'06 M45 Camshaft Sensor Loss of Power

[CaduTwo]

Hello. I swapped the camshaft sensor, changed the oil and filter, and have a loss of power on restart. There was just enough power to reverse off the ramps and then get stuck on the slightly sloped driveway with the same thing happening after a restart. Disconnected the battery to reset the ECM, same. Swapped back to the old part, same power loss after initial 5-10ft of movement. Does anyone know what I might be missing or have bumped that is causing the total loss of power?

The only cables I disconnected were the MAF and sensor itself, which didn't appear to have any corrosion or brittleness on the wire. The wiring harness tape however was cracked. I'll use some plastic safe Deoxit on the connectors.

Thank you very much.

I have previously swapped a failed crank sensor about 6,000mi ago.
New part: Hitachi CPS0165

[AZhitman]

Seems to me there should be a sensor reset/relearn procedure, most likely documented in the FSM.

[CaduTwo]

Seems to me there should be a sensor reset/relearn procedure, most likely documented in the FSM.

Thanks for replying. That's what I thought, but EC-391, Removal and Installation of Camshaft Position Sensor, just says refer to EM-84, a diagram showing location and the subsequent pages don't mention any relearn.

I'm searching to see if others like the crank or MAF related parts need to be relearned since the MAF was also unplugged but haven't seen anything yet.

[VStar650CL]

Crank and cam are just ordinary Hall sensors. There's no programming or reset involved, they either work right or don't. Did you clear codes after reinstalling the original part? If not, the ECM may still be in limp mode, and I don't think removing power will erase anything on an '06. For the most part, past about '01 ECM codes are all stored in flash or EEPROM and not RAM.

[CaduTwo]

The ECM was not in limp mode to begin with. The original code was P0021. The crank sensor had failed, with its own code(resolved with a plug n play new sensor), shortly after that appeared so I was swapping the camshaft sensor before moving on to the other more complicated possibilities like the timing chain / gallery gasket. The mechanic had said that they swapped it and P0021 was still there but since the crank they swapped with failed shortly after I was trying a new part.

There are currently no codes, just no power 3-5 seconds after starting. Since I removed the air intake/filter housing to access the cranksensor, I'm checking the wiring harness near it in case I disturbed/yanked them inadvertently with the intake housing legs on reinstallation but I haven't seen anything obvious.

Could changing the oil have worsened the P0021 issue?

[VStar650CL]

It's possible. P0021 is a performance code, it means the IVT angle commanded by the ECM isn't moving the bank2 intake cam phaser to the right place. It isn't usually a sensor problem. IIRC the oil galleries go right-left on axial VQ's , so if the oil is too thick the starvation will show up in bank2 first. If the crank was sludgy it's also possible a gallery passage or IVT solenoid got plugged by debris which was scrubbed loose by detergent in the fresh oil. It's also possible (maybe probable if the new crank sensor is aftermarket) that the crank sensor is causing the whole issue and the ECM is blaming the wrong component. I don't like to harp on this, but you'll find it in here from me in lots of other places -- I can't begin to describe all the needless head-scratching and heartache I've seen over the years caused by aftermarket Hall sensors. There are lots of places on Nissan products where aftermarket parts are perfectly fine, but cam and crank sensors are not on the list.

BTW, P0011/P0021 do have a failsafe. They lock the cam phasers, and I think the VVEL controller will also lock the VVEL in response. So those codes will cause a substantial power loss. They're also 2-trip codes, so they won't turn on the MIL for the first cycle after clearing, and I'm pretty sure the failsafe won't clear until you either manually clear the codes or the ECM decides the phasers have passed SRT.

[CaduTwo]

Thanks. The vehicle in question is the '06 M45 w/ the VK not the VQ but I'll check for that as well. I'd read yours and other's warnings about aftermarket sensors and the replacement crank is a genuine Infiniti 23731-4M50D that has been running well. The replacement cam was a Hitachi CPS0165, but the camshaft that was already in there was aftermarket. I'm not sure if that was there a long time or not, since the vehicle was previously only serviced at the dealer or UpRev using Infiniti parts, so it's possible the mechanic investigating the P0021 had swapped that as a temporary check(sadly they passed, vehicle was taken to dealer and their head of service also passed(f cancer!) after swapping the oil and planning on measuring it after a certain amount of miles so that diag was in limbo and I am picking up from our last convos as enough time had passed that I needed the code fixed for registration).

Oddly I didn't notice any performance loss with the P0021 code. The oil didn't appear to be sludgy, and it was at the high level before the change, but there did appear to be a recent oil leak somewhere, with it on the outside of the pan but not pooling on the driveway.

