Ok. So I'm banging my head on the concrete for this one.

I have a P0356 ("F" Primary/Secondary Ignition circuit) and P0355 ("E" Primary/Secondary Ignition circuit) codes being thrown on my pacifica.

Naturally, I started with the spark plugs - installed NGK laser platinum. and at one point it deliberatly said missfire on cyl 6. Now i only have those 2 codes. It has a coil on plug setup so i moved the #6 pack to #3 to see if the problem would move - It did not. I still have the same codes and it drives like bat crap.


Ideas? I'd hate to say it but i was thinking PCM :-/

-Justin

 

also, I did notice a vacuum sound coming from under the intake. I was thinking it was that electric "throttle" choking the air out the intake resonator?. I couldnt tell you if it was always there or not. I was thinking no?


-Justin

 

anyone?

I'm still trying to look for an idea here..

I took the car in the shop last tuesday ish (10/8 ish), they diagnosed it to the PCM, and luckly it was covered under warranty and it got replaced. Picked it up this last tuesday (10/15) after they said it is driving fine.. threw a CEL before i got home. I ended up taking it back to the shop. tuesday night



So.. I called the shop on Thursday, after i took the car back; after it took them a week to meter and trace wires and eventually (at first) find that it in fact was the PCM. Now they said that the problem is a Motor mount, is causing the wires to tug on the motor/frame and causing it to misfire?

Does this sound legit? Tuesday i drove the car practically all the way home without a problem. Up and down hills, stop lights (from 58th and Garrison to Golden (Map link )) and didnt have a problem, then suddenly it threw a CEL at a stop light just off of simms and 8th?? (roughly 5 blocks from my house)

Am i crazy?

Any Input would be nice if you could. They are trying to stick me with a 250$ bill because the motor mount wasnt covered under the warranty and I could've done a stinking motor mount. I call B.S. because I'm thinking the mount would've had to completely busted to cause the wires to tug because there should've been plenty of slack on the wires. Along with that, they should've found that problem a week and half ago when they were looking at the wires, tracing and such, and went "hey, this doesnt have a whole lot of slack"

sorry for the rant.. I'm just trying to get a prospective on it. :-/

-Justin

 

I just went through this and mine turned out to be the plugs themselves. I changed back to the Champion dual platnum and all misfires went away. I had tried the AC Delco platnum plugs. The tip didn't extend nearly as far as the Champion plugs. The misfies started within a week of the AC delco plugs being installed.

The vacuum leak is where the resonator shaft comes out of the plastic manifold. You can confirm by wiggling the shaft while idling to hear the sound change. I worked 3 or 4 fat O-rings (for fuel injector on cadillac) over the lever arm. The all bau eliminated the vacuum leak.

 

Well, i started getting the missfires when i installed the champion platnum plugs.. i went with the NGK and at least its halfway driveable..

Well, got the car back and the wife turned around and drove it back agian.


I figured as much since it was a motor mount they said was to fix the problem - though, i saw the old one and i already knew it needed replacing. I popped the hood to look at the wire harness and, of course, there's plenty of slack. The biggest problem i have is the shop is the "dealer" shop for warranties and they were the only one that did PCM/ECU troubleshooting.

Apparently, I P-O'd the shop because I called and ripped the guy a new one. eff this, eff that, get your effing car out of here... I did call back and apologize for doing that and worked the situation back down.

I got the car back home and looked at the harness a bit and got the C.E.L. to go away, somehow.. it worked its way out. I'm thinking something wasn't fully "clicked" in when they installed the new PCM.


edit: the new CEL was P0355 which is coil primary/secondary circuit for cyl 5. this is the same code I had (along with P0356 same code but for #6) when i took the car in in the first place.. so now I'm back to square one.. :-/

::facepalm::

-Justin

 

ok.. update..

C.E.L. Came back.. going to tear into the wire harness this weekend to see if there isnt a short in the harness.. :-/

 

whats the last 8 of your vin? 355 is not the code that u are saying in fact
for an 04 CS with a 3.5 there is no such code avail.

 

and my vin is: *****4R182397

edit: isnt a CS a sebring?


-Justin

 

Try a different scanner there still is not a 355 or 356 listed for the Pac for thoes years but I did use your vin and there is a TSB for p300 here it is

Engine Stumble/Misfire - MIL Illumination
OVERVIEW:
This bulletin involves decarbonizing the combustion chamber and installing new exhaust
valve springs.
MODELS:
2004 (CS) Pacifica
NOTE: This bulletin applies to all 2004 CS vehicles built prior to February 1, 2004
(MDH 0201xx) equipped with a 3.5L engine (Sales Code EGN).
SYMPTOM/CONDITION:
Engine stumble and/or misfire. More noticeable during a light throttle tip-in or when
transaxle goes into lockup (approximately 47 m.p.h.). MIL illumination with Diagnostic
Trouble Codes (DTCs) P0300 through P0306, individual or multiple cylinder misfire.
DIAGNOSIS:
Using the Diagnostic Scan Tool (DRBIIIŽ) with the appropriate Diagnostic Procedures
Manual, verify all engine systems are functioning as designed. If the condition(s) and/or
DTC's listed are present, perform the Repair Procedure.
PARTS REQUIRED:
Qty. Part No. Description
12 04892082AA Spring, Exhaust Valve
1 04318001 Mopar Combustion Chamber Cleaner
NOTE: The new valve springs can be identified by white dye on the top coils. The
nominal spring force of the revised exhaust spring is 85 lbs. closed and 147
lbs. open.


CS is Pac 04 - 08
serbrings of that year are a JR or ST

 

interesting... I did use a different scanner and even the shop i took it to said the p0355/6

Question - For this primary/secondary ignition circuit code, Could it just be a bad couple of coil packs? I only ask because when I had it running back from the shop w/o a C.E.L. I pull the coil pack for #3 and got a P0353 code. Same description but for "C"(3).


the shop I took it to was very adamant that it was NOT a simple coil pack. I want to agree because I have tried moving #6 to #3 before and the code didnt follow.

today I'm going to pull apart the wire loom and see if i can see any frayed/fried wires since that shop said its likely that as a problem. I'm just spinning my tires with this one and its driving me nuts!


-Justin