Toyota Tacoma (2015-2018) Service Manual: Lost Communication with Power Source Control (B278C)

Toyota Tacoma (2015-2018) Service Manual / Multiplex Communication / Lin Communication System / Lost Communication with Power Source Control (B278C)

DESCRIPTION

DTC No.	DTC Detection Condition	Trouble Area
B278C	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 Techstream with the vehicle ignition switch off, connect the Techstream to the vehicle 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 Access. 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.
If the certification ECU (smart key ECU assembly) is replaced, register the keys (See page ).

PROCEDURE

CLEAR DTC

(a) Clear the DTCs (See page ).

2.	CHECK FOR DTC

(a) Check for DTCs (See page OK: ).

OK:

DTC B278C is not output.

USE SIMULATION METHOD TO CHECK

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

P/W Master Switch Communication Stop (B1206)

DESCRIPTION This DTC is stored when LIN communication between the power window regulator master switch assembly and main body ECU (multiplex network body ECU) stops for 10 seconds or more. ...

Front Passenger Side Door ECU Communication Stop (B2322)

DESCRIPTION This DTC is stored when LIN communication between the front power window regulator motor assembly RH and main body ECU (multiplex network body ECU) stops for 10 seconds or more. ...

Other materials:

TRAC OFF Indicator Light Remains ON
DESCRIPTION In 2WD mode: Operation of the VSC OFF switch changes the vehicle between normal mode, TRAC OFF mode (AUTO LSD mode) and VSC OFF mode. During normal mode, pressing the VSC OFF switch for a short amount of time changes the vehicle to TRAC OFF mode (AUTO LSD mode), TR ...

Vehicle Speed Sensor "A" No Signal (P050031)
DESCRIPTION The speed sensor detects the wheel speed and sends the appropriate signals to the skid control ECU. The skid control ECU converts these wheel speed signals into a pulse signal and outputs it to the ECM via the combination meter. The ECM determines the vehicle speed based on the fr ...

Operation Check
OPERATION CHECK 1. CHECK WIRELESS CHARGING SYSTEM OPERATION (a) Turn the ignition switch ON (IG or ACC). (b) Press the mobile wireless charger switch and check that the switch indicator light illuminates. Text in Illustration *a Switch Indicator Light (c) Plac ...