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:

Lost Communication with ECM / PCM "A" (U0100,U0126,U0129,U0142)
DESCRIPTION These DTCs are stored if there is a malfunction in the CAN communication system connected to the blind spot monitor sensor. HINT: If CAN communication system DTCs are stored, they may also be stored for other systems. DTC Code DTC Detection Condition ...

Precaution
PRECAUTION 1. The type of ignition switch used on this model differs depending on the specifications of the vehicle. The expressions listed in the table below are used in this section. Expression Ignition Switch (Position) Engine Switch (Condition) ...

Installation
INSTALLATION CAUTION / NOTICE / HINT HINT: Perform "Inspection After Repairs" after replacing the engine assembly, cylinder head sub-assembly, camshaft, No. 2 camshaft, No. 3 camshaft sub-assembly, No. 4 camshaft sub-assembly, camshaft timing gear assembly, camshaft timing exhaust g ...