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.Diagnosis System
DIAGNOSIS SYSTEM
1. DESCRIPTION
(a) Data of the system can be read from the Data Link Connector 3 (DLC3) of the
vehicle. Therefore, when the system seems to be malfunctioning, use the Techstream
to check for a malfunction and repair it.
2. CHECK DLC3
( ...
Short to GND in Immobiliser System Power Source Circuit (B278A)
DESCRIPTION
This DTC is stored when the engine switch power source supply line is open or
shorted.
DTC No.
DTC Detection Condition
Trouble Area
B278A
Engine switch power source supply line is ope ...
Problem Symptoms Table
PROBLEM SYMPTOMS TABLE
HINT:
Use the table below to help determine the cause of problem symptoms.
If multiple suspected areas are listed, the potential causes of the symptoms
are listed in order of probability in the "Suspected Area" ...