If I correctly understand what you are saying about the P0201 and P0202, you may have caused them by testing.


It is important to keep in mind that: "MANY DTCs are 'sticky'. The DTC 'stays' even if the condition is corrected or corrects itself." Some DTC will reset & clear automatically after some number of run cycles without the condition re-occurring. But we have to realize, the code does not 'necessarily' mean the condition is present RIGHT NOW. Same is true with your P0351.


And, a P0351 is not a misfire code. Compression check is NOT prescribed at this point.


The most common cause of P035x is momentary circuit open due to broken clip on COP. It can (sometimes) be a failure in ignition output circuit of the PCM. But, important thing is it is NOT a misfire. The PCM has detected something wrong in the circuit that makes the PCM 'THINK' it can't 'fire' the spark plug.


To protect the CAT, the PCM disables the injector on that cylinder so unburned fuel will not be dumped into the CAT. So you definitely 'feel' the miss - but truly is NOT a 'misfire' and does not increment the misfire counter(s).


This code might be the result of you simply unplug a COP momentarily while testing. But again, "+" is sourced to one side of the COP. The other terminal goes to the PCM and the PCM pulls it to ground to fire the plug. Clean connections in the PCM plug, and verify wire continuity - and defective circuitry in the PCM, but it is NOT a compression problem. Eliminate that DTC first -- then move on to any other DTCs.


That is my suggestion.




-----------EDIT


Another thought: The PCM ignition output circuitry is capable of sensing the reverse EMF, or 'kickback' from the collapsing coil field when it releases the grounded primary when the plug fires. If it fails to see that reverse voltage "KICK", it assumes a problem in the coil 'secondary' like an open or short or something bad wrong with the plug. The description of P035x is "Ignition Coil Primary/Secondary Circuit Malfunction".


I assume you have already tried swapping the COP to another position to see if the problem follows the COP. Another inexpensive and simple test before suspecting the PCM circuitry might be simply replace the Spark Plug.

 

today i replaced all wires, from pcm to injectors, cops e.t.c aaand car runs like a shelby gt500 but engine still shakes.. what dat means? also mil is gone and no more codes but shakes... shakes

 

and i have one question, i dont like 3 cop connector and how can i change it? only way is to cut bad ones and connect new?

 

Glad the MIL is gone and it runs like a Shelby GT500. That's a good thing. As for the COP connectors. If the clip is broken - cut the connector off and solder / heat shrink a new one on.


As for the shakes - can you make it quit by raising RPMs? If so, rev it and let off a few times - until you make it idle smooth. Then cut it off - unplug both VCT solenoids and go for a drive with them unplugged (You'll get a code because of it). If it doesn't idle rough at stops - replace the VCT solenoids. If it still does it - you may be in for a timing chain / guide / phaser job.

 

thanks lot my firend.... ill try it tommorow

 

hi guys.... problem found... its cylinder compression... in cylinder #1 its about 115 and others more than 180.... can i change piston myself? it costs to much for my country.. lowest price is 1000 gel(400$ its 2 month wage in georgia) :/ i have changed on russian cars but navigator has soooo difficult engine :/

 

Just because the compression is low doesn't necessarily mean it's the piston. It could be valves or a head gasket. A borescope may help narrow it down.

 

ouch im sorry not piston i think valve, if it is gasket why only cylinder #1 and not 1,2,3 and 4 together?

 

i have another engine with 100k miles and which will be better? change engine or only valve? valve replacement willnt be easy.. im scared

 

Neither is going to be particularly easy. And I can understand the 'scared', but I wouldn't do either until I knew more about what is going on.




Did your compression test include a 'leak down test'?

 

what is leak down test? and now new code u0100 ecm/pcm comunication problem... what can be problem nothing changed.. only new faulty code.. from where i cant understand, car was in garage 2 days and than u0100 :/

 

A compression test gauge has a one way (check valve) holding the highest pressure reading achieved during the compression stroke until you reset the gauge. A leak down test, on the other, hand involves 'artificially' injecting compressed pressure into a cylinder, (when both valves are closed of course), and see how long it takes for the pressure to 'leak down'.


You can usually tell where the pressure is going if it leaks down too rapidly by monitoring / listening at throttle body, Oil filler tube, or exhaust. I recall a post where the engine 'passed' a leak down test but had very low compression on one cylinder. A leaky injector had leaked fuel and ALMOST hydro-locked a cylinder and "BENT" a connecting rod, but the engine would still run. Piston just wasn't coming all the way to the top of the stroke! Hope this isn't your problem.


But 'AGAIN', you could also possibly sort a little of this out by borescoping it like @glc suggested. At any rate, I would try to figure out what is going on before deciding what to do.

 

How can i resolve u0100 problem? I checked wires is ok, all fuses are ok, wires under drivers panel are all good, whats more? Pcm failure?

 

And today i saw my cars interior lights are pulsating, when engine is running not running and only internior lights headlights are ok like a alternator....

 

Sorry for the 'crappy problems' you're having. Sounds like electrical and they are the type almost NO ONE can predict or be much help on without hands on trying different stuff - even when it seems silly.


The best I can offer is to say that 'bad or poor grounds' are very disruptive (and hard to find). Also, my experience has taught me to place higher confidence in the specific meanings of codes. The U0100 description is "Lost communications with the PCM". That report cannot be coming from the PCM, but suggests the code reader was able to communicate - and now can't.


I would start by cleaning ALL GROUNDS that I can find starting from the battery. (That could also explain your unsteady interior lights). Clean ALL connectors to the PCM with a good contact spray cleaner (with battery disconnected of course). I would remove the PCM and its frame bracket and clean ALL ground lugs that I can find.


"The U0100 could even be in the scanner port connections - or the scanner itself. Try another one before you suspect the PCM itself - although it could in fact be a bad PCM. But I'm not ready to jump on that conclusion because the definition of the code suggests it is not DEAD DEAD.