PUSH-BUTTON START, Diagnostic DTC:B27A5

DTC Code DTC Name
B27A5 Open in Front Floor Electrical Key Oscillator Circuit

DESCRIPTION

The certification ECU (smart key ECU assembly) generates a request signal and transmits the signal to the No. 3 indoor electrical key antenna assembly (front floor). For the No. 3 indoor electrical key antenna assembly (front 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 B27A5 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 (front floor) (between terminals CLG5 and ANTE5, or terminals CG5B and CLGB).

DTC No. Detection Item DTC Detection Condition Trouble Area Note
B27A5 Open in Front Floor Electrical Key Oscillator Circuit An open circuit is detected in the circuit between the certification ECU (smart key ECU assembly) and No. 3 indoor electrical key antenna assembly (front floor) (CLG5 - ANTE5, CG5B - CLGB) (1 trip detection logic*).
  • Wire harness or connector

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

  • Certification ECU (smart key ECU assembly)


    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 front 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
B27A5 Key diagnostic mode can be used to perform troubleshooting

WIRING DIAGRAM

A01KS2UE09

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 Click here. Troubleshoot the push-button start after confirming that the communication systems are functioning properly.

  • When using the GTS with the power 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 the entry and start system (for Entry Function) precaution.

    Click here

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

  • The No. 3 indoor electrical key antenna assembly (front floor) has an antenna coil between terminals ANTE5 and CLGB.

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

      OK
      Connectors are properly connected.
      Result
      Proceed to
      OK
      NG

    NG
    OK
  2. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - NO. 3 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY)


    1. Disconnect the E33 and E35 certification ECU (smart key ECU assembly) connectors.

    2. Disconnect the L24 No. 3 indoor electrical key antenna assembly (front floor) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E35-3 (CLG5) - L24-1 (ANTE5) Always Below 1 Ω
      E35-2 (CG5B) - L24-3 (CLGB) Always Below 1 Ω
      E33-11 (E) - Body ground Always Below 1 Ω
      E35-3 (CLG5) or L24-1 (ANTE5) - Body ground Always 10 kΩ or higher
      E35-2 (CG5B) or L24-3 (CLGB) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG
    OK
  3. CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) (OUTPUT TO NO. 3 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY)


    1. Connect the E33 and E35 certification ECU (smart key ECU assembly) connectors.

      A01KRE1C45
      *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
    2. Connect the L24 No. 3 indoor electrical key antenna assembly (front floor) connector.

    3. Using an oscilloscope, check the waveform.

      OK
      Tester Connection Condition Tool Setting Specified Condition
      E35-3 (CLG5) - E33-11 (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)

      E35-2 (CG5B) - E33-11 (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)

      Result
      Proceed to
      OK
      NG

    NG
    OK
  4. REPLACE NO. 3 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (FRONT FLOOR)


    1. Temporarily replace the No. 3 indoor electrical key antenna assembly (front floor) with a new or known good 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 B27A5 is not output.
      Result
      Proceed to
      OK
      NG

    OK
    NG