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:

Rear differential lock system
The rear differential lock system is provided for use only when wheel spinning occurs in a ditch or on a slippery or rugged surface. The rear differential lock system is effective in case one of the rear wheels is spinning. Press the RR DIFF LOCK switch to lock the rear differential. At thi ...

Theft Deterrent System Unexpectedly Sets Itself
DESCRIPTION A situation in which the theft deterrent system unexpectedly sets itself can be caused when the main body ECU (multiplex network body ECU) cannot detect whether a door is open or closed. If the theft deterrent system unexpectedly sets itself, there may be a malfunction in a court ...

Front Passenger Side Seat Heater does not Operate
DESCRIPTION When the seat heater switch on the air conditioning control assembly is operated, the air conditioning amplifier assembly receives the signal. The air conditioning amplifier assembly receives the signal and operates the front seat heater. WIRING DIAGRAM CAUTION / NOTICE / HINT ...