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Home >> Lexus >> 2017 >> GX 460 Base >> Repair and Diagnosis (Single Page) >> Steering >> Steering Column >> Steering Lock System (Diagnostic Codes & Symptom Tests) >> Steering Lock System >> Unable to Unlock Steering Wheel (Engine cannot Start) [08/2019 - 08/2022] >> Procedure

Unable to Unlock Steering Wheel (Engine cannot Start) [08/2019 - 08/2022]: Procedure

  1. CHECK POWER SOURCE MODE CHANGING FUNCTION (SWITCH CONDITION) 
    1. Check the power source mode change.

      Refer to OPERATION CHECK [08/2019 - 08/2022]

      OK

      The power source mode changes to on (IG).

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    GO TO SMART ACCESS SYSTEM WITH PUSH-BUTTON START (for Start Function) (Power Source Mode does not Change to ON (IG and ACC)). Refer to  Power Source Mode does not Change to ON (IG and ACC) [08/2019 - ] 

    Result: 

    OK 

    See step  2

  2. CHECK INDICATOR 
    1. With the engine switch on (IG), check that push engine switch while turning steering wheel in either direction is displayed on the multi-information display in the combination meter assembly.

      Result

      Result Proceed to
      Push engine switch while turning steering wheel in either direction is displayed. A
      Push engine switch while turning steering wheel in either direction is not displayed. B

    Result: 

    B 

    See step  4

    Result: 

    A 

    See step  3

  3. CHECK STEERING UNLOCK 
    1. Turn the steering wheel left and right, and then press the engine switch.
    2. Check that the steering is unlocked.

      Result

      Result Proceed to
      The steering is unlocked. A
      The steering is not unlocked. B

    Result: 

    A 

    END (STEERING LOCK IS NORMAL) 

    Result: 

    B 

    See step  4

  4. CHECK FOR DTC 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Body Electrical / Smart Access / Trouble Codes.
    5. Check for DTCs and note any DTCs that are output.

      Result

      Result Proceed to
      DTCs are not output. A
      DTCs are output. B

    Result: 

    B 

    GO TO DIAGNOSTIC PROCEDURE INDICATED BY OUTPUT DTC 

    for Entry Function:

    Refer to DIAGNOSTIC TROUBLE CODE CHART [08/2019 - ]

    for Start Function:

    Refer to DIAGNOSTIC TROUBLE CODE CHART [08/2019 - 08/2021] , or refer to DIAGNOSTIC TROUBLE CODE CHART [08/2021 - 08/2022]

    Result: 

    A 

    See step  5

  5. READ VALUE USING TECHSTREAM (UNLOCK REQUEST RECEIVE) 
    1. Enter the following menus: Body Electrical / Smart Access / Data List.
    2. Read the Data List according to the display on the Techstream.
      SMART ACCESS

      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Unlock Request Receive Status of steering unlock command from certification ECU (smart key ECU assembly)/
      OK or NG      		 OK: Unlock request signal received within 10 seconds of engine switch being turned on (IG) or on (ACC) or of an engine start operation being performed
      NG: Engine switch not turned on (IG) or on (ACC) and engine start operation not being performed
      • The engine cannot be started when an unlock request signal cannot be received.
      • If OK is not displayed even though the steering unlock conditions are met, the certification ECU (smart key ECU assembly) may be malfunctioning.

      OK

      Within 10 seconds of turning the engine switch on (ACC) or on (IG) or starting the engine, the Data List item changes to "OK".

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  14

    Result: 

    OK 

    See step  6

  6. READ VALUE USING TECHSTREAM (S CODE CHECK) 
    1. Enter the following menus: Body Electrical / Smart Access / Data List.
    2. Read the Data List according to the display on the Techstream.
      SMART ACCESS

      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      S Code Check S code verification result/
      OK or NG      		 OK: Verification result normal
      NG: Verification result abnormal      		 When NG is displayed:
      • The ID code for the certification ECU (smart key ECU assembly) or ID code box (immobiliser code ECU) is not registered, or the certification ECU (smart key ECU assembly) or ID code box (immobiliser code ECU) is malfunctioning.
      • The steering cannot be locked.
      • The steering cannot be unlocked (the engine cannot be started).

