I lost my key and remote for my Highlander near my house. I have the spare key and remote for now, but is it possible to change the key and remote to keep the car safe? I’m worried that someone who found the key might come back to steal my car. Appreciate any advice!
You’ll need to reset the immobilizer so that the car forgets the lost remote. A dealer or locksmith can do this. Afterward, you’d need to change all the key cylinders in the car to make sure the lost key can’t be used. This would leave you with a fob that doesn’t match the new key and a new key with its own set of locks.
@Bao
How much did it cost you to do all that, if you don’t mind me asking?
Olin said:
@Bao
How much did it cost you to do all that, if you don’t mind me asking?
I don’t remember the exact cost because we don’t handle that often at my dealership, but changing the lock set would cost at least a couple hundred bucks.
@Bao
Okay, thanks for the info! I’ll check with the local dealership to get a quote.
You’ll need a special OBD II scanner designed for Toyotas. Here’s the one we got off Amazon.
When you program the new key, any old keys won’t work anymore. That means you’ll be safe. 
Black Friday might have a deal for around $120 (that’s what I paid last year on a lightning deal). I know it’s a bit pricey, but it’s still cheaper than going to a pro who’ll charge you $100 for just one key. Hope that helps!
@Wolf
So this is just for the remote, right? What about the physical keys?
Olin said:
@Wolf
So this is just for the remote, right? What about the physical keys?
Oh, you meant the main fob with the key? Well, the good news is, after you reprogram the keys, any old ones will only open the doors but won’t start the car.
If the fob is dead, you can still start the car using the physical key, by holding the fob near the start button, but only if it’s the correct fob. The wrong fob won’t be able to start the car. When you reprogram the fobs, the old ones won’t work at all.
As for getting new physical keys made, there are a lot of places that can do that. I’m not sure about the cost of changing locks, but that’s your other option if you don’t want to just reprogram the keys. A fob usually costs $25-$40, and the scanner is about $125+. You can compare prices to see what makes the most sense for you. I’d also recommend keeping a closer eye on your car for a few months. If you don’t already have outdoor cameras, it might be worth investing in some. Sorry you’re dealing with this!
@Wolf
Ah… this is an older Highlander without a start button. The remote only locks/unlocks the doors, and I have to use the physical key to start the engine. Thanks for the tips! Looks like I’ll get quotes from the local dealership. Also, I have cameras outside my house, but unfortunately, they didn’t capture who took my keychain when it fell nearby.
@Olin
Oh, gotcha! A lot of older Toyotas didn’t have the start button, so I forget about that. Looks like your options are either to change the locks or get copies made. Keeping a close eye on it is probably your best bet right now. Sorry you’re dealing with this! Hopefully, someone else who knows more about key-based start cars can give more advice. Good luck! 