Careful! Don't use the wrong key!
 

Yesterday started out great. I changed all my differential fluids (Thanks Mann777 for washer part#s). Went to start the car but accidentally used a wrong Lexus key. No problem, I'm thinking, and get the correct key. However, the correct key doesn't turn either. So I'm thinking it maybe a security feature and reset the computer. Nothing. The key just won't turn.

It wasn't until I started doing the search that this is a rather common problems with various Lexus models. My understanding is that the internal parts (perhaps a spring) of the lock cylinder gets old and if a wrong key is used, the pins and wafers stay jammed and does not return to neutral position. Hence the correct key doesn't work either. After wrestling with it for an hour, I finally took the dash apart and gave a few good taps on the cylinder. That freed up whatever was jammed and the correct key worked.

I take my GX on a remote expedition trips, and this issue is now starting to get me worried. I don't want to end up stranded miles away from the road. It looks like I can get a new ignition switch/cylinder for around $130. I'm going to start calling around the local locksmith but does anyone know for a certain that you can get the new cylinder keyed to your existing keys? I don't want to have two different keys for ignition and locks.... and people have reported spending up to $900 for the dealer to replace the entire locking system. I plan on just replacing the cylinder myself. Thanks.

How did that happen?

I doubt a BMW key will fit so no worries over here...but even if my wife had a Lexus I would be able to tell my set of keys from hers. :p

• Mine: Lexus key, house key
• Hers: BMW key, CVS card, Walgreens card, Publix card, GYM card, Toys R Us card, USB, house key, our old house key, lock box key, safety deposit box key, some other keys that we have no clue what they're too....you get the point.

I've accidentally put my LS400 key in, but its pretty similar and slides right in. Same size and everything. Which kind of key did you stick in the first time?

It was for ES300. I was baffled at first and searched the internet. Many people have reported the same thing when they accidentally used a wrong Lexus key.

I called a local locksmith and he told me it would cost about $100 to re-key the lock cylinder. I'm replacing it as an insurance.

Past threads have discussed this problem. The tumblers or springs in the ignition get stuck. You can tap on the inserted key with the butt of a screwdriver or small hammer. Once it works lubricate with graphite not WD 40.
Spraying compressed air in cylinder was also used

Yes, many people have reported that tapping the key worked for them. I tried that method to no avail. I had to remove the lower portion of the dash and give the cylinder a good whack in order to free up the jammed spings/wafers.

It worked!!
 

Thank you to who posted this. Second time this happened. Last time it was my toddler, this time it was me. Didn't want to pay $125 for mechanic to replace part and have to get car towed, rent a car to get to work tomorrow... This was the only solution that got my key to turn. Many many thanks!!!

Your wife has more keys/stuff on a key ring than a janitor! Lol

Used wrong key in Lexus 430 now key won't turn
 

I followed directions in the other posts and wiggled the key while wiggling the steering wheel. Freed up the mechanism and
problem solved. Sprayed some WD40 to clean out gunk so it does not happen again.

My wife did this a couple years ago. The Rx330 and the GX470 keys are identical. We dont keep items hanging on our keys. Dry lube helped and massively wiggling the key for quite a while freed it. I havent had another issue since.

You guys still have Toys R Us?

That post was from before they went bankrupt.