tomtrap

I have a 94 jgc with a security module issue. I am getting ready to replace the current pcm with a non-security pcm. Do i need to disconnect the security module before I install the non-security pcm?

ol"blue

I'm not positive on this, but someone correct me if I'm wrong.
1. Disconnect the battery;
2. Disconnect the Security Module;
3. Disconnect the PCM and replace with non security PCM;
4. Reconnect battery and start vehicle. It will probably show a CEL because the battery/PCM was disconnected. It should be a code 12, Battery or PCM power recently lost.
You'll need to run it for a while for it to learn the parameters. It will take 50 key starts to get rid of any stored codes with no recurrence.

Willys55

In addition to that Dan,
With all doors closed, lock and unlock the cargo door, start the vehicle, then behind the glove box remove the security module while the vehicle is still running( will be either blue or black box,labeled security). The PCM, will log the last know security identification signal and will no longer activate the theft mode. If you try doing this on the GC with the PCM that is programmed for the security module and you do it while the engine is off.......it will remain in theft deterrent mode until the security module is re-installed or replaced and the PCM may need to be programmed to accept the signal from it.

tomtrap

Thanks for the info-the only problem I have is that I can't get the jeep started. The security system is keeping it from running. I have not been able to reset...I beleive from everything that I've read I probably have lock tumbler issues and I don't have the remote. I guess I'll go with Dan's instructions and disconnect battery, disconnect S/M, replace PCM. I'll let you know the outcome. Thanks again!

ok93zj

I think you can cut a wire too. I don't remember which one but it's something to look into so you don't have to replace the PCM.

ol"blue

You'd better follow Willys55's info, and ignore mine. He knows these vehicles a lot better than I do.

ok93zj

Here is what I was referring to. I found it after a quick google search. I know somebody that had to do this because they couldn't get the jeep started to take out the security module with it running and it worked.

under the driver side kick panel, find the yellow and purple wire, SPLICE into it, and ground it out: this will disable the alarm system.

Willys55

That's not always the case Dan, but thanks for the compliment.

Your still number one in my book good buddy....

Willys55

Yup, I do remember doing that once, that's the security wire that feeds to the rear door latch, grounding it out is the same as unlocking the rear cargo door with the key.

ol"blue

Good info, thanks for posting that. I lost that when my computer crashed.

Thanks, and I've always said you're the go-to guy around here for info Russ. I've told people to PM you for help on numerous occasions.

tomtrap

Thanks to all that offered the much needed help. Just in case anyone else is experiencing this problem here is what I have found out.

I did ground the purple and yellow wire behind the kick panel AND behind the door panel. Did both because the first one didn't get any results. Neither did the second.

Unhooked the battery-again- found the security module under the dash and behind the glove box. Disconnected it in preparation for installing the non-security PCM. Just for grins hooked the battery up and tried to start. It has been starting ever since! The non-security PCM should be in today and I will probably go ahead and install it. Being someone that would much rather doctor a horse than doctor a vehicle this whole security issue has been frustrating. Even though it is starting now I'm not totally convinced I had anything to do with finding a solution. I thinnk these GC's have a mind of their own. Again thanks for all of the help. If any of you have a horse problem I'll be glad to return the favor!

ok93zj

Good deal. I'm glad mine doesn't have a security system in it.