Smart Key Battery Drain

[tagheuer]

We have a 2011 Limited with 24,000 miles on it. Use the truck in a very "typical" fashion, i.e. drive to and from work, drop kids off at day care on the way, so probably 4 open/close cycles.

About a month or two ago the battery on my smartkey was low, so I replaced it.

Today it is reading low again....???

At night the vehicle is parked in a garage, and the key is stored inside, probably at least 40 feet away behind drywall, steel door, etc.

Our other car is a 2012 VW GTI which does not have a smartkey.

My key ring has the Toyota Smartkey, VW key and two HID Prox key fobs (those grey electronic "keys" that are used to open doors, etc).

I wonder if these HID Prox keys could be causing the battery drain issue, it is my understanding they work on a similar perhaps related technology. They do not have batteries in them, they pick up current from another source...ie when you place them close to the electronic sensor lock I guess they pick up current and send a code and unlock (I'm guessing here a bit).

The HID keys could be a total red herring too....any ideas before I take into dealer?

It seems pretty crazy that I have to replace the battery twice already in a 2011....maybe its a fluke that I got a bad battery?

Does dealer try to troubleshoot or just replace the keyfob? (I'm under factory warranty)

http://www.gokeyless.com/product/600...8051-prox-fobs

[workerant]

likely they'll just replace since that is super cheap and super faster.

Usually when there is a communication, the led on the key blinks. Keep an eye on ur key for that. Could be the batt they put in last was old to start.

[tagheuer]

I already replaced the battery myself last month, and its dead again.

I was asking whether they might just replace the whole keyfob instead of trying to troubleshoot it.

Its a pretty cheap part for them, although they charge us hundreds of dollars for it.

[workerant]

is your other fob battery drain the same?

u r still under warranty, better get it taken care of.

[tagheuer]

update, apparently I am the only person in the known universe experiencing this issue.

My smart key batteries continue to drain, our truck is a 2011 and has only 29,000 miles.

The batteries have been replaced twice. This is totally abnormal, according to dealer, batteries should last 3-4 years under normal use.

First dealer simply changed battery...that fixed for a few months, now draining again.

Second trip to dealer, they didn't offer a concrete explaination/solution, rather they just said they are ordering new fob.

This time, the service advisor suggested that the VW GTI key might be interfering and causing the problem....and said I should keep them separate.

I am going to try this....

But this seems very bizarre to me....this is the same smartkey system used across the entire Toyota line, and surely by now someone else must have encountered a similar issue....

any ideas?

[DeWat]

I do remember reading somewhere in the manual (I'm at work now) something to the effect of it being good to keep the smartkey away from other electronics, like cell phones, because they cause (?trick?) the smartkey into repidly discharging its battery. My interpretation of this is that the cell phome makes the smartkey think that it is being querried, so it continually transmits. I will have to find the statement when I get home unless someone else finds it first.

[workerant]

There is a way to turn off the smart key from transmitting, it'll be like the regular keyless entry remote.... something to do with the button dance. I never check into it but you could try that as a temp fix.

[tagheuer]

Originally Posted by DeWat

I do remember reading somewhere in the manual (I'm at work now) something to the effect of it being good to keep the smartkey away from other electronics, like cell phones, because they cause (?trick?) the smartkey into repidly discharging its battery. My interpretation of this is that the cell phome makes the smartkey think that it is being querried, so it continually transmits. I will have to find the statement when I get home unless someone else finds it first.

Hm....so I can't have a cell phone in my pocket or anywhere near me when I open, close and/or start the vehicle?

I use an iphone...doesn't just about everybody (other than those people living in 3rd world countries) have a cell phone on them when they are out and about in their vehicles?

I use an iPhone if that makes any difference, but have never had a similar problem with all other smart keys, like those used in Infiniti/Nissan, several BMWs etc...

[DeWat]

Originally Posted by tagheuer

Hm....so I can't have a cell phone in my pocket or anywhere near me when I open, close and/or start the vehicle?

I use an iphone...doesn't just about everybody (other than those people living in 3rd world countries) have a cell phone on them when they are out and about in their vehicles?

