So I made the mistake of trying to replace the battery. Didn't have any problems doing that of course, until I realized that the immobilizer was now locked and the security light now on constantly. I've tried everything with no luck. (I pulled one of the modules under the hood, light went of but car still wouldn't start)

What also complicates matters is I have half a key fob stuck in the ignition when it broke off months ago (The car starts up with no issues like that, just use a flathead to turn it). But I don't know if that is affecting anything or not, I don't think it is. That seems to be stuck in the ignition as well, I have a drywall screw I used to get a grip on it through the plastic and it will not come out or even move. Anyway.....

I've tried pulling fuses every other trick in the book with remotes and it simply will not start. Went to the dealer and they basically told me "tow it in and we'll see, you know those immobilizers go bad every once in a while". This was particularly funny after I read a story on the internet of someone towing their car in with the same problem, and them claiming that the immobilizer was "bad" and she needed a new one for $700. That is BS, and honestly the car just isn't worth it to be putting a massive amount of money into it anyway. Dealer was talking about $200 just to figure out what it was, then reprogramming, maybe new keys etc etc. I went in to talk to them personally and wasn't exactly filled with confidence they even knew how to fix it from the answers and tone they had.

I have found a way online that you can wire the fuel pump directly to the battery (something with starter too), but that is pretty complicated and everyone I have talked to says they have never done it before and again leave it pretty open ended as far as cost and if it will even work or not. I have never been in a situation so ridiculous in my entire life, but I have to figure out something or buy another car I guess. I am pretty helpless at this point, I am about to go try to take the module out and leave it out and start (I just pulled it/put it back in the first time not thinking to just leave it out).

Anyone has any insight throw it at me. I'm out of options at this point. Thanks.

to NICO!

I'll do some thinking on this. Hopefully someone else can chime in too.

Thank You so much. I am at a total loss and really don't have a lot of money to sink into this thing.

Here is the way someone bypassed it on a 99 I30.

So I started to look at disabling it. With the anti theft relay on the passenger side by firewall out and jump the middle pin to the pin towards the front (there is no pin 4 as I've seen posted, it just skips 4 for some reason) it makes the start inhibit relay by diver headlight click and you can crank the car but still will not start.

If you read what is going on, I got the car to crank by bypassing the theft relay making the starter inhibit relay work. Need fuel system to turn on now which its not because of NATS.

Gas in the intake will work so it is not getting injector pulse or fuel pump. So what is the next step to get the fuel system working? Oddly there is a small wire from the 15a fuel pump fuse under dash going towards the back of the car, don't know what thats about yet... There is power at the fuse.

I ran a wire from the fuel pump fuse under the carpet to under the back seat where the fuel pump hatch and wiring is. Tapped into the black and yellow wire and sure enough the fuel pump comes on when the key is on and the car starts.

Also still have to leave the starter inhibit relay out and pins jumped.

Bigslick, which battery did you replace - the car battery or key fob battery?

Sometimes the transponder chip will fall out while servicing the key fob; and as much as your buttons still open the doors, the antenna by the ignition cylinder sees no approved entry.

mac,if your saying the "tip" of key is ALWAYS in ignition lock cylinder , there are key recognition switches in the column probably/possibly on yours.NOT GETTING THAT OUT I believe is the simplest thing screwing with Immobilizer. Try two sharp pointed carbon steel knives while helper holds a powerful "magnet chaser" against broken key ,pry . Super skinney needle nose try ,whatever? Probably if you did "Whatever it takes" to get this out , solves these issues. $40 to Locksmith?
p.s. NEVER put battery Vdc directly to a fuel pump(even if fused) THEY NEED to be"fed" through F/pump CONTROLLER and DROPPING RESISTOR usually!

Sorry it has been a minute guys, been trying to find someone to help me on this but no one wants to mess with it, It is dealer or bust. I thought for sure a car alarm place would but even they shut me down pretty quick.

Anyway, as far as the battery, I replaced the car battery AND the key fobs since they were dead as I had not used them in forever. I replaced the key batteries myself in the auto parts store and the chips were put back in, they are tiny and grey I know exactly what you are talking about. That isn't the issue.

Now as far as the ignition is concerned, if I have to replace the ignition, then get a new key/programming I am going to be up near $800 alone probably. I still don't have the slightest idea why the half of the key won't come out even when I have a solid grip on it. There is a drywall screw embedded in the plastic a good 1/8th inch deep, and it will not even budge. Nothing.

Anyway the car is now sitting in my driveway, collecting dust, and on craigslist to see if anyone wants it for a parts car. I actually just got it towed here so haven't had much time to really mess with it but I will see if I can figure out anything. I still can't even believe all this over a freaking battery replacement. Insanity.

Where are you located, do you mind posting info/ the craigslist link?

I was changing map light bulb in my 2002 q-45 and shorted it and blew the fuse, this cause my steering wheel and ignition to lock. Well both are on the same circuit it the 8th fuse on bottom row , 10amp , replace it and everything works fine.