# Burning up ignition coils



## Shelby30 (Oct 4, 2020)

I am having the exact same problem with my daughters car burnt up 3 coils if you find out what is going on with yours could you please give info Thanks


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## TetraHC (May 13, 2020)

Had anyone had any luck? I’m having the same issue. Thanks
Tommy


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## blueblurr_2v (Oct 11, 2020)

Did you ever fix this problem?


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## Shelby30 (Oct 4, 2020)

Nope We put a new ECM on my Daughters car had it flashed and its still burning up coils


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## ChuckDaniels (Sep 30, 2020)

hello all,
Sorry i have been absent, Life gets in the way. So through my troubleshooting i have found that the number one coil driver wire and the number one injector driver wire had a resistance of about 50 M ohms. That is with the three ECM connectors unplugged as well as the coil and the four injectors. The driver wires are in no way connected and there for should be an open circuit when checking resistance between them. So the the amp draw and/or the short in the coil caused the ECM plug to be compromised. The No. one coil driver is pin one and the No. one inj. wire is pin two. It seems when the coil went out it also got hot enough to smoke the ECM plug and or the driver in the ECM. My local chevy dealer was too expensive and could not get a new engine harness at this time, so i went to a local pick your part junk yard and was able to acquire just the ECM plug that was bad. I spiced in the new/used plug and so far so good. So, the long and short of it is.. I replaced the ECM connector that housed the coil driver wires. And a word to the wise, Buy ACDelco. Through all of this Ive learned something about this car just does not like after market parts. I hope this helps someone. Please let me know what you find out on yours.
Thanks,
Chuck Daniels


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## Shelby30 (Oct 4, 2020)

Update on my daughters car after recommendation we checked the thermostat sensor plug it had antifreeze in it so we replace the Complete thermostat housing And sensor And a new coil on it fired it up and let it sit and run for 45 minutes with no problems thought we had it fixed when We went to test drive it ,it quit and blow the number nine fuse it didn’t burn the coil this time but it continue to blow the #9 fuse every time we replace it 
its been in the shop for 5 days now and still doing the same thing


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## ChuckDaniels (Sep 30, 2020)

The thermostat sensor is in no way connected to the coil circuit. The number nine fuse is for injectors one and three according to the diagram. But all four injectors share the same power supply and it happens to be the power supply to the coil. If your blowing the fuse and were burning up the coil you probably have a short in the wiring harness itself. After burning up multiple coils myself I found the injector and coil driver wires shorted within the ECM plug on the harness


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## Xxviper06xX (Nov 21, 2020)

ChuckDaniels said:


> The thermostat sensor is in no way connected to the coil circuit. The number nine fuse is for injectors one and three according to the diagram. But all four injectors share the same power supply and it happens to be the power supply to the coil. If your blowing the fuse and were burning up the coil you probably have a short in the wiring harness itself. After burning up multiple coils myself I found the injector and coil driver wires shorted within the ECM plug on the harness


This was exactly my same issue.


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## Xxviper06xX (Nov 21, 2020)

Had the same issue, as ChuckDaniels says it ended up being a short in the ECM plug between the coil 1 and the injector 1 wires. Its was a simple fix. Don't even have to buy a new harness or plug. The plug comes apart very easily. Simply remove the top of the plug then you can remove the piece of the plug that the pins slide into to expose the wire slots. They pull out easily from the back. Clean any corrosion on the wire ends and within the plug and apply a thin layer of dielectric grease to the outside of the wire slots, push back in and reassemble the plug.


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## Xxviper06xX (Nov 21, 2020)

blueblurr_2v said:


> Did you ever fix this problem?


If you haven't gotten it fixed check the last few posts.


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## Xxviper06xX (Nov 21, 2020)

Shelby30 said:


> Nope We put a new ECM on my Daughters car had it flashed and its still burning up coils


Check last few posts I think we have this problem solved


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## Shelby30 (Oct 4, 2020)

Xxviper06xX said:


> Check last few posts I think we have this problem solved


Thank you so much my daughters car has been in the shop for over 2 months and they still haven’t figured out what’s wrong with it my husband is gonna try what you said was wrong


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## Xxviper06xX (Nov 21, 2020)

Shelby30 said:


> Thank you so much my daughters car has been in the shop for over 2 months and they still haven’t figured out what’s wrong with it going tomorrow to pick it up and my husband is gonna try what you said was wrong


Let us know how it goes!


