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:

Terminals Of Ecu
TERMINALS OF ECU 1. CHECK MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Text in Illustration *1 Main Body ECU (Multiplex Network Body ECU) - - (a) Disconnect the driver side junction block and main body ECU (multiplex network body ECU) connect ...

Acceleration Sensor Malfunction (C1420)
DESCRIPTION Refer to DTCs C1419 and C1435 (See page ). DTC Code DTC Detection Condition Trouble Area C1420 After the difference between GL1 and GL2 becomes 0.6 G or more with the vehicle stationary, the difference remains 0.4 G or m ...

Clutch Switch Circuit
DESCRIPTION Clutch switch circuit inspection is necessary for manual transmission vehicles. When the clutch pedal is released, the ECM receives the positive (+) battery voltage through the ECU-IG NO. 2 fuse and ignition switch. While the clutch pedal is depressed, the clutch switch assembly se ...