Keys (programming etc.)

[Rubberhead]

I've got a '03 V8 and my wife is driving a 4.0L '07 Eddie Bauer.

I'd like to get my wife's car and my son's car to work with the same key. I'm thinking I can get a single key cut like my wifes along one edge and my son's along the opposite edge.

Two questions:

1) The big question: If I get a single key cut like my wife's Ex on one side and my son's Escape on the other will it work in both cars, assuming I put it in the right way depending on the vehicle? The real question is does the ignition key "look" at both edges of a symmetrically cut key or only one edge?

2) Can two vehicles be programmed to repsond to the same chip in one key?

 

[A Wise Guy]

I have often wondered about cutting different cars on different sides of the key also so I can't help you there. As for the programming the vehicles won't care. They just look at the value of the chip.

 

[Gus Gorilla]

Hey, Instead of cutting a PATs coded key two different ways at a $50 pop you could go to the local hardware store and cut a $2 key. Just a normal all steel key will go in the ignition and turn. You'll get a theft light but if it turns to the START position your in business. And A Wise Guy is just that. Wise enough to know that the cars don't care. He's right, each key has a type of digital signature or serial number. The car learns that key code xxxxxxx is valid and allows the start. The key never changes it's code.

 

[kstrayhorn]

but if he does that, it will only work in one of the cars, right? he needs one key to work in both. Isn't the only way to do that is to have two identical ignitions? Shouldn't he go to Ford and get a replacement ignition for one of them and install it in the other car? That way, one key will start both, right?

 

[Gus Gorilla]

When you get a replacement ignition you get replacement keys to match it. They usually do not go to the trouble anymore of changing out tumblers to make it match. And for it to work in two vehicles you may be able to cut one side of the key for the X and the other for the Escape. This is the part in question. In years past the ignition is only actually reading one side of the key. So the other could be whatever you want. Long long ago in a car culture far far away your ignition key only had one side cut. Like a house key.

 

[imp]

Looks to me, IMHO, that: 1) Obviously, the lock cylinder tumblers ride on one edge of the double-sided key only. Only reason for double-side teeth is convenience of inserting it quickly into the cylinder.

2) The PCM "reads" the 2 keys supplied with it originally. More can be customer-programmed, as long as both original keys are available. There IS a means of programming a bunch of PCMs, as in fleet use, to use the same key. I believe I saw this in a Ford Owner's Manual. imp

 

[Gus Gorilla]

IMP.
Your rignt. But if you take the truck in to the dealership they can erase any keys that the PCM has stored. Also as a note. The PCM isn't always the module which saves the "good" keys in memory. Some vehicles use the IC and others have a dedicated module. Either way. On late models you can have up to 4 keys with the remote in the key head and 8 keys total. Older trucks can have 8 total but only come with 2. With 2 you can key cycle and program more of your own (up to 8).

 

[kstrayhorn]

That's what I was saying, having two different keys on one woud be more frustrating for me because I would forget that one side doesn't work and I would jam the wrong key in the wron ignotion