Having some issues with unstable idling, lean fuel, made many tests, replaced all sensors, but keep getting 0335, crank sensor. Replaced 3 times, but still there. Have disconnected one camshaft sensor, and got same 0335 code! And the engine is running same without the sensor! Starts the same, rev up the same! Disconnected the sevond cam sensor, and engine is still running same!
Any ideas?

Once a code gets thrown and the engine is running in failsafe, the ECM often stops looking for other DTC's and won't throw codes in systems it isn't looking at because failsafe has "locked" them. Cam phasers run in the neutral position in most "reduced power" failsafes, so the ECM probably isn't looking. That's a common circumstance, we just had a Quest in the shop yesterday which had induction codes because of a crappy MAF, then started throwing P0021's for the front bank phaser as soon as the induction codes were resolved and cleared. The ECM simply wasn't looking at phaser timing because the induction codes put the engine in open-loop failsafe. The upshot is, you can't necessarily tell anything about a given subsystem when there are codes in other parts of the engine.

That said, it's common for a lot of Nissan ECM's to get confused about cam and crank sensors and blame the wrong culprit, and it's also common for Hall sensors to misbehave during cranking and then work fine once the engine fires. The first things you should be checking for are solid power and ground at all three primary sensors (crank and both intake cams), good pin-fits at all three, and no debris on the reluctor wheels. If those check out, then you may need scope the sensors or simply replace all three to rule out a dicey one.

Thanks for the super detailed reply. I appreciate it. I have replaced all 3 sensors, checked for 12V and ground. Checked the crank sensor with scop. All were great. With Autoengiuity, i saw -28, to -30 in the right and left cam timing, so im confused. And when i have disconnected the cam sensors, it did not get into fail safe mode, i think, because i could rev up the engine to high rpm, and the feedback to the pedal was normal. Is it normal ?
What can be the reason to keep getting 0335? Running lean? And rough idling? No vaccum leak, tested with smoke machine, fuel flow and pressure is perfect, replaced maf....really upsetting

If those readings were at idle then something is very wrong with your cam timing, they should both be reading around zero at idle (the FSM says +/- 5 deg but that's unusual, more than +/- 2 is usually an issue) and only advance much when you goose the gas. It's unlikely both sensors are misreading, and a jumped chain isn't likely either because the VK's have two main chains, not a main and sub chains like a VQ. So unless something is wrong with your crank sprocket or your scanner is lying, the only likely issue is low oil pressure to the whole timing cover.

I will check it again with diff scanner.
But is it posdible that engine works the sane with abd without the cam sensors being connected?

Most (but not all) Nissan ECM's will start off the crank sensor if the cam sensors are inoperable, and they'll pretty much all keep running that way if the cam sensors are yanked with the engine running. So yes, that's possible.

i understand.... i thought that is a reason for my issue...
so now i am stuck and do not know how to solve the problem. i am also not sure that the 0335 and the lean/rough idle is the same problem
thank you for trying to help me.

I don't think you're going to find the answer without an oscilloscope verification of the cam/crank relationship, an oil pressure check, and if that all passes, yanking the timing cover. With the cam timing way off on both banks, I only see three possibilities, your ECM has lost its mind, your oil pump is bad, or something is seriously amiss in your timing chains, crank sprocket, or timing cover oil passages.

oscilliscope done already with no issue. ECM i had another one that Z-fever has done for me long time ago, and it works the same. oilpressure is really good. i gues i am about to take a look at the timing chain and cover.
will update soon.

Did you verify the relationship with the scope, not just the signal integrity? You need to put one of the cams and the crank up at the same time, and count pulses from TDC to capture whether the scan data of -30 degrees is accurate. If it isn't then it pretty much means either your scanner is wonky or your ECM is insane, because one of them is reporting things that aren't true. Otherwise you have a problem in the valve train or an oil pressure issue and you need to find out which. I won't say it's impossible for both chains to jump by exactly the same amount, just unlikely.

i did not. mine is one channel. i will do that for sure. i hope i will understand what i will see in the scope

Oh, whoa, it just occurred to me, you have the same setup as the gen1 Titan VK's. You have three cam sensors, not two. The actual sync signal for both cams comes from a separate "phase" sensor on the left bank cam. It's located at the front of the engine on the VK45, looks to be right above the A/C Compressor. See EC-825 here:
https://www.nicoclub.com/service-manual ... 5%2Fec.pdf

The "cam sensors" on top of the engine are actually called "intake control" sensors and put out a simple 1-pulse sync signal indicating cam advance, the complex 1-2-3-4 pulse signal that syncs the cams to the crank comes from the third sensor. Check out this VK56 diagram from the Rotkee wavebase:
https://rotkee.com/en/wavebase/good-tim ... ?system=51

The blue channel is the crank, green/red are the intake control pulses, and brown is the phase signal. Hall sensors can fail in a mode called "phase shift" where they trigger later than they should, and in this case I bet that's what happening. The ECM is blaming the crank sensor for not being synchronized because the phase sensor is working but late, so it can't tell who's at fault and the data shows a shift on both cams and not just one. Try replacing the phase sensor, I bet that's your issue.

