Have a couple of codes on scanner
Thread Starter
Teching In
Joined: Feb 2017
Posts: 9
Likes: 1
From: Loganville, GA
Have a couple of codes on scanner A few weeks back I knew there was somewhat of a misfire at low speed and the car stalled out on me twice at idle.
Last weekend I went ahead and changed the plugs and wires, still the same. WOT it runs just fine.
Bought a scan tool that arrived today and I have:
P0102 MAF Circuit Low Input
P0103 MAF Circuit High Input
P0351 Ignition Coil A Primary / Secondary Circuit Malfunction
I will deal with the first two later, but the P0351 is most likely the root of the problem.
Started to ohm test driver side coils all 4 seem within a few ohms of each other A-B 30+- A-C 30+- A-D 48+-
So I was getting ready to pull the coil rack off of the passenger side, but thought I would see if there is a link to check the wiring / ohms on the wires to the coil packs before I plug the ones back in on the drivers side.
Any other tips would be appreciated. Using a Fluke 87 for the test.
2002 LS1 Texas Torquer 3 and PRC / LS6 Heads
Last weekend I went ahead and changed the plugs and wires, still the same. WOT it runs just fine.
Bought a scan tool that arrived today and I have:
P0102 MAF Circuit Low Input
P0103 MAF Circuit High Input
P0351 Ignition Coil A Primary / Secondary Circuit Malfunction
I will deal with the first two later, but the P0351 is most likely the root of the problem.
Started to ohm test driver side coils all 4 seem within a few ohms of each other A-B 30+- A-C 30+- A-D 48+-
So I was getting ready to pull the coil rack off of the passenger side, but thought I would see if there is a link to check the wiring / ohms on the wires to the coil packs before I plug the ones back in on the drivers side.
Any other tips would be appreciated. Using a Fluke 87 for the test.
2002 LS1 Texas Torquer 3 and PRC / LS6 Heads
A few weeks back I knew there was somewhat of a misfire at low speed and the car stalled out on me twice at idle.
Last weekend I went ahead and changed the plugs and wires, still the same. WOT it runs just fine.
Bought a scan tool that arrived today and I have:
P0102 MAF Circuit Low Input
P0103 MAF Circuit High Input
P0351 Ignition Coil A Primary / Secondary Circuit Malfunction
I will deal with the first two later, but the P0351 is most likely the root of the problem.
Started to ohm test driver side coils all 4 seem within a few ohms of each other A-B 30+- A-C 30+- A-D 48+-
So I was getting ready to pull the coil rack off of the passenger side, but thought I would see if there is a link to check the wiring / ohms on the wires to the coil packs before I plug the ones back in on the drivers side.
Any other tips would be appreciated. Using a Fluke 87 for the test.
2002 LS1 Texas Torquer 3 and PRC / LS6 Heads
Last weekend I went ahead and changed the plugs and wires, still the same. WOT it runs just fine.
Bought a scan tool that arrived today and I have:
P0102 MAF Circuit Low Input
P0103 MAF Circuit High Input
P0351 Ignition Coil A Primary / Secondary Circuit Malfunction
I will deal with the first two later, but the P0351 is most likely the root of the problem.
Started to ohm test driver side coils all 4 seem within a few ohms of each other A-B 30+- A-C 30+- A-D 48+-
So I was getting ready to pull the coil rack off of the passenger side, but thought I would see if there is a link to check the wiring / ohms on the wires to the coil packs before I plug the ones back in on the drivers side.
Any other tips would be appreciated. Using a Fluke 87 for the test.
2002 LS1 Texas Torquer 3 and PRC / LS6 Heads
Thread Starter
Teching In
Joined: Feb 2017
Posts: 9
Likes: 1
From: Loganville, GA
"It sounds like you are already on the proper diagnostic path, so unless it takes you to a dead end, I see no reason to sidetrack you at this point."
Well I guess I was just curious if anyone had some real input of whether I was going down the right track or not. New to the LS engines, I thought there maybe a better way, than the way I am doing this.
Anyway, I finished with the coils. #8 had the most significant change of them all.
A-B 40, A-C, 40 and A-D 72, no changes between B-C, but B-D & C-D has about 14 ohms different then the other coils. So the resistance average is about 12 ohms higher on B&C and 24 Ohms higher on D.
