RXSF

Lately I keep getting this error message on the instrument cluster even though the key is in the vehicle. It can happen while moving or also when I try to start the car. I even had to hold the key up to the starter button to start one time. I am about to order a new battery for the key but I don't think it is due to low battery. I have never gotten the low battery message on the dash.

I wonder if anyone else has experienced this. Not sure if the key is faulty or if it is the sensor in the car. Anywhoo troubleshooting common sense tells me I should change the battery first and see.

fryzia23

Key batteries should be changed within 15-20k miles. When the battery life goes low your key range greatly decreases and you will be getting that message until you put the key closer to the start button. Im sure quick battery swap will fix your problem.

RXSF

My car had less than 12000 miles but yeah I'll change and see. You should get the low battery message though

kitlz

Battery changes are included with certain services., I believe the 15Ks. I don't wait and just change mine every year.

I had the key not detected error once getting into the RX. I figured it was some random thing. Hopefully changing the battery will resolve it.

LexRexBlue

I've had this problem. They changed my battery a few times already. The car only has 10,000 miles now. They are not sues what is causing it.

AlexB

This can happen if you have a cell phone or other RF device close to your key, it interferes with the communication between the car and the key.

LexRexBlue

It is unrealistic for any woman with a purse to have her cell phone far from the key! Besides if that were the case it should be a problem all the time not just at specific incidences. I've been told that thick leather (I don't consider my leather purse thick) could be the problem along with the magnetic closures. Again if that were the problem it should happen all the time. Sometimes the door won't unlock unless I bring the bag closer to the door handle.

DunWkg

There are multiple sensors in the car i would think there is some overlap. Doesn't the car "ping" the fob, then the fob responds. The fob doesn't transmit unless pinged. The reason they say don't leave the fob in the car all the time as it drains the fob battery. Your fob may be going bad, more than a battery problem.

AlexB

Unrealistic or not, the fact is that your car uses RF signals to communicate with the key. Our radio waves are jammed full of devices these days and some can interfere with others. When you have a weak cell signal, your phone will transmit at a higher power level trying to communicate with a cell tower. It is always communicating with the celular network whether you're actually using it or not. So that could explain why you have difficulty some times and not others.

DunWkg

Is it both keys(fobs)? Switch batteries between the fobs and see if the problem follows the battery.

billy44bo

Just for fun, try it with you phone off to see if it will still give you the error. How long have you had your car? Think time would be more a factor than how many miles are on the car. I change both batteries out on my car 15 months of used just happen to been 14k miles on the car.

LexRexBlue

I had issues again a week after they replaced the batteries.

Alpy64

Not sure the battery key as something to do with mileage or km but months of use and how much time the key is activated when using the car (activating/deactivating car systems, etc.)
One of the 2 "classic" key has been changed after one year if use eventhough I sometime use the card key alone (it is always in my cards and money wallet/billfold, that means perhaps also activated when I have the classic key with me).
Change of the battery was not free of charge... lexus is luxury car... and service as well ;-)

RXSF

I should try using the second key fob. I have owned the car since November 2010 so not even two years of ownership. i always just use the one key fob.

As for the RF signal, that could very well be the case. I had my iphone in the drink holder plugged into the USB cord and I also had the key in the drink holder...

billy44bo

You can do this for yourself it takes less than 10 minutes and the pictures on how to do it are in the manual . I got two batteries for less than $6.00 at Home Depot. Sure you dealer got more than that from you.