P0356 ignition coil

zerokool said:

So I had the ignition fuse under the hood pop and my car is now getting P0356 and sometimes P355. I replaced the coil pack on #6 and nothing changed.
checked the connection. Swapped the new coil with #4 and the problem stayed on#6 so the original coil was good. The connection with pcm looked good. The connection to the coil looks good. Sprayed contract cleaner in both connections, no change..
ideas?

Click to expand...

Maybe too if you haven’t tried inspecting the spark plug that might be part of the issue. I would definitely give it a shot.

peva said:

View attachment 43324
It may be a bad PCM output #6 (sometimes 5) intermittently shorting solid on.

Normal ignition duty cycle (dwell) is low - but shorting gives 100% duty cycle for the durationn of the short, which pulls a lot of current, blowing the fuse. Seen a few threads over the years with this behavior with bad PCM. (From the code description, the PCM may actually not be sensing the current correctly, so it increases the dwell, which increases the current, which, again, it's not sensing, fuse blows from the high current.) The coils have been known to get hot and go bad from this failure. Hopefully your coils are OK - worry about that after replacing the PCM.

Click to expand...

you sound like you think its the pcm... i was leaning towards that as i have checked the connections, replaced the coils and-spark plugs

JordanS said:

Maybe too if you haven’t tried inspecting the spark plug that might be part of the issue. I would definitely give it a shot.

Click to expand...

I failed to mention this but that was the first thing i did.. ngk platinum "oe style" whatever that means ..

zerokool said:

I failed to mention this but that was the first thing i did.. ngk platinum "oe style" whatever that means ..

Click to expand...

NGK was what came from the factory in many of the 2nd gen LH cars (I think the 2.7's came with Champions - but maybe only in the first few years, otherwise NGK). Good choice.

Yes - I hesitate to make predictions anymore, but in this case, I expect your PCM to be the problem - based on what the codes are telling you and several threads in the past on coil primary issues (blown ignition fuse and sometimes burned coils - which I don't think you've seen yet, because fuse has been blowing).

So after replacing the pcm the car turns off right away.. how do i turn off skim

All the ****ing dealers around me are scheduled out until ****ing June. God ****ing dam everyone

peva said:

NGK was what came from the factory in many of the 2nd gen LH cars (I think the 2.7's came with Champions - but maybe only in the first few years, otherwise NGK). Good choice.

Yes - I hesitate to make predictions anymore, but in this case, I expect your PCM to be the problem - based on what the codes are telling you and several threads in the past on coil primary issues (blown ignition fuse and sometimes burned coils - which I don't think you've seen yet, because fuse has been blowing).

Click to expand...

You nailed it the pcm shot itself out

I'm gonna go back to the parts yard and hope that 300 M special has the key in the car so I can pull the key the security transponder in the BCM Peva do you know if my security key and transponder will work with the BCM and PCM of the donor car, or do all four parts have to match the same car

You'll need the PCM, SKIM, keys. If you want the security system to work, then grab the key cylinders for the ignition, door, trunk, glove box as well (or just tape the appropriate key to the SKIM and nix the security feature).

I could be wrong, but I don't believe BCM is in the mix. I have a Special, so I never did the Special PCM mod. I picked up a PCM from a 2002 Special last year and figured I'd have it flashed to my car if I ever needed it, since it's not my primary car and can wait.

@peva pcm and bcm from donor 2002 trep without security system.. the car turns on and then off after 2-3 seconds

pcm from donor 2003 special and the car turns on and then off after 2-3 seconds. Ive unplugged the sentry module from under the steering column..

i need to leave town.& this makes no sense

LUNAT1C said:

You'll need the PCM, SKIM, keys. If you want the security system to work, then grab the key cylinders for the ignition, door, trunk, glove box as well (or just tape the appropriate key to the SKIM and nix the security feature).

I could be wrong, but I don't believe BCM is in the mix. I have a Special, so I never did the Special PCM mod. I picked up a PCM from a 2002 Special last year and figured I'd have it flashed to my car if I ever needed it, since it's not my primary car and can wait.

Click to expand...

