Cocal

Both of these are possible, but I think the latter is more probable as to insert the key is very awkward and sometime one wishes for a 3rd hand.

jjscsix

Good one! I guess they figured it’s my fourth Lexus, if I can’t figure this stuff by now I’m beyond hope

bamalam

The 'Like' button is insufficient. Trying things on our own vehicles to answer forum questions is a good way to give back to the community. Disconnecting the battery and trying what you did in the stinking cold weather is above and beyond - and deserving of the Distinguished Service Medal. Well done, and thank you.

mak99

This thread brings up a related question, regarding an RX450h where the battery is in the rear hatch storage area. I've accessed mine when the back door was open, and not sure if you could access from within the car if the back door could not be opened

(EDIT - you can at least manually/mechanically open the back door from inside the cargo area, per page 148 of the 2019 RX450h manual).

So if your 4G RX450h battery dies, prepare to do some awkward crawling back into the cargo area!

JeffKeryk

We keep out 2021 RX450h F Sport in our Petaluma house which is 90 miles from our Los Gatos house. Petaluma is north of SF in the beautiful wine country.
Well, the battery was dead from sitting too long. I pulled the steel key out of the fob to unlock the door.
I couldn't turn it; it was too hard to turn. I used a pliers to gently unlock and then open the door.
I could feel it operate and then pulled the handle as usual.

I keep jumpers at our 3 properties and jumped it from the engine side using the post and an engine ground, since the battery is in the rear.
I have since purchased a NOCO 1 Amp battery maintainer from Amazon for $30.

I did crawl into the rear but was unable to open the rear hatch. There really should be a clearly visible lever to do so in case of an accident or fire.

rc16

Thank you so much for posting this note. My situation is very similar to yours in that my RX350 sits on Long Islang about 60 miles from my home. My battery was dead and my car locked when I tried to open the door with the mechanical key. I could not open it and never thought to use a pliers. Instead, I thought that the mechanical key was not a mechanical at all but that the car battery was needed to open the door (since it is mentioned in the manual that it could also open the other doors and also that when it is said that the battery was depleted it was meant to be the remote battery). Well, next time I go to get the car, I will try to carefully use the pliers to open the door as you did and hope that it will work.

JeffKeryk

Good luck. I would get a NOCO Genius or something similar. I can't wait to hook up the one I just got to wifey's RX!
By the way, I have used the fob key on other cars, so I was pretty confident it would work.

PhxBill

I would spray the lock mechanism liberally with a penetrating spray like Kroil or even WD40. I have heard that the lack of use allows the mechanism to seize slightly but a little lubrication in the key slot can free the lock up.

jcg0324

Don't use plain WD-40. Use WD-40 Silicone quick drying. It is really good stuff. It will lubricate, waterproof and protect from rust.

jjscsix

I’m pretty amazed at the problems people are having. It sounds unlike Lexus reputation for quality. I would have been worried about breaking something by using pliers. Breaking either the key or the mechanism would turn into a far bigger expense.

Cocal

All mechanical parts need lubrication, the less used the more it's needed.

jcg0324

Good point Cocal. I will go out and lube that key spot today. I have some WD-40 "specialist" Silicone dry lubricant. Eventually all mechanical parts get corrosion and dirt and crud. Here is a simple and easy preventative maint. application.

Cocal

If you can get a can of KRONE rust proofing I'd spray that in the lock it will do even more than silicone to prevent corrosion & rust

mak99

^^ Good recommendation on using s silicone spray and regularly exercising the lock. I think I'll spray the silicone directly on the key then insert into the lock and operate a few times, maybe on the days I have the oil changed...

madh

On my 2016, the mechanical key turns but the door does not unlock. Do I have something wrong with the door cylinder? Any ideas on how to get into this car (battery's dead)?