I have a 2002 Jeep Grand Cherokee and I was turning right from a stoplight when the engine died. There was no sputtering just a sudden loss of the engine, power steering and power brakes. I coasted to a stop and turned the ignition off and was able to start the engine. The radio which was playing never quit.

SOURCE: 2002 Jeep Grand Cherokee Lardo misfiring

You say you changed the cam sensor. A1391 code is a crank sensor on the top of the trans. bell housing.

SOURCE: 2002 jeep cherokee laredo

My 98 Jeep Grand Cherokee had the same problem. Over heated when standing still. Took it to dealer and they could not find any problem with cooling fan. After doing my own investigation I found out that the electric cooling fan would begin to seize up after about 1hr. of operating. (gets hot)

The dealer would look at fan and see that it was running and think its ok. The problem is, it wasn't running fast enough.

I have a relay on the right side of front fender and jumped the fan to stay on with motor off. (must know what your doing). After about 1hr. fan started slowing way down. Returned it to dealer told them what the problem was. They were not smart enough to jump the relay so they put a couple hundred miles on it even though i told them it works OK when moving. Make sure you tell dealer to use the relay to jump.
Replace cooling fan motor. Works great

SOURCE: 2002 wj jeep grand cherokee p1756

The governor pressure sensor is the most likley cause however an inspection of fluid or debris in trans pan would be a good idea to make sure there's nothing excessive in it. Attached is a list of possible causes however the senor would be the most common.

POSSIBLE CAUSES

• Powertrain control module
• 5 volt supply circuit open
• Check transmission fluid level and condition
• GOV press sensor signal circuit shorted to voltage
• GOV press sensor signal circuit shorted to sensor ground
• GOV press sensor signal circuit shorted to ground
• GOV pressure sensor signal circuit open
• Sensor ground circuit open
• GOV press sensor signal circuit shorted to voltage inside transmission
• 5 volt supply circuit open inside transmission
• Intermittent governor pressure solenoid
• Internal transmission problem
• Oil burnt or oil pan has excessive debris
• Other transmission DTC'S
• GOV press sensor signal circuit shorted to sensor ground inside transmission
• Valve body
• GOV press sensor signal circuit shorted to ground inside transmission
• GOV press sensor signal circuit open inside transmission
• GOV press sensor ground circuit open inside transmission
• Governor pressure sensor (high)

SOURCE: How do you program a 2002 Jeep Grand Cherokee FOB?

if you have an original working fob and your owner's manual,it will explain procedure,otherwise will have to go to dealer to be programmed

SOURCE: 2002 jeep grand cherokee fan not working?????

Replace the fan relay switch. The dealer will charge you 400 to pull the bumper off, or you can buy the part for 45 and cut the hole in the plastic near the passenger headlight assembly and replace it yourself. There are instructions for this procedure on the web somewhere. I have had this problem more than once with my 02 GC V6.