HELP! 4 of 6 coilpack primary circuit open

Hey TW. Long time lurker and searcher. I typically don't post but me and my brother are at our wits end.

Problem:
2013 V6 4.0

Via an Autel diagnostic tool, I get P0351, P0352, P0353, P0354.

Symptoms:
After start up, engine sounds like its knocking like crazy. After troubleshooting and resetting codes. The codes come back immediately after resetting.

What we just changed:
Spark plugs, MAF cleaning, air filter, pass side CV.

Previous troubleshooting:
I've found all of the electrical diagrams and somewhat familiar now. So far we have...
Turnover engine with coils unplugged. NO knocking sound. Put old plugs back in. Checked all grounds at driver fender, passenger fender, two locations on back of block near firewall. Visually checked all connectors (including J12 and EA1). Unplugged one coil at a time cleared codes and reread. Codes come back immediately. Swapped coils with one not throwing a code. No change same codes return. Checked all fuses for good measure. Physically checked all sensors for good connection. Next steps are to probe the circuit and check for resistance and voltages.

If you read all of this. Thanks in advance for all of your help!

 

Have you checked powers and grounds at the coils?

 

That's our next step. Probing for resistance and voltage checks. Didn't have one handy so have to wait for tomorrow after work.

 

Hey there buddy.
Here’s a good link to info where someone had a similar problem.
https://www.tacomaworld.com/threads/2005-4-0l-no-spark.745353/#post-26538019

Feel free to continue with your help here.

But I think you’ll find the good info in the link.

 

Thanks. It did give me some additional info in the troubleshooting guide. And I'll have a clearer understanding tomorrow after I probe

 

Not a huge fan of resistance checks as they can sometimes lead you to believe a circuit is good when in fact it can't carry a load, they are usually ok for signal and sense circuits but not really for load bearing circuits.
Also remember if you check voltage with a voltmeter the circuit needs to be loaded, using a test light is a much better test as it proves the circuit can carry at least some load.

 

Any signs of rodents in engine bay, has truck ever been submerged in water? Seems like you have ruled out basics of ignition, could be a crusty/ corroded ground, fuse block or chewed wire somewhere in the loom.

 

No to either scenario. I firmly believe it has something to do with one of the things we changed as it ran fine before. I just came seem to undo it.

 

What was done prior to this happening?

 

True, it has to be something simple that was overlooked would be my guess if it ran fine before.

 

Changed spark plugs, MAF cleaning, air filter, and CV axle.

 

Can't see any of that having anything to do with it unless wires got broken or pinched, have you checked the grounds at ground point EE?

 

Yes. Still intact. I checked EF for good measure as well.

 

This is just a thought but did you put the correct plugs in it and not ones that were too long?

 

I got these from the stealership. Also swapped the old plugs back in with no changes.

 

Ok just making sure.
I'm out of simple things to check, your gona have to get the test light and meter and see what's missing.
A scope would be required to see the coil control (IGT) and ignition confirmation (IGF) signals but you can check powers and grounds with a test light and ohm out the wiring to the PCM with a meter.

 

Thanks for your input! It's definitely a good sanity check to make sure I didn't miss anything simple.

 

I mean aside from coils not being plugged in all the way, pinched wires, or bent pins (can't see that happening on 4 coils) I can't see how the stated work could have caused this.
The coils all share the same power and ground, each coil has it's own control wire but they go straight to the PCM, the ignition confirmation wires are all spliced together at the J12 junction connector and then a single wire goes back to the PCM for those signals.
I'd have to look on my truck how the harnesses are routed but I don't think there's any engine related wiring near the areas that would have to be messed with the change a CV axle.

 

Yup all that logic makes since. The closest wires are the grounds at EE. Connector EA1 (B+) is in the fuse box near the battery but I've checked that. One other thing I will try is unplugging the battery for a longer time in attempt to "reset the ecu" in case for some reason those permanent codes can't be reset via OBD2. But I'm reaching for anything at this point. I'll just have to spend some time to probe and confirm circuits tomorrow. Worst case start throwing parts at it.

 

Make any progress in determining what happened?