Let's Talk Key Fobs....
 

So, we have an Impala with one factory key fob, which it's numbers happen to be a match to my Monte. I added an aftermarket remote start with keyless entry (giving my wife effectively two aftermarket fobs that do remote start and keyless entry).

At this point the factory keyless entry fob for the Impala is pretty useless (it's the third wheel in the fob relationship game at this point). Programming the fobs via the radio to ADD fobs, piece of cake... But, how can I de-program the only factory fob we have for the Impala so I can then re-program it and add it to the Monte??

Ideas?? Thanks gang!!

Just reprogram it to the Monte. It will only open the Monte from that point on.

yup that is all you have to do but you have to program them both I think.

Really, it's that easy? Once I program it to the Monte (along with re-program my existing fob) it will only work on the Monte (not both the Monte and the Impala)?

Sounds easy enough, I may give that a try tonight. Sounds like I was over engineering this task. Thanks!

I know it's hard to believe but GM actually did make something easy for once.

FAIL!

I just went outside, entered the programming mode on the Monte, re-programmed my fob and added the Impala fob. Exited and both fobs work on the Monte, but the Impala fob still controlled the Impala at the same time it controlled the Monte. I de-programmed it from the Monte by re-programming only one fob.

I had a weird feeling about that (seemed two easy). The fobs are apparently not bidirectional (when programming, they can dispatch their coding, but lacks technology to receive information back from the car).

If I go to the Impala, enter programming mode and don't program anything, I makes no changes.

Any other ideas??

Are both cars in range of each other when your trying to reprogram it? Thats the only thing I could think of.

Why is the factory fob working with an aftermarket alarm is my question? With that being said did you try to reprogram the aftermarket alarm with the two remotes?

Once the car "knows" the remote it "knows" the remote. Not sure if you can enter program mode for the Impala and not use the old remote, just wait until the car times out of program mode if that will erase the memory.

When I bought my Z28 it didn't have a remote, I programmed one of mine from my (at the time) Z34. If the two cars were parked close enough the remote for the Z28 would work on the Monte. If you find someone with a remote that you can program the Impala with then your old remote would be free, however whoever's remote you "borrow" will then be able to unlock the Impala. Can you track down the receiver unit in the Impala and disconnect it??? Unsure what effects that may have on any other system in the car.

***edit****
Unsure what year your Impala is, went with an 2004. Looks like it maybe in the defrost vent area:
http://www.compnine.com/index.php?u=...10&grouptype=B

Good Luck, keep us informed.

It should not matter that while I'm programming the remote from the Impala to the Monte Carlo if they are in range (only the Monte is in programming mod, so the Impala is oblivious to any remotes being programmed).

The remotes are uni-directional (they ONLY transmit out, they do not receive). So when you program the remote to a car the car recognizes that remotes signature. Since the remotes are not bidirectional (also receive data from the car), they do not care what car(s) they are linked to as they never have to "verify" what car they are working on.

The Impala has a factory keyless entry which is still enabled (and I have zero interest in dis-abling it, just de-programming the fob from it for the time being). I added an aftermarket remote start that has a keyless entry. To allow my wife to only carry one fob I wired the remote start's keyless entry into the car. Now we have three fobs for the Impala (2 that do keyless entry and remote start via the aftermarket system and one that only does keyless entry via the factory system). The factory Impala fob is NOT interacting with the aftermarket system, nor is the aftermarket alarm in programming mode at the time I am programming the fob to the Monte.
My Monte has a factory keyless entry and uses the same fob as the factory Impala fob. Since I only have one fob for the Monte (and two keys), I wanted to program the Impala fob to the Monte and de-program it (so the Monte now has two fobs).

The shop manual states when programming a new fob, have ALL fobs (up to 4) available. The reason is when you entry the factory programming mod, once you program a fob (even if it's the original one with the vehicle) it erases the car's memory of what fobs it has recognized and rebuilds it's database of fobs. So when I learned the factory Impala fob now was operating both cars, on the Monte, I re-entered the fob programming and programmed ONLY the original Monte fob, once I exited programming, the Monte no longer recognized the Impala fob. I tried letting the programming cycle time out on the Impala, and that did not change a thing, as since I did not attempt to program a fob, it appears to assume no changes were required.

So far, the only way I am seeing to delete the fob memory on the factory keyless entry is to have a fob that you do not use with a car and use it strictly to program into the keyless entry as garbage fob. But if I have to buy a 3rd factory fob, that makes all this a dead topic (as then I'll just program the 3rd fob to the Monte and be done).
My goal was to make use of something we already have, but I don't want to physically disable the factory keyless entry on the Impala (in the event I ever want to program a factory fob, I don't want to need to reconnect something first).