Anti-theft Light Blinking

This morning I noticed my Anti-theft light started blinking when I turned off my 2015 Tundra. It has never done this before. If I turn on the truck it disappears. If I turn off and lock the truck the light goes from blinking to a solid light (also something I've never noticed before). Otherwise everything is fine. It starts, locks, and unlocks. Looked online but couldn't find anything specific to my issue. Also couldn't find anything in the owner's manual. A lot of online search results state that it should always be blinking when the key is out of the ignition but I'm 100% sure this has never been the case before this morning (been in the truck many times without the key in the ignition and never noticed this).

 

My 2015 alarm light blinks approximately every 2 seconds with the key out of the ignition and the doors closed.

 

1-2. Theft deterrent system
Engine immobilizer system
The indicator light flashes after
the key has been removed from
the engine switch to indicate that
the system is operating.
The indicator light stops flashing
after the registered key has been
inserted into the engine switch to
indicate that the system has been
canceled.
■System maintenance
The vehicle has a maintenance-free type engine immobilizer system.
■Conditions that may cause the system to malfunction
●If the grip portion of the key is in contact with a metallic object
●If the key is in close proximity to or touching a key to the security system
(key with a built-in transponder chip) of another vehicle
: If equipped
The vehicle’s keys have built-in transponder chips that prevent
the engine from starting if a key has not been previously registered
in the vehicle’s on-board computer.
Never leave the keys inside the vehicle when you leave the vehicle.
This system is designed to help prevent vehicle theft but does
not guarantee absolute security against all vehicle thefts.
1-2. Theft deterrent system 79
1
For safety and security
■Certifications for the engine immobilizer system
 For vehicles sold in the U.S.A.
FCC ID: MOZRI-21BTY
This device complies with Part 15 of the FCC Rules. Operation is subject to
the following two conditions: (1) this device may not cause harmful interference,
and (2) this device must accept any interference received, including
interference that may cause undesired operation.
 For vehicles sold in Canada
This device complied with RSS-210 of Industry Canada.
Operation is subject to the following two conditions: (1) this device may not
cause interference, and (2) this device must accept any interference, including
interference that may cause undesired operation of the device.
CAUTION
■Certifications for the immobilizer system
Changes or modifications not expressly approved by the party responsible
for compliance could void the user’s authority to operate the equipment.
NOTICE
■To ensure the system operates correctly
Do not modify or remove the system. If modified or removed, the proper
operation of the system cannot be guaranteed.
80 1-2. Theft deterrent system
Alarm
The alarm uses light and sound to give an alert when an intrusion is
detected.
The alarm is triggered in the following situations when the alarm is
set:
● A locked door is unlocked or opened in any way other than using a
key or wireless remote control. (The doors will lock again automatically.)
● The hood is opened.
● Vehicles with the glass breakage sensor: The side windows are
tapped or broken.
Close the doors and hood, and
lock all the doors. The system will
be set automatically after 30 seconds.
The indicator light changes from
being on to flashing when the system
is set.
Do one of the following to deactivate or stop the alarms:
● Unlock the doors.
● Turn the engine switch to the “ACC” or “ON” position, or start the
engine. (The alarm will be deactivated or stopped after a few seconds.)
: If equipped

 

Chances are it's always blinked and you never noticed it..
It's hard to see in the daylight and a bit dim at night.
My 2014 has been doing it for 8 years..

Welcome to the forum..

Mine blinks all the time when getting in and out of the truck.
I never noticed what made it go off, I thought it was starting the truck.
But now I know it's when you stick the key in the ignition..

I learned something today..

 

Ok, awesome - thanks everyone for all of the quick replies. Guess I've just never noticed it before now. I won't worry about it then

 

Welcome from NY.

 

Low battery key fob with my experience.