My check engine light came on and it gave me the code p1140 and the description is intake valve timing Sol ckt bank 1.
After my searches online I'm confused cause some people are saying cam position sensor and I've yet to find a proper thread that shows how to fix it or what it actually is.

Thanks in advance

This thread should give you exactly what you're looking for. Per Towncivilian's first reply, try swapping the sensors between the driver and passenger's sides and see if the code moves. The link in his second reply is a page that has extensive info on the problem and how exactly to fix it.

thanks for the reply and links i will definitely check it out. what problem does it cause to the truck cause i don't notice anything wrong with it.

Sure thing, let us know how it goes!

The sensor is used by the ECU to determine the timing of fuel injection and spark, so your timing (and fuel economy) may be a bit off. My guess is that it's currently either taking a best guess based on the other sensor's input or not making any adjustments until the sensor is replaced. You'd probably start noticing it more as time went on.

most definitely will let you know once i fix it.
my fuel needle is messed up maybe that's why haven't noticed lol i made a thread on it.

lol true that

If your due for an oil change do that as well.

*update*
the actual part that clears this code is called camshaft position sensor. i replaced it and the engine light went away.

*update*
my brother cleared the engine light while i wasn't there so the light was gone but now it's back. i think i swapped out the wrong sensor cause i know there's 2 but i can't find the other one. the i replaced was the one in the front of the right side.

You need to replace the one on the passenger side for P1140.

is that under the truck?

asnorton44 wrote:You need to replace the one on the passenger side for P1140.

is that on the bottom of the truck bro?

nyc_ink wrote:is that under the truck?

Nope its to the right of the battery kinda tucked under a few things. Just remove the battery and its not too hard to get to.

asnorton44 wrote:

nyc_ink wrote:is that under the truck?

Nope its to the right of the battery kinda tucked under a few things. Just remove the battery and its not too hard to get to.

k cool thank you. I'll try it tomorrow and report back. my brother cleared the code and got me hyped smh lol

asnorton44 wrote:

nyc_ink wrote:is that under the truck?

Nope its to the right of the battery kinda tucked under a few things. Just remove the battery and its not too hard to get to.

swapped it out and put the other one back and the check engine light didn't clear on its own so i cleared it and hopefully it stays off lol dude that sensor was caked up in old oil gunk. looked bad made me want to get a oil flush for my next oil change.

As stated, if the sensor is bad, the light will come back on. Your code will be slightly different, because the bad sensor will be on the other side of the engine. Just figure out which one is bad based on the codes and replace it.

nyc_ink wrote:swapped it out and put the other one back and the check engine light didn't clear on its own so i cleared it and hopefully it stays off lol dude that sensor was caked up in old oil gunk. looked bad made me want to get a oil flush for my next oil change.

It won't clear immediately you will have to drive some miles. Hopefully doesn't come back on after you erased it though.

Hey all,

I have a 2002 qx4 with a consistent P1140 code. The code pops up as soon as the engine is on, and no sooner do I clear it then it comes right back up again. I have extensive wiring tech background and have even pulled the engine harness and gone through it extensively. At one point, the previous owner had installed an incorrect IACV and broke the connector in order to force it into the IACV, so I am wondering if that might have something to do with the issue. Here is what I have done so far:

Going through the FSM, I have tested the ground terminal for continuity on both B1 and B2 connectors, both have good grounds. Checked power terminals and both have good power. Checked continuity from the middle terminal to pins 79 and 89 of the ecu, both have good continuity. I have all brand new cam and crank sensors, swapped them all around and still P1140 every time. I also have replaced the cam solenoids with new ones and switched back and forth to the original and new, neither makes a difference, P1140 all day long. I even ran a completely new signal wire from the middle terminal to the ECU and bypassed the original signal wire in the offset chance the signal is being interfered with somewhere, still P1140 all day.

What is left? Is the probability in favor of a bad ecu circuit? Any assistance is much appreciated.

Not really sure why my thread was merged, my situation is different from the one posted above and I was relatively thorough regarding my troubleshooting. Not quite as simple as replacing a sensor and moving on, or do we always combine threads if it's remotely the same thing someone posted about in the past?

Well, you did some good electrical dianostics. Since you have new parts on both sides, the conclusion is either a bad ECM or you have an oil pressure problem to the solenoid. Cam advance is done by applying oil pressure.

You may want to just have Infiniti do a diagnostic to confirm. They can use the CONSULT tool to look at the signal received from each cam position sensor, then look at the duty cycle the ECM is ordering for both solenoids.