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## Mudjeeper (Nov 23, 2020)

Xxviper06xX said:


> Had the same issue, as ChuckDaniels says it ended up being a short in the ECM plug between the coil 1 and the injector 1 wires. Its was a simple fix. Don't even have to buy a new harness or plug. The plug comes apart very easily. Simply remove the top of the plug then you can remove the piece of the plug that the pins slide into to expose the wire slots. They pull out easily from the back. Clean any corrosion on the wire ends and within the plug and apply a thin layer of dielectric grease to the outside of the wire slots, push back in and reassemble the plug.


My son's 2014 1.4T is doing the exact same thing..burning coils at#1 like crazy..thanks for the info.I'll give that a try tomorrow.
Mike


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## Shelby30 (Oct 4, 2020)

Xxviper06xX said:


> Had the same issue, as ChuckDaniels says it ended up being a short in the ECM plug between the coil 1 and the injector 1 wires. Its was a simple fix. Don't even have to buy a new harness or plug. The plug comes apart very easily. Simply remove the top of the plug then you can remove the piece of the plug that the pins slide into to expose the wire slots. They pull out easily from the back. Clean any corrosion on the wire ends and within the plug and apply a thin layer of dielectric grease to the outside of the wire slots, push back in and reassemble the plug.


Thank you all so much that was exactly what was wrong with my daughters


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## Blasirl (Mar 31, 2015)

ChuckDaniels said:


> Hello all,
> My car started running poorly with the check engine light flashing. The codes P0301 (cylinder 1 misfire), P2301 (Ign. coil A primary control circuit high), P0351 (ign. coil A primary/secondary circuit). I replaced the coil and the spark plugs The car ran perfectly fine for two days and then it happened again, with the same codes. I then exchanged the coil and the car ran fine everyday for about one week and then the same codes again and running poorly, but this time the coil completely burnt out the side smoking pretty good at cylinder one. I'm sure something is causing my coils to short out. I physically hand traced the wires from the ignition coil to the ECM, ground and fuse panel. The wires are in good condition with no breaks, melting or chaffing. I also checked the resistance from end to end unplugged on each of the wires and had low resistance on each one. The pins on both ends of the harness are free of corrosion. The one thing I have noticed is that when the key is on and the engine not running, coils 2, 3, and 4 all have 10mV coming from the ECM, coil number 1 has 58mV. That is with coil disconnected. The power wire is good. The ground is good, and the low reference ground is good. Is this a clear indication that the ECM is to blame for frying the coil? Does anyone know of any other checks I can perform to verify if the ECM is to blame? Has anybody encountered anything similar? Intermittent electrical are issues always difficult. Thank you in advance for any input, advice and wisdom.
> Year. 2016 ( Date of manufacture 06/2015)
> Engine. 1.4 Turbo EcoTec ( LDV/Tier2)
> ...


So did the fix listed above by Xxviper06xX in post #10 work for you? Has this been solved?


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## Mike Tripp (Dec 21, 2020)

The thermostat control power supply is tied into the circuit with the coil and fuel injectors. Look at a wiring diagram if you can get your hands on one. IF YOU HAVE COOLANT IN THE THERMOSTAT CONTROL CONNECTOR THAT IS THE ROOT CAUSE. Aftermarket thermostat housings cause corrosion at ECM...


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## mcandrew72 (May 22, 2017)

Here comes this issue again. I really thought this ECM wiring harness would be my issue. First the car started running rough and mis-firing. I changed the coil pack with new AC Delco pack. It fixed it for probably about 6 months. To be fair it was not driven everyday. Then about July 1st my wife had to drive it everyday to work. Ran fine the entire month of July. Then literally the day after my wife got her car back we started it and the coil pack melted in that 1st location as everyone else's. I thought.. oh.. bad pack. I went to GM and they warranty exchanged it. To be safe I put all new AC Delco plugs in it. Started the car and literally within 1min the new coil pack started smoking and melted in the same place. I found this discussion and thought it would be the issue. I pulled the ECM harness and I have zero continuity between pin 1 and 2... as well as zero from pin 2 to the coil one wire at the coil plug. I get good continuity at from pin one to the coil plug.

