Three years ago M-B's so-called "keyless go" was a stand-alone option which I avoided in my SLK55 AMG. "Pointless technology," thought I, "another problem waiting to happen," etc. In a few months the Merc will be replaced by an F-Type S in which the keyless start-stop feature is standard.

My question concerns the advisability of leaving the Smart Key in the car when it's in my garage — something I've always done with my conventional fob. According to quick general search here (not limited to the F-Type), and simplifying a bit, there are basically two schools of thought:
1. Yes, you can leave the key in the car. The car won't lock when the key is in it, so no problem.
2. No, don't do it. It will prevent some of the functions from shutting down, or at least delay it, thus draining the battery.

Oddly enough, there's nothing in the manual on this. So what say the experts here? What's the truth? Do you leave your Smart Key in the car? If not, how far does it have to be before the car can go to sleep?

N.B.: Theft from my garage is not a concern. My question relates exclusively to the electronics.

Thanks.

 

I never leave my key in the car. It's always in my pocket. Why would I ever make it easy to steal? You can't lock it with the key in the car. If anyone ever got into my garage they open the door and press the start button. I'm sure my insurance company wouldn't like that too much either.

 

Theft from my garage is not a concern. I should have specified, TXJagR: LEAVING SECURITY CONSIDERATIONS ASIDE.

 

All I can tell you is what my salesperson told me during my initiation to the car [re] leaving the smart key in the car:

DON'T.

(And while I realize that you probably would like to know why - and I seem to recall that he did tell me - all I can remember was the word "don't". So I don't...and it makes sense to me not to. Key always in my pocket. Sorry to leave you hanging).

 

The car won't completely sleep with the fob in it. With all the battery issues Jags have, it makes no sense to not get the car completely shut down when not in use. That requires locking it, even in one's own garage.

 

The Meridian vacuum tube amplifiers won't shut down otherwise.

 

+1

 

I will tell you I leave my key in my car all the time in my garage. My car sits sometimes for a very long time (in the winter for months) and I have never experienced any issues whats so ever with my car. Everything shuts down as normal and the battery is fine. It is all preference. There is no one in my home to drive the car and no chance of theft at all. So it is all up to you but from my experience it does nothing to the car.

 

"The car won't completely sleep with the fob in it" (lhoboy).

"Everything shuts down as normal" (ftypeguy).

This is a straightforward factual disagreement which should be easily settled — or so it would seem. Isn't there anything in the Jag documentation on this? ANYTHING? Any techies out there who know for sure? If so, where did you get your info?

 

while I have no first hand experience, this makes the most sense to me. The car's accessories are not on until you press the gas pedal without the brake. once you turn off the car, the car is off. the key unit is just a sensor that is always on, to detect if the key is nearby so that you can start the car. completely different systems would make more sense.

 

Not having made that exact statement, I, in truth, have no direct knowledge regarding any matters related to clairvoyant key fobs. I was merely using the opportunity to interject the concept of vacuum tubes to mock Meridian's supposed supremacy in the audio market (as many would debate on this forum).

 

I think this question can be settled rather easily.

When you shut the car down, the emergency flasher indicator light in the center of the console stays lit for perhaps 10 minutes or more before the light extinguishes. While I always take my fob inside with me, I'll try leaving it in the garage next to the car.

It that indicator light stays on, that would mean the car is not "going to sleep."

 

Sorry, lhoboy, that quote was from Nookieman, not you.

 

Yes, Foosh, that would settle it, assuming that no other, less visible functions remain active in addition to the light that you mention. That assumption is precisely what the disagreement is about.

Instead of leaving your key close to the car, could you leave it IN the car? (I'd do it but it'll be months before I have my car.)

Thanks.

 

No problem.

 

I cannot comment specifically for jaguar but typically keyless-go style systems work as follows:

The RFHUB module is in charge of sensing the keys location. It is sensitive enough to tell if the key is inside or outside the car, what side of the car the key is on and how far away it is. The RFHUB is always away looking for the key, regardless of its location.

When the key is spotted near the vehicle the RFHUB wakes up the BCM (center of vehicle command) which allows you to unlock the doors/enter the vehicle and cycle the ignition or use accessories. If you leave the key in or near the vehicle (usually within about 5 feet) the RFHUB will never let the BCM go to sleep and it will remain active.

This will draw extra power, but without doing a parasitic drain test I cannot tell you by how much. Each vehicle is different in how much extra power is needed to run the BCM based on how much it has to do when awake with the key off.

Your battery will die more quickly, but it's hard to say how much more quickly without testing it.

 

Frenchy,

I just did as you requested and left the fob in the center console cupholder. The hazard light extinguished as usual after 10-15 minutes, and everything appears to be shut down. However, you're right that it's possible other functions remain active, as Stohlen noted above.

 

I noticed on my 2015 R that if I single-locked the car (press the lock button on fob only once) both the driver and passenger door "lock" LEDs stayed lit, as well as the hazard light in center of console. They stayed lit all night, because when I checked the next morning, they were still lit. Once, when I had to let it sit for a couple days without driving it, I noticed a "Low Battery" warning in the drivers information area of the dash when I started it.

Then I started double-locking it (press lock button once, then once again within a couple seconds) and the same LEDs and hazard light went out after about 10 minutes or so, and I never saw the "Low Battery" message again.

So now I've started making sure I double-lock it, because it does seem to put it in a lower power consumption mode.

 

Don't know about the Jag, but I do know that the Land Rovers will not fully shut down to sleep mode unless it is locked. Land River owners have found that leaving the car unlocked for long periods will result in flat batteries.

 

Not shure about the F-type, but in some cars with OEM-alarm system, one click will lock the doors and activate the alarm, but two clicks will deactivate the alarm (probabely so that it will not drain the battery when left for longer periods and a few other reasons as well).