HELP. Cylinder 3 not firing!!
HELP. Cylinder 3 not firing!!
Cylinder 3 not firing.
supposedly all wiring checks out.
thought it was the ecm, had the ecm opened to get rebuilt (thought the terminal that fires cylinder 3 was fried) WAS NOT THE CASE. Ecm is fine.
Cylinder 3 coil pack doesn’t ignite.
Power & ground to the coil pack is good - no pulse power,
before sending in the ecm, spark plugs & coil packs were changed. Didn’t make a difference in the issue.
WHAT COULD IT BE?
please any advice/info is appreciated my g has been down for over a week I just want to drive her again.
thanks!!
supposedly all wiring checks out.
thought it was the ecm, had the ecm opened to get rebuilt (thought the terminal that fires cylinder 3 was fried) WAS NOT THE CASE. Ecm is fine.
Cylinder 3 coil pack doesn’t ignite.
Power & ground to the coil pack is good - no pulse power,
before sending in the ecm, spark plugs & coil packs were changed. Didn’t make a difference in the issue.
WHAT COULD IT BE?
please any advice/info is appreciated my g has been down for over a week I just want to drive her again.
thanks!!
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From: Washington State
Coupe 6MT Premium RAS
The ECM doesn't pulse power to the coil, it pulses the GROUND.
First thing to do is visibly watch for spark, take out the spark plug, put it back into the coil pack, hold the ground strap about 1/4" away from the aluminum intake manifold with a LEATHER GLOVED HAND holding onto the coil pack (or you'll zap yourself silly). Then have someone else crank the engine while you watch for spark.
If no spark then take the entire coil pack/spark plug assembly from another cylinder, plug it into cyl3, and do that same test, then take the cyl3 stuff, plug it into the other cylinder and verify that everything is actually sparking. This way you rule out the coil pack and spark plug as being potentially bad.
If you still don't have spark then it's either a wiring or ECM issue, ring out the coil pack harness wires.
Pin 1 is the blue/red stripe wire and it goes to pin 61 on the ECM.
Pin 2 is a black wire and should have continuity to ground.
Pin 3 is white/blue stripe and should have 12v
If the spark plug does work when plugged in to cyl 3 while doing the visual spark test then it's most likely a fuel injector.
If the spark plug does NOT work while plugged in to cyl 3, but WILL work in other cylinders, and the wiring all rings out, then it's probably a failed ECM.
A failed ECM is very unlikely, far more likely it's either a bad injector or bad wiring.
First thing to do is visibly watch for spark, take out the spark plug, put it back into the coil pack, hold the ground strap about 1/4" away from the aluminum intake manifold with a LEATHER GLOVED HAND holding onto the coil pack (or you'll zap yourself silly). Then have someone else crank the engine while you watch for spark.
If no spark then take the entire coil pack/spark plug assembly from another cylinder, plug it into cyl3, and do that same test, then take the cyl3 stuff, plug it into the other cylinder and verify that everything is actually sparking. This way you rule out the coil pack and spark plug as being potentially bad.
If you still don't have spark then it's either a wiring or ECM issue, ring out the coil pack harness wires.
Pin 1 is the blue/red stripe wire and it goes to pin 61 on the ECM.
Pin 2 is a black wire and should have continuity to ground.
Pin 3 is white/blue stripe and should have 12v
If the spark plug does work when plugged in to cyl 3 while doing the visual spark test then it's most likely a fuel injector.
If the spark plug does NOT work while plugged in to cyl 3, but WILL work in other cylinders, and the wiring all rings out, then it's probably a failed ECM.
A failed ECM is very unlikely, far more likely it's either a bad injector or bad wiring.
The ECM doesn't pulse power to the coil, it pulses the GROUND.
First thing to do is visibly watch for spark, take out the spark plug, put it back into the coil pack, hold the ground strap about 1/4" away from the aluminum intake manifold with a LEATHER GLOVED HAND holding onto the coil pack (or you'll zap yourself silly). Then have someone else crank the engine while you watch for spark.
If no spark then take the entire coil pack/spark plug assembly from another cylinder, plug it into cyl3, and do that same test, then take the cyl3 stuff, plug it into the other cylinder and verify that everything is actually sparking. This way you rule out the coil pack and spark plug as being potentially bad.
If you still don't have spark then it's either a wiring or ECM issue, ring out the coil pack harness wires.
Pin 1 is the blue/red stripe wire and it goes to pin 61 on the ECM.
Pin 2 is a black wire and should have continuity to ground.
Pin 3 is white/blue stripe and should have 12v
If the spark plug does work when plugged in to cyl 3 while doing the visual spark test then it's most likely a fuel injector.
