      SMART ACCESS

      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      L Code Check L code match record/ NG or OK NG: L code not matched
      OK: L code matched
      -

      OK

      OK is displayed on the Techstream.

      RESULT

      Result Proceed to
      OK A
      NG (w/ VGRS) B
      NG (w/o VGRS) C

    Result:  A

    END (ID CODE BOX IS DEFECTIVE) 

    Result:  B

    REPLACE STEERING LOCK ACTUATOR ASSEMBLY (STEERING LOCK ECU) 

    (Refer to REMOVAL [09/2015 - ] )

    Result:  C

    REPLACE STEERING LOCK ACTUATOR ASSEMBLY (STEERING LOCK ECU) 

    (Refer to REMOVAL [09/2015 - ] )