We were driving down the road last night and our Jeep hesitated for a second and then died. It cranks good but will not restart. I hauled it home and here is what I have found: Fuel pump is not working- changed relay and checked fuse. No fire to plugs. Fuel gauge reads empty but I have 1/2 tank. Key light comes on when I try to start it. Check engine light comes on after leaving key in run position for about 30 seconds. I tried to scan it and the scanner seems to be linking but the the scanner reads "error". PCM fuse is good. It is a 4.0L 6cyl. automatic trans.

Use the ignition key on-off method to retrieve any fault codes:
Insert the key into the ignition, turn the key to the ON (not start) position, then to the OFF position. Do this three times in succession, at the third ON, leave it ON and look at the odometer. The mileage should be replaced by trouble code/s (pxxxx) or read "done" if none are present.

Post any codes here for help.

I tried the key on/off method this am. No matter how many times I did it the odometer still just read the mileage. I talked to the service mgr at the dealer and he said that it sounded like and electrical problem with the PCM but didn't have any suggestions except to bring in to him. Any ideas ?? Thanks

I guess that's a possibility but I would try it again. If doesn't work this time, turn the key on/off one more time than you have previously done, ie. if you think you have been turning the key on & off 3 times, try 4. If that doesn't work try one less turn. I've known a few people who were getting it wrong on their first attempts.

Remember it has to be done in fairly rapid succession - I've messed up the timing and count a couple of times myself even though I'm familiar with the process.

I had a period with some of these symptoms. Mine would restart usually, you just did not know how long it would take. I also had no codes in the system. I eventually replaced the crankshaft position sensor per some info here and have been good for about a year now. It was explained to me that since the CPS was faulty, it did not know the crank was turning so the brain didn't realize it should be running so there was no fire or fuel being delivered.

do you hear any clicking leave the key on for about 5 min see if the realys start to click if it does ur compouter is gone