Failing to investigate the cause of the following warnings may lead to the system operating abnormally and possibly cause an accident.
Have the vehicle inspected by your Toyota dealer immediately.


Stop the vehicle immediately.
Follow the correction procedures.Lost Communication with Power Source Control (B278C)
DESCRIPTION
This DTC is stored when LIN communication between the certification ECU (smart
key ECU assembly) and power management control ECU stops for more than 10 seconds.
DTC Code
DTC Detection Condition
Trouble Area
...
On-vehicle Inspection
ON-VEHICLE INSPECTION
PROCEDURE
1. PERFORM SPARK TEST
(a) Check for DTCs (See page ).
NOTICE:
If any DTC is output, perform troubleshooting procedures for that DTC.
(b) Remove the ignition coils and spark plugs (See page
).
(c) Disconnect ...
Disassembly
DISASSEMBLY
CAUTION / NOTICE / HINT
NOTICE:
When disassembling the multiplex network door ECU, eliminate static electricity
by touching the vehicle body to prevent the components from being damaged.
PROCEDURE
1. REMOVE MULTIPLEX NETWORK DOOR ECU
...