LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Toyota >> 2021 >> Venza LE >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Anti-Theft Systems >> Smart Key System (For Start Function) - Symptom Tests (2 Of 2) >> SMART KEY SYSTEM (for Start Function) >> Unable to Unlock Steering Wheel (Hybrid Control System cannot Start) [07/2020 - ] >> Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Unable to Unlock Steering Wheel (Hybrid Control System cannot Start) [07/2020 - ]: Procedure

  1. CHECK POWER SWITCH (SWITCH CONDITION) 
    1. Check the power source mode change.
      1. When the electrical key transmitter sub-assembly is inside the vehicle and the shift lever is in P, check that pressing the power switch with the brake pedal released causes the power source mode to change as follows:

        OK

        Off → ACC → ON → Off

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    GO TO OTHER PROBLEM. Refer to  PROBLEM SYMPTOMS TABLE [07/2020 - 12/2021]  , or refer to  PROBLEM SYMPTOMS TABLE [12/2021 - ] 

    Result: 

    OK 

    See step  2

  2. CHECK MULTI-INFORMATION DISPLAY 
    1. With the ignition switch ON, check that Steering Lock active is displayed on the multi-information display in the combination meter assembly.

      Result

      Result Proceed to
      Steering Lock active is displayed A
      Steering Lock active is not displayed B

    Result: 

    B 

    See step  5

    Result: 

    A 

    See step  3

  3. CHECK STEERING UNLOCK 
    1. Turn the steering wheel left and right, and then press the power 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 NORMAL) 

    Result: 

    B 

    See step  4

  4. CHECK FOR DTC 
    1. Check for DTCs.

      Body Electrical > Smart Key > Trouble Codes 

      NOTE:

      If a malfunction occurs, do not remove/install the vehicle auxiliary battery before checking for DTCs.

      OK

      DTCs are not output.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    GO TO DIAGNOSTIC TROUBLE CODE CHART. Refer to  DIAGNOSTIC TROUBLE CODE CHART [07/2020 - 12/2021]  , or refer to  DIAGNOSTIC TROUBLE CODE CHART [12/2021 - ] 

    Result: 

    OK 

    See step  5

  5. READ VALUE USING GTS (STEERING UNLOCK REQUEST RECEIVE) 
    1. 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 Unlock Request Receive Status of steering unlock command from certification ECU (smart key ECU assembly) OK or NG OK: Certification ECU (smart key ECU assembly) sends steering unlock command (within 10 seconds of ignition switch turned ACC or ON, or of hybrid control system start operation performed)
      NG: Certification ECU (smart key ECU assembly) does not send steering unlock command (ignition switch not turned ACC or ON, and hybrid control system start operation not performed)
      • The hybrid control system 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.

      Body Electrical > Smart Key > Data List 

      Tester Display
      Steering Unlock Request Receive

      OK

      Within 10 seconds of turning the ignition switch to ACC or ON or starting the hybrid control system, 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 GTS (S CODE CHECK) 
    1. 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
      S Code Check Verification result between certification ECU (smart key ECU assembly) and ID code box (immobilizer code ECU) 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 (immobilizer code ECU) is not registered, or the certification ECU (smart key ECU assembly) or ID code box (immobilizer code ECU) is malfunctioning.
      • The steering cannot be locked.
      • The steering cannot be unlocked (the hybrid control system cannot be started).

      Body Electrical > Smart Key > Data List 

      Tester Display
      S Code Check

      OK

      OK is displayed on the GTS.

