Oil pressure drop

Replace the oil pump, the computer might be sensing low oil pressure and protecting your motor. Not to expensive and you can do it yourself, go grab a Haynes manual or do some online research on how to drop the pan and how to replace and prime the pump.

When you do this kind of stuff finding the problum is like eliminating possibilites, so think of everything associated and start with the most logical/ cheapest to do first. There are also alot of factors, more info on the jeep, mileage, and drive train are important peaces of info in a situation like this.

Cj-

Same problem here with all the same fixes you mentioned. Looks like you have an 03X (seems kind of soon to be replacing an oil pump but who knows) unless you have some other Jeep, so assuming you have a 4.0 your last bet is to change the oil pump as Clayton mentioned. That's what I'll be doing sometime within the next few months. My Jeep isn't my DD or else it would have been done already.

There's no mention in the FSM of the PCM shutting down the engine for low oil pressure.

The pressure sensor feeds data to the PCM which in turn supplies it to the cluster.

I would pull the white connector from the PCM, make sure it's clean and reconnect it just to say you did. (Disconnect the battery first).

Also might try the cluster test routine.

With the key off, push and hold the trip reset button. While still holding it, turn the key to on, but do not start it. Release the button.

It will go through a test sequence lighting various lights and sweeping the needles of the gauges.

It will also display any fault codes that have occurred. If there are none it will display "no FAULtS".

Jeep techs. are generally idiots when it comes to troubleshooting problems that aren't listed in a manual somewhere.

My Wife's TJ had a random no start condition.

We spent close to $2K on a new PCM and fuel pump at the dealer.

I ended up finding a loose connector in the wiring harness.

That fixed the problem.

Couple questions:

1. Can you hear the fuel pump run when you turn the key to RUN ?

2. Do the gauges act normally when to turn the key to RUN ? (Does the fuel gauge and volts gauge move up to where they should be ?)

Its a long shot but I would do two things. First, pull the gauge cluster out of the dash, clean and grease the connections behind it. Ive had a few XJx and tjs that would throw random check gauges light and loose oil pressure. Usually ened up being dirty/loose or corroded connections behind the cluster.They are notorious for this. Its possible that the loose connection is grounding out on something causing it to stall. Its easy to remove and way cheaper than a new harness. Second thing I would look at is the ignition switch located on the side of the column(not the tumbler). My TJ was having all kinds of issues starting for a while and after replaceing everything cps, coil rail, plugs, tumbler....The list goes on. I pulled appart the switch on the column and found that it was severly corroded. Replaced it with another one I had from an XJ and it starts every time. BTW....Prior to fixing it, my TJ randomly shut off on me more than a few times just idling in the driveway ....It did it another time after I rolled it too.....(although thats a horse of a different color). Again these are just cheap and easy options before dumping $$$ on harness / pcm swaps.
Ed

Quote from redsox514

disconnected the wiring on the PCM like suggested and now the car wont start at all.

Did you have the battery disconnected when you did this?

Are there any codes present now ?