I am at a loss. I assume I can not drive it or it might literally catch fire or damage the engine since it is not firing one cylinder. The GM dealer is about 7 miles away so I guess I will have it towed to them in the morning.

Anyone on here have any updates on this issue? Are there any other known causes?


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## TheRealHip (Sep 1, 2014)

The leading cause of premature failure of an ignition coil is due to a worn or bad spark plug ignition cable.


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## Blasirl (Mar 31, 2015)

TheRealHip said:


> The leading cause of premature failure of an ignition coil is due to a worn or bad spark plug ignition cable.


There are no coil wires on a COP system.


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## Blasirl (Mar 31, 2015)

mcandrew72 said:


> Here comes this issue again. I really thought this ECM wiring harness would be my issue. First the car started running rough and mis-firing. I changed the coil pack with new AC Delco pack. It fixed it for probably about 6 months. To be fair it was not driven everyday. Then about July 1st my wife had to drive it everyday to work. Ran fine the entire month of July. Then literally the day after my wife got her car back we started it and the coil pack melted in that 1st location as everyone else's. I thought.. oh.. bad pack. I went to GM and they warranty exchanged it. To be safe I put all new AC Delco plugs in it. Started the car and literally within 1min the new coil pack started smoking and melted in the same place. I found this discussion and thought it would be the issue. I pulled the ECM harness and I have zero continuity between pin 1 and 2... as well as zero from pin 2 to the coil one wire at the coil plug. I get good continuity at from pin one to the coil plug.
> 
> I am at a loss. I assume I can not drive it or it might literally catch fire or damage the engine since it is not firing one cylinder. The GM dealer is about 7 miles away so I guess I will have it towed to them in the morning.
> 
> Anyone on here have any updates on this issue? Are there any other known causes?


#16-NA-015: Engine Stall or Stumble - Replace Coil Connector - (Jan 21, 2016)

https://static.nhtsa.gov/odi/tsbs/2016/MC-10112283-9999.pdf









Standard Motor Products S1380 Standard Pigtails & Socke


Standard Motor Products S1380 Standard Pigtails & Socke




autoplicity.com





Pull the ECM connector and look for corrosion. If you have any read this:
Burning up Coil pack

or

Pull off the spark plugs boot and inspect the spring. It should have a resistor pellet integrated into. Measure the resistance of the spring from one end, to the end of the resistor pellet(looks like a tiny fuse or capsule usually). You should have somewhere between 800-1200ohms resistance. If you just have a plain spring, or if the resistance is below 800 or so, that's why you're blowing out coils. (Courtesy of Ma v e n)


And lastly:






https://static.nhtsa.gov/odi/tsbs/2016/MC-10112283-9999.pdf

Tips to ensure no misfires occur:

Remove the coil pack. If the boots are stuck on, use a small screwdriver or pick with some dielectric grease on it to go around the outside of the boot and then possibly the inside of the boot to help aid in removal.

Remember to (p)re-gap your plugs to .028, (0.24 if tuned)

*Set gap with the black portion of this tool.*










To increase the gap size bend the ground strap up to the desired height. DO NOT LET THE GAPPING TOOL TOUCH THE *IRIDIUM* CENTER ELECTRODE OR PORCELAIN.

*Measure the gap with feeler gauges.*










*Throw this away.*












Torque to 18 ft-lbs with no anti-seize on the threads of a stock type plug.

Ensure the boots have no rips/tears or holes in them, lightly coat them with dielectric/silicone grease and make sure the resister springs are clean and not caught up in the boots when you install them.

If the plugs look bad, consider these:

*-BKR8EIX-2668* (iridium plugs), ~$25, expect ~10-15k regaps on these, ~40-50k overall life.
*-BKR7E-4644* (nickel/copper plugs), ~$8, expect 15-25K out of these plugs, with a regap or two required at 5-8k intervals on stock tune.