      OK

      OK is displayed on the Techstream.

      HINT: 

      Reasons for verification failure:

      • The certification ECU (smart key ECU assembly) or ID code box (immobiliser code ECU) is malfunctioning.
      • There is a problem with the communication between ECUs.
      • An ECU is replaced, but is not registered.
      • An ECU is replaced with an ECU which has a code already stored in it.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  13

    Result: 

    OK 

    See step  7

  7. READ VALUE USING TECHSTREAM (L CODE CHECK) 
    1. Enter the following menus: Body Electrical / Smart Access / Data List.
    2. Read the Data List according to the display on the Techstream.
      SMART ACCESS

      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      L Code Check Verification result between ID code box (immobiliser code ECU) and steering lock ECU (steering lock actuator assembly)/
      OK or NG      		 OK: Verification result normal
      NG: Verification result abnormal      		 When NG is displayed:
      • The ID code for the ID code box (immobiliser code ECU) or steering lock ECU (steering lock actuator assembly) is not registered, or the ID code box (immobiliser code ECU) or steering lock ECU (steering lock actuator assembly) is malfunctioning.
      • The steering cannot be locked.
      • The steering cannot be unlocked (the engine cannot be started).

      OK

      OK is displayed on the Techstream.

      HINT: 

      Reasons for verification failure:

      • The steering lock ECU (steering lock actuator assembly) or ID code box (immobiliser code ECU) is malfunctioning.
      • There is a problem with the communication between ECUs.
      • An ECU is replaced, but is not registered.
      • An ECU is replaced with an ECU which has a code already stored in it.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  12

    Result: 

    OK 

    See step  8

  8. CHECK HARNESS AND CONNECTOR (STEERING LOCK ECU (STEERING LOCK ACTUATOR ASSEMBLY) - POWER SUPPLY AND BODY GROUND) 
    1. Disconnect the G23 steering lock ECU (steering lock actuator assembly) connector.
      GTY954716Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Steering Lock ECU (Steering Lock Actuator Assembly))
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      G23-1 (GND) - Body ground Always Below 1 Ω
      NOTE:

      If the result is not as specified, check for looseness in the ground cable connection.

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

      Standard Voltage

      Tester Connection Condition Specified Condition
      G23-7 (B) - Body ground Always 11 to 14 V

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  9

  9. CHECK STEERING LOCK ECU (STEERING LOCK ACTUATOR ASSEMBLY) (MOTOR ACTIVATION COMMAND SIGNAL) 
    1. Reconnect the steering lock ECU (steering lock actuator assembly) connector.
    2. Using an oscilloscope, check the waveform.

      OK

      Tester Connection Tool Setting Condition Specified Condition
      G23-3 (IGE) - G23-1 (GND) 2 V/DIV., 200 ms./DIV. Any door opened when following conditions are met, and then steering lock motor activated:
      • Shift state park (P)
      • Steering lock unlocked in advance by carrying key and turning engine switch on (IG)
      • After above conditions are met, engine switch turned off
      		 Pulse generation
      (See waveform)

      HINT: 

      • When taking measurements when the lock motor is stopped, it is not necessary to perform any operations.
      • In order to take measurements when the lock motor is operating, perform either of the following operations:
        • To unlock the steering, carry the key and turn the engine switch on (ACC) or on (IG).
        • To lock the steering, turn the engine switch off with the shift state park (P), and then open a door.
      GTY955428Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (Steering Lock ECU (Steering Lock Actuator Assembly))
      *b Waveform
      *c Steering Lock Motor not Operating
      *d Steering Lock Motor Operating

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE STEERING LOCK ECU (STEERING LOCK ACTUATOR ASSEMBLY). Refer to  DISASSEMBLY [08/2019 - 08/2022] 

    Result: 

    NG 

    See step  10

  10. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - STEERING LOCK ECU (STEERING LOCK ACTUATOR ASSEMBLY)) 
    1. Disconnect the G23 steering lock ECU (steering lock actuator assembly) connector.
    2. Disconnect the G113 certification ECU (smart key ECU assembly) connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      G23-3 (IGE) - G113-24 (SLR+) Always Below 1 Ω
      G23-3 (IGE) or G113-24 (SLR+) - Other terminals and body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  11

