PUSH-BUTTON START, 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 in the cabin, 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 No. Detection Item DTC Detection Condition Trouble Area Note
B27A6 Open in Rear Floor Electrical Key Oscillator 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 (rear floor) (CLG6 - ANTE6, CG6B - CLGB) (1 trip detection logic*).

  • Certification ECU (smart key ECU assembly)

  • No. 2 indoor electrical key antenna assembly (rear floor)

  • 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

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


  • Power source mode does not change when engine switch pressed

  • Electrical key transmitter sub-assembly locked inside vehicle

 -
Related Data List and Active Test
DTC No. Data List and Active Test
B27A6 Key diagnostic mode can be used to perform troubleshooting

WIRING DIAGRAM

A01Q96FE10
A01Q96FE11

CAUTION / NOTICE / HINT

Note


  • The push-button start uses the LIN communication system and CAN communication system. Inspect the communication function by following How to Proceed with Troubleshooting. Troubleshoot the push-button start after confirming that the communication systems are functioning properly.

    Click here

  • When using the GTS with the engine 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(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 push-button start Precaution.

    Click here

  • 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 No. 2 indoor electrical key antenna assembly (rear floor).

      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 (REAR FLOOR))


    1. for LHD


      1. Disconnect the T1 and A21 certification ECU (smart key ECU assembly) connectors.

      2. Disconnect the U10 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
        T1-11 (CLG6) - U10-1 (ANTE6) Always Below 1 Ω
        T1-10 (CG6B) - U10-3 (CLGB) Always Below 1 Ω
        A21-11 (E) - Body ground Always Below 1 Ω
        T1-11 (CLG6) or U10-1 (ANTE6) - Body ground Always 10 kΩ or higher
        T1-10 (CG6B) or U10-3 (CLGB) - Body ground Always 10 kΩ or higher

      4. Reconnect the T1 and A21 certification ECU (smart key ECU assembly) connectors.

      5. Reconnect the U10 No. 2 indoor electrical key antenna assembly (rear floor) connector.

    2. for RHD


      1. Disconnect the U1 and A21 certification ECU (smart key ECU assembly) connectors.

      2. Disconnect the U10 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
        U1-11 (CLG6) - U10-1 (ANTE6) Always Below 1 Ω
        U1-10 (CG6B) - U10-3 (CLGB) Always Below 1 Ω
        A21-11 (E) - Body ground Always Below 1 Ω
        U1-11 (CLG6) or U10-1 (ANTE6) - Body ground Always 10 kΩ or higher
        U1-10 (CG6B) or U10-3 (CLGB) - Body ground Always 10 kΩ or higher

      4. Reconnect the U1 and A21 certification ECU (smart key ECU assembly) connectors.

      5. Reconnect the U10 No. 2 indoor electrical key antenna assembly (rear floor) connector.

      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 (REAR FLOOR))

    A01QC54C51
    *A for LHD *B for RHD
    *a

    Component with harness connected

    (Certification ECU (Smart Key ECU Assembly))

    		 *b Waveform
    *c Within approximately 30 seconds from when the door is closed *d After approximately 30 seconds from when the door is closed

    1. Using an oscilloscope, check the waveform.

      OK
      Tester Connection Switch Condition Tool Setting Specified Condition

      T1-11 (CLG6) - A21-11 (E)*1

      U1-11 (CLG6) - A21-11 (E)*2

        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)

      T1-10 (CG6B) - A21-11 (E)*1

      U1-10 (CG6B) - A21-11 (E)*2

        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: for LHD

      • *2: for RHD

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    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 one.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  5. CLEAR DTC


    1. Clear the DTCs.


      Body Electrical > Entry&Start > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

  6. CHECK FOR DTC


    1. Check for DTCs.


      Body Electrical > Entry&Start > Trouble Codes
      OK
      DTC B27A6 is not output.
      Result
      Proceed to
      OK
      NG

    OK

    END (NO. 2 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (REAR FLOOR) WAS DEFECTIVE)

    NG

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)