Ignition coil D code keeps coming up

D

Diplomat 1

Active LVC Member
Joined
Oct 30, 2013
Messages
137
Reaction score
0
Location
Long Island
So after u guys helped me with my cooling issue I need ur help on this. It's a recurring code I c hanged coil and plug twice but still keep gettin it any ideas? I really think maybe the ecm is goin bad or only work cold and I don't know what to do. I do want to do a compression test how would I go about doin that on this car? I have done them on other cars but what's the best way to cut off fuel for the test and do I also need to keep the throttle plate open fully? Thanks any help would be great
 
Are you getting code P0354 - "Ignition Coil "D" Primary/Secondary Circuit" or P0304 - "Cylinder 4 Misfire Detected" ? The two do have different meanings.

If it is P0354, then are you sure you are picking the correct "#4" coil? There's no point to doing a compression test because this code indicates an electrical problem only.

If it is P0304, it could be that it is actually not #4. (The cylinder number in the case of the P030x codes is really just a good guess.) This could also be a fuel or compression issue. Make sure the connector to the #4 injector is on good. For the compression test, either pull the fuel pump fuse and let the engine die, or pull the fuel injector fuse. If you have gen II, then it's better not to try and hold the throttle open. It would upset the PCM and it would fight you. Holding the gas pedal all the way down should cause it to open it enough for you (clear flood mode).
 
I am getting p0354. Sorry for the confusion. I have changed the plug and
coil before at the same time and still come up. How can I go about diagnosing it properly ?

Coil d is the far back closest to firewall passenger side right
 
Make sure the positive side of the coil is getting +12V all the time the key is in the run position. Trace the negative side wiring from the coil to the PCM and do a continuity test and check resistance to ground. If all that is good (and assuming the coil and plug are good), then you are left with the PCM as the possible problem. (You did replace all the coils and plugs at the same time, right? You did you Motorcraft coils, right?)
 
I get the continutity test but check what resistance? I have replaced all but 2 coils but the one that keeps coming up wit the code has been changed. I changed coils at different times most of the time when that same code comes up for that cylinder.
 
The reason for the all coils question is that sometimes RF from a bad coil can cause false error codes. Also, often when one is bad, others are at least marginal.
The resistance check is to make sure there are no shorts to ground. Disconnect the coil and the PCM, then measure resistance between the negative wire in the harness and the ground (bare metal of the car/engine). It should read as over-range (higher resistance than your meter can read).

If all that passes, reconnect the coil, but not the PCM. Now measure the resistance between the #4 coil wire at the PCM connector and the COP fuse (under hood fuse box), then report that reading back here.
 
Oh I get it. U are talking about the harness that goes to the pcm and check the resistance on the harness side off the pcm to ground got u. Stupid question but where is pcm located. I will get back to u with readings
 
Passenger side on the firewall. The PCM is in front of the glove box on the inside. The engine harness connector to the PCM is on the firewall more or less inside the air box that the cabin filter goes in.
 
Kinda late didn't have time till today to work on it but I got a good positive reading on the ignition coil 4 (d) but I still having trouble tracing the wire back to the pcm. U are saying I should get to it from the inside of the car or the outside of the car thanks
 
unhook the PCM's harness, insert your test lead to the corresponding pin in that harness. the connectors are on the engine side.
 
I see these connectors but I don't think these are the ones

http://s15.postimg.org/65ohbr6h7/image.jpg

I can take off cowl cover off and go from there. Also will I have to reprogram the car in anyway if I take the connector off to check for continuity if I take the battery off? I don't wanna be stuck and have to reprogram the security on this car just want to make sure I will be good thanks
 
Diplomat 1 said:
I see these connectors but I don't think these are the ones

http://s15.postimg.org/65ohbr6h7/image.jpg

I can take off cowl cover off and go from there. Also will I have to reprogram the car in anyway if I take the connector off to check for continuity if I take the battery off? I don't wanna be stuck and have to reprogram the security on this car just want to make sure I will be good thanks
Click to expand...