Read _Hesitation Gone!_ for more info on the plugs.






A good replacement coil is the MSD Blaster OEM Replacement Coilpack 8236

How-To: Remove and Replace the Coil Pack and Spark Plugs.

While you are in there, if you have a cheap endoscope, look at the pistons. This can also tell you many things.


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## Naulty (10 mo ago)

Xxviper06xX said:


> Had the same issue, as ChuckDaniels says it ended up being a short in the ECM plug between the coil 1 and the injector 1 wires. Its was a simple fix. Don't even have to buy a new harness or plug. The plug comes apart very easily. Simply remove the top of the plug then you can remove the piece of the plug that the pins slide into to expose the wire slots. They pull out easily from the back. Clean any corrosion on the wire ends and within the plug and apply a thin layer of dielectric grease to the outside of the wire slots, push back in and reassemble the plug.


What plug are you talking about exactly? there are 3 plugs on the ECM and I cannot seem to find a proper wiring diagram to trace these wires out. do you have any pictures of this process? from what I could see I tried to remove the top of the injector plug but ended up pulling the wires right out. I am not used to GMs method of unpinning and pinning plugs.


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## Mudjeeper (Nov 23, 2020)

Naulty said:


> What plug are you talking about exactly? there are 3 plugs on the ECM and I cannot seem to find a proper wiring diagram to trace these wires out. do you have any pictures of this process? from what I could see I tried to remove the top of the injector plug but ended up pulling the wires right out. I am not used to GMs method of unpinning and pinning plugs.


It's the middle plug connector on the ecm.. once you pull it the



Mudjeeper said:


> It's the middle plug connector on the ecm.. once you pull it the


pin cover pops off the connector.. then just look for corrosion


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## Naulty (10 mo ago)

Yes, I understand the ECM plastic covers. I'm wondering if he was referring to de-pinning the plugs to clean corrosion. I removed the covers and sprayed electronic cleaner didn't see any discoloring or corrosion before spraying. I'm stuck either chasing down a problem that doesn't exist, or putting in a new coil and it burning up again. Mine is cracked on cylinder 1, and sent a cloud of smoke after replacing fuse #9. I would hate to put in a new coil and waste $100+ without fixing a root cause, or at least ruling out a short in the wiring to be a problem. I'm trying to find a factory service manual or a wiring diagram but have had no luck, I'm left to removing the entire loom and hand tracing every wire.


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## Laith Cruze15LS (10 mo ago)

I have the same problem and the same codes 

My car started shaking and I had to replace the coil pack and the spark plugs. Then drove for two weeks nice and smooth, but suddenly again shaking. This time I put Delphi coil pack and took for a drive but the something, shaking and stopped.
Something I noticed, both coil packs got the burn on the left side as in the photo below. I do not know what else I should do? should I replace it again? should I replace the thermostat housing sensor? What are the ohm reads on the connector, please?
Auto clinics like GM dealer, Belle Tires, Midas in Michigan cost so much $labor$ and without warranty.
My car is Chevy Cruze 2015 LS


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## Laith Cruze15LS (10 mo ago)

I have an update.. 3/24/2022 4pm
I replaced the Coil pack connector and coil pack. BUT THE SAME THING 
I gave up and went to Midas, Canton MI, then they replaced the thermostat housing W sensor (TA2003DL) and throt body htr asm pipe (25192905) they charged me for only these two parts $411! .BUT, It is worth it,  and No shaking and no burn.

Another update: 3/25/2022 6 am
I have check engine


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## AutumnCruzeRS (Sep 10, 2012)

Get a free code reading from your local AutoZone parts store. Let us know the code they pull. Could be unrelated to latest issue you had


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## Naulty (10 mo ago)

I have my own scanner. didn't get a chance to read the codes before I tore into it. I decided to get new AC Delco Iridium spark plugs yesterday and threw those in with the proper .028 gap. after looking over the wiring some more, I found everything to be within spec. Threw the new Delphi coil pack in and prayed that it didn't pop. for good measure I pulled the coolant heater plug just to be safe. It fired right up! I'm leaning towards the coil pack which was black in color with no markings was an aftermarket one and the car didn't like that.