[VStar650CL]

Sorry, forgot this was your 45 and not the 37. Brain fart.

Leaks won't generally affect the IVT's unless it's a leaky gallery gasket, and those are a) internal and b) are strictly a VQ issue. However, the oil still takes a steep climb through small passages on a VK and a leaky main tensioner can cause starvation of the cam phasers. I'd try a new bank2 IVT solenoid before anything else, and make sure the engine has the right weight of oil (no thicker than 10W40 and no thinner than 5W30).

[CaduTwo]

ty. The old and new oil is 5w-30 full synthetic. On this VK the passenger solenoid is blocked by the engine without taking off the entire housing. This is not mentioned in the Infiniti billing time est(0.5hr) I'd removed the driver side solenoid and it was clean, and tapping both with 12v power heard the clicks.

Is the housing removal / new liquid gasket something an amateur should attempt? I worked with aero mfg machinery and lab equipment so I lack the mechanic experience/wisdom to know what downstream surprises lurk beyond the FSM procedures.

Is there anything else I should check / preemptively fix while that cover is removed?

[VStar650CL]

I'm probably the wrong guy to ask about that, I'm a Nissan tech and I recall working on a VK45 exactly once. However, the exploded drawing shows the solenoids both located in the phaser covers and not the timing cover, so I think at worst you'd need to unbolt the phaser cover to R&R the solenoid. They're in more or less the same position on the VK56, and while they're a PITA to get at, they aren't impossible.

[CaduTwo]

Thanks. I started it to today to see if there was any improvement with oil/sludge shifting around and a P0104 code appeared for the MAF. That'd point to a break in the wiring harness or connector when it was disconnected for the camshaft installation. I was quite gentle with it, had given it a cursory visual inspection and put some DeOxit on the contacts after the initial loss of power, but will clean it with some MAF cleaner and check the fuse and part with a multimeter now.

[VStar650CL]

Is that a typo? P0104 doesn't show as good code on an '06 VK45. If it's P0102/P0103 then it's a flatline code and you're right that the culprit is probably wiring. If it's P0101 then it probably isn't the MAF causing the issue, unless it's just dirty. P0101 is a performance code, it's essentially a "catchall" for any induction problem the ECM can't sort out and identify. It's usually caused by debris in the MAF, a vacuum leak between the MAF and Throttle Body, or a bad PCV Valve.

[CaduTwo]

Good catch! It was a typo it's P0102. I'll check the MAF w/ a multimeter, but I saw that the ziptie for the MAF wire wasn't replaced when the mechanics were testing the other things (understandable, got it back mid-job after they had to go to the hospital), so the harness was probably bouncing around weakening the wire/connections since then.

[VStar650CL]

Good catch! It was a typo it's P0102. I'll check the MAF w/ a multimeter, but I saw that the ziptie for the MAF wire wasn't replaced when the mechanics were testing the other things (understandable, got it back mid-job after they had to go to the hospital), so the harness was probably bouncing around weakening the wire/connections since then.

That happens a lot. You'd think they'd use superflex wire on a connection that's going to twist every time the airbox cover is removed, but nooooooooooooooo. Gotta save that penny.

[CaduTwo]

Got the MAF connector going, codes reset and P0102 not coming back. Let it idle to warm up, loss of power is still there but it's not a total loss like when backing it off the ramps after the oil change. Car is moveable but only if above 3k RPM. On restart P0021 back w/ same power loss unless at above about 3k rpm. There was some smoke if revved that high coming out of the engine bay. I'm surprised that the issue showed up *after* the oil change but not before.

Looks like the next step is to remove the phaser cover, check the solenoid / swap it with the opposite bank and see if the problem still exists?

[VStar650CL]

Provided they're swappable, yes. Check the factory part numbers first and make sure they're the same, sometimes bank1/bank2 are different.

[CaduTwo]

Thanks, sorry for the slow response, family had an emergency.

I finally got the cover off, and there didn't seem to be much in the way of sludge that would clog the solenoid. The smartphone camera AI added quite a bit of sharpening and the oil residue was smoother than appears in the photo. Solenoid was clear and moving well with 12v test, and 8.7 ohms. FSM says 7-7.5ohm, but don't know if all models/revisions were the same as the original '06 solenoid.

Is the darker ring around the shaft of the camshaft sprocket enough buildup to cause problems? Can't see the sprocket teeth from here.

I guess the last thing on the list is checking the rest of the wiring harness, and then
FSM-EC-902

15. CHECK CAMSHAFT SPROCKET
Check accumulation of debris to the signal pick-up portion of the camshaft sprocket. Refer to EM-215, "CAM-SHAFT" .