No, it's not those by a long shot.
No, there's nothing to reprogram just from disconnecting the battery and unplugging the PCM.

http://deneau.info/ls/s6x~us~en~file=s6x3e006.htm~gen~ref.htm
 
I think I did it? Here is a pic

http://s22.postimg.org/ok8nka7ip/image.jpg

Looks like I have continuity straight to the pcm on the ground wire side (gray with green stripe) Does that automatically mean my pcm is no good? I have voltage at power side with key on engine off and now I have continuity on the ground wire. If it is the pcm can I just get one from a running car and put it in or does it have to be dealer only to be programmed back? Thanks again everyone
 
Assuming that all the checks were done and done correctly, then yes it would seem that only the PCM is left. If you put another PCM in, even if it is correctly configured for your car, the PATS will prevent you from starting the engine until your keys (at least two of them), your cluster, and your replacement PCM are all married together. More places/people than just the dealer have the tool for this, but for sure the dealer will.
Another (likely better) option is to remove your PCM and send it for repair. When it comes back repaired, no programming will be needed. You can just reinstall it, connect the battery, and start the engine.
 
I believe all the checks were done I checked power wire and have power and ground side wire for continuity and have that to pcm am I missing something? Any place you recommend that can fix the pcm? I want to fix this as cost effectively as possible. Thanks again Joegr
 
Member's on here have had good luck with these guys...

Telco said:
http://www.siaelec.com/
Click to expand...

And some advice about why it probably failed...

Telco said:
Good deal. I'd suggest replacing all the COPs and spark plugs before you start it, since it's suspected that a marginal coil is sending RF energy to the PCM causing the damage. You don't want to risk still having a marginal COP in there, which would blow the PCM again.
Click to expand...
 
Funny thing is that's who I found also gonna give them a call tomorrow. I am crossing my fingers that this is the problem. Also a little off topic but this has been my dads car and he has been putting in regular 89 octane gas and I know this car takes 93. Is the damage already done or can he switch to premium still? Just want to know that's again joegr
 
There's no reason at all that you can't switch to the 91+ that is is supposed to have. If any damage has been done (probably hasn't), then staying with low octane would only make it worse. Using the correct octane could only help.
 
Just got call from sia they said they bench tested the pcm and no misfires come up. I don't get it I did everything before to diagnose it correctly and they are saying it's not the problem and pcm is fine. They told me the transmission module was replaced which fixes another problem but the misfire for me is still gonna be there. I don't know wat to do anymore. What else could it be
 
Coil, plug, PCM, and wiring are the only possibilities for a P035x code. (Assumes that all coils and plugs were replaced with OEM.) If you've changed the coil (using OEM), the plug, and verified the PCM, then just the wiring is left.
 
It could be an intermittent connection, could be high resistance in a worn or corroded area. My multimeter beeps for continuity even with quite a bit of resistance. It reads light bulbs as continuous. In its defense, it does give the resistance reading when checking for continuity.

Anyway, point is, the beep doesn't tell you the whole story. Wiggle the wires. Read the resistance.
 
Merry Xmas everyone since it's hot today I have time to look at the wiring on my car. I very confused at this point because I am looking for continuity from the ignition cool wire to the pcm but I have continuity to wires that don't even match the color. Meaning I have one end of the Dvom on one side of the coil connector but I get continuity on almost 3-4 different wires on the pcmside. I tryed different connectors on both sides of the motor and same thing it seems like a short but how can all connectors be doin the same thing?one wire having continuity to 3 different wire on all connectors?. Only thing I can think of is the car has been sitting with the cowl cover off and it has rained a lot lately water got into the pcm connector and is giving false readings? Does that make sense? Could I have done damage to the connectors with the water? Thanks again
 
You must log in or register to reply here.

Members online

No members online now.
Total: 42 (members: 0, guests: 42)
Back
Top