If the spark plug does NOT work while plugged in to cyl 3, but WILL work in other cylinders, and the wiring all rings out, then it's probably a failed ECM.
A failed ECM is very unlikely, far more likely it's either a bad injector or bad wiring.
First thing to do is visibly watch for spark, take out the spark plug, put it back into the coil pack, hold the ground strap about 1/4" away from the aluminum intake manifold with a LEATHER GLOVED HAND holding onto the coil pack (or you'll zap yourself silly). Then have someone else crank the engine while you watch for spark.
If no spark then take the entire coil pack/spark plug assembly from another cylinder, plug it into cyl3, and do that same test, then take the cyl3 stuff, plug it into the other cylinder and verify that everything is actually sparking. This way you rule out the coil pack and spark plug as being potentially bad.
If you still don't have spark then it's either a wiring or ECM issue, ring out the coil pack harness wires.
Pin 1 is the blue/red stripe wire and it goes to pin 61 on the ECM.
Pin 2 is a black wire and should have continuity to ground.
Pin 3 is white/blue stripe and should have 12v
If the spark plug does work when plugged in to cyl 3 while doing the visual spark test then it's most likely a fuel injector.
If the spark plug does NOT work while plugged in to cyl 3, but WILL work in other cylinders, and the wiring all rings out, then it's probably a failed ECM.
A failed ECM is very unlikely, far more likely it's either a bad injector or bad wiring.
ecm is fine already got that checked out. That’s what we thought it was but the ecm is good.
wiring was also already checked - all wiring checked out.
Before anything I did put all new spark plugs & coils on the vehicle.
It’s not sparking at all. We are gonna put an injector in just for ***** and see what happens… but if it doesn’t fix it then I’m gonna get them to check all the wiring again… but they already checked everything and it was all good.
super frustrating.
The ECM doesn't pulse power to the coil, it pulses the GROUND.
First thing to do is visibly watch for spark, take out the spark plug, put it back into the coil pack, hold the ground strap about 1/4" away from the aluminum intake manifold with a LEATHER GLOVED HAND holding onto the coil pack (or you'll zap yourself silly). Then have someone else crank the engine while you watch for spark.
If no spark then take the entire coil pack/spark plug assembly from another cylinder, plug it into cyl3, and do that same test, then take the cyl3 stuff, plug it into the other cylinder and verify that everything is actually sparking. This way you rule out the coil pack and spark plug as being potentially bad.
If you still don't have spark then it's either a wiring or ECM issue, ring out the coil pack harness wires.
Pin 1 is the blue/red stripe wire and it goes to pin 61 on the ECM.
Pin 2 is a black wire and should have continuity to ground.
Pin 3 is white/blue stripe and should have 12v
If the spark plug does work when plugged in to cyl 3 while doing the visual spark test then it's most likely a fuel injector.
If the spark plug does NOT work while plugged in to cyl 3, but WILL work in other cylinders, and the wiring all rings out, then it's probably a failed ECM.
A failed ECM is very unlikely, far more likely it's either a bad injector or bad wiring.
First thing to do is visibly watch for spark, take out the spark plug, put it back into the coil pack, hold the ground strap about 1/4" away from the aluminum intake manifold with a LEATHER GLOVED HAND holding onto the coil pack (or you'll zap yourself silly). Then have someone else crank the engine while you watch for spark.
If no spark then take the entire coil pack/spark plug assembly from another cylinder, plug it into cyl3, and do that same test, then take the cyl3 stuff, plug it into the other cylinder and verify that everything is actually sparking. This way you rule out the coil pack and spark plug as being potentially bad.
If you still don't have spark then it's either a wiring or ECM issue, ring out the coil pack harness wires.
Pin 1 is the blue/red stripe wire and it goes to pin 61 on the ECM.
Pin 2 is a black wire and should have continuity to ground.
Pin 3 is white/blue stripe and should have 12v
If the spark plug does work when plugged in to cyl 3 while doing the visual spark test then it's most likely a fuel injector.
If the spark plug does NOT work while plugged in to cyl 3, but WILL work in other cylinders, and the wiring all rings out, then it's probably a failed ECM.
A failed ECM is very unlikely, far more likely it's either a bad injector or bad wiring.
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Joined: May 2017
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From: Washington State
Coupe 6MT Premium RAS
Has anyone actually SEEN THE SPARK with their own two eyes? Just because you threw parts at the car doesn't mean stuff works, gotta troubleshoot it properly. Pull coils and WATCH FOR SPARK to see if other cylinders have proper ignition, don't just blindly throw money (injectors) at the car hoping something might work.
Follow the steps I listed earlier.
