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DTC B2278: Engine/Power Switch Malfunction [10/2015 - ]: Procedure

  1. READ VALUE USING TECHSTREAM (START SWITCH1, START SWITCH2) 
    1. Connect the Techstream to the DLC3.
    2. Turn the power switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Body Electrical / Power Source Control / Data List.
    5. Read the Data List according to the display on the Techstream.

      Body Electrical > Power Source Control > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Start Switch1 Power switch 1 status OFF or ON OFF: Power switch not pressed
      ON: Power switch pressed
      • If the power switch is pressed for a short time, the display may not change.
      • Use this item to determine if the power switch input signal is malfunctioning.
      Start Switch2 Power switch 2 status OFF or ON OFF: Power switch not pressed
      ON: Power switch pressed
      • Backup for power switch 1. However, when the power switch is pressed and held, the power source mode can only be changed when both power switch 1 and 2 are normal.
      • Behaves the same way as power switch 1.

      Body Electrical > Power Source Control > Data List 

      Tester Display
      Start Switch1
      Start Switch2

      OK

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

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  3

    Result: 

    OK 

    See step  2

  2. READ VALUE USING TECHSTREAM (START SWITCH1, START SWITCH2) 
    1. Connect the Techstream to the DLC3.
    2. Turn the power switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Body Electrical / Power Source Control / Data List.
    5. According to the display on the Techstream, read the Data List while wiggling the wire harness.

      Body Electrical > Power Source Control > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Start Switch1 Power switch 1 status OFF or ON OFF: Power switch not pressed
      ON: Power switch pressed
      • If the power switch is pressed for a short time, the display may not change.
      • Use this item to determine if the power switch input signal is malfunctioning.
      Start Switch2 Power switch 2 status OFF or ON OFF: Power switch not pressed
      ON: Power switch pressed
      • Backup for power switch 1. However, when the power switch is pressed and held, the power source mode can only be changed when both power switch 1 and 2 are normal.
      • Behaves the same way as power switch 1.

      Body Electrical > Power Source Control > Data List 

      Tester Display
      Start Switch1
      Start Switch2

      OK

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

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2015 - 08/2016]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [08/2016 - 12/2017]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [12/2017 - 03/2018]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [03/2018 - 08/2019]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [08/2019 - 07/2020]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [07/2020 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  3. CHECK HARNESS AND CONNECTOR (POWER SOURCE) 

    See step  1

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  4

  4. CHECK HARNESS AND CONNECTOR (GROUND) 

    See step  2

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  5

  5. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - POWER SWITCH) 
    1. Disconnect the J14 power switch connector.
    2. Measure the resistance according to the value (s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      J41-23 (SSW1) - J14-5 (SS1) Always Below 1 Ω
      J41-21 (SSW2) - J14-1 (SS2) Always Below 1 Ω
      J41-11 (AGND) - J14-6 (AGND) Always Below 1 Ω
      J41-23 (SSW1) or J14-5 (SS1) - Body ground Always 10 kΩ or higher
      J41-21 (SSW2) or J14-1 (SS2) - Body ground Always 10 kΩ or higher
      J41-11 (AGND) or J14-6 (AGND) - 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. INSPECT POWER SWITCH 
    1. Remove the power switch.

      Refer to REMOVAL [10/2015 - ]

    2. Inspect the power switch.

      Refer to INSPECTION [10/2015 - ]

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to  REMOVAL [10/2015 - 08/2016]  , or refer to  REMOVAL [08/2016 - 03/2018]  , or refer to  REMOVAL [03/2018 - 08/2019]  , or refer to  REMOVAL [08/2019 - ] 

    Result: 

    NG 

    REPLACE POWER SWITCH. Refer to  REMOVAL [10/2015 - ] 

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