2001 Pathfinder P1320
Customer came in with Check Engine light and code 'P1320', they had already replaced coil #1 with an aftermarket Hitachi unit. Being that the coils are not easily accessible I checked directly at the ECM and I scoped all the ignition coil trigger signals. I found that coil #1 had a waveform that was different than the rest, it peaked at around 3.3v and was not square while all the others were perfectly square and peaked close to 5v. Scoping directly at coil #1 produced the same signal. (see photos)
I continued by removing and inspecting the spark plug #1 which appeared in good condition, I swapped plugs 1 and 2 and rechecked #1 coil waveform. No change. #1 coil is different than all the rest but I was able to jimmy rig and swap coils 1 and 2, I then rechecked the signal. The bad signal followed the coil. Having found from past experiences that aftermarket coils on these vehicles can cause issues out of the box I advised replacing coil #1 with an OE unit.
After installing an OE coil I am getting the exact same waveform and code. Did I miss something? Could the OE coil be bad?
Oscar could the new coils just be different in wave form? I use hitachi and have not yet had an issue with them on nissan. If you think its a nother failed coil why not move it to a different cylinder and see if the waveform becomes like the reset. Also not to say you did it wrong but #1 is on passenger side furthest forward.(ive done it myself :)).
Whenever a code P1320 is encountered on Nissan vehicle it demands that all coils be replaced.
Oscar, my guess is that you are looking at the one good coil. You need to replace the others and I believe if you buy the other coils from SMP (O'Reilly or Napa Echlin will be the same part) you will find your patterns all match the #1 coil and your problem will be gone. The P1320 unfortunately is not coil specific but I think the difference in the pattern is significant, though since that is…
I think you may be right on this one, I was able to source known good and bad waveforms that confirm this. I'll look into this and see if I can't get this car sorted, thanks!
This capture is from an 01 Maxima 3.0 The blue CH A is the bad square 4.8v trigger to an aftermarket COP The tan CH D is the good 3.7v trigger signal to the good OE COPs The green CH C shows the aftermarket COP drawing only 5.3A and the good OE COPS draw 8A The red CH B is the aftermarket COP secondary
If you have no misfire issues, then check coil amperage of all coils , look for differences, cause even though it may fire ok, it will put a p1320 , and especially aftermarket, Would use O.E.only
The first picture you have is of a faulty coil. That would be the source of the 1320 code. If the 5 other coils look like that, they are bad. The second image is what it should look like. With a small ramp on the top of the IC control.
I've seen this in several case studies, and I think there was even a TSB, and in later model years, Nissan completely removed, DTC P1320 from their ECM software. Current ramp all the coils together. If they are not all the same ramp, that is your issue. You have to have six, all-matching coils.
Agree with Geoff. Current ramp all the coils together. Its the only way to eliminate the code.
You mean I finally learned something in a class that was correct Rudy? :-) Had that one three times, IIRC. I know it was in "Nissan Tips and Tricks" by SMP, and probably a few scope usage classes.
I agree with Richard that your first waveform indicates a bad coil. If new coil measures the same amplitude, I would say you have a bad new coil. I had a customer install a new coil from Kragen (now O'Reilly's) that had an IC control that was over 6 volts. I've seen new coils that displayed a square wave IC control that was around 3.5 volts and not set a code.
The one coil with the ramp is the GOOD one. Any coil with a square wave is bad. It may fire the spark plug but it will keep setting the code.
Thank you to everyone who responded! After learning that I was looking at the waveforms all wrong I was able to confirm that coil 1 was the sole good coil, throwing in a coil at cylinder 2 and scoping this further confirmed this for me as I saw the ramped 3.3v waveform. 5 more Hitachi coils remedied the issue and the car is back on the road, I'm still amazed that this car had 5 bad coils. Thanks…
Oscar, In this case bad is kind of a relative term. Those coils can fire the spark plug just fine. It's just that the internal circuitry of the trigger circuit doesn't satisfy the ignition circuit monitor (as seen in the scope pattern) and it sets the P1320. This seems to be mostly a Nissan thing because most of the trigger circuits I see on other cars are usually square waves.
Hi there, all your posts were very helpful. I’m very glad I found this forum in helping me find solutions to issues regarding my 2001 pathfinder. Thanks for all of your posts. I was able to resolve the issue on P0301 by replacing #1 coil but the code 1320 is still there. the engine is running great and can I ignore this SES withP1320 code anyway there is no longer any misfire?