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Home >> Toyota >> 2021 >> Highlander LE, 4WD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 112 (Smart Key System (For Start, HV) - Diagnostic Codes (2 Of 2) & Symptom Tests (1 Of 2)) >> SMART KEY SYSTEM (for Start Function, HV Model) >> Power Source Mode does not Change to ON (READY) [11/2023 - ] >> Procedure

Power Source Mode does not Change to ON (READY) [11/2023 - ]: Procedure

WARNING: This page is about a different variant/trim than selected.
  1. CHECK POWER SWITCH CONDITION 
    1. Get into the vehicle while carrying an electrical key transmitter sub-assembly.
    2. Move the shift position to P.
    3. With the brake pedal released, check that pressing the power switch causes the power source mode to change.

      Result

      Result Proceed to
      Power source mode changes: Off → ACC → ON → off A
      Power source mode does not change to ACC or ON B
      Power source mode changes to ON but not to ACC C
      Power source mode changes to ACC but not to ON D

    Result: 

    B 

    GO TO OTHER PROBLEM (Power Source Mode does not Change to ON (IG and ACC)). Refer to  Power Source Mode does not Change to ON (IG and ACC) [11/2023 - ]  

    Result: 

    C 

    GO TO OTHER PROBLEM (Power Source Mode does not Change to ON (ACC)). Refer to  Power Source Mode does not Change to ON (ACC) [11/2023 - ]  

    Result: 

    D 

    GO TO OTHER PROBLEM (Power Source Mode does not Change to ON (IG)). Refer to  Power Source Mode does not Change to ON (IG) [11/2023 - ]  

    Result: 

    A 

    See step  2

  2. READ VALUE USING GTS (STOP LIGHT SWITCH) 
    1. 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
      Stop Light Switch State of brake pedal OFF or ON OFF: Brake pedal released
      ON: Brake pedal depressed
      • Use this item to determine if the stop light switch assembly is malfunctioning.
      • The hybrid control system cannot be started when this item is OFF.
      • If the stop light switch assembly is malfunctioning, the hybrid control system can be started by pressing and holding the power switch for a certain period of time.

      Body Electrical > Power Source Control > Data List 

      Tester Display
      Stop Light Switch

      OK

      The GTS display changes correctly in response to the brake pedal operation.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  11

    Result: 

    OK 

    See step  3

  3. READ VALUE USING GTS (SHIFT P SIGNAL) 
    1. 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 position not in P
      ON: Shift position in P      		 Use this item to determine if the shift position switch is malfunctioning.

      Body Electrical > Power Source Control > Data List 

      Tester Display
      Shift P Signal

      OK

      The GTS display changes correctly in response to the shift position.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  8

    Result: 

    OK 

    See step  4

  4. READ VALUE USING GTS (POWER SUPPLY CONDITION) 
    1. 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
      Power Supply Condition Power supply state OFF, ACC ON, IGR ON, IGP ON or Starter ON OFF: Ignition switch off
      ACC ON: Ignition switch ACC
      IGR ON: Ignition switch ON
      IGP ON: Ignition switch ON
      Starter ON: Sending hybrid control system start request signal      		 -

      Body Electrical > Power Source Control > Data List 

      Tester Display
      Power Supply Condition
      NOTE:

      Check that the key indicator display is displayed on the multi-information display in the combination meter assembly, and then press the power switch.

      OK

      The GTS display changes correctly in response to the power switch operation.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  7

    Result: 

    OK 

    See step  5

  5. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - HYBRID VEHICLE CONTROL ECU) 
    1. Disconnect the A88 certification ECU (smart key ECU assembly) connector.
    2. Disconnect the H67 hybrid vehicle control ECU connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A88-2 (ST2) - H67-4 (ST2) Always Below 1 Ω
      A88-2 (ST2) or H67-4 (ST2) - 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 CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) 
    1. Connect the A88 certification ECU (smart key ECU assembly) connector.
    2. Connect the H67 hybrid vehicle control ECU connector.
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A88-2 (ST2) - Body ground With the brake pedal depressed, the power switch is pressed and held → After approx. 3 sec. has elapsed, the power switch is released 8.5 V or higher → 1.0 V or less
      GTY1178593Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (Certification ECU (Smart Key ECU Assembly))

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    GO TO HYBRID CONTROL SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [11/2023 - ] 

    Result: 

    NG 

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

  7. CHECK SECURITY INDICATOR LIGHT (IMMOBILIZER FUNCTION UNSET) 
    1. Get into the vehicle while carrying an electrical key transmitter sub-assembly.
    2. Move the shift position to P.
    3. Press the power switch with the brake pedal released and check that the security indicator light changes from blinking to off at the same time that the power source mode changes to ACC.

      OK

      The security indicator light changes from blinking to off at the same time that the power source mode changes to ACC.

      HINT: 

      The immobilizer function can be determined to be operating correctly if the security indicator light changes from blinking to off at the same time that the power source mode changes to ACC.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

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

    Result: 

    NG 

    GO TO OTHER PROBLEM (Immobilizer System does not Operate Properly). Refer to  Immobilizer System does not Operate Properly [11/2023 - ] 

  8. CHECK SHIFT LOCK CONTROL UNIT ASSEMBLY 
    1. Disconnect the H138 certification ECU (smart key ECU assembly) connector.
    2. Measure the registance according to the value(s) in the table below.

      Standard Registance

      Tester Connection Condition Specified Condition
      H138-14 (P) - Body ground Shift lever in P → Shift lever not in P 30 kΩ or higher → Below 200 Ω

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

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

    Result: 

    NG 

    See step  9

  9. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - SHIFT LOCK CONTROL UNIT ASSEMBLY) 
    1. Disconnect the H28 shift lock control unit assembly connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      H138-14 (P) - H28-3 (P2) Always Below 1 Ω
      H138-14 (P) or H28-3 (P2) - 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  10

  10. CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) 
    1. Connect the H138 certification ECU (smart key ECU assembly) connector.
    2. Connect the H28 shift lock control unit assembly connector.
    3. Measure the voltage according to the value(s) in the table below.
      GTY1178086Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (Certification ECU (Smart Key ECU Assembly))

      Standard Voltage

      Tester Connection Condition Specified Condition
      H138-22 (P) - Body ground Shift lever in P 9 V or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE SHIFT LOCK CONTROL UNIT ASSEMBLY. Refer to  DISASSEMBLY [12/2019 - ] 

    Result: 

    NG 

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

  11. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - POWER SOURCE AND BODY GROUND) 
    1. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A42-7 (B) - Body ground Ignition switch off 11 to 14 V
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A42-2 (GND) - Body ground Always Below 1 Ω

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  12

  12. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - STOP LIGHT SWITCH ASSEMBLY) 
    1. Disconnect the A88 certification ECU (smart key ECU assembly) connector.
    2. Disconnect the A32 hybrid vehicle control ECU connector.
    3. Disconnect the A42 stop light switch assembly connector.
    4. Disconnect the A57 No. 2 skid control ECU (brake actuator assembly) connector.
    5. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A88-21 (STP1) - A42-3 (L) Always Below 1 Ω
      A88-21 (STP1) or A42-3 (L) - 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  13

  13. CHECK STOP LIGHT SWITCH ASSEMBLY 
    1. Check the stop light switch assembly.

      Refer to ON-VEHICLE INSPECTION [12/2019 - ]

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

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

    Result: 

    NG 

    REPLACE STOP LIGHT SWITCH ASSEMBLY. Refer to  REMOVAL [12/2019 - ] 

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