I'm Confused! P1110/P1135 - VTC Camshaft or Crankshaft Sensor?

[bradesp]

Guys Help! My 01' QX4 shows two codes on the OBDII computer - P1110 and P1135. The dealer says replace both VTC sensors. So I've read through all the relevant posts here and I'm confused... Some say this is a Camshaft Sensor, some say it's a Crankshaft Senor, some say IVTC and some VTC... Some say RH Bank means Passenger Side, some say it means Drivers side... To top it all off the the online parts companies seem to call it different things as well.

So, please help me figure out what it is I'm trying to order... Is is ITVC? Is it VTC? Is it Camshaft or is it Crankshaft? The only part number I have acquired is 23731-2Y524. It's clear however I need TWO sensors, so I assume these are two different parts, yes? If so, it would be great if someone could help with the part numbers.

Thanks in advance for your help!

bradesp

[Pwnin O'Brien]

Ok, so let me start by letting you know what the codes are...

P1110: Intake Valve Timing Control (Right Hand, or Passenger Side)P1135: Intake Valve Timing Control (Left Hand, or Driver Side)

Straight from the service manual..."This mechanism hydraulically controls cam phases continuously with the fixed operating angle of the intake valve. The ECM receives signals such as crankshaft position, camshaft position, engine speed, and engine coolant temperature. Then, the ECM sends ON/OFF pulse duty signals to the camshaft timing control valve depending on driving status. This makes it possible to control the shut/open timing of the intake valve to increase engine torque in low/mid speed range and output in high-speed range."

This is a very common issue on 2001 QX4's for some reason. Many NICO members have run into the issue and there are lots of threads about it. There is even a write-up on how to tell if it's a sensor causing the issue (zerothread/116383). I do know that it is safe to drive the vehicle with these codes and some members do that as an alternative to diagnosing/repairing it.

Here are the possible causes for these two codes:

- Harness or connectors (Intake valve timing control position sensor circuit is open or shorted.) - Crankshaft position sensor (REF)- Crankshaft position sensor (POS)- Camshaft position sensor (PHASE)

Since you are getting both codes at the same time, one would deduct that you have a bad sensor (one of the three above). Since I don't have much experience with these two codes, hopefully another member who has had these and repaired the code can help you further.
Modified by Pwnin O'Brien at 9:37 PM 12/31/2009

[bradesp]

Thanks Pwnin,

The Dealer says specifically "Replace VTC Sensors"...

What is interesting is that in looking at all the various camshaft senors the only two that are described both as Camshaft and VTC (in the same description) are those listed at the link below. The third CamShaft sensor (the left lower) is referred to as a Phase sensor. The VTC senors for the left and right side appear identical. Perhaps this is what I need to order?

http://www.partsgeek.com/catal....html

[Pwnin O'Brien]

Well there isn't a specific VTC sensor, per se. The IVTC system will monitor the camshaft position sensors and the two crankshaft position sensors for the engine speed. A failure of any of these sensors can result in the P1110 and P1135 codes. When they say "replace the VTC sensors" they are speaking in generic terms. Did you take your vehicle to an Infiniti/Nissan dealership? If so, they should have hooked your vehicle up to the CONSULT-II computer which would tell them for sure what the issue is as they can monitor all of those sensors for possible failure.

You may want to call the dealer and ask them more specifically which sensor they recommend you replace. Ask for the specific sensor name (Crankshaft/Camshaft) and the sensor location with respect to the engine. It is even better if you can get them to print out the CONSULT-II screenshot of the failed sensor so you know for sure they have the issue pinpointed. If you paid a one hour diagnostic fee then they should have no problem showing you all of this information.

[bradesp]

The dealers service manager handed me a printout that simply said "replace two VTC sensors". It appears there are three Camshaft Sensors. Two are identical parts and are referenced as VTC Sensors and one is different in shape and size and is referred to as a Phase sensor... So that would suggest that the pair I need are the two that are identical.

[Pwnin O'Brien]

Looking at the '01 service manual I can only find one camshaft position sensor on the vehicle. I thought there were three camshaft position sensors but I may be wrong. It looks as though you only have one which is located on the front of the engine at the drivers side camshaft. This sensor may take no more than five minutes to replace in your driveway if it is indeed your issue.

Maybe someone with an '01 can chime in.

