AMagicalPancake

I am having some problems with my Cherokee auto shutoff I think. A couple of days ago my battery died which was strange, about a year and half old battery. I went to jump it and as soon as the batteries were connected, before my key was inserted, my after market headlights with day time running halo lights turned on, which is not supposed to happen until the car is on. But it started up just fine and drove fine. But once I went to remove the key the engine did not turn off, but the radio did. After a couple of times of turning the key it eventually turned off. After some research online it seems that it could have been a problem with the ignition switch, ignition cylinder, or auto shutoff relay. After replacing the Ignition switch and cylinder the same problem occurred. So I replaced the auto shutdown relay, autozone gave me a 4 prong relay instead of a 5 prong, (missing middle prong), but the voltage or amp? numbers were the same, I am planning on going to another auto parts store to get different relays with 5 prongs. This still did not turn the engine off, even after disconnecting the battery fully, which I did not even know was possible. So now I believe it is my ECM, I have had a problem with it in the past with my main clutched fan, but was able to bypass the ECM to get it to turn on correctly. So I know some part of my ECM is already broken, so it seems possible that it broke somewhere else too. I have not been able to find a new ECM anywhere, and have confirmed it is discontinued. I have not tested the ECM yet, but what else could it be? I am now looking into repairing my current ECM, if anyone has any thoughts on something else I should be doing or testing, or knows of a good place to get my ECM repaired at ?

1995 Jeep Cherokee, Country, Manual Transmission, 4L, 6 Cyl
ECM EU: 56028851

Location: SLC, Utah

awg

You need to do some systematic electrical fault finding, which it sounds like you already have

Please tell me you have the '95 FSM and have studied it

I lack familiarity with OBD1, but I personally think the PCM is less likely than some other problem

In the FSM, it gives a detailed explanation of the electrical circuit operation

You need to deduce what is powered with switch on and off etc, then check with backprobes to confirm

The ASD relay should have other relays in the PDC that are the same, swap them (mark first)

When you say you changed the ignition barrel, there can be 2 separate parts, the lock part, and the electrical part

If it is the PCM

Any 94-95 used PCM from eBay should work

otherwise there is a place in the USA that provides lifetime guarantee rebuilt for $350 I think

Type in the full part number of your "Jeep cherokee xj 56041xxx PCM" into Google and it will bring them up

AMagicalPancake

I have not read the FSM but I can look at the circuit operation so I can properly test.

Does using other PCM models affect emissions or other controls? or would any 94-95 (same engine and transmission) will work?

Dave51

Are there any wiring mods?

There are a bunch of companies that fix PCMs for ~$200. Can't vouch for any of them though.

Got soldering skilz? PCM problem is often fried cap(s) and replacement kits are readily available (just found out that old PCMs may have 4 caps instead or 3).

awg

You need to free download it, as it describes the exact sequence of how the ASD relay works, the ignition system, PCM, everything !

It is about 100 times quicker and cheaper to free download the 95 FSM, and study the relevant sections than haplessly replacing parts

make a backprobe with a pin and thin wire, and see whether voltage is/is not present at certain relay points and PCM pinouts

There is no way you can do this just with the circuit diagram, unless you are a trained electronics engineer (and you could not be, or you would have known to download the manual long before now)

As far as I know, the only issue with 94-95 PCM is auto/vs manual

enter your pcm number into google, its printed on the metal case

DanielBartlett

Replying for the updates.

Veeb0rg

I'd start with unplugging the headlights.