I use an iPhone if that makes any difference, but have never had a similar problem with all other smart keys, like those used in Infiniti/Nissan, several BMWs etc...

Believe me, I'm not trying to be smart. In fact, I thought along the exact same lines when I read the statement which is why I remember it. However, it (the statement) referred to storage of the smartkey, which I took to mean something along the lines of what you do with it when you're home.

[DeWat]

Found it looking around in the manual online. Section 1-2, "Smart Key System" says a lot about the operation of the battery in the smartkey. It even talks about how the smartkey can go to sleep, and things that make it wake up. There is also a lot of the "that just doesn't make sense" statements there, such as, the operation of the smartkey being affected by things like near a TV tower, carrying a cellular phone, multiple electronic keys in the vincinity, etc. The part I was specificaly talking about is on page 42, titled "Electronic key battery depletion" It cautions to avoid leaving the key within 3 feet of TV's, personal computers, recharging cellular phones or cordless phones, and table lamps. So to make sure that you are not causing the problem, you may want to bury your key at a minimum of 3 feet deep in the ground each time you come home (sarcasm fully intended towards the conditions that time). However, in all seriousness, I guess it is possible that you may be encountering one of these "situations".

[sweeneyp]

From what I know/read about the system, they key broadcasts at ~315mHz. But it will only do that if it receives a signal, otherwise its keeps quite to save power. The exterior/interior key oscillators in the car broadcast at 134kHz (at 92dB uV/m). The key activates and starts broadcasting first its ID code then later a vehicle ID code. There are a few RFID readers out there that operate at 134kHz, so that (or any device that outputs that frequency) will trip the smartkey and start burning battery life.


edit: though I keep my keys in my pocket near my smart phone all the time, it also sits next to an LCD monitor on my desk, so I vote toyota is just covering their legal backside with those statements....

[desertnate]

Originally Posted by sweeneyp

From what I know/read about the system, they key broadcasts at ~315mHz. But it will only do that if it receives a signal, otherwise its keeps quite to save power. The exterior/interior key oscillators in the car broadcast at 134kHz (at 92dB uV/m). The key activates and starts broadcasting first its ID code then later a vehicle ID code. There are a few RFID readers out there that operate at 134kHz, so that (or any device that outputs that frequency) will trip the smartkey and start burning battery life...

With the key using the RFID in that freq, I wonder if more problems like the OP is seeing will pop up as new cell phones start fielding the near field broad cast features like the new Samsung Galaxy has. The phone will be broadcasting away and the fob will be answering right back!

[tagheuer]

DeWat,

Thanks a million, I think you hit the nail on the head...I think what is happening is that we store our keys on the same little part of our kitchen counter where we keep our cellphones, and plug them in. It is literally a 2 foot square countertop/little corner....

I'm very glad to have found this as the possible cause, real easy fix, just move the keys.

I never paid much attention to those warnings, virtually every electronic device has interference etc, type warnings....which nobody really reads.

But in this case, if this is what is causing my problem, I can tell you that putting your key next to a charging cellphone will run the battery down in a matter of weeks, when it should last a matter of years.

There must be some odd quirk....because I doubt it does the same thing with computers etc.

FYI we use iPhones.

Thanks DeWat.

[summerwind]

Just out of curiosity which carrier are you on AT&T or Verizon?

Each use different frequencies and I was wondering if there is more interference from one carriers frequencies or the other.

Calk the question up to my Data Compulsive Disorder

[tagheuer]

I have an old (don't laugh) iPhone 3G, my wife has an iPhone 4s. We have been charging them within a foot or two of where our keys are stored.

So, again, I like most others don't really pay much attention to these warnings, because every electronic device has them, and most of us have wifi routers, cellphones, smart keys etc etc

IF this is the cause, keeping the key too close to a charging cellphone, which I suspect it is....you should be aware that this badly hammers the batteries.

I put a fresh battery in, and it seems to last only 3-4 weeks...so apparently the warning to avoid storing the key next to charging cellphones is the real deal....

the electromagnetic field is probably causing the key to transmit constantly.

Wonder what its doing to my brain?

we're all gonna die from something eventually...ugh.