Last Modified: 07-31-2024 6.11:8.1.0 Doc ID: RM1000000028K8U
Model Year Start: 2023 Model: GR Corolla Prod Date Range: [11/2022 -           ]
Title: THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Entry Function): B27A813; Outside Luggage Compartment (Back Door) Electrical key Antenna Circuit Open; 2023 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [11/2022 -        ]

DTC

B27A813

Outside Luggage Compartment (Back Door) Electrical key Antenna Circuit Open

DESCRIPTION

The certification ECU (smart key ECU assembly) generates a request signal and transmits the signal to the electrical key antenna (outside luggage compartment). For the electrical key antenna (outside luggage compartment) to detect when the electrical key transmitter sub-assembly is brought close to the vehicle, the received request signal is transmitted within approximately 1 m (3.28 ft.) of the back door*1 or luggage compartment door*2. DTC B27A813 is stored by the certification ECU (smart key ECU assembly) when an open is detected between the certification ECU (smart key ECU assembly) and electrical key antenna (outside luggage compartment).

  • *1: except Sedan
  • *2: for Sedan

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Note

B27A813

Outside Luggage Compartment (Back Door) Electrical key Antenna Circuit Open

An open is detected in the circuit between the certification ECU (smart key ECU assembly) and electrical key antenna (outside luggage compartment) (1 trip detection logic*).
  • Certification ECU (smart key ECU assembly)
  • Electrical key antenna (outside luggage compartment)
  • Harness or connector

DTC Output Confirmation Operation:

  • Any time
  • *: Only output while a malfunction is present and the ignition switch is ON.

Vehicle Condition and Fail-safe Operation when Malfunction Detected

Vehicle Condition when Malfunction Detected

Fail-safe Operation when Malfunction Detected

except Sedan:

  • Entry lock/unlock operation cannot be performed for back door

for Sedan:

  • Entry lock/unlock operation cannot be performed for luggage compartment door

-

Related Data List and Active Test

DTC No.

Data List and Active Test

B27A813

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

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

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

    Click here 2023 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [11/2022 -        ]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Entry Function): PRECAUTION

  • 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 electrical key antenna (outside luggage compartment).

OK:

Connectors are properly connected.

NG

CONNECT CONNECTORS PROPERLY
OK

2.

CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - ELECTRICAL KEY ANTENNA (OUTSIDE LUGGAGE COMPARTMENT))

(a) Disconnect the O174 certification ECU (smart key ECU assembly) connector.

(b) Disconnect the O39 electrical key antenna (outside luggage compartment) connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

O174-4 (CLG8) - O39-2 (ANTE8)

Always

Below 1 Ω

O174-3 (CG8B) - O39-1 (CLGB)

Always

Below 1 Ω

(d) Reconnect the O174 certification ECU (smart key ECU assembly) connector.

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

3.

CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) (OUTPUT TO ELECTRICAL KEY ANTENNA (OUTSIDE LUGGAGE COMPARTMENT))

*a

Component with harness connected

(Certification ECU (Smart Key ECU Assembly))

*b

Waveform 1

*c

Waveform 2

-

-

(a) Using an oscilloscope, check the waveform.

OK:

Tester Connection

Condition

Tool Setting

Specified Condition

O174-4 (CLG8) - I167-29 (E)

Procedure:

except Sedan:

  1. Ignition switch off
  2. Electrical key transmitter sub-assembly brought outside vehicle
  3. All doors closed
  4. Back door opener switch sub-assembly off → on

for Sedan:

  1. Ignition switch off
  2. Electrical key transmitter sub-assembly brought outside vehicle
  3. All doors closed
  4. Luggage electrical key switch off → on

5 V/DIV., 50 ms./DIV.

Pulse generation

(See waveform 1)

O174-3 (CG8B) - I167-29 (E)

Procedure:

except Sedan:

  1. Ignition switch off
  2. Electrical key transmitter sub-assembly brought outside vehicle
  3. All doors closed
  4. Back door opener switch sub-assembly off → on

for Sedan:

  1. Ignition switch off
  2. Electrical key transmitter sub-assembly brought outside vehicle
  3. All doors closed
  4. Luggage electrical key switch assembly off → on

5 V/DIV., 50 ms./DIV.

Pulse generation

(See waveform 2)
OK

REPLACE ELECTRICAL KEY ANTENNA (OUTSIDE LUGGAGE COMPARTMENT)

NG

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)