SMART ENTRY AND START SYSTEM(for Entry Function), Diagnostic DTC:B27A8

DTC Code DTC Name
B27A8 Open in Outside Luggage Compartment Electrical Key Antenna Circuit

DESCRIPTION

When the back door opener switch assembly is pressed, the certification ECU (smart key control ECU assembly) generates a request signal and sends it through the No. 2 indoor electrical key antenna assembly (back door).

The electrical key antenna transmits the received signal within an area of approximately 0.7 m (2.30 ft.) from the back door in order to detect the person carrying the electrical key transmitter sub-assembly.

DTC B27A8 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. 2 indoor electrical key antenna assembly (back door) (between terminals CLG8 and ANTE8, or terminals CG8B and CLGB).

DTC No. Detection Item DTC Detection Condition Trouble Area Note
B27A8 Open in Outside Luggage Compartment Electrical Key Antenna Circuit An open circuit is detected in the circuit between the certification ECU (smart key ECU assembly) and No. 2 indoor electrical key antenna assembly (back door) (CLG8 - ANTE8, CG8B - CLGB) (This is detected by the malfunction detection circuit in the certification ECU (smart key ECU assembly)) (1 trip detection logic*).

  • Harness or connector

  • No. 2 indoor electrical key antenna assembly (back door)

  • Certification ECU (smart key ECU assembly)

    DTC Output Confirmation Operation:

  • Any time

*: Only output while a malfunction is present.

Vehicle Condition and Fail-safe Operation when Malfunction Detected
Vehicle Condition when Malfunction Detected Vehicle Condition when Malfunction Detected
Entry lock/unlock operation cannot be performed for back door -
Related Data List and Active Test
DTC No. Data List and Active Test
B27A8 Key diagnostic mode can be used to perform troubleshooting

WIRING DIAGRAM

B003KV5E05

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 engine 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".

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. 2 indoor electrical key antenna assembly (back door).

      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) - NO. 2 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (BACK DOOR))


    1. Disconnect the G17 certification ECU (smart key ECU assembly) connector.

    2. Disconnect V11 No. 2 indoor electrical key antenna assembly (back door) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G17-8 (CLG8) - V11-1 (ANTE8) Always Below 1 Ω
      G17-24 (CG8B) - V11-3 (CLGB) Always Below 1 Ω
      G17-8 (CLG8) or V11-1 (ANTE8) - Body ground Always 10 kΩ or higher
      G17-24 (CG8B) or V11-3 (CLGB) - 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 NO. 2 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (BACK DOOR))


    1. Connect the G17 certification ECU (smart key ECU assembly) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G16-10 (E) - Body ground Always Below 1 Ω

    3. Using an oscilloscope, check the waveform.

      B003PSAC03
      *a

      Component with harness connected

      (Certification ECU (Smart Key ECU Assembly))

      		 *b Waveform 1
      *c Back door opener switch assembly is pressed - -
      OK
      Tester Connection Condition Tool Setting Specified Condition
      G17-8 (CLG8) - G16-10 (E)

      Procedure:


      1. Engine switch off

      2. All doors closed

      		 - Not pulse generation

      Procedure:


      1. Engine switch off

      2. All doors closed

      3. Back door opener switch assembly off → on.

      		 2 V/DIV., 500 ms./DIV.

      Pulse generation

      (See waveform 1)
      G17-24 (CG8B) - G16-10 (E)

      Procedure:


      1. Engine switch off

      2. All doors closed

      		 - Not pulse generation

      Procedure:


      1. Engine switch off

      2. All doors closed

      3. Back door opener switch assembly off → on.

      		 2 V/DIV., 500 ms./DIV.

      Pulse generation

      (See waveform 1)
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    OK

  4. REPLACE NO. 2 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (BACK DOOR)


    1. Temporarily replace the No. 2 indoor electrical key antenna assembly (back 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 the DTCs.

      Click here


      Body Electrical > Entry&Start > Trouble Codes
      OK
      DTC B27A8 is not output.
      Result
      Proceed to
      OK
      NG

    OK

    END (NO. 2 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (BACK DOOR) WAS DEFECTIVE)

    NG

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)