It may sound odd....but it could be a fuel head issue. Do you know if it has the 1st generation fuel head or the 2nd gen? A couple years back mine was running and just died for no apparent reason. It turns out it was the fuel head (I had the 1st gen at the time). Replacing it solves my problem. It could also be a failed crank position sensor.

Jim

The service manager is a dolt. They may not be able to figure it out but it's not a "common problem".

You say you replaced the ignition switch but that doesn't tell me if you replaced the true ignition switch on the left side of the steering column or the key switch and plastic rod that often breaks under the steering column. See viewtopic.php?f=5&t=61233&p=678574&hilit=+brother#p678574

A massive air leak in the fuel system, could be fuel filter head related, could stop the engine and prevent restart. See Sam's filter head bleeding video.

Faulty cam or crank position sensor or faulty fuel pressure sensor (won't let enough pressure build to fire fuel injectors).

Would be worth trying a known good battery. Battery can test good but not be good.

Check all fuses.

Doubt it's in "theft" mod. As I understand theft mod in this vehicle it will start but then die in like 10 seconds. I don't think there is a theft mod that prevents starting unless you have an aftermarket system. Now there is an little wire antenna thingy, I think, near the key that receives the key signal which could be broken but if it is I don't know what happens.

Nothing will communicate with the tranny or PCM except a dealer instrument or equivalent. Computer system is a kludge.

Does the engine turn over when you turn the ignition key but not start?

If not, what happens if you jumper pins 30 and 87 in the Starter Motor Relay socket.....engine should turn over.

You say that the security light stays on? Try jumper pins 30 and 87 in the Auto Shut Down Relay socket (ASD)....you may have a wiring problem that stops the ECU activating the ASD relay even though the ECM is happy with the code from the SKIM module....I had this problem!

What you describe has happened to me and its not fun.

If the security light (red dot) stays on you either need a new SKIM module
or a new antenna thingy that goes around the ignition key receiver.
You will most likely also need two new programmed keys.

It may sound odd....but it could be a fuel head issue. Do you know if it has the 1st generation fuel head or the 2nd gen? A couple years back mine was running and just died for no apparent reason. It turns out it was the fuel head (I had the 1st gen at the time). Replacing it solves my problem. It could also be a failed crank position sensor.

Jim

Will try.
Did it crank when you jumped the pins?
Where was the wiring problem,
Thanks!
Jim

The service manager is a dolt. They may not be able to figure it out but it's not a "common problem".

You say you replaced the ignition switch but that doesn't tell me if you replaced the true ignition switch on the left side of the steering column or the key switch and plastic rod that often breaks under the steering column. See viewtopic.php?f=5&t=61233&p=678574&hilit=+brother#p678574

A massive air leak in the fuel system, could be fuel filter head related, could stop the engine and prevent restart. See Sam's filter head bleeding video.

Faulty cam or crank position sensor or faulty fuel pressure sensor (won't let enough pressure build to fire fuel injectors).

Would be worth trying a known good battery. Battery can test good but not be good.

Check all fuses.




Doubt it's in "theft" mod. As I understand theft mod in this vehicle it will start but then die in like 10 seconds. I don't think there is a theft mod that prevents starting unless you have an aftermarket system. Now there is an little wire antenna thingy, I think, near the key that receives the key signal which could be broken but if it is I don't know what happens.

Nothing will communicate with the tranny or PCM except a dealer instrument or equivalent. Computer system is a kludge.

Thanks papdindgo!
We will be starting from the beginning again today.
1. check battery.
2. check ground in the ignition switch to see if either the switch or the actuator pin is broken.
3. we have access to a dealer instrument, that is how we got to talk to the Anti Theft system, which told us there was a communication error to the PCM and the TCM. That should be a clue, but as Great Minds Think Alike, Fools rarely Differ....so we are still scratching our heads.
4. We will look for wiring problems behind the fuel filter as mark2m stated he had....so wiring harness.
Thanks again. Will report later today.
Cheers!

Yes it cranked with the ASD relay pins 30 and 87 jumpered...and it started and ran fine. Left the jumper in for a while....no chance of the Jeep getting stolen if someone tries to start it without the correct chipped key in place in the ignition slot.

This will only work if the ECU is happy with the code it receives for the chipped key from the SKIM module but it...the ECU..is not getting confirmation back from the ASD relay that it...the relay... has energized properly.

I had a a broken wire going from the ECU to the ASD relay so that the "energize" voltage to the relay never got there. I replaced the wire with a new one.

Just an observation, if you think it might be a key problem;
I had a spare key made for the door only, to keep hidden under the vehicle. It is not a "smart" key.
If I put that key in the ignition and immediately crank it, the engine will run for one full second before it shuts off.
It is as if the vehicle gives you "the benefit of the doubt" before it gives up trying to read the key.
This is on a 2005 CRD

Thanks papdindgo!
We will be starting from the beginning again today.
1. check battery.
2. check ground in the ignition switch to see if either the switch or the actuator pin is broken.
3. we have access to a dealer instrument, that is how we got to talk to the Anti Theft system, which told us there was a communication error to the PCM and the TCM. That should be a clue, but as Great Minds Think Alike, Fools rarely Differ....so we are still scratching our heads.
4. We will look for wiring problems behind the fuel filter as mark2m stated he had....so wiring harness.
Thanks again. Will report later today.
Cheers!