dat dude

I have a Lexus RX350, I notice that whenever I turn my car off it says "Key Battery Low". I obviously know what this means but that message doesn't appear every time I turn the car off. I was wondering if this has happened to anybody yet.

LeoDLion

Might be marginal voltage that is hovering at the level where the message is generated. Just change the fob battery. Maybe change them all.

txes

Extremely easy to change.

Takes about 30 seconds from start to finish.

corradoMR2

Hasn't happened to me yet, but nice to you it gives off a warning in advance.

kitlz

That and low windshield wiper fluid. Time for a battery change.

raylor4

The message doesn't appear every time because the voltage in your fob is floating between just good enough and not good enough. Yes, it happened to us. I got our 2011 fob batts changed by the parts guy at our dealership. He showed me how to change one and watched me change the other one. Over-the-top service with a smile. No charge. If you want to do it yourself, the procedure is in your owner's manual, pg. 496. The mechanical key is used to open the fob. The batteries are standard button batts, CR1632, available everywhere. One per fob. Good luck.
Ray A.

ColAngus

Page 496, it is!

Score 1 for the search function. I don't know why I didn't think to look in the manual.

tqh

Raylor, mind if I ask which dealership it is?

krismorr8

I've been having the same issue... "I notice that whenever I turn my car off it says "Key Battery Low"

raylor4

Lexus of Roseville. Remember, this was a CPO only a month after purchase.
I think if you are nice to the person in the accessory shop, they will be nice to you.
My suggestion: Plan A - free fob batts from the dealer with install instructions.
Plan B - Purchase your own batts at the grocery or drug store and install them yourself. Easy-peasy as they say.
Tip - Use the mechanical key to pry open the fob.
Ray A.

rogerh00

hmm, It's page 792 in my 2013 RX manual.

corradoMR2

My wallet key card has just given me the low battery warning. The battery in this key is 20$! Must be how thin this battery is at about only 1mm.

hovbuild

4.72 at Amazon!

corradoMR2

Thanks for the find. I may order it and have it shipped to my US office.

ColAngus

Post #13 here:
https://www.clublexus.com/forums/rx-third-generation/705788-card-key-for-the-rx.html