alir1983

Any idea why the car beeps 3 times after locking it?

PFB

You didn't specify the year or model of your Lexus, so with no other information, all one can offer you is a guess.

Perhaps something is either open or the system mistakingly thinks that something is open. Example, door or trunk.

I'm sure that more specific info is available in your owner's manual.

This may also be an indication that your alarm is not activating, so check ALL of your fuses.

Phil

Picorosan

If it's a hybrid it means your car is still on and will not let you lock your doors if the engine is running.