Is there a TSB for the start/stop button on these cars ('07 GS350 in my case)? I recall reading something on the IS sub-forum about it, but I can't for the life of me find the thread right now, and I'm fairly certain the start/stop button (presuming that's where the receiver for the keys is) in my car is dying. I'm getting "key not detected" messages in spite of the keys having new (as of August) batteries, and the car hasn't complained about the key batteries being low.

 

Try a new battery August was 5 months ago and you could have got a dud good luck.

 

There is nothing wrong with your push button. Pretty often it is your cell phone interfering with the key fob signal. Do your keep your phone in the center console?

 

I would change the battery on the key fob and when you open the key fob clean the connections with alcohol and bend the tabs just slightly to make a better contact with the battery. This is what happened to me, and that key fob tweak helped fix it. I have never heard of push start buttons going bad

 

Tweaked my search language a bit, found the TSB I was looking for. L-SB-0161-08:
https://www.clublexus.com/forums/att...sb-0161-08.pdf

It is for a slightly different issue, but one which I've also experienced on three separate occasions.

The fact of the matter here guys is that both keys have fresh-enough batteries in them, it does it with both keys, and I have other vehicles with "smart keys" or "keyless go systems" or whatever you wish to call them and I'm pretty intimately familiar with how they work. This is why I keep my cell phone in my left pocket and my keys in my right pocket. It's also why I don't carry smart keys for more than one car at a time.

"It's not the button" is not a logically defensible conclusion at this point in time. It may indeed not be the button. I'm not drawing any conclusion one way or the other, and simply ruling it out at this juncture is not a great way to diagnose this issue for several reasons:

• It does it with both keys. Yes, both keys could have loose or corroded terminals-I"ll pull one apart and check; I picked up a new battery to throw in just in case-but the odds of both keys experiencing the same failure mode at the same time are, in my estimation, lower than a single point of failure elsewhere in the system (i.e. the button). Doubly so when the batteries are 4-5 months old and Mercedes, BMW, Subaru and Mopar smart keys are typically good for 12-18 months or more on a battery.
• As I understand it, the car is supposed to report low-battery conditions in the keys; if that is the case, it would also report issues with extremely poor contact due to loose terminals or corrosion (because in all three cases, the symptom is going to be abnormally low voltage, which will appear as a failing battery to the car irrespective of the root cause). This system may not be 100% reliable and its detection threshold may be too low, so the absence of complaints from the car is not itself proof of anything. It is a consideration, though.
• There is no ancillary evidence to support a conclusion that the transmitter in either key is not operating at full power; I can lock/unlock the car from quite some distance, and that has not changed at all.
• The button has been through at least one redesign to address performance deficiencies in other areas. This does not implicate the button (either directly or indirectly) as the root cause of my issue; it does indicate that the original button design had at least one issue that was serious enough for Toyota to spend the money to address it with a new revision, though.
• The buttons absolutely do fail. While it does not appear to be a common failure, some careful googling will turn up multiple accounts of cars that use this part being flatbedded to the dealership and having the start button-or, in some cases, the actual control unit for the whole smart key system-replaced to address it, and a handful of reports of the cars being dragged to dealerships without any reported resolution because the dealer couldn't properly diagnose the problem.
• I've experienced the exact issue with the button that TSB discusses. While that does not appear to be directly related to this issue, it absolutely could be, and it's also quite possible the button fails in more than one way.

In short, right now, there is not enough evidence to conclude anything with certainty. All I was looking to do is confirm that a TSB exists before I actually decide how I want to approach this.

And, TSB in hand, having confirmed the button was updated, what I'm going to do is pull one key apart, clean and tighten the contacts as ibidu1 suggested, install a new battery, and then take the car to the dealership for a 3rd key. Can't have too many spares anyhow.

While I'm at it, I'll throw in a new, updated start button just to eliminate that variable entirely. The button is cheap, the install looks to be trivial, and I am unreservedly intolerant of a car leaving me stranded somewhere-if I have to put this thing on a flatbed for anything that could be considered a failure on the car's part (as opposed to a dead battery, a blowout, an accident, etc.) it will be the last ride the car takes under my ownership.