My Jeep wont stay started

Will the engine stay running if you hold the accelerator pedal down 1/4"? Did you disconnect the battery during the recent service?

It is likely in anti-theft mode. Unlock a front door with the key to turn the system off. If that doesn't work, suspect a broken wire between the door hinges. This applies if the engine stalls after running for about two seconds.

The next thing is you need a scanner to view live data to see what the Engine Computer is responding to. I only have a Chrysler DRB3 scanner so I don't know how this information will be presented on other scanners. Mine lists the fuel pump as "off" or "allowed". "Off" means it's in anti-theft state.

By disconnecting the battery, the Engine Computer lost its memory. The only thing you're going to notice is really low idle speed. That makes it hard to start and will stall easily unless you hold the accelerator pedal down a little. The fix for that is real easy and just involves driving at highway speed. We'll discuss that later. Reconnecting the battery usually puts the system into theft mode and unlocking a front door or with the remote is all that's needed to disarm it. The clue is the engine will run for two seconds, then stall, even if the accelerator pedal is pressed. If your engine runs longer than that before stalling, you know the ignition and fuel systems are working, but one of them is quitting. That's another place where you need a scanner to see what the Engine Computer is seeing and responding to, and what it is commanding to turn on and what it isn't.

Welcome to our world! Please don't get me started on all the unnecessary use of technology that doesn't always benefit the car owner as much as it does the manufacturers. Be happy you don't have a GM product or a European import!