SMART ENTRY AND START SYSTEM (for Entry Function), Diagnostic DTC:B27A7

DTC Code DTC Name
B27A7 Open in Inside Luggage Compartment Electrical Key Oscillator Circuit

DESCRIPTION

The certification ECU (smart key ECU assembly) generates a request signal and transmits the signal to the No. 3 indoor electrical key antenna assembly (inside luggage compartment). For the No. 3 indoor electrical key antenna assembly (inside luggage compartment) to detect when the electrical key transmitter sub-assembly is inside the luggage compartment, the signal from the certification ECU (smart key ECU assembly) requesting a response from the electrical key transmitter sub-assembly is transmitted inside the luggage compartment. DTC B27A7 is stored by the certification ECU (smart key ECU assembly) when an open circuit is detected between the certification ECU (smart key ECU assembly) and No. 3 indoor electrical key antenna assembly (inside luggage compartment) (between terminals CLG7 and CLG6*1 or ANTE7*2, or terminals CG7B and CLGB).

DTC Code DTC Detection Condition Trouble Area DTC Output Confirmation Operation
B27A7 An open circuit is detected in the circuit between the certification ECU (smart key ECU assembly) and No. 3 indoor electrical key antenna assembly (inside luggage compartment) (CLG7 - CLG6*1 or ANTE7*2, CG7B - CLGB) (1 trip detection logic*3).

  • Wire harness or connector

  • No. 3 indoor electrical key antenna assembly (inside luggage compartment)

  • Certification ECU (smart key ECU assembly)

 Any time

Vehicle Condition and Fail-safe Operation when Malfunction Detected
Vehicle Condition when Malfunction Detected Fail-safe Operation when Malfunction Detected

When electrical key transmitter sub-assembly is in luggage compartment:


  • Electrical key transmitter sub-assembly becomes locked inside vehicle

 -
Related Data List and Active Test
DTC Code Data List and Active Test
B27A7 Key diagnostic mode can be used to perform troubleshooting

WIRING DIAGRAM

B000MDOE50

INSPECTION PROCEDURE

Note


  • The smart entry and start system (for Entry Function) uses a multiplex communication system (LIN communication system) and the CAN communication system. Inspect the communication function by following How to Proceed with Troubleshooting Click here. Troubleshoot the smart entry and start system (for Entry Function) after confirming that the communication systems are functioning properly.

  • When using the intelligent tester with the engine switch off to troubleshoot:

    Connect the intelligent tester to the DLC3 and turn a courtesy light switch on and off at 1.5-second intervals until communication between the intelligent tester and vehicle begins.

  • Before replacing the certification ECU (smart key ECU assembly), refer to the smart entry and start system (for Entry Function) precaution Click here.

  • After repair, confirm that no DTCs are output by performing the "DTC Output Confirmation Operation".

  • The No. 3 indoor electrical key antenna assembly (inside luggage compartment) has an antenna coil between CLG6*1 or ANTE7*2 and CLGB terminals.


    • *1: except TMMK Made

    • *2: for TMMK Made

PROCEDURE


  1. CHECK CONNECTOR CONNECTION


    1. Turn the engine switch off.

    2. Check that the connectors are properly connected to the certification ECU (smart key ECU assembly) and No. 3 indoor electrical key antenna assembly (inside luggage compartment).

      OK
      Connectors are properly connected.

    NG

    CONNECT CONNECTORS PROPERLY

    OK

  2. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - NO. 3 INDOOR ELECTRICAL KEY ANTENNA)


    1. Disconnect the O1 certification ECU (smart key ECU assembly) connector.

    2. Disconnect the N38 No. 3 indoor electrical key antenna assembly (inside luggage compartment) connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      except TMMK Made
      Tester Connection Condition Specified Condition
      O1-9 (CLG7) - N38-1 (CLG6) Always Below 1 Ω
      O1-8 (CG7B) - N38-3 (CLGB) Always Below 1 Ω
      A43-11 (E) - Body ground Always Below 1 Ω
      O1-9 (CLG7) or N38-1 (CLG6) - Body ground Always 10 kΩ or higher
      O1-8 (CG7B) or N38-3 (CLGB) - Body ground Always 10 kΩ or higher
      for TMMK Made
      Tester Connection Condition Specified Condition
      O1-9 (CLG7) - N38-1 (ANTE7) Always Below 1 Ω
      O1-8 (CG7B) - N38-3 (CLGB) Always Below 1 Ω
      A43-11 (E) - Body ground Always Below 1 Ω
      O1-9 (CLG7) or N38-1 (ANTE7) - Body ground Always 10 kΩ or higher
      O1-8 (CG7B) or N38-3 (CLGB) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) (OUTPUT TO NO. 3 INDOOR ELECTRICAL KEY ANTENNA)


    1. Connect the O1 certification ECU (smart key ECU assembly) connector.

      B000LSVE03
      Text in Illustration
      *1 Waveform - -
      *a

      Component with harness connected

      (Certification ECU (smart key ECU assembly))

      		 *b Before driver door lock sensor touched
      *c After driver door lock sensor touched - -

    2. Connect the N38 No. 3 indoor electrical key antenna assembly (inside luggage compartment) connector.

    3. Using an oscilloscope, check the waveform.

      OK
      Tester Connection Switch Condition Tool Setting Specified Condition
      O1-9 (CLG7) - A43-11 (E)

      Proceed:


      1. Engine switch off

      2. Electrical key transmitter sub-assembly not inside vehicle

      3. All doors closed

      4. Driver door lock sensor not touched → touched

      		 2 V/DIV., 500 ms/DIV. Pulse generation (See waveform)
      O1-8 (CG7B) - A43-11 (E)

      Proceed:


      1. Engine switch off

      2. Electrical key transmitter sub-assembly not inside vehicle

      3. All doors closed

      4. Driver door lock sensor not touched → touched

      		 2 V/DIV., 500 ms/DIV. Pulse generation (See waveform)

    NG

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    OK

  4. REPLACE NO. 3 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (INSIDE LUGGAGE COMPARTMENT)


    1. Temporarily replace the No. 3 indoor electrical key antenna assembly (inside luggage compartment) with a new or known good one Click here.


    NEXT

  5. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  6. CHECK FOR DTC


    1. Check for DTCs Click here.

      OK
      DTC B27A7 is not output.

    NG

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    OK

    END (NO. 3 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (INSIDE LUGGAGE COMPARTMENT) WAS DEFECTIVE)