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## Naulty (10 mo ago)

Laith Cruze15LS said:


> I have the same problem and the same codes
> 
> My car started shaking and I had to replace the coil pack and the spark plugs. Then drove for two weeks nice and smooth, but suddenly again shaking. This time I put Delphi coil pack and took for a drive but the something, shaking and stopped.
> Something I noticed, both coil packs got the burn on the left side as in the photo below. I do not know what else I should do? should I replace it again? should I replace the thermostat housing sensor? What are the ohm reads on the connector, please?
> ...



If you plan to use an OHM meter to take these readings make sure either of the batter posts are disconnected, you do not want to put power to a meter while reading OHMs these tests are performed with NO POWER. remove your key and disconnect your negative battery terminal. The same would apply to a continuity test there should be NO POWER when performing either of these tests, you will burn up your meter and you will have a bad time diagnosing the problem.

I tore into the 2nd ECM (K20) connector from the top is where all the wiring goes from the 7 pin connector. After tracing out my wiring harness I didn't find any breaks in my wiring and it all looked to be in good shape. I do not know the exact pin out numbers on the ECM connector (K20). After de-capping this harness plug at the ECM the black holding plate on top should come off relatively easily with light pressure from the corners or ends with a pick or fine screwdriver. This will expose the pins and give easier access to test these wires, careful to not put lots of pressure on the wires otherwise they will touch together and give you false readings.

All of my wiring was rung (continuity check) end to end to determine that they were in fact the proper wires, also I checked the 7 pins in the coil pack connector (K35) against ground and power. The 7 pin connector holding it with the tab above or upright is read RIGHT to LEFT pins A-B-C-D-E-F-G.











Pin A - (Red with blue stripe) is 12v power this wire should ring out to the red and blues in the ECM (K20) connector but not to ground. or Fuses 8 & 9 if this wire rings to ground there is a short in the power wires.

Pin B - (Black) is ground which goes straight to the engine block via a ring terminal right below the you can ring this to the battery negative terminal and should not ring to power pin A if you're getting a connection or ring between A and B there's a short between these two wires somewhere in the loom or in either connector. From what i've read most shorts occur in the (K20) connector

Pin C - is low reference ground which goes back to the ECM. this should read to ground but not power.

Pins D-E-F-G are all control TTL logic wires which carry 5v from the ECM to the coil to tell it when to fire a specific cylinder (1-2-3-4). these should NOT ring to Ground or Power. (pins A-B-C) or the battery (-) (+) posts. if these are ringing to power then there is 12v on a 5v circuit causing the short. the engine will still run but it will run poorly because of the constant 12v signal instead of a 5v control signal. If they're ringing to ground there's no signal going to the coil, path of least resistance. 

For me I traced these 4 wires (D-E-F-G) back through the loom to the 2nd ECM connector. These are control wires and are directly connected to the ECM. I found there to be around 0.2 OHMs on all 4 of these wires

All of these were tested from the 7-pin connector (K35) and these were my readings.

A - back to the ECM connector 0.3OHMs (did not ring to ground)
B - engine block ring terminal 0.1OHMs (did not ring to power)
C - Negative battery connection 0.4OHMs (did not ring to power)
D - back to the ECM connector 0.2OHMs (did not ring to either power or ground)
E - back to the ECM connector 0.2OHMs (did not ring to either power or ground)
F - back to the ECM connector 0.2OHMs (did not ring to either power or ground)
G - back to the ECM connector 0.2OHMs (did not ring to either power or ground)


I also found another test procedure from another forum post this can be helpful to determine what's going on so ill post it again. It refers to two connectors (K35) and (K20) I noted those in my post above to help clear confusion.










I hope some of this can help you.


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## Laith Cruze15LS (10 mo ago)

New update: 3/25/2022 12 pm, I got P0411 Secondary Air Injection system > Incorrect Flow Detected. 
Then I checked the Air pump, works fine.
I do not know what else causing this code, 
Could be the check valve or the fuse?


