Click here

SMART ENTRY AND START SYSTEM(for Entry Function), Diagnostic DTC:B27A7

Click here
Click here
DTC Code DTC Name
B27A7 Open in Inside Luggage Compartment Electrical Key Oscillator Circuit
Click here

DESCRIPTION

The certification ECU (smart key ECU assembly) generates a request signal and transmits the signal to the NO. 1 indoor electrical key antenna assembly (inside luggage compartment). For the NO. 1 indoor electrical key antenna assembly (inside luggage compartment) to detect when the electrical key transmitter sub-assembly is inside the luggage compartment, the signal from the certification ECU (smart key ECU assembly) requesting a response from the electrical key transmitter sub-assembly is transmitted inside the luggage compartment. DTC B27A7 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. 1 indoor electrical key antenna assembly (inside luggage compartment) (between terminals CLG7 and ANTE7, or terminals CG7B and CLGB).

DTC Code DTC Detection Condition Trouble Area DTC Output Confirmation Operation
B27A7 An open circuit is detected in the circuit between the certification ECU (smart key ECU assembly) and NO. 1 indoor electrical key antenna assembly (inside luggage compartment) (CLG7 - ANTE7, CG7B - CLGB) (1 trip detection logic*).

  • Wire harness or connector

  • NO. 1 indoor electrical key antenna assembly (inside luggage compartment)

  • Certification ECU (smart key ECU assembly)

 Any time

Table 1. Vehicle Condition and Fail-safe Operation when Malfunction Detected
Vehicle Condition when Malfunction Detected Fail-safe Operation when Malfunction Detected

When electrical key transmitter sub-assembly is in luggage compartment:


  • Electrical key transmitter sub-assembly becomes locked inside vehicle

 -
Table 2. Related Data List and Active Test
DTC Code Data List and Active Test
B27A7 Key diagnostic mode can be used to perform troubleshooting
Click here

WIRING DIAGRAM

Click here

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 (See page ).

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

  • The NO. 1 indoor electrical key antenna assembly (inside luggage compartment) has an antenna coil between ANTE7 and CLGB terminals.

Click here

Click here

PROCEDURE


  1. Click here

    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 NO. 1 indoor electrical key antenna assembly (inside luggage compartment).

      OK
      Connectors are properly connected.

  2. Click here

    CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - NO. 1 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY)


    1. Disconnect the Q2 and H57 certification ECU (smart key ECU assembly) connectors.

    2. Disconnect the Q25 NO. 1 indoor electrical key antenna assembly (inside luggage compartment) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Q2-4 (CLG7) - Q25-1 (ANTE7) Always Below 1 Ω
      Q2-3 (CG7B) - Q25-3 (CLGB) Always Below 1 Ω
      H57-1 (E) - Body ground Always Below 1 Ω
      Q2-4 (CLG7) or Q25-1 (ANTE7) - Body ground Always 10 kΩ or higher
      Q2-3 (CG7B) or Q25-3 (CLGB) - Body ground Always 10 kΩ or higher

    • OKClick here
    • NG

      REPAIR OR REPLACE HARNESS OR CONNECTOR

  3. Click here

    CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) (OUTPUT TO NO. 1 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY)


    1. A0004XBE02

      Connect the Q2 and H57 certification ECU (smart key ECU assembly) connectors.

      Table 3. Text in Illustration
      *1 Waveform - -
      *a

      Component with harness connected

      (Certification ECU (smart key ECU assembly))

      		 *b Before driver door lock sensor touched
      *c After driver door lock sensor touched - -

    2. Connect the Q25 NO. 1 indoor electrical key antenna assembly (inside luggage compartment) connector.

    3. Using an oscilloscope, check the waveform.

      OK
      Tester Connection Condition Tool Setting Specified Condition
      Q2-4 (CLG7) - H57-1 (E)

      Procedure:


      1. Power switch off

      2. Electrical key transmitter sub-assembly not inside vehicle

      3. All doors closed

      4. Driver door lock sensor not touched → touched

      		 2 V/DIV., 500 ms/DIV. Pulse generation (See waveform)
      Q2-3 (CG7B) - H57-1 (E)

      Procedure:


      1. Power switch off

      2. Electrical key transmitter sub-assembly not inside vehicle

      3. All doors closed

      4. Driver door lock sensor not touched → touched

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

    • OKClick here
    • NG

      REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

  4. Click here

    REPLACE NO. 1 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (INSIDE LUGGAGE COMPARTMENT)


    1. Temporarily replace the NO. 1 indoor electrical key antenna assembly (inside luggage compartment) with a new or known good one (Click here).


  5. Click here

    CLEAR DTC


    1. Clear the DTCs (Click here).


  6. Click here

    CHECK FOR DTC


    1. Check for DTCs (Click here).

      OK
      DTC B27A7 is not output.

    • OK

      END (NO. 1 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (INSIDE LUGGAGE COMPARTMENT) WAS DEFECTIVE)

    • NG

      REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)