Car Tech forum: Possible electr. problem (strange)-2003 Jeep Grand Cherokee

I'll bet good money that your crank position sensor has gone bad. I think your other problems may be ancillary, caused by the engine temporarily shutting down. When the engine stops running, all of your power accessories are trying to run off the battery by itself; not good. That's [bad crank position sensor]a common problem with late model Jeeps. I can't say 100% that's your problem, but worth investigating further. Hope that helps you.

1991 Cherokee Classic 264,000mi
1996 Grand Cherokee Laredo (ZJ) 132,000mi

I have this same vehicle. I do know if you have a repair manual? you can turn your key on /off/on/off/on and this will bring up a code on your odometer. only if your check engine light is on. Hope this helps.

I had this same problem with my 2003 GC. I replaced a number of parts, including the starter, ignition switch, and one of my O2 sensors. I still had the problem. While I was under the jeep, I noticed a sensor connector on my transmission bell housing was loose. It ended up being the Park-Neutral-Position sensor. I replaced the sensor and the connector and have not had any of the same problems. The parts weren't expensive, but they are uncommon, so I had to order them. Most parts stores can order it and have it in a day. Hope this helps.

My 2002 Grand Cherokee did the same things described above. The gauges would go crazy while driving. The radio would pop. The car sometimes wouldnt start and then run fine for weeks.
I took the battery in and had it tested at pep boys. They said it was fine.
I had it trouble checked at my local mechanic. But every time I took it in, it would run perfectly.
Finally after about 5 months of this the car finally died for good.
I had it towed to the dealer.
He looks at it and says, "Oh, you need a new battery!.
New battery installed.
All problems gone.

When start engine, rpms revs excessively high. Then when driving, around 50 mph and put pedal on the floor, it barely accelerates. When slowing down to about 20 mph it like doesn't shift down and the car shakes. The check engine light code is for evap. There are no codes regarding the transmission or anything other than evap. We have taken it to a transmission shop today, and they experienced the shudder, but thought that changing the filter and fluid would help. It didn't. I have taken it to an automotive shop and they put it on the machine and couldn't find anything wrong with my car. It doesn't do it all the time, but within the last few days, it is doing it more often. Very frustrated!! Please help. Been dealing with this for 3 months.