If the ECM is ok, it orders the appropriate duty cycle to both sides, but the one solenoid does not respond due to a lack of oil pressure. The ECM will then increase the duty cycle and get no response. Repeating cycle.

It then sets the 1140 code.

The oil pressure problem is caused by a bad timing cover gasket leak. So, you must pull the front of the engine apart to fix. Unfortunately, I think the gasket is ONLY available with a new timing cover. Pricey.

You will want to confirm with the dealer - but my guess wold be the ECM is ok.

Post back and let us know what you find out!

Thanks! The fact that the code is thrown even with then engine off tells me it's not an oil pressure issue, but an electrical issue. When Searching forums for similar issues, I have seen people say "if the code is thrown immediately, it is an electrical issue and not a mechanical or solenoid issue," but then they never go on to explain what sort of electrical issue it could possibly be and what would be the culprit. Based on the fsm, my only thought would be a bad ecu. I was hoping someone else could verify a similar experience, but given the obscene level of sabotage this vehicle had when I received it, a bad ecu would not seem outside the realm of possibility although it does run and drive just fine now that I've replaced so many sensors, gaskets, solenoids and other components to get it there. My next step was to have it scanned but I always check with forums for known fixes whenever I can avoid spending money at a dealership. Looks like that's my next stop, thank you for the followup!

Also, I did have the timing covers apart initially when I first got the car in not-running condition. I checked the timing and reinstalled the front timing cover using rtv. Do you know which gasket could be causing an oil pressure issue? Is it one internally in the timing cover? I've had them off a few times and I'm getting pretty good at it, I can rip most of the motor apart and put it all back together within 2-3 hours so it's no big deal at this point. Here's a list of what I've done so far to the q:

Here's a brief list of what I found:

-No butterflies at all in the intake mani, both sets were completely removed. Replaced the entire intake manifold with one from a junkyard car.

-Iacv from a completely wrong car, the stock connector for it was hacked up and shoved in. I repinned a new connector and replaced the iacv with a new oem unit

-Iacv wiring blew the original ecu, so I had to replace that and the key and immobilizer. Didn't realize the iacv was the culprit until I had already replaced the ecu with the current one.

-Fuel pump was floating around freely in the gas tank, not secured into the little plastic retainer as it should've been. Secured it properly and replaced the fuel pump assembly top hat oring.

-None of the front cam/crank sensors were for the right vehicle, some didn't even fit or have the right connector type or even the correct number of connector terminals. Replaced all with new oem sensors.

-Both thermostats were gone completely, and the hose that runs from the block to the rear thermostat had been replaced with a standard hose which was completely kinked blocking all coolant flow. Replaced with new oem thermostats and block-to-crossover tube hose.

-Crossover tube had no gaskets, no rtv and nuts were finger loose. Crossover tube mating surface to the head was extremely gouged. Replaced crossover tube and gaskets with new oem units.

-Cyls 4 and 6 coil pack connectors were switched

-Clutch fan was shot and did not appear to be correct for the vehicle, didn't match the correct oem unit I replaced it with.

-Knock sensor connector was gone and the terminals were RTVed into place into the sensor terminals, no telling if they made adequate contact or not. Replaced the injector/knock sensor subharness and knock sensor with new oem unit.

-Engine bay was missing most of the mounting brackets, hardware was all mismatched garbage with SAE drive specs, a bunch of stripped out bolt holes, etc. Replaced everything with good hardware/brackets from junkyard car, tapped bolt holes that were stripped. All good as new now.

-Replaced many gaskets including the oil cooler orings and corresponding coolant hoses, transfer case motor oring, transmission torque converter solenoid, trans strainer and oring, and pan gasket. Replaced spark plugs with brand new ones. Swapped in new cam solenoids as mentioned above. New trans fluid and transfer case fluid.

I think sabotage was the correct word. Although overall the vehicle appeared to be in excellent condition and had only one owner, it would seem that owner dropped the car off with someone beyond amateur and they managed to wreak havoc. The car sat since 2007 and I've now been daily driving it for several months with only the code p1140 giving me issues. Fuel mileage is rather low - around 12mpg in the mountains and I think the code is a likely culprit.

Short on time here, I will try to check back later, but I need to understand exactly how and when p1140 gets set.

You have cleared all codes, you turn the ignition switch to "on" or "start" and the code sets? Code sets before you ever try to start the engine?