Also, how EXACTLY did they test the ECM? This isn't something you can just visually look at or test with a meter, you have to actually watch spark at the spark plug to see if it's working (or there's a way to test with an oscilloscope by referencing through your 12v signal), if they didn't see spark on cylinder 3 how EXACTLY have tested the ECM? If you have ground (pin2), 12v power (pin3), and verified continuity on pin1 back to the ECM, and have independently tested that same coil pack and spark plug on a different cylinder, but do not actually have spark on only cylinder 3 then it's a bad ECM. Those are literally the exact troubleshooting steps, you need to verify this is EXACTLY what they did to test it.
-Make sure that coil pack and spark plug ignites on another cylinder, you have to see it with your eyes while the spark plug is out of the cylinder. Then you have verified the coil and spark plug work, just because it's new doesn't mean it works.
-Verify power and ground on the pin 3, requires a digital multimeter.
-Verify continuity of pin1 back to ECM harness pin 61.
If you don't have spark on cylinder 3, but you DO have spark on the rest of the cylinders then it's a bad ECM.
If you DO have spark then it's something else, possibly a bad injector (swap injectors with cylinder 1 or 5 and see if the P0303 code turns into P0301 or P0305 depending on cylinder). Possibly some sort of mechanical failure like a valve kaboomed, or the cylinder itself might have shat it's rings, compression test will verify the mechanical integrity of the cylinder to make sure it CAN work. Since this is such a simple test and you will already have the spark plug out it should be done since it takes about 30 seconds. Make sure the cylinder has at least 150psi which is below spec but even a 150psi cylinder will still ignite.
Troubleshoot, don't just throw parts at a car unless you are ok with gambling and likely wasting money.
Follow the steps I listed earlier.
Also, how EXACTLY did they test the ECM? This isn't something you can just visually look at or test with a meter, you have to actually watch spark at the spark plug to see if it's working (or there's a way to test with an oscilloscope by referencing through your 12v signal), if they didn't see spark on cylinder 3 how EXACTLY have tested the ECM? If you have ground (pin2), 12v power (pin3), and verified continuity on pin1 back to the ECM, and have independently tested that same coil pack and spark plug on a different cylinder, but do not actually have spark on only cylinder 3 then it's a bad ECM. Those are literally the exact troubleshooting steps, you need to verify this is EXACTLY what they did to test it.
-Make sure that coil pack and spark plug ignites on another cylinder, you have to see it with your eyes while the spark plug is out of the cylinder. Then you have verified the coil and spark plug work, just because it's new doesn't mean it works.
-Verify power and ground on the pin 3, requires a digital multimeter.
-Verify continuity of pin1 back to ECM harness pin 61.
If you don't have spark on cylinder 3, but you DO have spark on the rest of the cylinders then it's a bad ECM.
If you DO have spark then it's something else, possibly a bad injector (swap injectors with cylinder 1 or 5 and see if the P0303 code turns into P0301 or P0305 depending on cylinder). Possibly some sort of mechanical failure like a valve kaboomed, or the cylinder itself might have shat it's rings, compression test will verify the mechanical integrity of the cylinder to make sure it CAN work. Since this is such a simple test and you will already have the spark plug out it should be done since it takes about 30 seconds. Make sure the cylinder has at least 150psi which is below spec but even a 150psi cylinder will still ignite.
Troubleshoot, don't just throw parts at a car unless you are ok with gambling and likely wasting money.
Has anyone actually SEEN THE SPARK with their own two eyes? Just because you threw parts at the car doesn't mean stuff works, gotta troubleshoot it properly. Pull coils and WATCH FOR SPARK to see if other cylinders have proper ignition, don't just blindly throw money (injectors) at the car hoping something might work.
Follow the steps I listed earlier.
Also, how EXACTLY did they test the ECM? This isn't something you can just visually look at or test with a meter, you have to actually watch spark at the spark plug to see if it's working (or there's a way to test with an oscilloscope by referencing through your 12v signal), if they didn't see spark on cylinder 3 how EXACTLY have tested the ECM? If you have ground (pin2), 12v power (pin3), and verified continuity on pin1 back to the ECM, and have independently tested that same coil pack and spark plug on a different cylinder, but do not actually have spark on only cylinder 3 then it's a bad ECM. Those are literally the exact troubleshooting steps, you need to verify this is EXACTLY what they did to test it.
-Make sure that coil pack and spark plug ignites on another cylinder, you have to see it with your eyes while the spark plug is out of the cylinder. Then you have verified the coil and spark plug work, just because it's new doesn't mean it works.
-Verify power and ground on the pin 3, requires a digital multimeter.
