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 (smart key ECU assembly) generates a request signal and transmits the signal to the NO. 1 indoor electrical key antenna assembly (front floor). For the NO. 1 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. 1 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. 1 indoor electrical key antenna assembly (front floor) (CLG5 - ANTE5, CG5B - CLGB) (1 trip detection logic*).

  • Wire harness or connector

  • NO. 1 indoor electrical key antenna assembly (front floor)

  • Certification ECU (smart key ECU assembly)

  • DTC Output Confirmation Operation

  • Any time

  • *: Only output while a malfunction is present.

Table 1. 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 engine switch pressed

  • Electrical key transmitter sub-assembly locked inside vehicle

-
Table 2. 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

B320942E42

CAUTION / NOTICE / HINT

Note:

  • The entry and start system (for Entry Function) uses the LIN communication system and CAN communication system. Inspect the communication function by following How to Proceed with Troubleshooting (Click here). Troubleshoot the entry and start system (for Entry Function) after confirming that the communication systems are functioning properly.

  • 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 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. 1 indoor electrical key antenna assembly (front floor) has an antenna coil between terminals ANTE5 and CLGB.

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

      OK

      Connectors are properly connected.

    Result

    Proceed to

    OK

    NG
    NG

    CONNECT CONNECTORS PROPERLY

    OK

  2. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - NO. 1 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY)

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

    2. Disconnect the L24 NO. 1 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

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) (OUTPUT TO NO. 1 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY)

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

      B271428C26

      *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. 1 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. 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)

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

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    OK

  4. REPLACE NO. 1 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (FRONT FLOOR)

    1. Temporarily replace the NO. 1 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

    END (NO. 1 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (FRONT FLOOR) WAS DEFECTIVE)

    NG

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)