New flashing immobilizer light.

The engine immobilizer light started flashing today for no reason I can figure. Searches here haven't been helpful. I have a 2018 SR with no aftermarket doo dads. Dead key fob battery? It's never been changed that I know of unless they did it during scheduled maintenance at the dealership. Thanks for any help.

 

More data required.
When exactly does it flash, (key in ignition, key out, etc), and at any times does it not flash?
Also I assume you have a mechanical H-key, not keyless ignition, right?

 

Vehicles without a smart key system: The indicator light flashes after the key has been removed from the engine switch to indicate that the system is operating.
Vehicles with a smart key system: The indicator light flashes after the engine switch has been turned off to indicate that the system is operating.

 

This thread may help.

Immobilizer Light blinks while driving

 

Thanks. I honestly don't know if I have smart key. It's the regular push button fob. I don't have push button start, it requires the key.

It has never done this before. There used to be a pin point red light that blinked when the truck was locked, now this new light flashes only when the truck is parked and off. It's not lit in the photo but you can see it.

As soon as you start the truck it turns off.

 

Sounds like it is supposed to operate

 

OK - I guess it just decided to start working. I've owned the truck for over a year and never saw this before. Starts/runs fine, I'll call the dealership today to confirm. Thanks much for the input.