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DTC B2271: Ignition Hold Monitor Malfunction [10/2014 - ]: Procedure

  1. CHECK HARNESS AND CONNECTOR (POWER SOURCE) 
    1. Disconnect the I53 certification ECU (smart key ECU assembly) connector.
      GTY514149Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Certification ECU (Smart Key ECU Assembly))
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      I53-10 (+B) - Body ground Always 11 to 14 V

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR IN CIRCUIT CONNECTED TO POWER SOURCE 

    Result: 

    OK 

    See step  2

  2. CHECK HARNESS AND CONNECTOR (GROUND) 
    1. Disconnect the I53 certification ECU (smart key ECU assembly) connector.
    2. Measure the resistance according to the value(s) in the table below.
      GTY514150Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Certification ECU (Smart Key ECU Assembly))

      Standard Resistance

      Tester Connection Condition Specified Condition
      I53-11 (E) - Body ground Always Below 1 Ω

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  3

  3. CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) 
    1. Measure the voltage according to the value(s) in the table below.
      GTY516487Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (Certification ECU (Smart Key ECU Assembly))

      Standard Voltage

      Tester Connection Condition Specified Condition
      I51-3 (IG1D) - Body ground Power switch on (ACC) → Power switch on (IG) 1 V or less → 9 V or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    END (TEMPORARY CONNECTION FAILURE IS SUSPECTED). Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2014 - 09/2017]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [09/2017 - 05/2019]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [05/2019 - 10/2019]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2019 - 07/2020]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [07/2020 - ] 

    Result: 

    NG 

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to  REMOVAL [10/2014 - ] 

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