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## Laith Cruze15LS (10 mo ago)

New update 3/25/2022 6pm . I drove back to Midas (around 10 miles) and scan it again.
I got these:

P0351
P0411
P0411
P0420
P2301
Looks like I have a short in somewhere and going to burn my coil pack again


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## Naulty (10 mo ago)

possibly the coolant heater connection on the driver side right below the intake pipe there's a electrical connector pointing straight up. Also check out your injector wiring they share the same power supply.


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## Laith Cruze15LS (10 mo ago)

New update: 3/26/2022 morning, I don't trust Midas anymore. 
I have to check where is the short.
I watched YouTube in the posted above. And understood everything. 
I unplugged all three ecm connectors and coil pack and coil pack connector just like above YouTube, and I followed pin D, Blue/violet, to the middle ECM connector. I successfully pulled this pin, blue/violet (pin 1) from the middle ecm connector and also pulled pin 2 of the ecm middle connector and SAW some green corrosion, so I thought this is short. So I cleaned out the corrosion by dioxide spray g5 and I test them together.. but still seeing a short (200 k ohm).
Here are some pictures


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## Laith Cruze15LS (10 mo ago)

New update evening: Is pin1 and 2 of K20 connector, supposed to be shorted or not?
If not, where is the short then?
I saw the diagram that the pin1 goes to pin D coil pack connector. And pin2 goes to fuel injector wire control circuit 1.
So why they are shorted? And from where?


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## Naulty (10 mo ago)

It might be somewhere in the loom. That 7 pin connector is not stock and has been changed. You can tell from the splices and the white wiring coming off of it. I'd peel back more tape and pull off the corrugated wire protection and check further into the harness to see if there's any frayed wires.


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## Laith Cruze15LS (10 mo ago)

Naulty said:


> If you plan to use an OHM meter to take these readings make sure either of the batter posts are disconnected, you do not want to put power to a meter while reading OHMs these tests are performed with NO POWER. remove your key and disconnect your negative battery terminal. The same would apply to a continuity test there should be NO POWER when performing either of these tests, you will burn up your meter and you will have a bad time diagnosing the problem.
> 
> I tore into the 2nd ECM (K20) connector from the top is where all the wiring goes from the 7 pin connector. After tracing out my wiring harness I didn't find any breaks in my wiring and it all looked to be in good shape. I do not know the exact pin out numbers on the ECM connector (K20). After de-capping this harness plug at the ECM the black holding plate on top should come off relatively easily with light pressure from the corners or ends with a pick or fine screwdriver. This will expose the pins and give easier access to test these wires, careful to not put lots of pressure on the wires otherwise they will touch together and give you false readings.
> 
> ...


Thank you, I really needed these readings. I have to continue tomorrow morning.
By the way, I did this test today:

Unplugged all the connectors (the 3 ECM connectors, and the coil-pack connector) and the coil-pack.
Read between pin1 (Ign coil1) & pin2( fuel injector wire circuit 1) on K20 for continuty and found it is 200 kohm.
I pulled these two pins out from the K20, confirmed not teaching, but still reading the 200 kohm.
Do not you think it must be no connection between these two pins of K20? 
Appreciate the answer.


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## Naulty (10 mo ago)

The 12v power (pin A on the 7 pin connector) is apart of the fuel injector circuit it's connected by a red wire with a blue stripe. If you open the harness up, a bigger gauge wire goes from the K20 connector to a factory splice. This splice has multiple 16-gauge wires off of it which feeds power to each injector and other devices. I didn't trace them all so I don't know exactly what it all feeds.


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## Laith Cruze15LS (10 mo ago)

Naulty said:


> The 12v power (pin A on the 7 pin connector) is apart of the fuel injector circuit it's connected by a red wire with a blue stripe. If you open the harness up, a bigger gauge wire goes from the K20 connector to a factory splice. This splice has multiple 16-gauge wires off of it which feeds power to each injector and other devices. I didn't trace them all so I don't know exactly what it all feeds.


Thank you for the reply. I have to order Caig Deoxit Gold G5 from Amazon. pray it to the connectors to eliminate the corrosion. Did you do that?