      HINT: 

      Reasons for verification failure:

      • The certification ECU (smart key ECU assembly) or ID code box (immobilizer code ECU) is malfunctioning.
      • There is a problem with the communication between ECUs.
      • An ECU was replaced, but not registered.
      • An ECU was replaced with an ECU which has already been registered to another vehicle.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  13

    Result: 

    OK 

    See step  7

  7. READ VALUE USING GTS (L CODE CHECK) 
    1. 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
      L Code Check Verification result between ID code box (immobilizer code ECU) and steering lock ECU (steering lock actuator or upper bracket assembly) OK or NG OK: Verification result normal
      NG: Verification result abnormal      		 When NG is displayed:
      • The ID code for the ID code box (immobilizer code ECU) or steering lock ECU (steering lock actuator or upper bracket assembly) is not registered, or the ID code box (immobilizer code ECU) or steering lock ECU (steering lock actuator or upper bracket assembly) is malfunctioning.
      • The steering cannot be locked.
      • The steering cannot be unlocked (the hybrid control system 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 

    See step  12

    Result: 

    OK 

    See step  8

  8. CHECK HARNESS AND CONNECTOR (POWER SOURCE AND GROUND) 
    1. Disconnect the E54 steering lock ECU (steering lock actuator or upper bracket assembly) connector.
    2. Measure the resistance according to the value(s) in the table below.
      GTY977617Courtesy 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
      E54-1 (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
      E54-7 (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 OR UPPER BRACKET ASSEMBLY) 
    1. Reconnect the E54 steering lock ECU (steering lock actuator or upper bracket assembly) connector.
    2. Check the signal waveform according to the condition(s) in the table below.
      GTY972822Courtesy 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
      MEASUREMENT CONDITION

      Item Content
      Tester Connection E54-3 (IGE) - E54-1 (GND)
      Tool Setting 2 V/DIV., 200 ms./DIV.
      Condition Steering lock motor operating when all conditions met, and then door opened:
      • Shift lever in P
      • Steering unlocked
      • Ignition switch turned off

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY). Refer to  DISASSEMBLY [07/2020 - 12/2021]  , or refer to  DISASSEMBLY [12/2021 - ] 

    Result: 

    NG 

    See step  10

  10. CHECK HARNESS AND CONNECTOR (STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY) - CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)) 
    1. Disconnect the E54 steering lock ECU (steering lock actuator or upper bracket assembly) connector.
    2. Disconnect the E52 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
      E54-3 (IGE) - E52-24 (SLR+) Always Below 1 Ω
      E54-3 (IGE) or E52-24 (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 (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY) 
    1. Connect the E54 steering lock ECU (steering lock actuator or upper bracket assembly) connector.
      GTY1018976Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (Steering Lock ECU (Steering Lock Actuator or Upper Bracket Assembly))
    2. Connect the E52 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
      E54-3 (IGE) - Body ground Ignition switch off 11 to 14 V

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to  REMOVAL [07/2020 - ] 

    Result: 

    NG 

    REPLACE STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY). Refer to  DISASSEMBLY [07/2020 - 12/2021]  , or refer to  DISASSEMBLY [12/2021 - ] 

  12. CHECK STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY) 
    1. Replace the steering lock ECU (steering lock actuator or upper bracket assembly) with a new one and perform registration.

      HINT: 

    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
      L Code Check Verification result between ID code box (immobilizer code ECU) and steering lock ECU (steering lock actuator or upper bracket assembly) OK or NG OK: Verification result normal
      NG: Verification result abnormal      		 When NG is displayed:
      • The ID code for the ID code box (immobilizer code ECU) or steering lock ECU (steering lock actuator or upper bracket assembly) is not registered, or the ID code box (immobilizer code ECU) or steering lock ECU (steering lock actuator or upper bracket assembly) is malfunctioning.
      • The steering cannot be locked.
      • The steering cannot be unlocked (the hybrid control system cannot be started).

