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

Note

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*).

  • Wire harness or connector

  • Front door outside handle assembly (for driver door)

  • Certification ECU (smart key ECU assembly)

  • DTC Output Confirmation Operation

  • 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

B281953E77

CAUTION / NOTICE / HINT

Note:

  • The entry and start system (for Entry Function) uses the LIN communication system and CAN communication system. Inspect the communication function by following How to Proceed with Troubleshooting (Click hereClick 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 engine switch off, connect the GTS to the DLC3 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 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 entry and start system (for Entry Function) Precaution.

    Click here

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

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

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 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)

    1. Disconnect the E33 and E35 certification ECU (smart key ECU assembly) connectors.

    2. Disconnect the H13*1 or G7*2 front door outside handle assembly (for driver door) connector.

      • *1: for LHD

      • *2: for RHD

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

      Standard Resistance

      Table 3. for LHD

      Tester Connection

      Condition

      Specified Condition

      E35-12 (CLG1) - H13-6(ANT1)

      Always

      Below 1 Ω

      E35-13 (CG1B) - H13-3(ANT2)

      Always

      Below 1 Ω

      E33-11 (E) - Body ground

      Always

      Below 1 Ω

      H13-2 (GND) - Body ground

      Always

      Below 1 Ω

      E35-12 (CLG1) or H13-6(ANT1) - Body ground

      Always

      10 kΩ or higher

      E35-13 (CG1B) or H13-3(ANT2) - Body ground

      Always

      10 kΩ or higher
      Table 4. for RHD

      Tester Connection

      Condition

      Specified Condition

      E35-12 (CLG1) - G7-6(ANT1)

      Always

      Below 1 Ω

      E35-13 (CG1B) - G7-3(ANT2)

      Always

      Below 1 Ω

      E33-11 (E) - Body ground

      Always

      Below 1 Ω

      G7-2 (GND) - Body ground

      Always

      Below 1 Ω

      E35-12 (CLG1) or G7-6(ANT1) - Body ground

      Always

      10 kΩ or higher

      E35-13 (CG1B) or G7-3(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 E33 and E35 certification ECU (smart key ECU assembly) connectors.

      B271427C22

      *a

      Component with harness connected

      (Certification ECU (Smart Key ECU Assembly))

      *b

      Waveform 1

      *c

      Waveform 2

      -

      -

    2. Connect the H13*1 or G7*2 front door outside handle assembly (for driver door) connector.

      • *1: for LHD

      • *2: for RHD

    3. Using an oscilloscope, check the waveform.

      OK

      Tester Connection

      Condition

      Tool Setting

      Specified Condition

      E35-12 (CLG1) - E33-11 (E)

      Procedure:

      1. Engine 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)

      E35-12 (CLG1) - E33-11 (E)

      Procedure:

      1. Engine 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)

      E35-13 (CG1B) - E33-11 (E)

      Procedure:

      1. Engine 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)

    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.

      for Sedan:Click here

      except Sedan:Click hereClick here

    Result

    Proceed to

    NEXT
    NEXT

  5. CLEAR DTC

    1. Clear the DTCs.

      Body Electrical > Entry&Start > Clear DTCs

    Result

    Proceed to

    NEXT
    NEXT

  6. CHECK FOR DTC

    1. Check for DTCs.

      Body Electrical > Entry&Start > Trouble Codes

      OK

      DTC B27A1 is not output.

    Result

    Proceed to

    OK

    NG
    OK

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

    NG

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)