I have a 2003 Jeep Grand Cherokee 6 cyl. I am getting fault codes P0351,P0352 and P0353 which is defined as #1,#2 and#3 ignition coil circuit and code P0505 JEEP Idle Control System Malfunction and code P1495 JEEP EVAP Leak Detection Pump Solenoid Circuit Condition. The problem I'm having is at times the engine will bog down and lose all power and sometimes just completly quits. I can stop the vechicle and turn the key switch off and start the engine and it will run just fine. I have replaced the cam and crankcase sensors and the fuel filter.Which one of the fault codes do you think would cause this condition? Thanks

SOURCE: 1996 jeep Grand Cherokee has a scan code P0351.It says

Wiggle the connectors on the PCM during those four or five minutes...
I'm going to try the hose clamp fix myself. I have been struggling with stalling for about a month now. As a matter of fact, my PCM looks just like the one with the hose clamp. Connector C1 (black) missing the locking tab. I have tried the screw repair and zip ties. Zip ties worked for about a week and then I had a hiccup followed two days later by a full blown stall. Now it's stalling about 4 to 6 times in a one way trip to work (11 miles).
I was able to procure a clamp tonight and got it installed. When I go home we'll see. I was throwing a P0351 code with a code 43. This is an aggravating fault to be sure. I am an aircraft electrician by trade so and thanks to the volumes of people who have had this problem I have been able to do some really good fault isolation.
It exists either in the C1 connector for me or the PCM. Initially I changed the TPS and then found found C1 ready to fall off the PCM (Thus the zip ties).
Later I found that even though zip tied wiggling the harness could duplicate the fault. So another zip tie around the harness to pull tension on the connector. The fault returned. I also took a rubber mallet to the computer while the engine is running and duplicated the fault as well.
At this point I'll try the hose clamp and see how that works out. Either I don't have a good connection on C1 or the male pin 7 in the computer is a problem. Since I have an obvious defect in the locking tab on the C1 connector I'm swaying towards that. I want to talk a little system knowledge here courtesy of a guy who posted on CNet.
1. P0351 is a coil code. However:
a. The coil receives a signal from the PCM connector C1 Pin 7 to "fire".
b. There are only two wires at the coil, signal wire from the PCM pin 7 and a ground wire.
c. In order for the PCM to throw code P0351 the PCM had to fail to send the proper fire signal. Of course this assumes that you have a known good coil, clean ground and no breaks in your wiring.

2. A multimeter checks continuity not integrity. The average 18 gauge wire has 22 individual copper conductors(wires) inside the insulation. You can have 21 broken strands and still read full continuity through that single strand of wire. But that single strand of wire will not be able to handle the signal being sent to the coil (load). A load light will always check integrity AND continuity. A weak light means not enough current going through the wire and a strong light means good wire integrity.
3. So with this said, In order for P0351 to set, the computer has to give an erroneous signal to fire. Pin 7 is an OUTPUT. Now is this caused by a bad computer? Possible. A bad connection? More likely.

Let's face it computers will fail, but in my 22 years of electrical experience bad/loose/dirty connection points are the weakest link. A cold solder joint on the PC board in the computer? Yes, however this will generally show up shortly after the vehicle rolls off the assmbly line. Not 13 years later!
As for the "screw" fix. I read a post from an engineer who scraped all the resin out of the PCM to see what was on the board. The long screws go to a NYLON nut on the board. But does not come near the current path of the PC board.

SOURCE: jeep codes location of unit

Got me a complete manual for 199 jeep factory model and found location of each individual unit in question. Manual gives u possible solution to each code and repair and or replace. As a mechanic myself testing, trouble shooting and repair was not that difficult. Shift solenoid was very difficult to get to. Located under the head lamp passenger side.

SOURCE: Actually I have 3 codes

1. Check up the intake system for air leaks. Just spray carburretor cleaner product around intake manifold area, engine idling. If the engine rpm will raise up, there are air leaks. Replace intake manifold gasket, and test again the engine for air leaks. Check up also the exhaust pipes for air leaks. Inspect the exhaust pipes for gases leaks. Repair & replace bad components if necessary. If everything is all right regarding air leaks, and the fault code 171 still occurs, replace the bank 1 upstream oxygen sensor.
2. If the CKP sensor has been changed with new one, just replace the Camshaft Position (CMP) sensor, and test again the engine. If the fault code 320 still occurs, check the harness wire by wire & connection plugs pins, and repair damages. This code must be erased definitely.
3. Replace ignition coil and test again the engine. The fault code 351 must be erased definitely.

Good Luck!

SOURCE: driving down the road and

I'm assuming you have the 4.0 engine. Before that, I'd probably see if all of your ground wires are intact and properly fastened to the engine and battery. There are 2 bolts for grounds on the engine block on the passenger side near the bottom. There also should be a braided ground wire bolted to a stud on the the valve cover I believe.