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## Naulty (10 mo ago)

No I bought CRC electrical component cleaner from my local parts store 









Amazon.com: CRC 05103 QD Electronic Cleaner -11 Wt Oz : Health & Household


Buy CRC 05103 QD Electronic Cleaner -11 Wt Oz: All-Purpose Cleaners - Amazon.com ✓ FREE DELIVERY possible on eligible purchases



www.amazon.com


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## Blasirl (Mar 31, 2015)

This could be due to a bad coil ground

coil ground


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## Laith Cruze15LS (10 mo ago)

New update: 3/27/2022
problem fixed! 
The corrosion between pin1 (5volt) & pin2 (12volt) was causing a short on the K20 connector. I used Deoxit Gold G5 Contact Cleaner and Deoxidizer to spray it to the connector. 
Plug everything back.
Run it for a few miles...

3/28/2022:
I got another check engine  
This time is P0420
I have to read this to know better.








Code P0420 Causes


My 2014 Cruze with 1.4 is running fine but we had an engine light and there’s a P0420 code. Hesitate to mess with plugs given the trouble people have with plug boots tearing. Is there a way to figure out if it’s the plugs, 02 sensors, or ??? I am going to replace the air filter. I disconnected...




www.cruzetalk.com


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## Naulty (10 mo ago)

I'd first check the wiring on the O2 sensor plug make sure it is free of debris and corrosion. Not sure what engine you have but the 1.4L Turbo it's right in between the 7-pin connector and the MAP on the intake. 

Next you could test your O2 sensor to make sure it's not burnt up or out of spec. 

After that, you'd have to remove your exhaust to inspect the honeycomb on the catalytic converter. Just to be sure it isn't blown out or has a hole in it. Can bring it to an exhaust shop and they can do it fairly quick and cheap after ruling out the circuitry.


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## Laith Cruze15LS (10 mo ago)

New update: 
Thank you Naulty for the clarification.
3/29/2022. Relaxing from the crazy shorts that I had.  
But I have to fix this P0420 problem. 
I have to check as Naulty said. 
1- O2 sensors 1 and 2 
2- Catalytic converter.

But I do not have a jack  

I am looking to purchase the parts first and then find an exhaust shop close by to replace them.


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## Laith Cruze15LS (10 mo ago)

New update:
4/12/2022

I replaced both O2 sensors, upstream 55572215 & downstream 55572216. Drove 10 miles.. Check the engine again. Code P0420 again 
I plugged the engine scanner and read how much the value of these sensors:
Sensor upstream readings < sensor downstream readings  
(Sensor1 = between 0.134 to 0.712
Sensor2 = between 0.234 to 0.971)
I don't know why sensor1 (upstream) is lower than sensor2 (downstream) :/
I don't know what else I can think, it could be sensot2 is shorted with another wire :/ I can to see the diagram of the car.

Another test I did is:
I unplugged both sensors, I got a 1.27 value reading on the engine scanner, which I believe it is the default value of GM cruze. From that, I know my sensors are good.


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## metz1076 (10 mo ago)

ChuckDaniels said:


> hello all,
> Sorry i have been absent, Life gets in the way. So through my troubleshooting i have found that the number one coil driver wire and the number one injector driver wire had a resistance of about 50 M ohms. That is with the three ECM connectors unplugged as well as the coil and the four injectors. The driver wires are in no way connected and there for should be an open circuit when checking resistance between them. So the the amp draw and/or the short in the coil caused the ECM plug to be compromised. The No. one coil driver is pin one and the No. one inj. wire is pin two. It seems when the coil went out it also got hot enough to smoke the ECM plug and or the driver in the ECM. My local chevy dealer was too expensive and could not get a new engine harness at this time, so i went to a local pick your part junk yard and was able to acquire just the ECM plug that was bad. I spiced in the new/used plug and so far so good. So, the long and short of it is.. I replaced the ECM connector that housed the coil driver wires. And a word to the wise, Buy ACDelco. Through all of this Ive learned something about this car just does not like after market parts. I hope this helps someone. Please let me know what you find out on yours.
> Thanks,
> Chuck Daniels


coolant traveling up thru wire causing corrosion on inside of of connector at ecm is what i have been reading.what plug is it i am currently chasing the short.Also recall on negative battery cable.


