Immobilizer, transponder, extra key solution...???

Hey all. Ive been searching for awhile, but havent seen exactly what Im proposing to try.

First off, I just bought a 2001 XJ Limited. Loaded with all the goodies. Now...I only got one darn key. And its the big fattie grey one which I assume has the transponder deal inside. I need more keys...

It also has an aftermarket alarm on it...which Im not crazy about. So Ide also like to get some stock key fobs, remove the alarm, add a kill switch, and be done with it.

here is my actual question. The key... If I get some regular, thin, black keys cut, and I use it in the ignition, and HOLD the grey key near the lock cylinder, will the Jeep run? Or does it somehow transmit through the metal portion of the key?

My idea is to just take the column apart, and tape/glue the grey key inside the column. Then I can just use regular keys in the ignition, and the transponder will just be there... I have my doubts that this will work, but I wanted to see if anyone thought it would?

I havent checked with a dealer to see how much the new key/programming would cost. And if its somewhat reasonable, Ide consider it, because once I have two keys, I can do the rest myself. But, if my idea will work....F it. Ill have other security measures in place anyway..

Let me know what you think/know about the idea...!

J.

here is my actual question. The key... If I get some regular, thin, black keys cut, and I use it in the ignition, and HOLD the grey key near the lock cylinder, will the Jeep run?

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Yes this will work.

My idea is to just take the column apart, and tape/glue the grey key inside the column. Then I can just use regular keys in the ignition, and the transponder will just be there... I have my doubts that this will work, but I wanted to see if anyone thought it would?

Click to expand...

The antenna for reading the transponder is wrapped around the housing by the lock cylinder. Glue/tape the transponder as close to the lock cylinder as possible and it should work.

I havent checked with a dealer to see how much the new key/programming would cost

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$25 to $60 depends where you go. Call around to find the best price.

Sweet! Im going to try it after work. Just gonna go get a regular key cut and see what happens.

I called the dealer today. He told me about 100 bucks for a new key, and programming. And if I wanted two key fobs, that would be another 100 bucks...and the programming fee would be taken care of with the key programming. So $200 gets me a new key, and two key fobs.

So...here is what Im sort of thinking. I can either A) go to him, spend the 200, have two sets of good keys and fobs. Then, get two more keys off ebay for cheap, get them cut, and program them myself. And just keep using the immobilizer system.

...or B) order two regular keys on ebay for a couple bucks, tape my good key to the cylinder or wherever it works, and only get the key fobs from the dealer.

Im going to see how the idea of mounting the key works first... thanks for the feedback!

J.

EDIT:... just out of curiousity. If I try to run the jeep with a normal key, and the transmitter not in range, Im assuming it will start, run, then shut off. Does this do anything terrible? like not allow me to start it later with the good key? I just dont want it to do something silly like lock the PCM or something. If it works sort of like the GM vats system, I guess it will be ok. I just watn to test things out...

What year did they start putting chips in the keys? I have a 2000 and as far as I know it does not have a chip in the key but maybe I am wrong. I made a copy of the key but didn't get one with a chip in it, as far as I know it works fine.

that's what i was fixing to say.. I have a 2001 sport. Has the large grey rubber key and the factory door lock/unlock panic remote. I also received a regular cut key with it and it works just fine...

From what I understand, the immobilizer function was an option you could add on. The way its supposed to work is a regular key can start the car...but it will shut off after 10 seconds or something like that...

Im still going to try a regular key. Just see what happens.

Out of curiousity, do you have alittle light on your dash, upper left hand corner, than looks like a key with a "NO" symbol over it? Mine has that light and it self checks with the other lights during start up...

J.

Mine has that key symbol but I am not sure if it lights up or not. I actually took my girlfriends car today and she will be driving my Jeep if she goes anywhere. The key that came from my XJ is round and says Jeep on one side and has a chrysler sign on the other side, it looks to thin to have a chip in it but then again I have no idea how small the chips are.

The "transponder" key is thick and grey. The regular key is black and thin, and sort of indents in the middle... Like its slightly dished. The Grey keys kind of buldge out.

I think my plans have changed to ordering a few uncut keys from ebay, along with some remotes, and just having my dealer cut and program them. He says he'll cut them for free...and $40 to program. So Ill come out ok on the deal. Im still going to experiment with a regular key though...and with my idea of putting the transponder key near the cylinder and using a regular key... Just for craps and giggles.


J.

You bought the green limited?

Yup... I tried callin you the other night. I dont think I left a message though. Meant to try you again, just havent had time. I gotta stop up and show ya...its sweet so far. They cut me a killer deal on it and really took care of me.

Know anyone that wants a 94 two door on 33s with lots of goodies?

J.

ghettocruiser said:

Im still going to experiment with a regular key though...and with my idea of putting the transponder key near the cylinder and using a regular key... Just for craps and giggles.


J.

