[Surferdude]

As some of you may be aware, I have had a "door only" key cut so I can lock the car and take it with me in the surf without damaging the electronics in the "real" keys.

So, it occured to me the other day that the transponder tells the engine it's OK to start when you turn the key. Which I guess is common knowledge.

My question is this. How would my engine know if the transponder was actually attached to the head of the key turning the ignition. In other words, if the "real" transponder key was in close proximity to the door key and I used the door key to start the car, would the engine still start?

Why is this even important? Well I seem to remember a couple of people having a problem with the key shaft breaking off from the fob. Which meant a lot of money for a new fob. My "door" key cost me $55.00 (it's actually a Toyota blank). So maybe if you had a broken key shaft you could get a blank key cut and just keep it on a key ring with the fob containing the transponder.

Is there anyone out there who might be able to answer this?

It'll bug me now till I know the answer so I guess I'll eventually go ask the locksmith who cut my blank next time I'm nearby.

[asathorny]

As some of you may be aware, I have had a "door only" key cut so I can lock the car and take it with me in the surf without damaging the electronics in the "real" keys.

So, it occured to me the other day that the transponder tells the engine it's OK to start when you turn the key. Which I guess is common knowledge.

My question is this. How would my engine know if the transponder was actually attached to the head of the key turning the ignition. In other words, if the "real" transponder key was in close proximity to the door key and I used the door key to start the car, would the engine still start?

Why is this even important? Well I seem to remember a couple of people having a problem with the key shaft breaking off from the fob. Which meant a lot of money for a new fob. My "door" key cost me $55.00 (it's actually a Toyota blank). So maybe if you had a broken key shaft you could get a blank key cut and just keep it on a key ring with the fob containing the transponder.

Is there anyone out there who might be able to answer this?

It'll bug me now till I know the answer so I guess I'll eventually go ask the locksmith who cut my blank next time I'm nearby.

But it seems to me that you are ideally placed to answer this question for us all !!!!!!  I mean, you do have a door only key dontcha???   and it's safe to assume you have a *REAL* key.   So why not get in the car with the *REAL* key in yer pocket and start the engine with the other key and tell us all what happens.   

[asathorny]

Oh I see, I was under the impression you'd already cut the blank.    <sigh>

Well, go for it, you'll know before you get to starting the engine me thinks, I opened the door one time when the fob appeared to have failed and the alarm went off.  As soon as I shut the door the key fob started to work correctly and pretty soon we were all back too normal...

Your puzzle is of great interest tho, as you say if you snap the shaft, and you correct, it'd be a real money saver   

My question is this. How would my engine know if the transponder was actually attached to the head of the key turning the ignition. In other words, if the "real" transponder key was in close proximity to the door key and I used the door key to start the car, would the engine still start?

I'm certain the answer is yes. The proximity is, as I understand it, to the "antenna" near the ignition switch not the key itself. How close it has to be I don't know but as said you should be able to experiment. 

[Surferdude]

asa, I have already cut the blank. It's been in use since about 2 weeks after I bought the car.
And yes, I am aware of my unique position to test out the theory.
Up till now I've been held back by the (vague) memory that when transponders first came into use, any effort to start the car with a non transponder key scrambles something in the ECU and can wreck it.
I can however, try the alarm thingy. I'll do that today. Later -  it's a bit early yet.
No. Wait. That's already been done. My daughter tried to open the door with the key once when I'd locked it with the remote. Alarm went off. I think that's different to the transponder.
Anyone know if it's possible to damage the ECU if I try to start it?

[asathorny]

asa, I have already cut the blank. It's been in use since about 2 weeks after I bought the car.
And yes, I am aware of my unique position to test out the theory.
Up till now I've been held back by the (vague) memory that when transponders first came into use, any effort to start the car with a non transponder key scrambles something in the ECU and can wreck it.
I can however, try the alarm thingy. I'll do that today. Later -  it's a bit early yet.
No. Wait. That's already been done. My daughter tried to open the door with the key once when I'd locked it with the remote. Alarm went off. I think that's different to the transponder.
Anyone know if it's possible to damage the ECU if I try to start it?

Ah right, I now understand your caution....  MMmm   I would be reticent also.  Although it would be useful to know.   Having said that I do have two transponder keys one of which I have only ever used once to check it out.  But ya never know when this sorta knowledge come in useful   

I can however, try the alarm thingy. I'll do that today. Later -  it's a bit early yet.
No. Wait. That's already been done. My daughter tried to open the door with the key once when I'd locked it with the remote. Alarm went off.

That's because the car was opened before the alarm was turned off, which it normally does when using the remote to unlock the door - it disables alarm then unlocks. Once alarm goes off it will only stop if you either start the car or toggle the alarm on/off with the fob.

I have a spare key with an transponder but no remote buttons for wife's Getz. I can use it for every day use (starts the car) but the alarm remains disabled after the car is locked and it does, as I said, trip the alarm if it was previously locked with the fob key.

I can't imagine you can cause any damage by trying to start the car with your spare key. That would surely happen occasionally in the field when/if a transponder failed. Can't imagine a policy to cause damage getting implemented. It just won't start.

[Surferdude]

I can however, try the alarm thingy. I'll do that today. Later -  it's a bit early yet.
No. Wait. That's already been done. My daughter tried to open the door with the key once when I'd locked it with the remote. Alarm went off.

That's because the car was opened before the alarm was turned off, which it normally does when using the remote to unlock the door - it disables alarm then unlocks. Once alarm goes off it will only stop if you either start the car or toggle the alarm on/off with the fob.

I have a spare key with an transponder but no remote buttons for wife's Getz. I can use it for every day use (starts the car) but the alarm remains disabled after the car is locked and it does, as I said, trip the alarm if it was previously locked with the fob key.

I can't imagine you can cause any damage by trying to start the car with your spare key. That would surely happen occasionally in the field when/if a transponder failed. Can't imagine a policy to cause damage getting implemented. It just won't start.

Yeah. I understand about the alarm set up.
I agree about the transponder too. Just that, being in the industry, I've "heard stories". So I might go ask the locksmith. Just to be on the safe side.