Last Modified: 07-31-2024 6.11:8.1.0 Doc ID: RM1000000028LVP
Model Year Start: 2023 Model: GR Corolla Prod Date Range: [11/2022 -           ]
Title: NETWORKING: LIN COMMUNICATION SYSTEM: B278588; Communication between ECUs connected by LIN Bus off; 2023 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [11/2022 -        ]

DTC

B278588

Communication between ECUs connected by LIN Bus off

DESCRIPTION

This DTC is stored when LIN communication between the certification ECU (smart key ECU assembly), steering lock ECU (steering lock actuator with ECU assembly)* and ID code box (immobiliser code ECU) stops for 10 seconds or more.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

DTC Output from

B278588

Communication between ECUs connected by LIN Bus off

No communication between steering lock ECU (steering lock actuator with ECU assembly)*, ID code box (immobiliser code ECU) and certification ECU (smart key ECU assembly) for 10 seconds or more.
  • Certification ECU (smart key ECU assembly)
  • Steering lock ECU (steering lock actuator with ECU assembly)*
  • ID code box (immobiliser code ECU)
  • Wire harness or connector

Smart Key
  • *: w/ Steering Lock

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • Before performing the inspection, check that DTC B278187, B278987 or B278C87 is not output.

    Click here 2023 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [11/2022 -        ]; NETWORKING: LIN COMMUNICATION SYSTEM: HOW TO PROCEED WITH TROUBLESHOOTING

  • When using the GTS with the ignition switch off, perform lock and unlock operations using the door control switch of the multiplex network master switch assembly at intervals of 1.5 seconds or less until communication between the GTS and the vehicle begins, and then select the vehicle model manually.

    Then select Model Code "KEY REGIST" under manual mode and enter the following menus: Body Electrical / Smart Key (CAN). While using the GTS, periodically perform lock and unlock operations using the door control switch of the multiplex network master switch assembly 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), ID code box (immobiliser code ECU) or steering lock ECU (steering lock actuator with ECU assembly), refer to Registration.

    for HV Model: Click here 2023 - 2025 MY Corolla Corolla HV [09/2022 -        ]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV Model): REGISTRATION

    for Gasoline Model: 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

PROCEDURE

1.

SYSTEM CHECK

(a) Check the vehicle specification.

Result

Proceed to

w/ Steering Lock

A

w/o Steering Lock

B
B

GO TO STEP 5

A

2.

CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - EACH ECU)

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

(b) Disconnect the I59 steering lock ECU (steering lock actuator with ECU assembly) connector.

(c) Disconnect the I20 ID code box (immobiliser code ECU) connector.

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

NOTICE:

Make sure that each ECU is in sleep mode before performing the inspection. To enter sleep mode, turn the ignition switch from ON to off and wait for 180 seconds or more without operating any switches.

Standard Resistance:

Tester Connection

Condition

Specified Condition

I167-8 (LIN) - I59-5 (LIN)

Ignition switch off

Below 1 Ω

I167-8 (LIN) - I20-2 (LIN1)

Ignition switch off

Below 1 Ω

I167-8 (LIN), I59-5 (LIN) or I20-2 (LIN1) - Body ground

Ignition switch off

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

3.

CHECK FOR DTC

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

(b) Connect the I20 ID code box (immobiliser code ECU) connector.

(c) Clear the DTCs.

Body Electrical > Smart Key > Clear DTCs

(d) Recheck for DTCs.

Body Electrical > Smart Key > Trouble Codes

Result

Proceed to

DTC B278588 is output

A

DTC B278588 is not output

B
B

REPLACE STEERING LOCK ECU (STEERING LOCK ACTUATOR WITH ECU ASSEMBLY)

A

4.

CHECK FOR DTC

(a) Connect the I59 steering lock ECU (steering lock actuator with ECU assembly) connector.

(b) Disconnect the I20 ID code box (immobiliser code ECU) connector.

(c) Clear the DTCs.

Body Electrical > Smart Key > Clear DTCs

(d) Recheck for DTCs.

Body Electrical > Smart Key > Trouble Codes

Result

Proceed to

DTC B278588 is output

A

DTC B278588 is not output

B
A

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

B

REPLACE ID CODE BOX (IMMOBILISER CODE ECU)

5.

CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - ID CODE BOX (IMMOBILISER CODE ECU))

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

(b) Disconnect the I20 ID code box (immobiliser code ECU) connector.

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

NOTICE:

Make sure that each ECU is in sleep mode before performing the inspection. To enter sleep mode, turn the ignition switch from ON to off and wait for 180 seconds or more without operating any switches.

Standard Resistance:

Tester Connection

Condition

Specified Condition

I167-8 (LIN) - I20-2 (LIN1)

Ignition switch off

Below 1 Ω

I167-8 (LIN) or I20-2 (LIN1) - Body ground

Ignition switch off

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

6.

CHECK FOR DTC

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

(b) Clear the DTCs.

Body Electrical > Smart Key > Clear DTCs

(c) Recheck for DTCs.

Body Electrical > Smart Key > Trouble Codes

Result

Proceed to

DTC B278588 is output

A

DTC B278588 is not output

B
A

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

B

REPLACE ID CODE BOX (IMMOBILISER CODE ECU)