ENTRY AND START SYSTEM (for Entry Function), Diagnostic DTC:B27A5

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

DESCRIPTION

The certification ECU generates a request signal and transmits the signal to the indoor electrical key oscillator (front floor). The indoor electrical key oscillator (front floor) detects that the electrical key is inside the vehicle and transmits the request signal received from the certification ECU. DTC B27A5 is stored by the certification ECU when an open circuit is detected in the circuit between the certification ECU and indoor electrical key oscillator (front floor) (CLG5 - CLG3, CG5B - CLGB).

DTC Code DTC Detection Condition Trouble Area
B27A5 Open circuit is detected in the circuit between the certification ECU and indoor electrical key oscillator (front floor) (CLG5 - CLG3, CG5B - CLGB).

  • Wire harness or connector

  • Indoor electrical key oscillator (front floor)

  • Certification ECU

WIRING DIAGRAM

A003DGDE03

INSPECTION PROCEDURE

Note

When using the intelligent tester with the engine switch off to troubleshoot: Connect the intelligent tester to the DLC3, and turn a courtesy light switch on and off at 1.5-second intervals until communication between the tester and vehicle begins.

PROCEDURE


  1. CHECK CONNECTOR CONNECTION CONDITION


    1. Turn the engine switch off.

    2. Check that the connectors are properly connected to the certification ECU and indoor electrical key oscillator (front floor).

      OK
      Connectors are properly connected.

    NG

    CONNECT CONNECTORS PROPERLY

    OK

  2. CHECK HARNESS AND CONNECTOR (INDOOR ELECTRICAL KEY OSCILLATOR - CERTIFICATION ECU)


    1. A003D56E05
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Indoor Electrical Key Oscillator (Front Floor))
      *2

      Front view of wire harness connector

      (to Certification ECU)

      Disconnect the D54 ECU connector.

    2. Disconnect the D55 oscillator connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D55-1 (CLG3) - D54-7 (CLG5) Always Below 1 Ω
      D55-3 (CLGB) - D54-8 (CG5B) Always Below 1 Ω
      D54-7 (CLG5) - Body ground Always 10 kΩ or higher
      D54-8 (CG5B) - Body ground Always 10 kΩ or higher
      D54-15 (E) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT CERTIFICATION ECU


    1. A003BGKE07
      Text in Illustration
      *1

      Component with harness connected

      (Certification ECU)

      Reconnect the D54 ECU connector.

    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      D54-7 (CLG5) - D54-15 (E) Engine switch off, all doors closed, key not in cabin and lock sensor off No Pulse generation
      D54-7 (CLG5) - D54-15 (E) Engine switch off, all doors closed, key not in cabin and lock sensor on Pulse generation
      D54-8 (CG5B) - D54-15 (E) Engine switch off, all doors closed, key not in cabin and lock sensor off No Pulse generation
      D54-8 (CG5B) - D54-15 (E) Engine switch off, all doors closed, key not in cabin and lock sensor on Pulse generation

    NG

    REPLACE CERTIFICATION ECU

    OK

  4. REPLACE INDOOR ELECTRICAL KEY OSCILLATOR (FRONT FLOOR)


    1. Temporarily replace the indoor electrical key oscillator (front floor) with a new or normally functioning one Click here.


    NEXT

  5. CHECK FOR DTC


    1. Clear the DTCs Click here.

    2. Recheck for DTCs Click here.

      OK
      B27A5 output does not recur.

    NG

    REPLACE CERTIFICATION ECU

    OK

    END (INDOOR ELECTRICAL KEY OSCILLATOR IS DEFECTIVE)