  11. CHECK STEERING LOCK ECU 
    1. Reconnect the steering lock ECU (steering lock actuator assembly) connector.
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      G23-3 (IGE) - Body ground Always 11 to 14 V
      GTY956015Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (Steering Lock ECU (Steering Lock Actuator Assembly))

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to  REMOVAL [08/2019 - 08/2021]  , or refer to  REMOVAL [08/2021 - ] 

    Result: 

    NG 

    REPLACE STEERING LOCK ECU (STEERING LOCK ACTUATOR ASSEMBLY). Refer to  DISASSEMBLY [08/2019 - 08/2022] 

  12. CHECK STEERING LOCK ECU (STEERING LOCK ACTUATOR ASSEMBLY) 
    1. Replace the steering lock ECU (steering lock actuator assembly) with a new one.

      Refer to DISASSEMBLY [08/2019 - 08/2022]

    2. Enter the following menus: Body Electrical / Smart Access / Data List.
    3. Read the Data List according to the display on the Techstream.
      SMART ACCESS

      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      L Code Check Verification result between ID code box (immobiliser code ECU) and steering lock ECU (steering lock actuator assembly)/
      OK or NG      		 OK: Verification result normal
      NG: Verification result abnormal      		 When NG is displayed:
      • The ID code for the ID code box (immobiliser code ECU) or steering lock ECU (steering lock actuator assembly) is not registered, or the ID code box (immobiliser code ECU) or steering lock ECU (steering lock actuator assembly) is malfunctioning.
      • The steering cannot be locked.
      • The steering cannot be unlocked (the engine cannot be started).

      OK

      OK is displayed on the Techstream.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    END (STEERING LOCK ECU (STEERING LOCK ACTUATOR ASSEMBLY) WAS DEFECTIVE) 

    Result: 

    NG 

    REPLACE ID CODE BOX (IMMOBILISER CODE ECU). Refer to  REMOVAL [08/2015 - ] 

  13. CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) 
    1. Replace the certification ECU (smart key ECU assembly) with a new one and perform registration again.

      Refer to REMOVAL [08/2019 - 08/2021] , or refer to REMOVAL [08/2021 - ]

      HINT: 

      Refer to Registration.

      Refer to REGISTRATION [08/2019 - 08/2021] , or refer to REGISTRATION [08/2021 - 08/2022]

    2. Enter the following menus: Body Electrical / Smart Access / Data List.
    3. Read the Data List according to the display on the Techstream.
      SMART ACCESS

      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      S Code Check S code verification result/
      OK or NG      		 OK: Verification result normal
      NG: Verification result abnormal      		 When NG is displayed:
      • The ID code for the certification ECU (smart key ECU assembly) or ID code box (immobiliser code ECU) is not registered, or the certification ECU (smart key ECU assembly) or ID code box (immobiliser code ECU) is malfunctioning.
      • The steering cannot be locked.
      • The steering cannot be unlocked (the engine cannot be started).

      OK

      OK is displayed on the Techstream.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    END (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) WAS DEFECTIVE) 

    Result: 

    NG 

    REPLACE ID CODE BOX (IMMOBILISER CODE ECU). Refer to  REMOVAL [08/2015 - ] 

  14. CHECK STEERING LOCK ECU (STEERING LOCK ACTUATOR ASSEMBLY) 
    1. Measure the voltage according to the value(s) in the table below.
      GTY955689Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (Steering Lock ECU (Steering Lock Actuator Assembly))

      Standard Voltage

      Tester Connection Condition Specified Condition
      G23-4 (SLP1) - Body ground Always 11 to 14 V

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  17

    Result: 

    OK 

    See step  15

  15. READ VALUE USING TECHSTREAM (STEERING UNLOCK) 
    1. Check that the steering is locked.
    2. Enter the following menus: Body Electrical / Smart Access / Data List.
    3. Read the Data List according to the display on the Techstream.
      SMART ACCESS

      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Steering Unlock Steering lock ECU (steering lock actuator assembly) unlock confirmation status/
      Unset or Set      		 Unset: Unlock not confirmed
      Set: Unlock confirmed      		 When Unset is displayed, the steering is not unlocked (the engine cannot be started).

