I'm getting these two codes and rough running intermittently. Plugs are relatiely new and the problem has been there for quite a while through a couple sets of plugs, so I am assuming I hae coil issues. Now I am also getting the TCS/Slip lights on when it runs rough. I could use some diagnostic help.

The rough running is too intermittent to do the "pull the coils one by one" test.

1. Is it fairly safe to assume this is just a coil issue?

2. Do the tests with the voltmeter help on the when you have intermittent misfires? Or do they only catch really dead ones?

3. How do those green connectors come off the coils? I tried pulling the little green tab up, and pushing it down, but it would not release. I'm trying very hard not to break one of them :-)

Thanks,

 

I have the same famous P1320 code on my own 4th gen, 95. I was told they could not pinpoint which ones were not firing BUT that the carbon fouling on my plugs was most likely from bad ignition. The 4th gens were notable for their faulty coil packs, with the '99 year being the worst off. I would replace the coils (which is going to be pricey) So lets wrap it up this way...

1) Yeah, most likely ignition coil issues.

2) The voltmeter tests CAN help if you know what the proper resistance is (which, I don't myself, sorry) BUT they do almost catch every dead coil.

3) Those connectors can be a real pain, but just squeeze the little catch and use a flathead screwdriver to GENTLY pry it off backwards while you squeze.

 

I have a 99 max with Auto trans the P1320 Code as well.

Replaced all Ignition coils and spark plugs, MAF, CrankSensor 120deg (front).
Car runs great but throws the P1320 code Immediately...
Broken wire in the wiring harness? Anybody ever found a broken wire?
Specifically, it one of the six ignition wires correct? or could it be other wires. How did you do it?

I was working on the car and the keys lost programming. Tech at Nissan said that if you remove the ECM harness for more than 10 minutes you increase your chances of losing the key programming. So how do you woork on the wiring harness without uplugging it? What makes the keys lose their programming and lock down the car?
Is there a way of supplying Voltage to the ECM so the IMMU doesnot lock out the Car?
Need some Nissan Tech help.
427-4

 

i know snap on and matco both sell whats called a memeory back up that plugs into your lighter and supplies just enough voltage to keep your pcm from losing memory. as far as your code 1320 try to find a diagnostic flow chart on a site like mitchell on demand or all data and go that route thats how we do it at the shop i work at.

 

I am getting to the bottom of the P1320 code. First You must have a Code reader and some knowledge of electronics....wish I had more myself.

If your car runs rough it is one of the Ign coils or one of six wires from the ECM that are broken. Usually a 301-306 code is generated at well. Check it by unplugging each ign coil and watch for the rpm drop. I had 740 rpm with 6 cyl and 724 with 5 cyl.

If your car works fine but shows a P1320 code it is the Front mounted crankshaft sensor. The wiring harness is damaged. The ground sheilding is killing the signal to the ECM. Measure the ECM Pins 46 & 47 (2.3V Pulse signal average vs ECM ground pin 25. mine measured 0.9 DC volts. Oil & heat most likely cause of wire insulation degrading.

So how did I check the existing wiring harness? I bought an extra ECM plug and wires from Pull-A-Part and extra electrical connectors for the Ign Coils. Removing the wires from the old ECM harness I soldered long leads to the Ign coil to bypass the wiring harness. Ran the wires through the window to the engine bay. The ECM will put out the Ign signal that averages 1.4 to 1.8 DC Volts on a digital multi meter.

When the P1320 code stayed on. I jumpered the ECM to the Crank sensor (REF). Interesting enough the code stayed on. I then unplugged the crank sensor (REF) and the P1320 code went out. (the engine will stay running) Of course the P1335 code came on. When I replaced the wires to the stock position P1320 came back. Unplugging the Crankshaft sensor (REF) Code 1320 went away again. Then I knew it was the lower wiring harness. You with me?

I thought I would give a technical write up just in case anyone else is have problems with a phanthom CEL.
427-4

 

I replaced the lower wiring harness and it did not fix the problem code P1320 still on.
Strange that when you unplug the Crankshaft pos (REF) sensor the p1320 code goes away. Could it be I have a bad ECM?

Any Nissan techs out there that can shed some light on this problem?
427-4

 

I have a 99 se-limited and i have severe loss of power. I had a code 0305 and replaced the number 5 coil. Ran great for 4k miles, then all at once power loss again.. I pulled the entire front bank of coils and the car ran the same. I didn't think a 6 cyl would run on three cylinders? Any advise for a noob? I dont want to throw parts at it until i am certain of the problem. Error codes 0300 and p1320 are all that show now. Thanks a ton!