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:

Steering Angle Sensor Zero Point Malfunction (C1290)
DESCRIPTION The skid control ECU (master cylinder solenoid) acquires steering angle sensor zero point every time the ignition switch is turned to ON and the vehicle is driven at 35 km/h (22 mph) or more for approximately 5 seconds. The ECU also stores the previous zero point. If the front wh ...

Steering Angle Sensor Internal Circuit (C1433)
DESCRIPTION The skid control ECU (brake actuator assembly) outputs this DTC when it receives an internal malfunction signal from the steering angle sensor. DTC No. Detection Item DTC Detection Condition Trouble Area C1433 St ...

On-vehicle Inspection
ON-VEHICLE INSPECTION PROCEDURE 1. INSPECT FOR COOLANT LEAK HINT: The sliding surface inside the engine water pump assembly is lubricated by engine coolant. As some engine coolant is discharged during normal operation, engine coolant residue (solids) may be found on the drain plu ...