SMART KEY SYSTEM (for Entry Function), Diagnostic DTC:B27A6

DTC Code DTC Name
B27A6 Open in Rear Floor Electrical Key Oscillator Circuit

DESCRIPTION

The certification ECU (smart key ECU assembly) generates a request signal and transmits the signal to the No. 2 indoor electrical key antenna assembly (rear floor). For the No. 2 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 B27A6 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 (rear floor) (between terminals CLG6 and ANTE6, or terminals CG6B and CLGB).

DTC Code DTC Detection Condition Trouble Area DTC Output Confirmation Operation
B27A6 An open circuit is detected in the circuit between the certification ECU (smart key ECU assembly) and No. 2 indoor electrical key antenna assembly (rear floor) (CLG6 - ANTE6, CG6B - CLGB) (1 trip detection logic*).
  • Wire harness or connector

  • No. 2 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

When electrical key transmitter sub-assembly is in rear seat area:

  • Power source mode does not change when power switch pressed

  • Electrical key transmitter sub-assembly locked inside vehicle

-
Related Data List and Active Test
DTC Code Data List and Active Test
B27A6 Key diagnostic mode can be used to perform troubleshooting

WIRING DIAGRAM

A011W8ME57

INSPECTION PROCEDURE

Note

  • The smart key 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 key system (for Entry Function) after confirming that the communication systems are functioning properly.

  • When using the Techstream with the power switch off to troubleshoot:

    Connect the Techstream to the DLC3 and turn a courtesy light switch on and off at 1.5-second intervals until communication between the Techstream and vehicle begins.

  • Before replacing the certification ECU (smart key ECU assembly), refer to the smart key system (for Entry Function) precaution Click here.

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

  • The No. 2 indoor electrical key antenna assembly (rear floor) has an antenna coil between ANTE6 and CLGB terminals.

PROCEDURE

  1. 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. 2 indoor electrical key antenna assembly (rear floor).

      OK
      Connectors are properly connected.
    NG
    OK
  2. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - NO. 2 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY)

    1. Disconnect the O2 and I86 certification ECU (smart key ECU assembly) connectors.

    2. Disconnect the N10 No. 2 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
      O2-14 (CLG6) - N10-1 (ANTE6) Always Below 1 Ω
      O2-5 (CG6B) - N10-3 (CLGB) Always Below 1 Ω
      I86-1 (E) - Body ground Always Below 1 Ω
      O2-14 (CLG6) or N10-1 (ANTE6) - Body ground Always 10 kΩ or higher
      O2-5 (CG6B) or N10-3 (CLGB) - Body ground Always 10 kΩ or higher
    NG
    OK
  3. CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) (OUTPUT TO NO. 2 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY)

    1. Connect the O2 and I86 certification ECU (smart key ECU assembly) connectors.

      A011VLSE04
      Text in Illustration
      *1 Waveform - -
      *a

      Component with harness connected

      (Certification ECU (smart key ECU assembly))

      *b Within approximately 30 seconds from when the door is closed
      *c After approximately 30 seconds from when the door is closed - -
    2. Connect the N10 No. 2 indoor electrical key antenna assembly (rear floor) connector.

    3. Using an oscilloscope, check the waveform.

      OK
      Tester Connection Switch Condition Tool Setting Specified Condition
      O2-14 (CLG6) - I86-1 (E)

      Procedure:

      1. Power 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)
      O2-5 (CG6B) - I86-1 (E)

      Procedure:

      1. Power 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)
    NG
    OK
  4. REPLACE NO. 2 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (REAR FLOOR)

    1. Temporarily replace the No. 2 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 B27A6 is not output.
    NG
    OK