Toyota Yaris: Lin Communication System / Power Source Control System Missing Message (B278C87)

Toyota Yaris XP210 (2020-2026) Reapir and Service Manual / Power Source & Network / Networking / Lin Communication System / Power Source Control System Missing Message (B278C87)

DESCRIPTION

When an internal malfunction is detected in the certification ECU (smart key ECU assembly), this DTC is stored.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

B278C87

Power Source Control System Missing Message

An internal malfunction occurs in the certification ECU (smart key ECU assembly).

Certification ECU (smart key ECU assembly)

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 / 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 Registration.

PROCEDURE

1.

CLEAR DTC

(a) Clear the DTCs.

Body Electrical > Smart Key > Clear DTCs
NEXT

2.

CHECK FOR DTC

(a) Check for DTCs.

Body Electrical > Smart Key > Trouble Codes

Result

Proceed to

DTC 278588 is output

A

DTC 278588 is not output

B

A

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

B

USE SIMULATION METHOD TO CHECK

    ID-BOX Missing Message (B278987)

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

    Network Gateway Ecu

    ..

    Other information:

    Toyota Yaris XP210 (2020-2026) Reapir and Service Manual: Disassembly


    DISASSEMBLY CAUTION / NOTICE / HINT The necessary procedures (adjustment, calibration, initialization, or registration) that must be performed after parts are removed and installed, or replaced during the front door removal/installation are shown below...

    Toyota Yaris XP210 (2020-2026) Owner's Manual: SRS Air Bag Deployment Criteria


    This chart indicates the applicable SRS equipment that will deploy depending on the type of collision. (The illustrations are the representative cases of collisions.) X:The SRS air bag equipment is designed to deploy in a collision. * 1: The front passenger front and side air bags and the seat belt pretensioner are designed to deploy when the front passenger occupant classification sensor detects a passenger sitting on the front passenger’s seat...

    Categories

    Fuel-Filler Lid and Cap

    WARNING

    When removing the fuel-filler cap, loosen the cap slightly and wait for any hissing to stop, then remove it

    Fuel spray is dangerous. Fuel can burn skin and eyes and cause illness if ingested. Fuel spray is released when there is pressure in the fuel tank and the fuel-filler cap is removed too quickly.

    read more

     
    Copyright © 2026 www.toyaris4.com