I have a P0351 code on my jeep 4.0 the jeep has bad idle and no power

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P0351 - OBD-II Trouble Code

Auto Systems and Repair

Ignition Coil "A" Circuit Primary/Secondary Malfunction Our emissions expert has put together the following information about the P0351 fault code. We have also included diagnostic procedures you can take to your repair shop if the mechanic is having difficulty analyzing the code.
OBD II Fault Code

• OBD II P0351 Ignition Coil "A" Circuit Primary/Secondary Malfunction

What does this mean? The ignition coil or coils are responsible for igniting the air/fuel mixture inside the combustion chambers. Without reliable performance from the ignition coil(s) the vehicle will stumble and misfire.
Code P0351 indicates there's an electrical problem in either the primary ( the computer side ) or the secondary ( the spark plug side ) of the Ignition Coil "A" Circuit.
Symptoms

• Check Engine Light will illuminate
• Engine idles rough
• Engine misfires on acceleration
• In rare cases, the engine may not exhibit noticeable symptoms

Common Problems That Trigger the P0351 Code

• Defective Ignition Coil(s)
• Defective Spark Plug(s)
• Intake Manifold Vacuum leaks
• Carbon buildup in the Throttle Body air passages
• Defective Idle Air Control Valve or Electronic Body

Common Misdiagnosis

• Ignition coil(s) replaced when cause of the malfunction was a vacuum leak
• Spark Plugs replaced when cause of the malfunction was a vacuum leak

Your vehicle does not have a IAC valve ! Your vehicle has electronic throttle control . P0351 probably a wiring issue or open driver inside the PCM for cylinder # one . Your best bet take it to the dealer , you have not the knowledge or tools to diagnose this problem ! You are obviously using some cheap code reader to pull codes with or you wouldn't come up with P0508 . Factory service info. does not show Po508 for that vehicle. Plus working for ford i know for a fact this vehicle does not have IAC . If the driver inside the PCM is bad it will need to go to dealer anyway for programming .

google it or better get the FSM for your car, and read how to do the tests, that prove what causes each DTC.
505 idle speed failure.
351
http://www.obd-codes.com/p0351

there are 5 engines, so first find that out,.
351
ignition Coil # 1 Primary Circuit Peak primary circuit current not achieved with maximum dwell time.
this means the coil primary is open (other books show the fail is for too low current (open coil in COP)

505
Engine started; system voltage over 11.5v and the PCM detected an unexpected voltage condition on one or more of the IAC motor circuits for 2.75 seconds with the IAC motor active.

id fix the 351, cop coil , its probably bad, or bad connections to it.
then clean the iSC,
then reset all codes, with a scan tool
drive 20 miles or until CEL glows, driving and the rescan.

I would check Cam Position Sensor as is directly related with ignition. Power loss is due to the ECU going on "limp mode" to prevent further damage.
I hope this helps!

sounds like the coil for number 4 is bad swap it with another cylinder and see if the skip follows the coil

I have seen many, many, and I mean many hard luck stories about jeeps. I own one and have recently fought through my own experiences. First, are you getting a check engine light or any DTC trouble codes. Like p9138 or p0351? 351 is the kicker. It could be the cps ( crank position sensor ) or the ecm / pcm ( computer brain ) or even possibly fuel pressure @ the fuel trim rail. check out www.cnet.com there are hundreds, if not thousands of stories from real people like us who have experienced everything from apparent haunted equipment to simple fuses. In most cases, it is the cps ( crank position sensor ) or the computer ( ecm / pcm ). Electronic control module / power control module , this is the same piece of equipment. just goes by either name. there is a master mechanic named Damian007 on that site and he can diagnose any jeep blindfolded. I recently had to back out 2 screws on my computer 1/4" each to get my jeep to even start again. Insane and incredible at the same time. Jeep runs like it is fresh off the assembly line with improved gas mileage and a smooth idle. He can definitely lead you on the right course of action without shelling out thousands to incompetent mechanics who have no clue as to why your jeep does what it does. That includes most jeep specialty mechanics.

P0351 Ignition Coil (A) Cyl.1 Prim./Sec. Circ Malfunction 16735 is the vehicle missing if it isnt reset code if it comes back change plugs and wires

The codes you mention 301-302-303 are all misfire in the respective cylinders. you should replace the coil, while you are at it also verify the condition od the sparkplugs.

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.