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That will definently work. It is how we do remote start systems on them. If you try to start the jeep with a regular key it will just crank and flash the key light on the dash, it wont actually start up. I think it kills the ignition or fuel injectors at the ECU. You will have to take the plastic surround off the column and kinda play with it to find the right placement or just remove the ring and ziptie the key inside it and stuff it in the dash

OK...I did some playing around with it. Got a key cut at ACE hardware tonight to experiment with.

First...with the correct key, the little symbol on the dash will self check, then go off. Before you even crank the engine, the light is off.

With the new key (no chip), the light will self check, go off for a second, then flash. Upon cranking, the motor WILL crank and fire. Runs fine for about 5 seconds or so, then shuts right down. Motor will re-crank and re-fire right away, and do the same thing. Its exactly like GM's VATS system as far as how it acts.

Now, if I place the grey key (with chip) under the column, near the ignition cylinder, the non-chip key will start the jeep and it will run fine. After a few seconds, you can remove the grey key, and the engine will not shut off. It will remain running.

Not really new info for some of you, but I couldnt find it anywhere by searching. In fact, the jeep service tech told me the key had to be IN the cylinder...and that it wouldnt work held near it. But...surprise...they were wrong.

I still think Im just going to get some more transponder keys. Im actually just glad to know that the system works. Its actually fairly effective. That coupled with a kill switch will be enough security for me. I can remove the POS alarm thats on there, and just use the factory keyless entry stuff. I wasnt about to buy expensive keys and have them prgrammed and what not if the sentry system did nothing. So my test served its purpose I guess.

J.

Sometimes you can disable these systems by holding the key next to the ign. lock and starting the car with a regular key. Then remove the transponder key fron the area while the engine is running. After this is done, the system is diabled and will now start with a regular key 'until" the reads the transponder signal again. If it does, it will reactivate the system again. This will work on some systems. I haven't tried this on an XJ, though.

You can deactivate the Vats system like this except the vats system uses hardwired contacts that touch the resistor in the key. To deactivate this system, pull the hush panel and start the car with the vats key. While it's running disconnect the small wire connector that comes down and out the inside of the collumn. It's yellow or orange. This will deactivate the vats system. This procedure comes in handy when either the contacts in the ignition or key become worn and cause intermitant start problems.

Eh...not sure I agree with those methods... I tried doing that with the XJ, and as soon as you shut the jeep off, and try to start it again with the regular key, it wont run. Its PCM based and works on a check system I think. It does a check during the ignition on sequence, then as long as the signal is present it will disable it until the next key cycle.

On VATs, I know that doesnt work. The PCM requires a 50 Hz signal from the BCM to disable the security. Even if you remove all the components besides the PCM, the PCM will still be looking for the signal to run. I just do an LS1 swap car, and had to deal with the vats. Guys with the system in their cars can get around it by adding the correct resistance to the wires for the system.

The only other ways to do it are to flashing it out of the PCM, or building a 50 Hz generator and hooking it to the correct pin on the PCM. Thats what I did. Build a simple box and had the car running. Later I flashed it out of the PCM during tuning.

I figured Ide update this after I get the keys and fobs programed at the dealer...just so anyone that comes across this thread will have more info.

I ordered 4 keys, and 3 key fobs off ebay. As well as two normal Jeep keys for lock spares and maybe a hide away key. I ended up spending about 60 bucks including shipping for all of that. Thats the price of ONE key at the dealer pretty much.

I figure Ill use a standard key as a hide away key. Since it will let me get in the jeep if I ever lock the keys in. If someone finds it, they can get in, but cant drive the jeep away. Works for me...

J.

Stand by my statements. It will work on some systems.
It will work on vats systems. I've done it, many times. The security light will stay on while its disabled. You just have to do the sequence right Been a locksmith for 24 years. Decoded computers, replaced ignitions and made keys from scratch

Bumping this just to let you all know what I ended up doing....

First, the sentry system. There is NO way to de-progam this unless you can somehow flash it out of the system. The guy at the dealership let me play with the DRBII tool some yesterday. There seemed to be settings that allowed you to disable it, but I didnt mess with it. But I learned some about the system, and the PCM by playing with the machine.

Anyway... I bought 4 sentry key blanks, and 3 factory key fobs off ebay. Got the keys cut for FREE at ACE hardware. Since I wasnt buying any blanks, they didnt charge me.

Stopped by my dealership, and had them program ONE key, and the key fobs. The whole process took about 10 minutes. The key was the longest part. The key fobs were cake. It just asked to press the unlock button, and you press it, and thats it. Its programmed.

I got home, and programmed the other 3 sentry keys on my own. I could have had the shop do it...but I wanted to do it myself since I could.

Cost me $46...and paying that was worth spending a few minutes with the cute girl at the front desk who rings you out.

Its nice to have back up keys...just in case. I was nervous having only one key.

J.