Key Fob Phobia !!!!

[CFD]

Key Fob Phobia

I know there's a lot of threads on the fob/recall etc. but I didn't want to clutter them up.

Here's my story. I had a broken switch on my fob so used that one for the recall to get a couple of free keys to play with. I programed a new fob to get rid of the bulky factory one. i then transfered the circuit board from my workind fob to the one I am working on, I then took one of the extra keys, and removed the blade to use with my fob. Neither of them work. Lol. I tried programing them both but they still don't work. I can us the blade from my key, use my oem working fob to turn it but it still won,t work. I've tried all sorts of combos but nothing works.

Any brilliant ideas, I'm developing a phobia with this friggin thing.

[punkindave]

If it's like most other cars, there's a RFID chip either in the fob or on the key that must be programmed to the car at the dealer. (Not the same as programming the remote)

[CFD]

Originally Posted by punkindave

If it's like most other cars, there's a RFID chip either in the fob or on the key that must be programmed to the car at the dealer. (Not the same as programming the remote)

I am using an oem knob and the recall keys. They have been programmed by the dealer.

[CFD]

This is bothering the hell out of me. Lol

The key blade itself must be in some way unique. The chip is either in the fob or the black plastic part of the key. If that is true, which I believe is, then why wont the blade off of one of the recall keys work with the other fob.

[gingdakan]

i think so,They have been programmed by the dealer.

[gofastwclass]

Originally Posted by CFD

Key Fob Phobia

I know there's a lot of threads on the fob/recall etc. but I didn't want to clutter them up.

Here's my story. I had a broken switch on my fob so used that one for the recall to get a couple of free keys to play with. I programed a new fob to get rid of the bulky factory one. i then transfered the circuit board from my workind fob to the one I am working on, I then took one of the extra keys, and removed the blade to use with my fob. Neither of them work. Lol. I tried programing them both but they still don't work. I can us the blade from my key, use my oem working fob to turn it but it still won,t work. I've tried all sorts of combos but nothing works.

Any brilliant ideas, I'm developing a phobia with this friggin thing.

I'm not sure I understand what you are trying to do. What fob is smaller than the factory one? Have any pictures?

What procedure did you use to program the fob? I wasn't aware we could program new keys / fobs without dealer equipment (Tech 2 or whatever they use these days).

[CFD]

This may help explaining the problem

Took my oem fob in for the recall, came back with my original fob less the switch blade key and two programmed keys.

I then took a pair of side cutters and removed the blade from the key as seen in the pictures, the small piece I am pointing to is the chip.

From there I took the circuit board and put it in the fob I am designing, similar to what you would do when buying an aftermarket fob.

Now the fob does not work nor does the key.

I can take the blade portion of the key, which was programed by the dealer and known to work and put it in the ignition, using the oem fob I did not do the recall on turn they key and it will still not work

[drakedgar]

Hmm.... a few things I would look at if I were you:

1. Since the smaller fob is made of metal it might be blocking the RF signal. But since you already tried switching back to the old fob and it still didn't work....

2. The battery might have shorted, if the + and - side of the battery touched the metal fob at the same time.

3. Same as with #2 one of the small capacitors on the chip might have shorted if there was no insulation between the chip and the fob.

I would recommend testing for a node using a multimeter making sure that no positive node is touching a negative one. Also it's really hard to tell from the pictures but I would add more insulation between the chip/battery and the fob (duct tape works).

Also insulation will protect the chip against Electrostatic Discharge which now that I think about it, it could be another reason why the keyfob is not working.

Hope this helps! Good luck!

[CFD]

Originally Posted by drakedgar

Hmm.... a few things I would look at if I were you:

1. Since the smaller fob is made of metal it might be blocking the RF signal. But since you already tried switching back to the old fob and it still didn't work....

2. The battery might have shorted, if the + and - side of the battery touched the metal fob at the same time.

3. Same as with #2 one of the small capacitors on the chip might have shorted if there was no insulation between the chip and the fob.

I would recommend testing for a node using a multimeter making sure that no positive node is touching a negative one. Also it's really hard to tell from the pictures but I would add more insulation between the chip/battery and the fob (duct tape works).

Also insulation will protect the chip against Electrostatic Discharge which now that I think about it, it could be another reason why the keyfob is not working.

