truck throwing P3449 after spark plug change

[Andy578]

anyone else had this happen? my code reader is saying something about cylinder 7 deactivation circuit. took it for a test drive around the block and about 1/4 mile in the truck completely died. sat for about 5 min and it restarted and i drove around for a good 30 min without any issues. rpm holds steady and the truck seems to idle just fine but i can't get rid of the code

 

[turkeybird56]

P3449 IS: Cylinder 7 deactivation,/intake valve control circuit open. Now, U said U got after replacing plugs? Check that U properly seated the wires/coil pack unit on plugs...

After that, write this info down and talk to a good mechanic, as I am only a backyard guy, can;t work on this computer electrical monsters ne more

Repair note from Internet: see URL:
https://repairpal.com/obd-ii-code-p3449-cylinder-7-deactivation-intake-valve-control-circuit-open

https://www.autocodes.com/p3449.html


I would definitely check and make sure that the coil pack, etc is properly on "both plugs". You may want to even disconnect and reconnect on cylinder # 7 to confirm. If after reseating, etc and still get code, than a trip to a reputable mechanic may be in order. I know there is a clip on the wiring harness that sits with the pack at the plug, did you forget to engage clip? just another thought....

 

[Andy578]

that one is such a pain to get at so i never actually disconnected the wire so it should be fine. i suppose maybe the coil didn't seat properly but you'd think that'd make it misfire like crazy. either way i'll likely run it into the shop, i lost enough blood changing the damn plugs lol

 

[Andy578]

now it's also showing a misfire and low ionization on #3. i'm thinking the truck doesn't like these plugs

 

[crackerjack1957]

now it's also showing a misfire and low ionization on #3. i'm thinking the truck doesn't like these plugs

So which plugs did you use.....must not have been OEM/NGK

 

[Andy578]

So which plugs did you use.....must not have been OEM/NGK

bosch iridium. searching around apparently the hemi only likes the NGK coppers so i'm assuming that's why i'm having issues

 

[crackerjack1957]

bosch iridium. searching around apparently the hemi only likes the NGK coppers so i'm assuming that's why i'm having issues

If you have the 2014 you will need the NGK Iridium, early 2013 & older used copper.
NGK 92145 ($5.70 each @RockAuto)

 

[Andy578]

If you have the 2014 you will need the NGK Iridium, early 2013 & older used copper.
NGK 92145 ($5.70 each @RockAuto)

ah ok that makes sense, it got dark out so never actually checked the manual. you'd think the Bosch and NGK Iridium would be fairly interchangeable tho

 

[crackerjack1957]

ah ok that makes sense, it got dark out so never actually checked the manual. you'd think the Bosch and NGK Iridium would be fairly interchangeable tho

Yeah NGK is OEM though.....possible there is another problem

 

[Andy578]

Yeah NGK is OEM though.....possible there is another problem

i can't really see it being another problem but who knows. truck was completely fine this morning before i changed them and only had issues after changing so it's gotta be related. don't think i damaged anything while changing them especially since i only actually disconnected 5 of the coil packs

 

[crackerjack1957]

i can't really see it being another problem but who knows. truck was completely fine this morning before i changed them and only had issues after changing so it's gotta be related. don't think i damaged anything while changing them especially since i only actually disconnected 5 of the coil packs

Okay did not realize there was not a problem before the plug change, thought you were changing them out because there was a problem.
So you had over 100k on the other plugs?

 

[turkeybird56]

Hmmm, sounds like a plug issue, the Hemi are stupid particular, like the ED on things. that being said, another hmmmm. When I was looking at plugs for my Honda Trike, I was going to go Iridium, but talked to lead Mech at Honda and he said unless doing super hot high speed runs, stay with standard NGK, which is what I used. I have read on issues on the different Iridium,., between heat and spark etc.,. just not know enough to say yea or nay...IMHO

 

[crackerjack1957]

From ALLData for 2014 Ram 1500

 

[crackerjack1957]

now it's also showing a misfire and low ionization on #3. i'm thinking the truck doesn't like these plugs

What was the code on this 1.....will look at possible causes.

 

[Andy578]

Okay did not realize there was not a problem before the plug change, thought you were changing them out because there was a problem.
So you had over 100k on the other plugs?

sitting around 115,000km. only real issue is i noticed is it hesitates starting a bit more now that it's getting cold out so i figured i'd change the plugs. the old plugs do look a bit rough and the threads on em were getting fairly rusty so probably best to get them out before they get stuck.

What was the code on this 1.....will look at possible causes.

P0303. i swapped the coil packs from #7 to #2 to see if that changed anything and it was only after doing that did the P0303 code pop up. i never even touched #3 while doing that so doesn't really make sense. the misfire was also pretty noticeable at idle and up to around 2000rpm but completely unnoticeable at higher rpm

From ALLData for 2014 Ram 1500

hmm that last bit has me wondering if i didn't somehow bump the PCM or wires the wrong way while doing those back plugs. i tried to be pretty careful around there but who knows. that could explain why the truck died on the test drive. when it died it just flat out shut off and started flashing messages on the dash about servicing the brake controller, 4WD, and airbag. it was about 5 min before it'd let me start it again and had a small red flashing light on the dash. also plugged the code reader in during that time and i didn't see any other codes other then what i already mentioned BUT it also wouldn't let me clear the codes either. it kept claiming it couldn't clear codes with the engine running which was obviously not running at the time

 

[crackerjack1957]

From ALLData 2014 Ram 1500 (P0303)
Both codes have the PCM possible cause
Maybe disconnect battery & check all connections that you could have possibly affected while changing out plugs

 

[Andy578]

From ALLData 2014 Ram 1500 (P0303)
Both codes have the PCM possible cause
Maybe disconnect battery & check all connections that you could have possibly affected while changing out plugs

Disconnected the battery and let it sit all night and it made no difference. Also tried reconnecting the PCM cables but the damn lever things snapped off. They sit there tight enough I wouldn’t think I would have disturbed them while changing the plugs but who knows

 

[crackerjack1957]

Disconnected the battery and let it sit all night and it made no difference. Also tried reconnecting the PCM cables but the damn lever things snapped off. They sit there tight enough I wouldn’t think I wouldn’t have disturbed them while changing the plugs but who knows

Seen a post a while back where someone found a source for those clips.
Not sure what to say about cause of codes....maybe someone else has an idea.

 

[crackerjack1957]

Here are the 2 posts discussing broken lever on PCM harness connector.
1st one has link for lever.

https://www.ramforum.com/threads/help-pcm-engine-harness-connector-broken.105771/

https://www.ramforum.com/threads/help-broken-pcm-connector-red-locking-lever.121708/

 

[Andy578]

Here are the 2 posts discussing broken lever on PCM harness connector.
1st one has link for lever.

https://www.ramforum.com/threads/help-pcm-engine-harness-connector-broken.105771/

https://www.ramforum.com/threads/help-broken-pcm-connector-red-locking-lever.121708/

those are priced pretty decently. ordered 4 of the things. hopefully won't need them but the shipping was the same either way so 4 made more sense

had the truck towed to the dealer and they are saying initial diagnostic is a PCM issue but it was the end of the day so they won't know for sure until tomorrow. i'm hoping maybe it's salvageable but that seems unlikely. they are quoting nearly $2000 for replacement tho, seems pretty excessive to me