2011 Aveo Misfire (recurring problem)

Hey guys and gals! I am the "Mechanic" of my family and have noticed a recurring problem with the 2011 Chevy Aveo w/ Auto Trans. The #3 Coil has failed on 2 coil/coil packs. I haven't seen a permanent fix for this. How do I know it is the #3 coil? I have replaced the spark plugs with no improvement on the problem. #3 plug was wet from fuel not being ignited. Injector is still working properly. I quadruple checked the quick connect connection. Disconnected then reconnected multiple times. I bought a used, known working replacement. Problem was fixed. Until the replacement started recently exhibiting the same problem. Car has +75k miles on it. Original OEM coil failed @ around 65k miles.

Is there a fix for this design flaw?

I wonder if you have a problem with your wires. Maybe a short inside the wire causing it to blow out. Here is a link to testing your spark plug wires. Includes a video:

Checking spark plug wires using two simple strategies

are you sure the #3 injector isn't sticking open flooding the cylinder?

Quote:

---

Originally Posted by xintersecty

I wonder if you have a problem with your wires. Maybe a short inside the wire causing it to blow out. Here is a link to testing your spark plug wires. Includes a video:

Checking spark plug wires using two simple strategies

---

The 2009+ model Aveo's are ecotech engines. These are "coil-on-plug" so there are NO wires to check.

Quote:

---

Originally Posted by EAD15

The 2009+ model Aveo's are ecotech engines. These are "coil-on-plug" so there are NO wires to check.

---

Wow, OK I know how to deal with that. Get a spark plug tester. I have a coil on plug in my boat. So I use a spark tester with a sealed cylinder to check it.
Dorman® 86579 - In-Line Spark Checker

I use that on my boat.

I forgot to mention that the code pulled states it's #3 misfiring. I'll have to pull that code again. I can't remember it.

Quote:

---

Originally Posted by xintersecty

Wow, OK I know how to deal with that. Get a spark plug tester. I have a coil on plug in my boat. So I use a spark tester with a sealed cylinder to check it.
Dorman® 86579 - In-Line Spark Checker

I use that on my boat.

---

I don't think I would be able to use that correctly. The Coil pack for these newer Aveos are 1 piece. So if I need to test #3 for sure with that tool, all 4 would be disconnected. Though, I may end up purchasing that for later use

Wow your right. That sucks. Either you buy four plug testers or you had two bad coil packs in a row.
Attachment 9065

So the next thing is to isolate the wire feeding that plug and make sure it's firing. It almost looks like there is send/return for each coil. So each coil must be individually fused. At least that's what I found on my boat. Did you check your fuses? So it must go from the fuse to the computer, and then to the coil pack. So at each stage there must be way of checking the wires.

Quote:

---

Originally Posted by xintersecty

Wow your right. That sucks. Either you buy four plug testers or you had two bad coil packs in a row.
Attachment 9065

So the next thing is to isolate the wire feeding that plug and make sure it's firing. It almost looks like there is send/return for each coil. So each coil must be individually fused. At least that's what I found on my boat. Did you check your fuses? So it must go from the fuse to the computer, and then to the coil pack. So at each stage there must be way of checking the wires.

---

I haven't fully understood why this is happening yet. I installed another known good, used coil pack from a reputable used auto part warehouse. Problem solved. At least for now. For what it's worth, this replacement has black grounding sleeves as opposed to the "regular" shiny metal sleeves.

I now have 2 coil packs that I can use as guinea pigs for testing. Looking at the connectors on the coil pack, there are 7 pins. IDK what each one's use is for, but I will find out. For now though, I have some epoxy to remove to get to those circuit boards.

Well 4 out of seven are the circuits to signal the coil. I am willing to bet that there is 4 signal and 3 ground. The grounds are all common. It takes a lot of energy to charge a coil. See the wiki on construction and modern cars: Ignition coil - Wikipedia, the free encyclopedia

Quote:

---

Originally Posted by xintersecty

Well 4 out of seven are the circuits to signal the coil. I am willing to bet that there is 4 signal and 3 ground. The grounds are all common. It takes a lot of energy to charge a coil. See the wiki on construction and modern cars: Ignition coil - Wikipedia, the free encyclopedia

---

perhaps I can be of assistance; this is the 2010-2011 Wiring Diagram for the Coil Pack and the VVT Actuators.

http://i112.photobucket.com/albums/n...psaj4hq4mz.jpg

Quote:

---

Originally Posted by 2010AveoLT

perhaps I can be of assistance; this is the 2010-2011 Wiring Diagram for the Coil Pack and the VVT Actuators.

---

Thanks for posting the picture

Wow I learned a thing or two. I spent a good morning scratching my head over this schematic and try to figure out why there is a chassis ground vs. earth ground.
Attachment 9066

Then it hit me: Radio Shielding! So the yellow wire going in is earth ground. Notice that all the coils are connect to the earth ground. This is the same ground as the negative terminal in the battery. So the energy is flowing from ground into the coils and towards the potential (signal). Now see the dotted loop around the signal wires (chassis ground). This forms an EMF shield from the high energy being created on the spark side. I am willing to bet that the chassis ground goes through an RC circuit to filter out the spark plug noise.