[Chuck Tribolet]

I have an '01 PF and have had this problem off and on for several years. It'soccasional in other Nissan/Infiniti vehicles with that engine, but most commonon '01 PF/QX4. It would be really interesting to know why.

There's a camshaft position sensor on each cam. IIRC, the US passenger sidesensor is on the side of the head, forward, the US driver's side sensor is onthe front of the head. They are O-ring sealed so you can pull them out withoutneeding a new gasket if you are careful. Be sure to rub a little engine oil onthe O-ring before reassembly so that it slides into place without deforming.

There's also a crankshaft position sensor somewhere down low. Maybe twoof them.

The dealer replaced the solenoids on mine. It didn't help.

I can pretty much keep the codes away if I use the 1500-2500 RPM rangeas little as possible, especially when accelerator or going up hill. I figuredthis out by reading out the freeze frame a bunch of times.

My theory is that it's caused by the oil pressure getting a bit low (mine has175,000 miles, 1/3 towing my boat.) The cam advance is oil pressure powered. Keeping the revs up keeps the oil pressure up. I also switchedfrom 5W30 Castrol GTX to 10W40 Castrol GTX, and that seemed to help too.

[dbgeek]

Just to add another data point:I've been through the whole MAF, O2 sensor hell, including P1140 (?). Once I fixed all of those issues, our 01 Pathfinder with 165k miles has been code-free for 75k miles while using 10w30 Castrol oil. I figured the 5qt walmart Mobil 1 would give me a bit longer change interval, so I used 5w30 because it is 'recommended'.

Pathfinder started showing P1110, which I would reset, and it comes back...

Changed oil to Mobil 1 10w40, reset code, and no codes come back. Yay.

I do quite a bit of 1500-2500 rpm cruising, even uphill. I think Chuck hit it - low oil pressure resulting in the cam adjustment not happening.

YMMVPete

[bradesp]

Pete,

I'm not sure I follow what you actually did to clear up your issue...

Did you actually replace the MAF/02 Sensor and then switch to the different oil type / weight or did you simply have the codes reset and switch to 10w30 Castrol Oil?

Thanks!

Brad

Just to add another data point:I've been through the whole MAF, O2 sensor hell, including P1140 (?). Once I fixed all of those issues, our 01 Pathfinder with 165k miles has been code-free for 75k miles while using 10w30 Castrol oil. I figured the 5qt walmart Mobil 1 would give me a bit longer change interval, so I used 5w30 because it is 'recommended'.

Pathfinder started showing P1110, which I would reset, and it comes back...

Changed oil to Mobil 1 10w40, reset code, and no codes come back. Yay.

I do quite a bit of 1500-2500 rpm cruising, even uphill. I think Chuck hit it - low oil pressure resulting in the cam adjustment not happening.

YMMVPete

[dbgeek]

When I purchased the Pathfinder at 58k miles, it had the typical issues with P1140, then MAF, then O2 sensors, reprogram ECU for O2s, etc. I fixed all of them by 75k miles. I was just making a point that it had the typical sensor/solenoid issues years ago that I fixed.

Fast forward 75-80k miles of happy, code-free driving (using 10w30 oil) to about 160k miles.

THEN I decided I wanted to go 7.5k between changes and used 5w30 M1 oil. Code P1110 appeared and kept reappearing after reset. I verified the operation of the solenoids and swapped sensors with known good units. No change in P1110, it kept re-appearing.

After reading a couple of posts like Chuck's, I decided to try going to a higher weight oil. Swapped to 10w40 M1, and the code has not re-appeared.

I think that insufficient oil pressure was causing the cams not to advance the correct amount, thus throwing the code.

[Pwnin O'Brien]

I think we need a technical sticky on these codes (when they show up at the same time) since this has been happening a lot lately. Why is it, though, that this issue is predominantly on 2001's? That's one thing I can't understand. Is the lubrication system different on a 2001 where it has lower pressure at the IVT control valve when compared to newer models? Or is this indicative of a malfunctioning IVT control valve where it's not opening completely thus not allowing the timing to advance/retard properly?

[mrpatel302]

hey got a similar issue here. i was wondering what the oil pressure in the engine should be. i did a few tests and im getting 25 psi at idle and as you rev it goes up considerably. im talking about the engine oil pressure.. please advise
do you think this is still low