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:

Fuel Pump Ecu
Components COMPONENTS ILLUSTRATION Removal REMOVAL PROCEDURE 1. PRECAUTION NOTICE: After turning the ignition switch off, waiting time may be required before disconnecting the cable from the battery terminal. Therefore, make sure to read the disconnecting the cable from the battery ...

TC and CG Terminal Circuit
DESCRIPTION Connecting terminals TC and CG of the DLC3 causes the ECU to display the DTC by blinking the ABS warning light and slip indicator light. WIRING DIAGRAM CAUTION / NOTICE / HINT NOTICE: When replacing the skid control ECU (brake actuator assembly), perform zero point calibration ...

Illumination Circuit
DESCRIPTION Power is supplied to the radio and display receiver assembly and steering pad switch assembly illumination when the light control switch is in the TAIL or HEAD position. WIRING DIAGRAM CAUTION / NOTICE / HINT NOTICE: The vehicle is equipped with a Supplemental Restrain ...