P0325 Code

2000 NISSAN FRONTIER
207,500 MILES • 3.3L • 6 CYL • 4WD • AUTOMATIC
Avatar
SZALKUSKT
  • MEMBER
  • 274 POSTS
I have the truck listed above. Manufactured 08/1999. I am diagnosing it for a friend of mine. He has complained of hard starting issues at different times. I have driven it. It drives at cruise speeds okay but with 207,000 miles it seems to cruise okay at highway speeds. It does have hard starting problems intermittently. First thing I did was scan OBDII for codes and I have a P0325 code and a P0325 "pending" code. I know it is a knock sensor 1 circuit malfunction. I understand that the sensor is under the intake manifold. I have read that knock sensor is not important but me I know it is coming on for a reason. I cleared the codes and started engine back up and codes reappeared quickly. Also, there is No CEL light on instrument panel, only the codes P0325 twice on my scanner. P0325 and P0325 "pending". I want to know how the P0325 can affect my drivability or hard starting or idle issues. Thanks.
May 31, 2018 at 8:18 PM
Advertisement
Avatar
JIS001
  • CERTIFIED EXPERT
  • 3,412 POSTS
Hello SZALKUSKT and thank you for using 2CarPros. Nissan has always had an issue with posting that fault code with the knock sensor. The code will not go away no matter what you do. So for now you should ignore the fault code and actually try to duplicate the concern.

When your friend has the no start condition does the vehicle crank over? If you have a no crank no start condition then look at the warning relay but I would suspect the park/neutral relay. But as stated earlier, you would need to duplicate the concern and when it does not start does the vehicle crank over? Let us know.
Images (Click to enlarge)
Attached Media
Attached Media
Jun 1, 2018 at 1:19 AM
Avatar
SZALKUSKT
  • MEMBER
  • 274 POSTS
Actually the truck has hard starting. What I mean is that it starts but very sloppy. It takes an extended amount of cranking in order for it to start up, but it does start sometimes with more cranking. Also, what usually causes the knock sensor codes on these particular vehicles?
Jun 1, 2018 at 1:49 PM
Advertisement
Avatar
JIS001
  • CERTIFIED EXPERT
  • 3,412 POSTS
Check your distributor. I have seen them go bad. Remove the distributor and move the rotor back and forth fast. The gear at the bottom should move with it. If there is any play then replace the distributor. That play will cause a hard start and rough running. If okay then check your fuel pressure. As for the knock sensor code, it could just be a ghost code. A misfire or wrong fuel causing pre detonation can cause it to post that code also.
Jun 3, 2018 at 7:26 PM
Avatar
SZALKUSKT
  • MEMBER
  • 274 POSTS
I removed distributor cap and rotor to find that the screw that goes down inside the center metal base of the distributor was loose. I put Locktite and re-secured it along with a new cap and rotor and Locktite the screw also that holds the rotor to that metal base which was loose causing the whole rotor to be loose and wobbly. So I put new plugs, wires and distributor cap and rotor. Engine seems to run better and more power with first cold start up after all the maintenance I did. We will see in coming days how it performs. I will reply back to report on it as it is not my car. I will explain to my friend all that is going on.
Jun 3, 2018 at 10:34 PM
Avatar
JIS001
  • CERTIFIED EXPERT
  • 3,412 POSTS
Thank you for the reply back and let us know if the truck is still running good.
Jun 4, 2018 at 5:27 PM
Avatar
SZALKUSKT
  • MEMBER
  • 274 POSTS
Seems to be better but still low performance and I have noticed that once warmed up the engine will idle at 1,200 rpm's and at different times intermittently at 700 to 800. I think it might have an idle air problem also causing the poor performance on start ups. Also, before I changed the cap and rotor I got shocked from voltage bleeding through the old cap and wires when I placed my hand on top of the distributor while running. Now with new wires and cap it is okay. I am just thinking still having noticeable low power and performance so maybe distributor is weak or worn. I really think the idle variance at different times is in acceptable also.
Jun 4, 2018 at 6:18 PM
Avatar
SZALKUSKT
  • MEMBER
  • 274 POSTS
Hi, I still need some help please. I have noticed that the truck has idle speed variations. After driving it for thirty minutes pulling into the parking lot I noticed the rpm rising and when I put it in neutral or park the engine speed was 1,300 rpm's with A/C off. It does it unexpectedly and inconsistently. I have not removed the distributor yet as it is my friend’s car and he needs to allow me to work on it again. I was just thinking it is an IAC valve problem. Can a truck like this have IAC issues with no code?
Jun 9, 2018 at 1:48 AM
Avatar
JIS001
  • CERTIFIED EXPERT
  • 3,412 POSTS
If you corrected the hard start then I would suspect an idle air control fault. The OBD2 system should have detected this by now and posted a code. Also, verify the the engine coolant temperature sensor is reading correctly. If it is thinking it is cold it will raise the rpm high to try and "warm up" the engine.
Jun 9, 2018 at 10:46 PM
Avatar
SZALKUSKT
  • MEMBER
  • 274 POSTS
I have not had a code for the IAV valve. It does definitely have inconsistent idle values. How can I check the coolant temperature sensor if there is no code posted?
Jun 9, 2018 at 10:55 PM
Avatar
JIS001
  • CERTIFIED EXPERT
  • 3,412 POSTS
Once engine is at normal temperature back-probe the the signal return wire. Normally it should read under 1 volt, usually 0.50 volts. If higher it means it thinks it is colder. Also removing spark plugs. If they are wet with fuel it is dumping too much fuel also to try and make the idle high which in turn give you a hard start because the plugs are wet with fuel.
Jun 9, 2018 at 11:13 PM
Avatar
SZALKUSKT
  • MEMBER
  • 274 POSTS
Do you have a wiring diagram so I can determine which wire is the signal return wire?
Jun 13, 2018 at 11:06 AM
Avatar
JIS001
  • CERTIFIED EXPERT
  • 3,412 POSTS
Light green red stripe should be the 5 volt reference. Brown wire is the signal return. When engine fully warm the brown wire should read under 1 volt. Normally 0.50V.
Images (Click to enlarge)
Attached Media
Attached Media
Jun 13, 2018 at 10:07 PM