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Home >> Toyota >> 2021 >> Highlander LE, 4WD >> Repair and Diagnosis >> Body & Frame >> Door Locks >> Smart Key System (For Start, Except HV) - Symptom Tests (2 Of 2) >> SMART KEY SYSTEM (for Start Function, Gasoline Model) >> Steering Lock does not Lock [12/2019 - 10/2021] >> Procedure

Steering Lock does not Lock [12/2019 - 10/2021]: Procedure

  1. READ VALUE USING GTS (LOCK REQUEST RECEIVE) 
    1. Use the Data List to check if the steering lock command is functioning properly.

      Body Electrical > Smart Key > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Lock Request Receive Status of steering lock command from certification ECU (smart key ECU assembly) OK or NG OK: Certification ECU (smart key ECU assembly) sends steering lock command (within 10 seconds of any door opened with shift lever in P and ignition switch off)
      NG: Certification ECU (smart key ECU assembly) does not send steering lock command (no door opened with shift lever in P and ignition switch off)      		 If OK is not displayed even though the steering lock conditions are met, the certification ECU (smart key ECU assembly) may be malfunctioning.

      Body Electrical > Smart Key > Data List 

      Tester Display
      Lock Request Receive

      OK

      The certification ECU (smart key ECU assembly) receives a lock request signal within 10 seconds of turning the ignition switch from ON to ACC or off and opening a door with the shift lever in P, and OK is displayed on the GTS screen.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  7

    Result: 

    OK 

    See step  2

  2. READ VALUE USING GTS (L CODE CHECK) 
    1. Use the Data List to check if L code certification is functioning properly.

      Body Electrical > Smart Key > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      L Code Check Verification result between certification ECU (smart key ECU assembly) 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 certification ECU (smart key ECU assembly) or steering lock ECU (steering lock actuator assembly) is not registered, or the certification ECU (smart key ECU assembly) 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).

      Body Electrical > Smart Key > Data List 

      Tester Display
      L Code Check

      OK

      OK is displayed on the GTS.

      HINT: 

      Reasons for verification failure:

      • The steering lock ECU (steering lock actuator or upper bracket assembly) or certification ECU (smart key ECU assembly) 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 

    REPLACE STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY). Refer to  DISASSEMBLY [12/2019 - 10/2021] 

    Result: 

    OK 

    See step  3

  3. CHECK HARNESS AND CONNECTOR (POWER SOURCE) 
    1. Disconnect the H52 steering lock ECU (steering lock actuator or upper bracket assembly) connector.
    2. Measure the resistance and voltage according to the value(s) in the table below.
      GTY929340Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Steering Lock ECU Steering Lock Actuator or Upper Bracket Assembly))

      Standard Resistance

      Tester Connection Condition Specified Condition
      H52-1 (GND) - Body ground Always Below 1 Ω
      NOTE:

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

      Standard Voltage

      Tester Connection Condition Specified Condition
      H52-7 (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  4

  4. CHECK STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY) 
    1. Connect the H52 steering lock ECU (steering lock actuator or upper bracket assembly) connector.
    2. Move the shift lever to P and turn the ignition switch off.
    3. Check the signal waveform according to the condition(s) in the table below.
      GTY928927Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (Steering Lock ECU (Steering Lock Actuator or Upper Bracket Assembly))      		 *b Steering lock motor not operating
      *c Steering lock motor operating *d Waveform

      OK

      Tester Connection Condition Tool Setting Specified Condition
      H52-3 (IGE) - H52-1 (GND) 2 V/DIV., 200 ms./DIV. Steering lock motor not operating → Operating → Not operating 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 electrical key transmitter sub-assembly and turn the ignition switch to ACC or ON.
        • To lock the steering, turn the ignition switch off with the shift lever in P, and then open a door.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY). Refer to  DISASSEMBLY [12/2019 - 10/2021] 

    Result: 

    NG 

    See step  5

  5. CHECK HARNESS AND CONNECTOR (STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY) - CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)) 
    1. Disconnect the H52 steering lock ECU (steering lock actuator or upper bracket assembly) connector.
    2. Disconnect the H48 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
      H52-3 (IGE) - H48-25 (SLR+) Always Below 1 Ω
      H52-3 (IGE) or H48-25 (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  6

  6. CHECK STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY) 
    1. Connect the H52 steering lock ECU (steering lock actuator or upper bracket assembly) connector.
    2. Connect the H48 certification ECU (smart key ECU assembly) connector.
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      H52-3 (IGE) - Body ground Always 11 to 14 V
      GTY855282Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (Steering Lock ECU (Steering Lock Actuator or Upper Bracket Assembly))

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to  REMOVAL [12/2019 - 11/2023] 

    Result: 

    NG 

    REPLACE STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY). Refer to  DISASSEMBLY [12/2019 - 10/2021] 

  7. READ VALUE USING GTS (FL DOOR COURTESY SW) 
    1. Using the GTS, check the following main body ECU (multiplex network body ECU) Data List item by opening and closing the driver door to confirm the state of the front door courtesy light switch assembly.

      Body Electrical > Main Body > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      FL Door Courtesy SW Front door LH courtesy light switch signal OFF or ON OFF: Front door LH closed
      ON: Front door LH open      		 -

      Body Electrical > Main Body > Data List 

      Tester Display
      FL Door Courtesy SW

      OK

      The Data List item changes in accordance with the opening and closing of the driver door.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    GO TO LIGHTING SYSTEM (Front Door Courtesy Switch Circuit). Refer to  Front Door Courtesy Switch Circuit [12/2019 - 11/2023] 

    Result: 

    OK 

    See step  8

  8. READ VALUE USING GTS (SHIFT P SIGNAL) 
    1. Move the shift lever to P.
    2. Read the Data List according to the display on the GTS.

      Body Electrical > Power Source Control > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Shift P Signal Shift position P OFF or ON OFF: Shift lever not in P
      ON: Shift lever in P      		 Use this item to determine if the park/neutral position switch assembly is malfunctioning.

      Body Electrical > Power Source Control > Data List 

      Tester Display
      Shift P Signal

      OK

      ON is displayed on the GTS.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    GO TO OTHER PROBLEM. Refer to  PROBLEM SYMPTOMS TABLE [12/2019 - 10/2021] 

    Result: 

    OK 

    See step  9

  9. READ VALUE USING GTS (STEERING LOCK) 
    1. Check that the steering is unlocked.
    2. Read the Data List according to the display on the GTS.

      Body Electrical > Smart Key > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Steering Lock Steering lock ECU (steering lock actuator or upper bracket assembly) lock confirmation status Unset or Set Unset: Lock not confirmed
      Set: Lock confirmed      		 When Unset is displayed, the steering is not locked.

      Body Electrical > Smart Key > Data List 

      Tester Display
      Steering Lock

      OK

      Set is displayed on the GTS.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to  REMOVAL [12/2019 - 11/2023] 

    Result: 

    NG 

    REPLACE STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY). Refer to  DISASSEMBLY [12/2019 - 10/2021] 

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