      OK

      Set is displayed on the Techstream.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE STEERING LOCK ECU (STEERING LOCK ACTUATOR ASSEMBLY). Refer to  DISASSEMBLY [08/2019 - 08/2022] 

    Result: 

    OK 

    See step  16

  16. READ VALUE USING TECHSTREAM (UNLOCK REQUEST RECEIVE) 
    1. Replace the certification ECU (smart key ECU assembly) with a new one.

      Refer to REMOVAL [08/2019 - 08/2021] , or refer to REMOVAL [08/2021 - ]

    2. Perform registration.

      HINT: 

      Refer to Registration.

      Refer to REGISTRATION [08/2019 - 08/2021] , or refer to REGISTRATION [08/2021 - 08/2022]

    3. Enter the following menus: Body Electrical / Smart Access / Data List.
    4. Read the Data List according to the display on the Techstream.
      SMART ACCESS

      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Unlock Request Receive Status of steering unlock command from certification ECU (smart key ECU assembly)/
      OK or NG      		 OK: Unlock request signal received within 10 seconds of engine switch being turned on (IG) or on (ACC) or of an engine start operation being performed
      NG: Engine switch not turned on (IG) or on (ACC) and engine start operation not being performed
      • The engine cannot be started when an unlock request signal cannot be received.
      • If OK is not displayed even though the steering unlock conditions are met, the certification ECU (smart key ECU assembly) may be malfunctioning.

      OK

      Within 10 seconds of turning the engine switch on (ACC) or on (IG) or starting the engine, the Data List item changes to "OK".

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    END (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) WAS DEFECTIVE) 

    Result: 

    NG 

    REPLACE STEERING LOCK ECU (STEERING LOCK ACTUATOR ASSEMBLY). Refer to  DISASSEMBLY [08/2019 - 08/2022] 

  17. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - STEERING LOCK ECU (STEERING LOCK ACTUATOR ASSEMBLY)) 
    1. Disconnect the G23 steering lock ECU (steering lock actuator assembly) connector.
    2. Disconnect the G113 certification ECU (smart key ECU assembly) connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      G23-4 (SLP1) - G113-23 (SLP) Always Below 1 Ω
      G23-4 (SLP1) or G113-23 (SLP) - Other terminals and body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  18

  18. READ VALUE USING TECHSTREAM (UNLOCK REQUEST RECEIVE) 
    1. Replace the steering lock ECU (steering lock actuator assembly) with a new one.

      Refer to DISASSEMBLY [08/2019 - 08/2022]

    2. Perform registration.

      HINT: 

      Refer to Registration.

      Refer to REGISTRATION [08/2019 - 08/2021] , or refer to REGISTRATION [08/2021 - 08/2022]

    3. Enter the following menus: Body Electrical / Smart Access / Data List.
    4. Read the Data List according to the display on the Techstream.
      SMART ACCESS

      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Unlock Request Receive Status of steering unlock command from certification ECU (smart key ECU assembly)/
      OK or NG      		 OK: Unlock request signal received within 10 seconds of engine switch being turned on (IG) or on (ACC) or of an engine start operation being performed
      NG: Engine switch not turned on (IG) or on (ACC) and engine start operation not being performed
      • The engine cannot be started when an unlock request signal cannot be received.
      • If OK is not displayed even though the steering unlock conditions are met, the certification ECU (smart key ECU assembly) may be malfunctioning.

      OK

      Within 10 seconds of turning the engine switch on (ACC) or on (IG) or starting the engine, the Data List item changes to "OK".

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    END (STEERING LOCK ECU (STEERING LOCK ACTUATOR ASSEMBLY) WAS DEFECTIVE) 

    Result: 

    NG 

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to  REMOVAL [08/2019 - 08/2021]  , or refer to  REMOVAL [08/2021 - ] 

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