-Verify continuity of pin1 back to ECM harness pin 61.
If you don't have spark on cylinder 3, but you DO have spark on the rest of the cylinders then it's a bad ECM.
If you DO have spark then it's something else, possibly a bad injector (swap injectors with cylinder 1 or 5 and see if the P0303 code turns into P0301 or P0305 depending on cylinder). Possibly some sort of mechanical failure like a valve kaboomed, or the cylinder itself might have shat it's rings, compression test will verify the mechanical integrity of the cylinder to make sure it CAN work. Since this is such a simple test and you will already have the spark plug out it should be done since it takes about 30 seconds. Make sure the cylinder has at least 150psi which is below spec but even a 150psi cylinder will still ignite.
Troubleshoot, don't just throw parts at a car unless you are ok with gambling and likely wasting money.
Follow the steps I listed earlier.
Also, how EXACTLY did they test the ECM? This isn't something you can just visually look at or test with a meter, you have to actually watch spark at the spark plug to see if it's working (or there's a way to test with an oscilloscope by referencing through your 12v signal), if they didn't see spark on cylinder 3 how EXACTLY have tested the ECM? If you have ground (pin2), 12v power (pin3), and verified continuity on pin1 back to the ECM, and have independently tested that same coil pack and spark plug on a different cylinder, but do not actually have spark on only cylinder 3 then it's a bad ECM. Those are literally the exact troubleshooting steps, you need to verify this is EXACTLY what they did to test it.
-Make sure that coil pack and spark plug ignites on another cylinder, you have to see it with your eyes while the spark plug is out of the cylinder. Then you have verified the coil and spark plug work, just because it's new doesn't mean it works.
-Verify power and ground on the pin 3, requires a digital multimeter.
-Verify continuity of pin1 back to ECM harness pin 61.
If you don't have spark on cylinder 3, but you DO have spark on the rest of the cylinders then it's a bad ECM.
If you DO have spark then it's something else, possibly a bad injector (swap injectors with cylinder 1 or 5 and see if the P0303 code turns into P0301 or P0305 depending on cylinder). Possibly some sort of mechanical failure like a valve kaboomed, or the cylinder itself might have shat it's rings, compression test will verify the mechanical integrity of the cylinder to make sure it CAN work. Since this is such a simple test and you will already have the spark plug out it should be done since it takes about 30 seconds. Make sure the cylinder has at least 150psi which is below spec but even a 150psi cylinder will still ignite.
Troubleshoot, don't just throw parts at a car unless you are ok with gambling and likely wasting money.
Ecm was taken to an engineering place that opened it. Said there’s no problem. We thought the terminal in the ecm for that cylinder may have been fried. Once the place had it opened they said it’s not the ecm.
when wiring/pins were checked multimeter was used, everything checked out - but did see that there was no pulse in the one pin but power and ground were good there. Checked many other wires, including to the ecm and pins there.
It does not make sense.
I do not pay for parts unless it fixes the issue when it’s put on so I’m not worried about that.
3 different coil packs were tried in the beginning stages of trying to fix this issue 2 brand new ( one non oem and one oem & the 3rd was a used oem) made no difference
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Joined: May 2017
Posts: 14,837
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From: Washington State
Coupe 6MT Premium RAS
It looking like the ECM fried then. I would ask whoever tested the ECM exactly what troubleshooting steps they used. Sounds like they just opened the case and verified the pin wasn't broken. This won't test that the contact is actually closing though and there isn't a way to brute force the ECM into closing those contacts since it needs to have the NATS/IVIS start command sent to it from the BCM then also see data from the cam and crank sensors in order to even fire spark. Not something you can test with the ECM not installed in the car.
EDIT: Make sure you get the same ECM, the MEC number needs to match. It will also need to be programmed before it will work via either Nissan Datascan 2 or the dealership Consult-II/III tool. Be sure to have all your keys handy at that time because all the BCM needs to be programmed to accept all the key transponders at the same time as well.
If you're going to be doing this yourself with NDS2 you can use an online BCM decoder to get the pin number for the BCM by using this site. I know it says to enter the 20 digit number but you can just put in the 5 digit key from the BCM and it will work and give you the 4 digit pin number to program it.
http://keytechtools.com/bcmcodes/index.php
EDIT: Make sure you get the same ECM, the MEC number needs to match. It will also need to be programmed before it will work via either Nissan Datascan 2 or the dealership Consult-II/III tool. Be sure to have all your keys handy at that time because all the BCM needs to be programmed to accept all the key transponders at the same time as well.