Actually I checked it today to verify what I'd said before and I was mistaken. I had thought that it came on before starting the engine in my initial troubleshooting about a month ago, but when I checked it today the code did not throw until immediately after starting the engine. So in fact it could be an oil pressure issue I presume based on your earlier response. I can dive into the fsm a bit more, but do you have any direction as to where the seal/gasket would be leaking that could cause the issue? I have no problem tearing apart the timing cover but I want to know what to look for before I get into it. Thanks again for your help.

Any suggestions regarding which seal could be causing oil pressure issues to the solenoid? I've spent days of searching with nothing definitive, just comments that this gasket exists but no pictures or anything really helpful so I know what I'm even looking for or where on the timing cover it is placed.

Been looking for an old thread that had a few pics, but I have not found it. I will post something tomorrow either way.

Well, went looking for the thread I found several months ago, but it seems to have disappeared. So lets start with the parts diagram (you can find all the parts diagrams here) http://www.courtesyparts.com/pathfinder ... _4712.html

2001-2002 is about half way down the page. I have not had to pull my timing cover, but I assume things will become pretty apparent as you pull things apart. However, check out parts 13035h, ha, hb. Those are o-rings for oil ports. Could be part of the problem.

I did have another thought after I read your repair history. Normally, I would not consider it, but in this case I think it may be possible the heads have been pulled at some time on your engine. I think it is possible the timing chain up at the cam sprocket could be off one tooth. Every other repair that was done seems to have been screwed up in some way, so I think you would have to look closely at that if you pull the front of the engine apart. You said you had looked at the timing, but I wonder if you were really looking closely for that kind of problem. I know I probably would not be looking for one tooth off unless I knew the heads had been off.

If you want to get a little more comfortable that your wiring is ok, clear your codes, shut the engine off, and disconnect one sensor (i.e. - passenger bank cam position sensor). Restart the engine. You should get a circuit code thrown for that sensor only. Cam position sensors are p0340 and p0341, I think. Can't remember the circuit codes for the cam solenoids right off. Then shut down, reconnect the sensor. Restart and clear codes. The code should not come back of course.

If that works correctly for each sensor, you can be confident the engine is seeing that sensor electrically and looking for the sensor input. That should help determine that the ECM is seeing the sensor on the circuit throwing the p1140.

If they all throw circuit codes like they should, I would consider wiring to be ok.

I was also going to recommend calling the dealer with your VIN. There are several recalls that apply to you. I'm not sure if you know of them - but if you are going to keep the vehicle for awhile might as well get them done. They are discussed in the stickies at the beginning of the forum - air bags and strut tower rust.

You seem to have done a fair amount of wrench twisting in your time - where did you get your auto experience ?

Yeah timing was the first thing I checked. I bought it from a small time dealership that got it from an auction and tried to flip it, but couldn't get it running. He convinced me that the timing chain was broken and not to attempt to crank it, so I opened the timing covers and everything was not only intact, but in time as well.

I already did the cam sensor connector removal check to be sure I was getting the right code. When I remove the ds intake cam sensor I get the added p1145 along with the p1140. When I only remove the passenger cam sensor, I just get the same p1140. At this point I'm sure that if it is an electrical issue, it is within the ecu, but I can't rule out the oil pressure issue just yet. I also looked extensively through that diagram and could only see the orings, so I'm guessing that is what people mean when they refer to a rear timing cover seal. Shouldn't be difficult for me to check, will be a fun educational experience for me. That's how I've learned everything I know, experience and a whole lot of research. Thanks again for your help, I'll let you know what I find after I rip into the timing cover.

Well, if you want to have a little fun, there is one more thing you can do.

The electrical functions / mechanical functions for cam advance on both sides of the engine are the same. Just mirror images.

Take the driver side cam solenoid connector and jumper it to the passenger side solenoid. Jumper the passenger side cam solenoid connector to the driver side solenoid.
The ECM driver side circuits are now monitoring the passenger solenoid.
The ECM passenger side circuits are now monitoring the driver side solenoid.

Rev the engine a couple of times to make sure the solenoids operate.

*If the ECM is ok, the p1140 goes away, since the driver side solenoid is ok. (Computer thinks it is monitoring the passenger side solenoid)
*Code 1145 will get set. Driver side circuit of the ECM will now set the code for what it thinks is the driver side solenoid.

If the code changes when you swap sides, it is an engine problem.
If the code stays the same, it is an ECM problem.

Hope that makes sense. But I think you get the idea.

Very cool, I will try that this afternoon and report back with my findings.