SMART ENTRY AND START SYSTEM (for Entry Function), Diagnostic DTC:B27AA

DTC Code DTC Name
B27AA Open in Floor 2 Electrical Key Oscillator Circuit

DESCRIPTION

When any door is opened or closed, the certification ECU (smart key ECU assembly) generates a request signal and sends it to the No. 3 indoor electrical key antenna assembly (rear floor). For the No. 3 indoor electrical key antenna assembly (rear floor) to detect when the electrical key transmitter sub-assembly is inside the vehicle, the signal from the certification ECU (smart key ECU assembly) requesting a response from the electrical key transmitter sub-assembly is transmitted inside the vehicle.

DTC B27AA 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. 3 indoor electrical key antenna assembly (rear floor) (between terminals CLG6 and ANTE6, or terminals BGND and CLGB).

DTC Code DTC Detection Condition Trouble Area DTC Output Confirmation Operation
B27AA An open circuit is detected in the circuit between the certification ECU (smart key ECU assembly) and No. 3 indoor electrical key antenna assembly (rear floor) (CLG6 - ANTE6, BGND - CLGB) (1 trip detection logic*).

  • Harness or connector

  • No. 3 indoor electrical key antenna assembly (rear floor)

  • Certification ECU (smart key ECU assembly)

 Any time

Vehicle Condition and Fail-safe Operation when Malfunction Detected
Vehicle Condition when Malfunction Detected Fail-safe Operation when Malfunction Detected
Electrical key transmitter sub-assembly locked inside vehicle -
Related Data List and Active Test
DTC Code Data List and Active Test
B27AA Key diagnostic mode can be used to perform troubleshooting

WIRING DIAGRAM

A003CYQE42

INSPECTION PROCEDURE

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. 3 indoor electrical key antenna assembly (rear floor).

      OK
      Connectors are properly connected.

    NG

    CONNECT CONNECTORS PROPERLY

    OK

  2. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU [SMART KEY ECU ASSEMBLY] - NO. 3 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY [REAR FLOOR])


    1. Disconnect the B76 certification ECU (smart key ECU assembly) connector.

    2. Disconnect the Y6 No. 3 indoor electrical key antenna assembly (rear floor) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      B76-26 (CLG6) - Y6-1 (ANTE6) Always Below 1 Ω
      B76-9 (BGND) - Y6-2 (CLGB) Always Below 1 Ω
      B76-26 (CLG6) or Y6-1 (ANTE6) - Body ground Always 10 kΩ or higher
      B76-9 (BGND) or Y6-2 (CLGB) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) (OUTPUT TO NO. 3 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY [REAR FLOOR])


    1. Connect the B76 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
      B75-10 (E) - Body ground Always Below 1 Ω

    3. Using an oscilloscope, check the waveform.

      A003C9KE09
      Text in Illustration
      *a

      Component with harness connected

      (Certification ECU [Smart Key ECU Assembly])

      		 *b Waveform 1
      *c Within approximately 30 seconds from when the door is closed *d After approximately 30 seconds from when the door is closed
      OK
      Tester Connection Condition Tool Setting Specified Condition
      B76-26 (CLG6) - B75-10 (E)

      Procedure:


      1. Engine switch off

      2. Electrical key transmitter sub-assembly not inside vehicle

      3. Door is open

      4. Door is closed

      5. Within 30 seconds

      		 2 V/DIV., 500 ms/DIV. Pulse generation (See waveform 1)
      B76-9 (BGND) - B75-10 (E)

      Procedure:


      1. Engine switch off

      2. Electrical key transmitter sub-assembly not inside vehicle

      3. Door is open

      4. Door is closed

      5. Within 30 seconds

      		 2 V/DIV., 500 ms/DIV. Pulse generation (See waveform 1)

    NG

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    OK

  4. REPLACE NO. 3 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (REAR FLOOR)


    1. Temporarily replace the No. 3 indoor electrical key antenna assembly (rear floor) with a new or known good one Click here.


    NEXT

  5. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  6. CHECK FOR DTC


    1. Check for DTCs Click here.

      OK
      DTC B27AA is not output.

    NG

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    OK

    END (NO. 3 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY [REAR FLOOR] WAS DEFECTIVE)