Service Engine Light

I've got a 01 Pathfinder which, for the most part, I'm very happy with. The service engine light came on about 1,000 miles ago. The reason that the light came on is unknown to me although I was rather low on fuel when it showed it's ugly face. I'm pretty sure that is the reason but it has not gone off over the last thousand or so miles. The truck is running great right now and only has about 27,000 miles. I know that this has been discussed in previous threads and it seems to me that it's a common problem. I've done some research and it seems that every person that brings there vehicle into Nissan (not just Pathfinders) to get the problem fixed is hit with a rather large repair bill only to have the light go back on in a couple thousand miles. I enjoy doing work on my cars (nothing major mind you) just basic stuff like fluid changes and spark plugs. It's frustrating to me to have the SEL on and I don't want to pay Nissan several hundred dollars to hook their computer up to the vehicle, tell me some bogus repair that has to be made and just reset the computer. The reason I bought a Nissan is because I've owned several in the past with no problems (up to 200,000 miles). Well that's my thread. Just wanted to vent my frustrations. I guess I could put a picture of my wife over the light (make her glow). Problem solved.

You can take it to AutoZone, Advance Auto Parts, or Pep Boys and they will run a computer diagnostic for free (as opposed to the dealer or shop's $80) The problem is that if the diagnostic codes come up then there probably is something wrong not just a conspiracy to get money out of us. Also as I have found, the diagnostic codes are really just a starting point to diagnosing the problem for instance; I have a '97 SE that the SEL light came on and I took it to Advance and they ran the diagnostic, got the codes from the computer which ended up being an EGR code. The guy at Advance told me it meant that I needed a new EGR valve. I then took it to my mechanic who ran the same test, recieved the same codes but was able to trouble shoot the EGR system and not just tell me what it probably was. It ended up being the EGR solenoid not the valve. I think the reason why we see so many people having problems that won't go away is that the mechanics they're going to are hasty, dishonest, proud and incompitent. It's hard to find a mechanic who is darn good at what he does and from my experiences, the darn good ones are usually more honest because they can afford to be. All that to say; if it were me I'd get a free diagnostic and see if there are some things you could try yourself and/or look for a good honest mechanic. In my opinion, dealerships are the worst! If I were a bad-ass mechanic, I'd open my own shop not work and make money for Nissan! Good Luck!

You have to realize that for a vehicle like your Pathfinder there are probably 70+ unique trouble codes that trigger that light, my 97 has 67. For each of those unique trouble codes there might be just a couple of possible causes, but the majority of the codes have anywhere from 5-10 or more possible causes. So although it would seem pretty easy to fix the errors that trigger your light, it can be an exhaustive step by step process to correctly diagnose the true cause. But yes, many times dealers and mechanics take the short cut and replace parts on a hunch when they weren't the real cause of the error because doing all the diagnostic steps can take quite a while.

Your best bet is to use Autozone to read your codes for free, or you can get a code reader for fairly cheap now. With either of those you can read the specific error codes that triggered the light. Then get a subscription to ALLDATA.COM which will give you the specific Nissan diagnostic steps for each of those trouble codes, only $24.95. For many errors you can go through the steps and find the problem yourself. Even if you don't do the repairs yourself at least you can follow along with the mechanics steps to make sure things are being repaired correctly.

I just turned in my 01 Pathfinder for a 04. I love them. My 01 SES light came on at about 40,00 or so. Code P1140. Very common on the 01. If you go to Auto Zone to get code I'll bet thats it. It belongs to a Valve Timing Sensor. Locate on the front of the heads, one left, one right. They are interchangeble and relatively easy to replace. About $90. for the sensor. Good Luck
Scud

Hey Scud,
How does one figure out how to replace these sensors? Can someone who doesn't know anything about cars do it?

Anytime your SES light comes on and goes out, or stays on , a code{s} is set in the ECM memory.It remains there {light on or off} untill someone clears the memory.It may also store some important data{snapshot} of sensor inputs and actuator outputs at the time of failure..Most codes that are set are of the intermittant type.Depending on the severity of the code,your light might stay on but the cause of the light coming on is long gone.This creats a very frustrating and costly way of repairing these problems for those that don't follow repair flow charts for the specific codes.{dealership techs are some of the worst offenders.}This Autozone place sounds like they make a fortune by selling parts to people, that they don't need.
eg. Just because you pull a PO1140 code it does not mean the cam sensor is no good.It means the ECM detected a fault in the cam sensor circuit.This includes the sensor the actuator controlling the sensor,the wiring harness,or ECM itself.It may be common that cam sensors do fail, but not for everyone.You can take your chances that you have the same troubles as most other people but are you willing to take a chance {cost wise}.If I had Autozone read a code for me, I would take this information, get a manual and follow the specific diagnostic procedure for that code.Without following diagnostic procedures you only replace parts till the problem or the interest in solving it disappears.
This is just some information for those {no offence} who continue to "beat-up" the poor SES light, that is just trying to do it's job.

jojo, the fix is easy. The sensor is located on the front of the block. Two 10mm bolts and a few wires. There is a sensor on both sides left and right. I hear the right is most common. Mine was right. I don't know why. Part should be under $100. My dealer told me they are interchangeable. After replacement you'll have to reset the light. Buy the new one and you'll see what it looks like. Go for it!