Last Modified: 07-31-2024 6.11:8.1.0 Doc ID: RM1000000028KA7
Model Year Start: 2023 Model: GR Corolla Prod Date Range: [11/2022 -           ]
Title: THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): B27A513; Front Floor Electrical Key Oscillator Circuit Open; 2023 - 2025 MY Corolla Corolla Hatchback GR Corolla [11/2022 -        ]

DTC

B27A513

Front Floor Electrical Key Oscillator Circuit Open

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 B27A513 is stored by the certification ECU (smart key ECU assembly) when an open is detected between the certification ECU (smart key ECU assembly) and No. 1 indoor electrical key antenna assembly (front floor).

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Note

B27A513

Front Floor Electrical Key Oscillator Circuit Open

An open is detected in the circuit between the certification ECU (smart key ECU assembly) and No. 1 indoor electrical key antenna assembly (front floor) (1 trip detection logic*).
  • Certification ECU (smart key ECU assembly)
  • No. 1 indoor electrical key antenna assembly (front floor)
  • Wire harness or connector

DTC Output Confirmation Operation:

  • Any time
  • *: Only output while a malfunction is present.

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

-

Related Data List and Active Test

DTC No.

Data List and Active Test

B27A513

Key diagnostic mode can be used to perform troubleshooting

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • When using the GTS with the ignition 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 / Start Key(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.

  • The smart key system (for Start Function) uses the LIN communication system and CAN communication system. Inspect the communication function by following How to Proceed with Troubleshooting. Troubleshoot the smart key system (for Start Function) after confirming that the communication systems are functioning properly.

    Click here 2023 - 2025 MY Corolla Corolla Hatchback GR Corolla [11/2022 -        ]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): HOW TO PROCEED WITH TROUBLESHOOTING

  • Before replacing the certification ECU (smart key ECU assembly), refer to Registration.

    Click here 2023 - 2025 MY Corolla Corolla Hatchback GR Corolla [11/2022 -        ]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): REGISTRATION

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

PROCEDURE

1.

CHECK CONNECTOR CONNECTION

(a) 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.

NG

CONNECT CONNECTORS PROPERLY
OK

2.

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

Pre-procedure1

(a) Disconnect the I167 certification ECU (smart key ECU assembly) connector.

(b) Disconnect the I34 No. 1 indoor electrical key antenna assembly (front floor) connector.

Procedure1

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

I167-4 (CLG5) - I34-1 (ANTE5)

Always

Below 1 Ω

I167-5 (CG5B) - I34-2 (CLGB)

Always

Below 1 Ω

Post-procedure1

(d) None

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 (FRONT FLOOR))

Pre-procedure1

(a) Connect the I167 certification ECU (smart key ECU assembly) connector.

Procedure1

(b) Using an oscilloscope, check the waveform.

*a

Component with harness connected

(Certification ECU (Smart Key ECU Assembly))

*b

Waveform

*c

For 30 seconds after any door closed

*d

After 30 seconds or more have elapsed since any door closed

OK:

Tester Connection

Condition

Tool Setting

Specified Condition

I167-4 (CLG5) - I167-29 (E)

Procedure:

  1. Ignition switch off
  2. Electrical key transmitter sub-assembly not inside vehicle
  3. Within 30 seconds of closing any door

2 V/DIV., 500 ms/DIV.

Pulse generation

(See waveform)

I167-5 (CG5B) - I167-29 (E)

Procedure:

  1. Ignition switch off
  2. Electrical key transmitter sub-assembly not inside vehicle
  3. Within 30 seconds of closing any door

2 V/DIV., 500 ms/DIV.

Pulse generation

(See waveform)

Post-procedure1

(c) None

OK

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

NG

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)