If you're going to be doing this yourself with NDS2 you can use an online BCM decoder to get the pin number for the BCM by using this site. I know it says to enter the 20 digit number but you can just put in the 5 digit key from the BCM and it will work and give you the 4 digit pin number to program it.
http://keytechtools.com/bcmcodes/index.php
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It looking like the ECM fried then. I would ask whoever tested the ECM exactly what troubleshooting steps they used. Sounds like they just opened the case and verified the pin wasn't broken. This won't test that the contact is actually closing though and there isn't a way to brute force the ECM into closing those contacts since it needs to have the NATS/IVIS start command sent to it from the BCM then also see data from the cam and crank sensors in order to even fire spark. Not something you can test with the ECM not installed in the car.
EDIT: Make sure you get the same ECM, the MEC number needs to match. It will also need to be programmed before it will work via either Nissan Datascan 2 or the dealership Consult-II/III tool. Be sure to have all your keys handy at that time because all the BCM needs to be programmed to accept all the key transponders at the same time as well.
If you're going to be doing this yourself with NDS2 you can use an online BCM decoder to get the pin number for the BCM by using this site. I know it says to enter the 20 digit number but you can just put in the 5 digit key from the BCM and it will work and give you the 4 digit pin number to program it.
http://keytechtools.com/bcmcodes/index.php
EDIT: Make sure you get the same ECM, the MEC number needs to match. It will also need to be programmed before it will work via either Nissan Datascan 2 or the dealership Consult-II/III tool. Be sure to have all your keys handy at that time because all the BCM needs to be programmed to accept all the key transponders at the same time as well.
If you're going to be doing this yourself with NDS2 you can use an online BCM decoder to get the pin number for the BCM by using this site. I know it says to enter the 20 digit number but you can just put in the 5 digit key from the BCM and it will work and give you the 4 digit pin number to program it.
http://keytechtools.com/bcmcodes/index.php
wanted to give you update lol it’s burnt valve. So now I’m just gonna part out the car and buy another one I found a super clean 04 with lower kms and no rust imported to Canada from Texas or florida going to see it next week
nope not that I know of. I personally think it was my tune. It really sucks!!
Registered User
Joined: Jul 2023
Posts: 18
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G35 coupe
Same problem
Hey I know I am a bit late here, but I have the exact same problem as you described, although I am very curious as to why you weren't receiving the ecm pulses, resulting in no spark, and it turned out to be a blown valve??? That seems completely unrelated.
I have done all the checks as you guys discussed in the thread: ecu to coil pack harness connector continuity, power and ground are good, however the coil pack + spark will NOT spark for cyl 3. The same coil pack and spark work just fine on cyl 1. I have verified that there is no ecu signal at terminal 1 for the cylinder 3 connector so I was getting ready to call it an ECM issue which just seems incredibly, incredibly rare.
I suppose its worth a shot to send it in to be looked at but now you are making me want to check compression for cylinder 3 haha.
Man this is frustrating!!!
I have done all the checks as you guys discussed in the thread: ecu to coil pack harness connector continuity, power and ground are good, however the coil pack + spark will NOT spark for cyl 3. The same coil pack and spark work just fine on cyl 1. I have verified that there is no ecu signal at terminal 1 for the cylinder 3 connector so I was getting ready to call it an ECM issue which just seems incredibly, incredibly rare.
I suppose its worth a shot to send it in to be looked at but now you are making me want to check compression for cylinder 3 haha.
Man this is frustrating!!!
Registered User
Joined: Jul 2023
Posts: 18
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G35 coupe
From my tests, there is literally nothing else at this point that can be done except checking the ECM itself. I have never, ever, seen anything like this so I would be very surprised to find out that the output of the ECM for one single coilpack signal was bad coming from the actual ECM itself.
Worth a shot I guess..
Registered User
Joined: Feb 2018
Posts: 3,087
Likes: 445
From: LA, Cali
Yes I know, thats why I mentioned the irony of the OP having spark issues but finding out he blew a valve…
From my tests, there is literally nothing else at this point that can be done except checking the ECM itself. I have never, ever, seen anything like this so I would be very surprised to find out that the output of the ECM for one single coilpack signal was bad coming from the actual ECM itself.
Worth a shot I guess..
From my tests, there is literally nothing else at this point that can be done except checking the ECM itself. I have never, ever, seen anything like this so I would be very surprised to find out that the output of the ECM for one single coilpack signal was bad coming from the actual ECM itself.
Worth a shot I guess..
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From: Washington State
Coupe 6MT Premium RAS
I'm guessing it's a wiring issue. Need to verify you have 12vdc on the white/blue stripe wire, ground on the black wire, and the third wire for cylinder 3 is a blue/red stripe that needs to go back to the ECM pin 61.