[KEY NOT DETECTED] Camry hybrid keybob requires new battery?

After a 3 a.m. bloodelivery to a mountain hospital 170 miles from home, several times I tried to start the Camry.
KEY NOT DETECTED reads out!!
The key remote, in my EMS pants leg pocket, likely got cold walking outside in 15° F from a distant exit back around the hospital to the emergency entrance parking lot.

I held the remote in my hand to warm it, then held it close to the right side of the steering wheel and thengine started.

Does the remote not contain a passive transmitter which broadcasts a signal when close to the vehicle interior ignition transmitter?
(That day, I bought a replacement “button” battery at a grocery store which I placed in the glove box for when the remote goes totally dead. We rarely press any of its buttons.)
Thank you.

A good friend of mine is having problems with his new 2012 Camry Hybrid as well. He was stuck in the parking lot for several minutes as we left church. Do these vehicles not have a real key? I see some serious problems down the road for this “wireless” key system myself. Being stranded in the boonies is no fun at all. I will pass on the info about keeping a spare battery in the glove box.

Welcome to the world of automotive electronics…Since all these gadgets change every year or two, NOBODY ever learns how to fix this stuff…You start by replacing the cheapest stuff first and work your way up until it starts/runs…80% of the time it’s a bad connection someplace in the failed system…

Today, I wonder how many cars must be TOWED off the end of the assembly line rather than be driven off…Does all this bells and whistles technology accomplish anything??

Smart keys aren’t.

Does it require a battery? Or is there a “chip” or coil circuit which is detected by the ignition?
Does the battery power only the lock/unlock transmitter in the push-button remote?

Perhaps the OP should direct questions about the specifics of the chip key and remote to Toyota. These systems vary from car maker to car maker and sometimes model to model and even year to year.

Chip keys provided with new cars from the manufacturer do not have replaceable batteries. How long are such chip keys good? Forever?, 10 years? As far as I know these keys never need replacement.

Chip keys that you can buy from a hardware store and have programmed to work in your car DO have replaceable batteries. How long do these batteries last? So far, I have 2 years on such a key.

Remotes to open doors do have replaceable batteries. I find the batteries in these devices last 1 to 5 years depending on how often they are used.

Security systems that have a remote that needs to be in the “vicinity” of the car to allow a “start” button to work, some may have replaceable batteries and some may not. Good question for Toyota in this case.

The “Key not detected” message indicates the smart key is not transmitting a signal. This is usually caused by a dead or weak smart key battery. Aftermarket accessories can interfere with the smart key signal, I once found a camera charger in use blocking the signal in a car.

A smart key with a dead battery can be used like a transponder key when held close to the start switch.

"... the smart key is not transmitting a signal. This is usually caused by a dead or weak smart key battery."
So the smart key is constantly transmitting a signal? Then both batteries likely are getting low.

When I get access to the Camry, I’ll remove the remote battery and see if KEY NOT DETECTED appears.

Thank you.

When you are within range of the vehicle a signal from the vehicle will (usually after touching the door handle) “wake up” the smart key. Some electronic devices in your house can emit a “ping” or electronic noise that may “wake up” the smart key and reduce battery life. Don’t store the key on TV’s or near computers.

I had to replace the battery on the fob for my 7 not too long ago. My keyless entry button on the door wasn’t responding as quickly as it normally did, and even pressing the unlock button took several tries, yet it still detected the key enough inside the cabin to use the keyless start function.

Simply changing the battery should be enough to get it to work again