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DTC B2274: ACC Monitor Malfunction [08/2014 - ]: Procedure

  1. CHECK HARNESS AND CONNECTOR (POWER SOURCE) See step   1 

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

    OK: Go to next step 

  2. CHECK HARNESS AND CONNECTOR (GROUND) See step   2 

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  3. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY) 
    1. Disconnect the H56 certification ECU (smart key ECU assembly) connector.
    2. Disconnect the 3B instrument panel junction block assembly connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      H56-4 (ACCD) - 3B-23 Always Below 1 Ω
      3B-7 - Body ground Always Below 1 Ω
      H56-4 (ACCD) or 3B-23 - Body ground Always 10 kΩ or higher

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  4. CHECK INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY (ACC RELAY) 
    1. Remove the instrument panel junction block assembly.. Refer to REMOVAL [08/2014 - ]
      GTY366791Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *a Component without harness connected
      (Instrument Panel Junction Block Assembly)      		 - -
    2. Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.. Refer to REMOVAL [08/2014 - ]
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      • 3E-1 - 3B-37
      • 3E-1 - 3A-32
      		 Battery voltage not applied to terminals 3B-23 and 3B-7 10 kΩ or higher
      Battery voltage applied to terminals 3B-23 and 3B-7 Below 1 Ω

    NG → REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY 

    OK: Go to next step 

  5. INSPECT CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) 
    GTY416542Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Reconnect the H56 certification ECU (smart key ECU assembly) connector.
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      H56-4 (ACCD) - Body ground Engine switch off → Engine switch on (ACC) 1 V or less → 8.5 V or higher
      TEXT IN ILLUSTRATION

      *a Component with harness connected
      (Certification ECU (Smart Key ECU Assembly))

    NG → See step   6 

    OK → See step   7 

  6. REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to  REMOVAL [08/2014 - ] 
  7. USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [08/2014 - ] 
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