Hope this helps! Good luck!

The circuit board is not touching anything, I can operate it when not in the aluminum housing and it still doesn't work. It's hard to see in the picture but there is a non conductive plastic liner preventing the battery from shorting. I have checked with a meter to make sure nothing is shorted, the battery is fresh, there is continuity from the battery to the board

If any of the above were a problem it would explain why the fob I made does not work and where the circuit board has been handled and tossed around a bit I am not ruling out the possibility it is faulty but that would not explain why the key blade does not work, it is mechanical not electrical and does not work with the fob I made, the other key or the original unmolested oem fob. This is the part that I find most puzzling. The circuit board could be at fault although I don't think so, there is one switch for the security system that is broken but has been like that for a while, that's why I used that one for test purposes.

The only explanation I can come up with is that there must be some way that the actual blade and fob are mated but I cannot for the life of me see how. I'm obviously missing something.

[gofastwclass]

Um, wow, ok... (steps back.) You're MILES away from where I thought you were. Thanks for the pictures, it completely changes the direction I was thinking.

So when you try the modified key I'm assuming the car physically unlocks (releases the shifter, steering wheel and lights the dash) but doesn't start. Is that correct?

The custom fob is an interesting idea, I like where you're going.

[rant]
The key recall is completely ridicules. The key fobs aren't the problem, it's the placement of the ignition on the column. The lock cylinder needs to be on the top or better yet, the car needs to be push to start like most modern non-budget / economy vehicles.
[/rant]

[CFD]

Originally Posted by gofastwclass

Um, wow, ok... (steps back.) You're MILES away from where I thought you were. Thanks for the pictures, it completely changes the direction I was thinking.

So when you try the modified key I'm assuming the car physically unlocks (releases the shifter, steering wheel and lights the dash) but doesn't start. Is that correct?

The custom fob is an interesting idea, I like where you're going.

[rant]
The key recall is completely ridicules. The key fobs aren't the problem, it's the placement of the ignition on the column. The lock cylinder needs to be on the top or better yet, the car needs to be push to start like most modern non-budget / economy vehicles.
[/rant]

That is correct and the most puzzling part. The key I used was known to work before I butchered it. It will go in the ignition, turn, everything lights up and works but it will not engage the starter and the security light on the dash stays on. Now if I put the blade in the ignition and use my working oem fob to turn it, I get the same results.

If I start the car with the oem fob, shut it off and immediately put the key blade in and turn it it will start the car and everything works, the security light stays on, once you shut the car off the key blade will not work again.

This is why I'm thinking in someway the fob and blade or the blade and the plastic handle are mated but I cannot see how.


The end product will most likely be carbon fiber, I've only got enough in stock for one shot so I'm not going to machine it until everything is working.

[gofastwclass]

That sounds very frustrating. A real carbon fiber fob would be cool.

I had a former GM tech tell me there is some sort of proximity sensor that reads the chip in our keys. By design the chip in the key needs to be within a very small distance of that sensor. Is it possible the chip is simply too far away from the ignition?

Of course I'm sure you don't want to defeat the security system, but that could be an option as well.

[CFD]

Originally Posted by gofastwclass

That sounds very frustrating. A real carbon fiber fob would be cool.

I had a former GM tech tell me there is some sort of proximity sensor that reads the chip in our keys. By design the chip in the key needs to be within a very small distance of that sensor. Is it possible the chip is simply too far away from the ignition?

Of course I'm sure you don't want to defeat the security system, but that could be an option as well.

I thought of that but it's not the case. When the key blade is in the ignition it only sticks out about 3/8" so it's very difficult to turn so I use my oem key fob, I use the space under the fob key blade or the back plastic piece for a key ring so the fob is actually exactly as close as when using the fob.

Again this is why I'm so baffled, more about the key blade part than the fob not functioning although there is a good chance they are related.

[gofastwclass]

Originally Posted by CFD

I thought of that but it's not the case. When the key blade is in the ignition it only sticks out about 3/8" so it's very difficult to turn so I use my oem key fob, I use the space under the fob key blade or the back plastic piece for a key ring so the fob is actually exactly as close as when using the fob.

Again this is why I'm so baffled, more about the key blade part than the fob not functioning although there is a good chance they are related.

Shucks, I was hoping you hadn't thought of that.