Wow, I'm so excited that a stranger (by the way, what's your name?) invests so much for me, thinks of a solution for me and details in detail. This is really a no-brainer for me and I don't know how to express how much I appreciate it. I have to go out now for a surprise birthday for a friend and probably the whole party I will think about this solution (and I am already 62 years old and still excited) I was wrong all the way and referred to the sensors of the IVT. I probably forgot to mention that it is a VK45DE engine from a 2006 Infiniti M45 that I installed in a 1950 Pontiac and all that i am doing by myself' here in Tel-Aviv, Israel. Thanks again and I will update soon

Holy crap, that sounds like a cool project. My grandpa on Mom's side had a '51 Catalina straight-6, he adored that car and drove it well into the late '60's. I spent a lot of kid-time in the shotgun seat, so that really takes me back.

Mazel tov to you and your friend, have a great time at the party. I'm Gene and I'm a Nissan/ASE master tech, and I'm seven years your senior. I absolutely love being able to help with an offbeat project like your '50 Q-ship, so consider it my pleasure and privilege. You must post some pics!

i will try to take photos showing also the VK45 inside the bay

That's a gem!

Just came back from my parking place... unfortunstly, replacing the cam sensor did not change anything. I have few sensors, tried 4 of them. Also replaced with the IVT sensors, no change. In the beginning i had a feeling it was better but eventualky, its the same. It did not throw the 0335 code till now so maybe that is the only improve. But sometimes it start perfect and many times its not starting at all, sometimes with backfires. I do not have my laptop with me, but scanner shows short term fuel -25, means still lean, idling is rough....

Well, with those cam angles, it's time to check your patterns with a 2-channel scope and see if your ECM is crazy or not. Use the pattern for the Titan I posted as a reference, yours should be pretty much identical. Put the crank up on ch1 and the phase up on ch2. Notice that the first falling edge of phase always coincides with the middle of the "gap" in the crank pattern. If your pattern is significantly shifted from that position then your timing is jumped.

Thanks. Will do that on Friday. BTW, in order to use a scope do you another method than to strip the isolation from the signal wire?

You can back-probe the connectors with a small safety pin or t-pin, there's no reason to strip anything. Just slide the pin in under the rubber and push through until it makes contact with the neck of the connector pin.

Thanks. Will do that on Friday. BTW, in order to use a scope do you another method than to strip the isolation from the signal wire?

Ok great

udibl wrote: ↑

Mon Aug 28, 2023 10:59 am

Thanks. Will do that on Friday. BTW, in order to use a scope do you another method than to strip the isolation from the signal wire?

As crazy as this may sound, Remove and inspect the coil pack for cylinder 2. The one thats right under the oil filler cap. If that connector is oily, spray it down with brake parts cleaner and do the same for the coil pack. I went through the same as you and this turned out to be the culprit.
The cam and crank sensors all share the same power source. the oil build up on/in the connector was causing a short triggering the fault when there was nothing wrong with the sensors in the first place.

Crazy or not, i will surely try everything.... will try your idea and feedback here. Thanks!

crweaver wrote: ↑

Tue Aug 29, 2023 8:12 pm

As crazy as this may sound, Remove and inspect the coil pack for cylinder 2. The one thats right under the oil filler cap. If that connector is oily, spray it down with brake parts cleaner and do the same for the coil pack. I went through the same as you and this turned out to be the culprit.

That's not crazy, that's smart. Wiring is how the signal works and travels, it has to be good just like the sensor and reluctor. Excellent suggestion.

i have suspected that power might be a problem, 2 weeks ago and with the crank sensor is did live testing, connected multimeter to the wires while cranking and saw stable 12V even when the engine did not start so i understood its ok. fool me i did not do the cam. i will do the same to the cam sensor and also check coil 2 connector. thanks guys

i have another harness here in my office which i do not need, so i was wondering about the wires. i have open part of the hrnessfrom the CMP onwords and i have discovered that the CMP does not share same power and not even same ground with the coils. both IVT, CMP and CKP share same power and same ground.
still i will test the power while running the engine

Check ground integrity too. Back-probe the sensor grounds with the engine running and measure to the negative battery post. Anything above 50mV (0.05V) is trouble.

Just curious...I have read in the past where some cheap aftermarket sensors do not work work properly. Did you source OEM sensors?

Yes sure. All original sensors. I had aftermarket MAF but to be sure i have replaced it as well with original one