Toyota Avalon (XX50) 2019-2022 Service & Repair Manual: Lost Communication with Power Source Control (B278C)

DESCRIPTION

This DTC is stored when LIN communication between the certification ECU (smart key ECU assembly) and power management control ECU stops for 10 seconds or more.

HINT:

The power management control ECU is built into the certification ECU (smart key ECU assembly).

CAUTION / NOTICE / HINT

NOTICE:

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

  Click here

• 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 Model Code "KEY REGIST" 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.

PROCEDURE

(a) Clear the DTCs.

NEXT

(a) Check for DTCs.

OK:

DTC B278C is not output.

OK

USE SIMULATION METHOD TO CHECK

NG

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)