Rather than turning off the Smart Key system (the feature where you can unlock doors through proximity with the fob), you could just put your fobs in a Faraday bag. That would prevent a relay attack that would allow a thief to gracefully unlock the door and maybe even start the car with the help of a fob signal booster.

The advanced thieves are literally breaking into the car, then plugging a programmer into the OBD port and programming their own key fob in the computer in order to start the car and drive off. Or even more advanced, they're looking for other ways to access the CAN bus instead of the OBD port that can be reached from outside the vehicle. They're not messing with trying to unlock the doors through Smart Key or the relay method.

 

The problem is when you are outside the vehicle. Before you disable the fob you transmit proximity information back to the vehicle. The process of locking the fob causes a lock transmission back to the vehicle. When you return to the vehicle, you issue an unlock transmission from the fob, which wakes up the fob, unlocks the vehicle and continuously transmits proximity from the fob. It's during these times it's easy for experienced thieves to receive, and intercept the fob transmissions and replay them later. A faraday bag doesn't help here.

Very familiar with the CAN buss/external/left fender/bumper attack method.

 

Some vehicles are being attacked and stolen via the headlight. The drawbacks of everything being interconnected and computer controlled. The auto manufactures are slow to respond, and stupid for not thinking criminals would devise work around/exploits.

The joys of the not so smart key system.

 

Thanks, but I’m very well versed on all the methods of theft with these cars. Still looking for an answer to my question. Please advise.

 

Just talk to dealer and see if there is a charge for what you want or if they are even allowed to do it . Don't take a chance on messing something up yourself and voiding your warranty coverage of this feature . If you are going to be gone just take both keys with you or hide them really good .

 

From the 2023 Highlander 400+ page "short" manual the "C" column is dealer customized only - looking for an OBD device way to do the same as the dealer would:

 

If you don't want to pay to have the dealer deactivate the smart key sys in the car, just disconnect the 12V ground. Be sure the physical key will be able to unlock the driver door, so you can open the door and pop the hood to reconnect the 12V ground.

 

Thanks, but that's not a viable option, as I believe Highlanders require a lengthy re-init process of several ECU's after a battery removal. Also, wipes transmission memory of learned driving behavior. Very messy, and not something to do routinely.