I realize this is not a whole lot since winding's change from coil to coil, but if anyone has had some experience in testing these I would like to see if there is enough difference to say that this is a bad coil.
Thanks in advance.
Well I guess I was just curious if anyone had some real input of whether I was going down the right track or not. New to the LS engines, I thought there maybe a better way, than the way I am doing this.
Anyway, I finished with the coils. #8 had the most significant change of them all.
A-B 40, A-C, 40 and A-D 72, no changes between B-C, but B-D & C-D has about 14 ohms different then the other coils. So the resistance average is about 12 ohms higher on B&C and 24 Ohms higher on D.
I realize this is not a whole lot since winding's change from coil to coil, but if anyone has had some experience in testing these I would like to see if there is enough difference to say that this is a bad coil.
Thanks in advance.
"It sounds like you are already on the proper diagnostic path, so unless it takes you to a dead end, I see no reason to sidetrack you at this point."
Well I guess I was just curious if anyone had some real input of whether I was going down the right track or not. New to the LS engines, I thought there maybe a better way, than the way I am doing this.
Anyway, I finished with the coils. #8 had the most significant change of them all.
A-B 40, A-C, 40 and A-D 72, no changes between B-C, but B-D & C-D has about 14 ohms different then the other coils. So the resistance average is about 12 ohms higher on B&C and 24 Ohms higher on D.
I realize this is not a whole lot since winding's change from coil to coil, but if anyone has had some experience in testing these I would like to see if there is enough difference to say that this is a bad coil.
Thanks in advance.
Well I guess I was just curious if anyone had some real input of whether I was going down the right track or not. New to the LS engines, I thought there maybe a better way, than the way I am doing this.
Anyway, I finished with the coils. #8 had the most significant change of them all.
A-B 40, A-C, 40 and A-D 72, no changes between B-C, but B-D & C-D has about 14 ohms different then the other coils. So the resistance average is about 12 ohms higher on B&C and 24 Ohms higher on D.
I realize this is not a whole lot since winding's change from coil to coil, but if anyone has had some experience in testing these I would like to see if there is enough difference to say that this is a bad coil.
Thanks in advance.
Thread Starter
Teching In
Joined: Feb 2017
Posts: 9
Likes: 1
From: Loganville, GA
So I just swapped 1 & 3 and cleared the scan tool. Took it for a 20 minute test drive this AM and let it warm up. With scan tool in hand the only code I was getting was P0102.
Stopped to fill the tank and when I got on the 4 lane, I went to WOT for a few seconds and the code reappeared. It felt like I was running on 7, like I was before. So now I'm going to test the coil harness to see if I am getting the voltage / signals I need.
Any others that have experienced this, just let me know. I'm thinking either the ECU or bad wiring?
P0102 is a MAF low output code. completely unrelated to the coil pack problem. Make sure there is 12V between the MAF pink wire and black/white. With no vehicle type mentioned I'll guess it is a 02 LS1 with a 3 wire MAF.
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I think you misunderstood the meaning of my post. Checking the basics with proper equipment as you are doing is always the proper way to find a problem. I understand that some system types have known issues that can be tested as a shortcut to a full diagnosis, but that isn't the case here. LS1 style coils are extremely reliable, so you would look to wires or plugs first. You already did that, so as another person suggested, you could start swapping cylinders to see if the problem followed a coil. However, using a quality multimeter to narrow down your suspect coils is much preferred to blindly swapping them. As I stated, I would only start to point to low probability sidetracks if the method you are currently using leads to a dead end. I hate "wall of text" style posts, so sometimes my initial comments are overly brief.
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Verdad Gallardo Thread Starter
Teching In
Joined: Feb 2017
Posts: 9
Likes: 1
From: Loganville, GA
I went ahead and added a signature for the basic specs of the car. I'm curious now if it is the ECU causing the #1 Cylinder misfire, or if there is something else to check first?
Thanks again.
Thread Starter
Teching In
Joined: Feb 2017
Posts: 9
Likes: 1
From: Loganville, GA
Well I hate to see a trouble shooting thread go to waste, so this is what I found. Purple wire separated just outside of the main coil pack harness. It was barely touching and the cylinder was intermittent, sometimes working sometimes not. Anyway I repaired it and now I'm back to my 450HP once again!
