Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM100000001CY6E
Model Year Start: 2019 Model: GR Corolla Prod Date Range: [06/2018 - 09/2022]
Title: THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): B278A; Short to GND in Immobiliser System Power Source Circuit; 2019 - 2022 MY Corolla Corolla Hatchback GR Corolla [06/2018 - 09/2022]

DTC

B278A

Short to GND in Immobiliser System Power Source Circuit

DESCRIPTION

When there is a short to GND in the power supply for the transponder key amplifier of the engine switch, the certification ECU (smart key ECU assembly) stores this DTC.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Note

B278A

Short to GND in Immobiliser System Power Source Circuit

A short to GND in the power supply of the transponder key amplifier of the engine switch (VC5 - VC5) detected. (1 trip detection logic*)

Certification ECU (smart key ECU assembly)

DTC output confirmation operation:

for Manual Transaxle

  • With the electrical key transmitter sub-assembly held near the engine switch, an engine start operation is performed by pressing and holding the engine switch when the transmitter battery is depleted.

except Manual Transaxle

  • With the shift lever in P and the electrical key transmitter sub-assembly held near the engine switch, an engine start operation is performed by pressing and holding the engine switch when the transmitter battery is depleted.
  • *: 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

for Manual Transaxle

  • Engine cannot be started when transmitter battery is depleted by holding transmitter near engine switch and pressing and holding engine switch

except Manual Transaxle

  • Engine cannot be started when transmitter battery is depleted by holding transmitter near engine switch and pressing and holding engine switch with shift lever in P

-

Related Data List and Active Test

DTC No.

Data List and Active Test

B278A

-

CAUTION / NOTICE / HINT

NOTICE:

  • When using the Techstream with the engine switch off, connect the Techstream to the DLC3 and turn a courtesy light switch on and off at intervals of 1.5 seconds or less until communication between the Techstream and the vehicle begins. Then select the vehicle type under manual mode and enter the following menus Body Electrical Smart Key. While using the Techstream, periodically turn a courtesy light switch on and off at intervals of 1.5 seconds or less to maintain communication between the Techstream 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 2019 MY Corolla Corolla Hatchback GR Corolla [06/2018 - 01/2019]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): HOW TO PROCEED WITH TROUBLESHOOTING 2020 - 2022 MY Corolla Corolla Hatchback GR Corolla [01/2019 - 09/2022]; 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 2019 MY Corolla Corolla Hatchback GR Corolla [06/2018 - 01/2019]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): REGISTRATION 2020 MY Corolla Corolla Hatchback GR Corolla [01/2019 - 09/2019]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): REGISTRATION 2020 MY Corolla Corolla Hatchback GR Corolla [09/2019 - 04/2020]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): REGISTRATION 2021 - 2022 MY Corolla Corolla Hatchback GR Corolla [04/2020 - 09/2022]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): REGISTRATION

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

PROCEDURE

1.

CLEAR DTC

(a) Clear the DTCs.

Body Electrical > Smart Key > Clear DTCs

NEXT

2.

CHECK FOR DTC

(a) Perform "DTC Output Confirmation Operation" procedure.

(b) Check for DTCs.

Body Electrical > Smart Key > Trouble Codes

OK:

DTC B278A is not output.

OK

USE SIMULATION METHOD TO CHECK

NG

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) 2019 MY Corolla Corolla Hatchback Corolla HV GR Corolla [06/2018 - 01/2019]; THEFT DETERRENT / KEYLESS ENTRY: CERTIFICATION ECU: REMOVAL 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 03/2019]; THEFT DETERRENT / KEYLESS ENTRY: CERTIFICATION ECU: REMOVAL 2020 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [03/2019 - 09/2022]; THEFT DETERRENT / KEYLESS ENTRY: CERTIFICATION ECU: REMOVAL