2004 Jeep Grand Cherokee shutting off issue
 

Ok so my 04 Jeep Grand Cherokee has decided to throw in the towel. I was driving home from work the other day and the check gauge light came on. My voltage gauge was showing 9 volts then it just shut off and wouldn't start back. Jumped it and took it to get a new battery. While buying the battery I left it running and as we started to change the battery the radiator cracked. So I have changed that out and added more antifreeze, but now it will start and run fine for a few minutes then it starts to idle rough and when you give it gas it has a chatter sound then shortly after that it will shut off. Light smoke coming from near the oil cap and valve cover. Any ideas as to what this could be?

Is it throwing any codes?

No codes are showing up.

4.0 or 4.7?

I have a 2000, 4.7. When my PCM went out it would not stay running. It didn't over heat. The engine would shut down at any speed. Started off intermittent, and the frequency increased over a few months. I got no codes either on the odometer or with a scanner. Might be time to take it to a mechanic. I had to do that.

Curious as how they came up with that diagnosis of a bad PCM? (Just in case I run into the same thing in the future)

It was over 2 years ago and I don't recall the details. It was confusing because I took it to Mechanic 1. They did the analysis and told me it was the PCM. Up to that point I had not even heard of the term. He said he wanted no part of repairing it and just told me to get it off his property. My recollection was they used a scanner and got nothing. No readout, no information at all suggesting to them that the PCM had failed totally. I took it to Mechanic 2. They said the same thing and arranged for the dealer to install a MOPAR PCM. I am remembering that both mechanics could not obtain any information at all from the OBD. Try and disconnect the battery for hour and see if there is any improvement. That resets the PCM. Your radiator failing is likely a separate issue from the PCM.

My Jeep is the 4.0