ENTRY AND START SYSTEM(for Entry Function), Diagnostic DTC:B27A4

DTC Code DTC Name
B27A4 Open in Rear Door Electrical Antenna Circuit, Front Passengers Side

DESCRIPTION

The certification ECU (smart key ECU assembly) generates a request signal and transmits the signal to the rear door outside handle assembly (for front passenger side) (electrical key antenna) at intervals of 0.25 seconds. For the rear door outside handle assembly (for front passenger side) (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 rear door at intervals of 0.25 seconds. DTC B27A4 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 rear door outside handle assembly (for front passenger side) (electrical key antenna) (between terminals CLG4 and ANT1, or terminals CG4B and ANT2).

DTC No. Detection Item DTC Detection Condition Trouble Area Note
B27A4 Open in Rear Door Electrical Antenna Circuit, Front Passengers Side An open circuit is detected in the circuit between the certification ECU (smart key ECU assembly) and rear door outside handle assembly (for front passenger side) (CLG4 - ANT1, CG4B - ANT2) (This is detected by the malfunction detection circuit in the certification ECU (smart key ECU assembly)) (1 trip detection logic*).

  • Certification ECU (smart key ECU assembly)

  • Rear door outside handle assembly (for front passenger side)

  • Harness or connector

    DTC Output Confirmation Operation:

  • 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 rear door (for front passenger side) -
Related Data List and Active Test
DTC Code Data List and Active Test
B27A4 Key diagnostic mode can be used to perform troubleshooting

WIRING DIAGRAM

B004VACE34

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. Troubleshoot the entry and start system (for Entry Function) after confirming that the communication systems are functioning properly.

    Click here

  • When using the GTS with the power 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. 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 Service Bulletin.

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

PROCEDURE


  1. CHECK CONNECTOR CONNECTION


    1. Check that the connectors are properly connected to the certification ECU (smart key ECU assembly) and rear door outside handle assembly (for front passenger side).

      OK
      Connectors are properly connected.
      Result
      Proceed to
      OK
      NG

    NG

    CONNECT CONNECTORS PROPERLY

    OK

  2. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - REAR DOOR OUTSIDE HANDLE ASSEMBLY (FOR FRONT PASSENGER SIDE))


    1. Disconnect the L31 certification ECU (smart key ECU assembly) connectors.

    2. Disconnect the K5*1 or K19*2 rear door outside handle assembly (for front passenger side) connector.


      • *1: for LHD

      • *2: for RHD

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

      Standard Resistance
      for LHD:
      Tester Connection Condition Specified Condition
      L31-9 (CLG4) - K5-4 (ANT1) Always Below 1 Ω
      L31-8 (CG4B) - K5-5 (ANT2) Always Below 1 Ω
      for RHD:
      Tester Connection Condition Specified Condition
      L31-9 (CLG4) - K19-4 (ANT1) Always Below 1 Ω
      L31-8 (CG4B) - K19-5 (ANT2) Always Below 1 Ω

    4. Reconnect the L31 certification ECU (smart key ECU assembly) connectors.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) (OUTPUT TO REAR DOOR OUTSIDE HANDLE ASSEMBLY (FOR FRONT PASSENGER SIDE))

    B004XZCC21
    *a

    Component with harness connected

    (Certification ECU (Smart Key ECU Assembly))

    		 *b Waveform 1
    *c Waveform 2 *d Waveform 3
    *e Waveform 4 - -

    1. Using an oscilloscope, check the waveform.

      OK
      Tester Connection Condition Tool Setting Specified Condition
      L31-9 (CLG4) - G71-18 (E)

      Procedure:


      1. Power switch off

      2. All doors closed

      3. Electrical key transmitter sub-assembly not inside vehicle

      4. All doors locked through wireless operation

        (electrical key transmitter sub-assembly brought inside detection area*)

      		 5 V/DIV., 500 ms/DIV.

      Pulse generation

      (See waveform 1)

      Procedure:


      1. Power switch off

      2. All doors closed

      3. Electrical key transmitter sub-assembly not inside vehicle

      4. All doors locked through wireless operation

        (electrical key transmitter sub-assembly brought outside detection area*)

      		 5 V/DIV., 100 ms/DIV.

      Pulse generation

      (See waveform 2)
      L31-8 (CG4B) - G71-18 (E)

      Procedure:


      1. Power switch off

      2. All doors closed

      3. Electrical key transmitter sub-assembly not inside vehicle

      4. All doors locked through wireless operation

        (electrical key transmitter sub-assembly brought inside detection area*)

      		 5 V/DIV., 500 ms/DIV.

      Pulse generation

      (See waveform 3)

      Procedure:


      1. Power switch off

      2. All doors closed

      3. Electrical key transmitter sub-assembly not inside vehicle

      4. All doors locked through wireless operation

        (electrical key transmitter sub-assembly brought outside detection area*)

      		 5 V/DIV., 100 ms/DIV.

      Pulse generation

      (See waveform 4)

      • *: For details about the entry function detection area, refer to Operation Check.

        Click here

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE REAR DOOR OUTSIDE HANDLE ASSEMBLY (FOR FRONT PASSENGER SIDE) Click here

    NG

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)