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 (for driver door) [electrical key antenna] at intervals of 0.25 seconds. For the front door outside handle assembly (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 (for driver door) [electrical key antenna] (between terminals CLG1 and ANT1, or terminals CG1B and ANT2).

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

DTC Output from

B27A1

Open in Driver Side Electrical Antenna Circuit

An open circuit is detected in the circuit between the certification ECU (smart key ECU assembly) and front door outside handle assembly (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*).

  • Harness or connector

  • Front door outside handle assembly (for driver door)

  • Certification ECU (smart key ECU assembly)

Any time

*: Only output while a malfunction is present.

Table 1. 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

-
Table 2. 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

B341225E11

CAUTION / NOTICE / HINT

Note:

  • The 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 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. 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 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 (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 (for driver door).

      OK

      Connectors are properly connected.

    Result

    Proceed to

    OK

    NG
    NG

    CONNECT CONNECTORS PROPERLY

    OK

  2. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - FRONT DOOR OUTSIDE HANDLE ASSEMBLY AND BODY GROUND)

    • *1: for LHD

    • *2: for RHD

    1. Disconnect the G82 and G84 certification ECU (smart key ECU assembly) connectors.

    2. Disconnect the J6*1 or I6*2 front door outside handle assembly (for driver door) connector.

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

      Standard Resistance

      for LHD

      Tester Connection

      Condition

      Specified Condition

      G84-12 (CLG1) - J6-6 (ANT1)

      Always

      Below 1 Ω

      G84-13 (CG1B) - J6-3 (ANT2)

      Always

      Below 1 Ω

      G82-11 (E) - Body ground

      Always

      Below 1 Ω

      J6-2 (GND) - Body ground

      Always

      Below 1 Ω

      G84-12 (CLG1) or J6-6 (ANT1) - Body ground

      Always

      10 kΩ or higher

      G84-13 (CG1B) or J6-3 (ANT2) - Body ground

      Always

      10 kΩ or higher

      for RHD

      Tester Connection

      Condition

      Specified Condition

      G84-12 (CLG1) - I6-6 (ANT1)

      Always

      Below 1 Ω

      G84-13 (CG1B) - I6-3 (ANT2)

      Always

      Below 1 Ω

      G82-11 (E) - Body ground

      Always

      Below 1 Ω

      I6-2 (GND) - Body ground

      Always

      Below 1 Ω

      G84-12 (CLG1) or I6-6 (ANT1) - Body ground

      Always

      10 kΩ or higher

      G84-13 (CG1B) or I6-3 (ANT2) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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

    1. Connect the G82 and G84 certification ECU (smart key ECU assembly) connectors.

      B271427C24

      *a

      Component with harness connected

      (Certification ECU [Smart Key ECU Assembly])

      *b

      Waveform 1

      *c

      Waveform 2

      -

      -

    2. Using an oscilloscope, check the waveform.

      OK

      Tester Connection

      Switch Condition

      Tool Setting

      Specified Condition

      G84-12 (CLG1) - G82-11 (E)

      1. Procedure:

      2. Power switch off

      3. Electrical key transmitter sub-assembly brought outside vehicle

      4. All doors closed

      5. Electrical key transmitter sub-assembly not inside vehicle

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

      7. All doors locked through wireless operation

      2 V/DIV., 500 ms/DIV.

      Pulse generation

      (See waveform 1)

      G84-12 (CLG1) - G82-11 (E)

      1. Procedure:

      2. Power switch off

      3. Electrical key transmitter sub-assembly brought outside vehicle

      4. All doors closed

      5. Electrical key transmitter sub-assembly not inside vehicle

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

      7. All doors locked through wireless operation

      2 V/DIV., 500 ms/DIV.

      Pulse generation

      (See waveform 2)

      G84-13 (CG1B) - G82-11 (E)

      1. Procedure:

      2. Power switch off

      3. Electrical key transmitter sub-assembly brought outside vehicle

      4. All doors closed

      5. Electrical key transmitter sub-assembly not inside vehicle

      6. 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 hereClick here

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

        Click hereClick here

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    OK

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

    1. Temporarily replace the front door outside handle assembly (for driver door) with a new or known good one.

      Click here

    Result

    Proceed to

    NEXT
    NEXT

  5. CLEAR DTC

    1. Clear the DTCs.

      Click here

      Body Electrical > Entry&Start > Clear DTCs

    Result

    Proceed to

    NEXT
    NEXT

  6. CHECK FOR DTC

    1. Check for DTCs.

      Click here

      Body Electrical > Entry&Start > Trouble Codes

    Result

    Proceed to

    DTC B27A1 is not output

    DTC B27A1 is output
    DTC B27A1 is not output

    END (FRONT DOOR OUTSIDE HANDLE ASSEMBLY [FOR DRIVER DOOR] WAS DEFECTIVE)

    DTC B27A1 is output

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)