Workings of key transponder/transmitter vs newer.

[MWS]

From my understanding of the 986 key it consists of a RFID pill (which is read by a coil in the ignition and verified by the immobilizer) and a transmitter for remote locking/unlocking (I assume it also transmits the same code). My question is how is the operation of this key different from newer cars that have full keyless operation (key always in pocket)? Do these types of keys always transmit a signal, or do they only transmit when in proximity of vehicle? I know that something has to be different as I can't remember changing the battery in my Boxster key, but it seems like I need to change my batteries in my Audi keys almost annually.

Additionally, is there any communication between the Boxster key and the vehicle when the key is left in the car (say on the seat) and is static (no buttons pushed), or to look at it a different way, will leaving the key on the seat drain the key battery sooner?

Sorry if these are detailed questions, I'm just trying to understand the difference between the two types of keys. If anyone here has detailed information regarding the types, please feel free to share specifics.

As always, thanks in advance. We are all in this together.

[JFP in PA]

You got it in one: The newer keyless systems operate at a higher power level than the earlier "proximity" keys, which is why the batteries die faster. This is also how some cars disarm the alarm and unlock the driver's door as you approach.

The Boxster key is only active when within a certain distance of the key slot, other wise they cannot see each other. That said, I can't see why you would leave the key to the car laying about.

[MWS]

Originally Posted by JFP in PA

...The Boxster key is only active when within a certain distance of the key slot, other wise they cannot see each other. That said, I can't see why you would leave the key to the car laying about.

My question is based on the fact that I've developed the bad habit of leaving the key in the ash tray as the car is always garaged. I've been doing this for the past few years (I guess it is just a matter of convenience) and I haven't had to change the key battery, however it "seems" the interior lighting (dash, orientation lights, etc) stay on somewhat longer. I say "seems" because I haven't stood around with a stopwatch to check time with and without key inside car, and rather than having to do this was curious if key left inside vehicle would still cause some systems to draw power...hince asking about communication between key and car. I should mention that I leave the car on a battery tender so I haven't seen a drain on battery.

To nutshell my question...can key be left inside car (not in ignition) without consequence (aside from any security risks )?

[JFP in PA]

Originally Posted by MWS

My question is based on the fact that I've developed the bad habit of leaving the key in the ash tray as the car is always garaged. I've been doing this for the past few years (I guess it is just a matter of convenience) and I haven't had to change the key battery, however it "seems" the interior lighting (dash, orientation lights, etc) stay on somewhat longer. I say "seems" because I haven't stood around with a stopwatch to check time with and without key inside car, and rather than having to do this was curious if key left inside vehicle would still cause some systems to draw power...hince asking about communication between key and car. I should mention that I leave the car on a battery tender so I haven't seen a drain on battery.

To nutshell my question...can key be left inside car (not in ignition) without consequence (aside from any security risks )?

Proceed at your own risk here. First of all, many of these cars have factory alarm/immobilizer systems that are actually capable of arming themselves if left alone and unlocked/unarmed for a period of time, which would leave you with a locked car with the alarm on and with the keys in the ashtray.

If you are concerned about power draw, get a digital multimeter and check the car's mA draw over time; after an hour or so, you should see 40-60 mA, if it is more than that, then yes leaving the key in the car is drawing more power than normal, which cold lead to premature battery life.

[thstone]

Originally Posted by MWS

To nutshell my question...can key be left inside car (not in ignition) without consequence (aside from any security risks )?

I have a tendency to leave the key to my Spec Boxster race car in the car hanging from a short lanyard from the turn signal stalk. I started doing this at the race track because its super convenient to have the key hanging there, ready for use, without me having to mentally keep track of it. And since habits are... well, habits, I tend to do the same here at home.

With all of this being said, my key hangs 9" from the ignition switch for a month or so at a time and I haven't had any battery issues. YMMV.

There is nothing that I love more than a science experiment, so if I have some time tomorrow while getting the car ready to go racing this weekend, I might check the parasitic draw at the battery with and without the key in the car to see if there is any measurable difference.

[Geof3]

What JFP said. In order to have the car not lock and set automatically you need to lock it with the fob then unlock it. Ask me how I know. Let’s just say I’m glad my key was in the house...

[MWS]

Originally Posted by Geof3

What JFP said. In order to have the car not lock and set automatically you need to lock it with the fob then unlock it. Ask me how I know. Let’s just say I’m glad my key was in the house...

I'm asking. Lol. I always enjoy a good story, and maybe learn something.

I am very interested in details of this "self arming" feature (if I dare call it a feature). I know the car will re-lock if unlocked and door not opened, but this is the first thread I've read with spontaneous and unprompted arming...especially after a prolonged amount of time. All I can add is after 10+ years, I've never experienced this and now I find myself fearing something for what seems to be no reason at all. Grrr.