      Body Electrical > Smart Key > Data List 

      Tester Display
      L Code Check

      OK

      OK is displayed on the GTS.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    END (STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY) WAS DEFECTIVE) 

    Result: 

    NG 

    REPLACE ID CODE BOX (IMMOBILIZER CODE ECU). Refer to  REMOVAL [07/2020 - 10/2022]  , or refer to  REMOVAL [10/2022 - ] 

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

      HINT: 

    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
      S Code Check Verification result between certification ECU (smart key ECU assembly) and ID code box (immobilizer code ECU) 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 (immobilizer code ECU) is not registered, or the certification ECU (smart key ECU assembly) or ID code box (immobilizer code ECU) is malfunctioning.
      • The steering cannot be locked.
      • The steering cannot be unlocked (the hybrid control system cannot be started).

      Body Electrical > Smart Key > Data List 

      Tester Display
      S Code Check

      OK

      OK is displayed on the GTS.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

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

    Result: 

    NG 

    REPLACE ID CODE BOX (IMMOBILIZER CODE ECU). Refer to  REMOVAL [07/2020 - 10/2022]  , or refer to  REMOVAL [10/2022 - ] 

  14. CHECK STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY) 
    1. Measure the voltage according to the value(s) in the table below.
      GTY1018977Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (Steering Lock ECU (Steering Lock Actuator or Upper Bracket Assembly))

      Standard Voltage

      Tester Connection Condition Specified Condition
      E54-4 (SLP1) - Body ground Ignition switch off 11 to 14 V

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  16

    Result: 

    OK 

    See step  15

  15. READ VALUE USING GTS (STEERING UNLOCK REQUEST RECEIVE) 
    1. Replace the certification ECU (smart key ECU assembly) with a new one and perform registration.

      HINT: 

    2. Turn the ignition switch to ON.
    3. 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 Unlock Request Receive Status of steering unlock command from certification ECU (smart key ECU assembly) OK or NG OK: Certification ECU (smart key ECU assembly) sends steering unlock command (within 10 seconds of ignition switch turned ACC or ON, or of hybrid control system start operation performed)
      NG: Certification ECU (smart key ECU assembly) does not send steering unlock command (ignition switch not turned ACC or ON, and hybrid control system start operation not performed)
      • The hybrid control system 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.

      Body Electrical > Smart Key > Data List 

      Tester Display
      Steering Unlock Request Receive

      OK

      Within 10 seconds after the ignition switch is turned to ACC or ON or the hybrid control system is started, 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 ID CODE BOX (IMMOBILIZER CODE ECU). Refer to  REMOVAL [07/2020 - 10/2022]  , or refer to  REMOVAL [10/2022 - ] 

  16. CHECK HARNESS AND CONNECTOR (STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY) - CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)) 
    1. Disconnect the E54 steering lock ECU (steering lock actuator or upper bracket assembly) connector.
    2. Disconnect the E52 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
      E54-4 (SLP1) - E52-11 (SLP) Always Below 1 Ω
      E54-4 (SLP1) or E52-11 (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  17

  17. READ VALUE USING GTS (STEERING UNLOCK REQUEST RECEIVE) 
    1. Replace the steering lock ECU (steering lock actuator or upper bracket assembly) with a new one and perform registration.

      HINT: 

    2. Turn the ignition switch to ON.
    3. Use the Data List to check if the steering lock request is functioning properly.

      Body Electrical > Smart Key > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Steering Unlock Request Receive Status of steering unlock command from certification ECU (smart key ECU assembly) OK or NG OK: Certification ECU (smart key ECU assembly) sends steering unlock command (within 10 seconds of ignition switch turned ACC or ON, or of hybrid control system start operation performed)
      NG: Certification ECU (smart key ECU assembly) does not send steering unlock command (ignition switch not turned ACC or ON, and hybrid control system start operation not performed)
      • The hybrid control system 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.

      Body Electrical > Smart Key > Data List 

      Tester Display
      Steering Unlock Request Receive

      OK

      Within 10 seconds of turning the ignition switch to ACC or ON or starting the hybrid control system, the Data List item changes to "OK".

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    END (STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY) WAS) 

    Result: 

    NG 

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to  REMOVAL [07/2020 - ] 

scientia non olet · About LEMON Manuals