SMART ENTRY AND START SYSTEM(for Entry Function), Diagnostic DTC:B27A1

DTC Code DTC Name
B27A1 Open in Driver Side Electrical Antenna Circuit

DESCRIPTION

The certification ECU (smart key ECU assembly) generates a request signal and transmits the signal to the front door outside handle assembly LH (for driver door) [electrical key antenna] at intervals of 0.25 seconds. For the front door outside handle assembly LH (for driver door) [electrical key antenna] to detect when the electrical key transmitter sub-assembly is brought close to the vehicle, a signal requesting a response from the electrical key transmitter sub-assembly is transmitted within approximately 1 m (3.28 ft.) of the driver door at intervals of 0.25 seconds. DTC B27A1 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 front door outside handle assembly LH (for driver door) [electrical key antenna] (between terminals CLG1 and ANT1, or terminals CG1B and ANT2).

DTC Code DTC Detection Condition Trouble Area DTC Output Confirmation Operation
B27A1 An open circuit is detected in the circuit between the certification ECU (smart key ECU assembly) and front door outside handle assembly LH (for driver door) (CLG1 - ANT1, CG1B - ANT2) (This is detected by the malfunction detection circuit in the certification ECU (smart key ECU assembly)) (1 trip detection logic*).
  • Wire harness or connector

  • Front door outside handle assembly LH (for driver door)

  • 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
Entry lock/unlock operation cannot be performed for driver door -
Related Data List and Active Test
DTC Code Data List and Active Test
B27A1 Key diagnostic mode can be used to perform troubleshooting

WIRING DIAGRAM

A0007LEE02

CAUTION / NOTICE / HINT

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 GTS with the vehicle power switch off, connect the GTS to the vehicle and turn a courtesy light switch on and off at intervals of 1.5 seconds or less until communication between the GTS and the vehicle begins. Then select the Model Code "KEY REGIST" under manual mode and enter the following menus: Body Electrical / Entry&Start(CAN). While using the GTS, periodically turn a courtesy light switch on and off at intervals of 1.5 seconds or less to maintain communication between the GTS and the vehicle.

  • 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 front door outside handle assembly LH (for driver door) has an antenna coil between ANT1 and ANT2 terminals.

PROCEDURE


  1. CHECK CONNECTOR CONNECTION


    1. Turn the power switch off.

    2. Check that the connectors are properly connected to the certification ECU (smart key ECU assembly) and front door outside handle assembly LH (for driver door).

      OK
      Connectors are properly connected.

    NG
    OK
  2. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - FRONT DOOR OUTSIDE HANDLE ASSEMBLY LH)


    1. Disconnect the H57 certification ECU (smart key ECU assembly) connector.

    2. Disconnect the M11 front door outside handle assembly LH (for driver door) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H57-5 (CLG1) - M11-6 (ANT1) Always Below 1 Ω
      H57-4 (CG1B) - M11-3 (ANT2) Always Below 1 Ω
      H57-1 (E) - Body ground Always Below 1 Ω
      M11-2 (GND) - Body ground Always Below 1 Ω
      H57-5 (CLG1) or M11-6 (ANT1) - Body ground Always 10 kΩ or higher
      H57-4 (CG1B) or M11-3 (ANT2) - Body ground Always 10 kΩ or higher

    NG
    OK
  3. CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) (OUTPUT TO DRIVER SIDE ELECTRICAL KEY ANTENNA)


    1. Connect the H57 certification ECU (smart key ECU assembly) connector.

      A0007PIE02
      Text in Illustration
      *1 Waveform 1 *2 Waveform 2
      *a

      Component with harness connected

      (Certification ECU (smart key ECU assembly))

      - -
    2. Connect the M11 front door outside handle assembly LH (for driver door) connector.

    3. Using an oscilloscope, check the waveform.

      OK
      Tester Connection Condition Tool Setting Specified Condition
      H57-5 (CLG1) - H57-1 (E)

      Procedure:


      1. Power switch off

      2. Electrical key transmitter sub-assembly brought outside vehicle

      3. All doors closed

      4. Electrical key transmitter sub-assembly not inside vehicle

      5. Electrical key transmitter sub-assembly brought inside detection area*1

      6. All doors locked through wireless operation

      2 V/DIV., 500 ms/DIV. Pulse generation (See waveform 1)
      H57-5 (CLG1) - H57-1 (E)

      Procedure:


      1. Power switch off

      2. Electrical key transmitter sub-assembly brought outside vehicle

      3. All doors closed

      4. Electrical key transmitter sub-assembly not inside vehicle

      5. Electrical key transmitter sub-assembly brought outside detection area*2

      6. All doors locked through wireless operation

      2 V/DIV., 500 ms/DIV. Pulse generation (See waveform 2)
      H57-4 (CG1B) - H57-1 (E)

      Procedure:


      1. Power switch off

      2. Electrical key transmitter sub-assembly brought outside vehicle

      3. All doors closed

      4. Electrical key transmitter sub-assembly not inside vehicle

      5. All doors locked through wireless operation

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

      • *1: For details about the areas that are inside the entry function detection area, refer to Operation Check Click here.

      • *2: For details about the areas that are outside the entry function detection area, refer to Operation Check Click here.


    NG
    OK
  4. REPLACE FRONT DOOR OUTSIDE HANDLE ASSEMBLY LH (FOR DRIVER DOOR)


    1. Temporarily replace the front door outside handle assembly LH (for driver door) 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 B27A1 is not output.

    OK
    NG