ChuckDaniels said:


> Hello all,
> My car started running poorly with the check engine light flashing. The codes P0301 (cylinder 1 misfire), P2301 (Ign. coil A primary control circuit high), P0351 (ign. coil A primary/secondary circuit). I replaced the coil and the spark plugs The car ran perfectly fine for two days and then it happened again, with the same codes. I then exchanged the coil and the car ran fine everyday for about one week and then the same codes again and running poorly, but this time the coil completely burnt out the side smoking pretty good at cylinder one. I'm sure something is causing my coils to short out. I physically hand traced the wires from the ignition coil to the ECM, ground and fuse panel. The wires are in good condition with no breaks, melting or chaffing. I also checked the resistance from end to end unplugged on each of the wires and had low resistance on each one. The pins on both ends of the harness are free of corrosion. The one thing I have noticed is that when the key is on and the engine not running, coils 2, 3, and 4 all have 10mV coming from the ECM, coil number 1 has 58mV. That is with coil disconnected. The power wire is good. The ground is good, and the low reference ground is good. Is this a clear indication that the ECM is to blame for frying the coil? Does anyone know of any other checks I can perform to verify if the ECM is to blame? Has anybody encountered anything similar? Intermittent electrical are issues always difficult. Thank you in advance for any input, advice and wisdom.
> Year. 2016 ( Date of manufacture 06/2015)
> Engine. 1.4 Turbo EcoTec ( LDV/Tier2)
> ...





Shelby30 said:


> Thank you all so much that was exactly what was wrong with my daughters
> [/QUO


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## Laith Cruze15LS (10 mo ago)

New update:
5/12/2022
I replaced the Catalyic Converter and measrued the temperture.


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## Laith Cruze15LS (10 mo ago)

Then I reset the P0420 code and drove the car for 30 miles. So far, no check engine


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## Laith Cruze15LS (10 mo ago)

Just a recap what I have done from day 1 up to now:
1- Coil pack replaced
2- Spark plug replaced
3- Corrion was in causing a short in K20 ECM connector between +5 V and +12 V and was causing me burning the coil pack.
4- Coil-pack connector replaced.
5- Thermostate also was replaced.
6- Then finally, I replaced the O2 sensors (upstream and downstream) and replaced the Catalyic Convertor.
total time: from Feb 2022 - May 2022

MAN! Chevy Cruze is a nightmare!!!!


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## Laith Cruze15LS (10 mo ago)

New update:
5/17/2022
I got the check engine again P0420. I can't believe that! I am sooooo pissed off


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## metz1076 (10 mo ago)

Xxviper06xX said:


> Had the same issue, as ChuckDaniels says it ended up being a short in the ECM plug between the coil 1 and the injector 1 wires. Its was a simple fix. Don't even have to buy a new harness or plug. The plug comes apart very easily. Simply remove the top of the plug then you can remove the piece of the plug that the pins slide into to expose the wire slots. They pull out easily from the back. Clean any corrosion on the wire ends and within the plug and apply a thin layer of dielectric grease to the outside of the wire slots, push back in and reassemble the plug.


Is it the second connector to the ecm? How did you take the cover that comes off of connectors to clean plug connectors to ecm?


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## metz1076 (10 mo ago)

Mudjeeper said:


> It's the middle plug connector on the ecm.. once you pull it the
> 
> 
> pin cover pops off the connector.. then just look for corrosion


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## Laith Cruze15LS (10 mo ago)

I already did that, I sprayed by the dielectric grease, which is I believe this one:








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Then waited to get dry. Then plug the battery back, then ran the car around 30 miles then I GOT the P0420 back again.
😔
I do not know what else I suppose to do? 
Do you think there is a short on the O2 sensor downstream or upstream wire harness circuit? If so, do you have the wiring diagram so I can check the continuity between all the O2 sensors pins to the all ECM? 
Please advise.


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