I need to drive south. I dont ****ing care about skim, keys or ****ing god dam stupid security.. i need this pos to run, and get me to my moms in texas, 800 miles away then i can do what the **** ever i need to properly. I cant do it on 5 cylinders
I cannot get this thing to run with 2 different donor pcm's. One i can tell does not have security, unless the transponder by the keys was professionally removed and then had the panels reassembled..

Im so lost.
P.s. does anyone know there is a hidden black box in the bcm that is programmed to the fob?
Extra from the transponder on the column

zerokool said:

@peva pcm and bcm from donor 2002 trep without security system.. the car turns on and then off after 2-3 seconds

pcm from donor 2003 special and the car turns on and then off after 2-3 seconds.

Ive unplugged the sentry module from under the steering column..

i need to leave town.& this makes no sense

Click to expand...

Did you unplug the Sentry module before plugging in the new PCM the first time? I've read that if you power up the PCM with the Sentry module connected, the PCM immediately and permanently becomes a Sentry PCM (perhaps can be re-programmed by dealer to be non-Sentry?).

zerokool said:

I need to drive south. I dont *ing care about skim, keys or ****ing god dam stupid security.. i need this pos to run, and get me to my moms in texas, 800 miles away then i can do what the * ever i need to properly. I cant do it on 5 cylinders
I cannot get this thing to run with 2 different donor pcm's. One i can tell does not have security, unless the transponder by the keys was professionally removed and then had the panels reassembled..

Im so lost.
P.s. does anyone know there is a hidden black box in the bcm that is programmed to the fob?
Extra from the transponder on the column

Click to expand...

The RKE (Remote Keyless Entry) module is plugged into the BCM. Transfer your original RKE module to the new BCM. No programming needed.

I only know what I read on this subject. Fortunately for me, neither of my Concordes had Sentry, so I never had any hands on experience with it.

peva said:

Did you unplug the Sentry module before plugging in the new PCM the first time? I've read that if you power up the PCM with the Sentry module connected, the PCM immediately and permanently becomes a Sentry PCM (perhaps can be re-programmed by dealer to be non-Sentry?).


The RKE (Remote Keyless Entry) module is plugged into the BCM. Transfer your original RKE module to the new BCM. No programming needed.

I only know what I read on this subject. Fortunately for me, neither of my Concordes had Sentry, so I never had any hands on experience with it.

Click to expand...

whoah thats something to behold.. i believe i unplugged the skim module for the first test, in the parking lot of the parts yard, where it died right away (but revved smoothly for the few seconds it ran) then i went back in for the bcm ... but at some point plugged the sentry security module back in... for all intents purposes im trying to convert back to a plain lhs without security, like you have, just so i can get to my destination..

I literally rebuilt one of the heads, just to get a pcm problem right away.. i just need this pos to run normally to south where i can fix things properly, but later lol

So when i put the rfmodule for my fob back into the donor trep bcm , the car will not even start to then die 3 seconds later, just, nothing.... not even a click..

The stealerships told me they are not able to turnoff/disable the security..

I believe that once you plug it in, it is instantly "broke". And all your modules also become "broke". So the only thing you can do is swap in all the components from a non security car, or find the key...

But this is based on what I too remember reading...

Sent from my SM-G996U using Tapatalk

cdmccul said:

I believe that once you plug it in, it is instantly "broke". And all your modules also become "broke". So the only thing you can do is swap in all the components from a non security car, or find the key...

But this is based on what I too remember reading...

Sent from my SM-G996U using Tapatalk

Click to expand...

Thats exactly what i did... only to find the donor car parts had the same exact problem.. i have 2 donors ive picked from, a2003 special and a 2003 trep, base model. They both revs smoothly for the 3 seconds before they turn off

the bade model trep pcm is now throwing p0513 and p0633.. both skim key errors... 513 says wrong immobilizer key present and 633 says immobilizer key not programmed

Hmm.. ive tried so many things on both pcm's they are now both throwing p0513 and p0633... ill have to stop by the parts yard in the morning and get another donor pcm (looks like they have 2 or 3more cars there)