Is there anything I should do while this is open before putting it back together(other than replacing gaskets). Should any cleaner be used? Plastic safe like MAF?

There is also a small(not a big deal according to the mechanic who last saw it) oil leak around the intake covers. Is it possible that this is causing low oil pressure and the P0021, even immediately after an oil change?

[VStar650CL]

Hard to tell from the pics, but that o-ring looks pretty flat and here's a lot of brown in the passages. All it takes is a tiny leak or blockage to cause enough pressure loss to be problematic. Leaks can be down inside the oil gallery too, or in the cam phaser itself. It isn't necessarily in the cam cover.

[CaduTwo]

Ty. Yes the gasket is pretty flat, I'm replacing those gaskets before putting it back together. I meant to ask if it's appropriate to detach that phaser and inspect the inside? I didn't see it anywhere in the FSM diagnostic flowchart, but that also might be only for 120kmi the prem maint followed and not for things older.

Can you just take the phaser out without messing with the valve covers or anything special to fix the angle so it goes back in at the exact orientation? Don't want to pull it and see something rotate and not know how to get it back.

Prior to the oil change and loss of power, it had a constant P0021 that the mechanics weren't sure what was causing it because it was still running so well, is it possible the phaser was stuck in a position that was used most often for the same type of calm driving so didn't still passed inspection and sounded normal?

[VStar650CL]

It's possible something is wrong in the phaser but not exactly likely, unless maybe it's gooped up. Your engine looks pretty clean, so if the problem is oil then I'd say a leak is more likely than an obstruction.

[CaduTwo]

That's what I thought, but I've already taken the cover off and all that entails wondered if it'd be worth/possible to take off the phaser and inspect/clean it, rather than only put it back with new gaskets and hope it's correct, then have the larger job of taking off the valve cover and inspecting the oil pathways there.

[VStar650CL]

Nissan sells the phasers as an assembly, and frankly I've never had occasion to take a VK phaser apart. They're usually pretty simple, but some of them have trick little springs and can be nightmarish to reassemble if you take them completely apart. That's your call, I can't offer much help.

[CaduTwo]

Ah I think I answered my own question seeing the timing chain diagram. On EM-210 it shows that the timing chain is directly attached to both camshaft sprockets - on some vehicles it was sprocket->sprocket->chain so the first could be taken out but it doesn't look to be the case here with the timing chain tension.

Looks like if I take that phaser out I'd be taking off the whole front cover to get the timing chain back on.

[CaduTwo]

I took some better photos of the washer/gasket on the solenoid output. It does seem flat/flushed. The replacement gasket however, does not seem to be the correct part. FSM says replace o-ring after taking off VTC cover, and the part lookup is 13010H, but that is currently a donut shaped o-ring and the original looks like a flat cylindrical rubber washer/gasket. Original feels stuck. Is the black rubber in the photo a part of the oil filter assembly(15200M) that goes behind it and towards the camshaft?

If it's correct, how does one blindly center this o-ring between two flat vertical surfaces without it falling out when putting the VTC back on?

Tyvm for any suggestions.

[VStar650CL]

Use a little heavy grease to keep it in place. They always squash flat after they've been in awhile, but eventually they lose their spring and may cause trouble. The racing guys all replace them with Viton.

[CaduTwo]

TY. The new part(o-ring) does fit, with a slightly larger inner diameter, but the original was definitely a flat rubber washer so I guess they just changed somewhere along the way.
I cleaned the tube as much as I could from that end, put everything back together, and the P0021 is still there, but the limp mode has much more power in drive, but same very weak reverse.

Since there was a moderate improvement in forward power, would that imply that it's not quite as far out of phase after cleaning, and I should swap the valve cover gasket and inspect/clean the other end of VTC oil hole to check for clogs?

I got an xtool tablet with Nissan/Inf software to view the phase angle, but it has been unable to connect to the ECU. It does fine to the Q70h, so I'm checking to see if there's any pin problem or different pin-out mode to select for the tool. My cheap ELM bluetooth OBD scanner still works fine.

[CaduTwo]

Could oil in exhaust at 5k RPM+ be caused by the P0021 timing error, or could the oil leaking into the pistons at higher RPM/heat/pressure cause lower pressure elsewhere and trigger the P0021 code?

Passenger side(where the P0021 is) valve cover gasket needed to be replaced so checked the other things along the way.

Valve cover coil seals were leaky and the spark plug wells were filled with a significant amount of oil. Cleaned that up and put in new sparks. Old ones had moderate oil fouling and a small amount of carbon.
PCV was bad, swapped.
Camshaft didn't seem to have sludge. Checked groove beneath camshaft bracket and it was also clean.

Vehicle sounded much better and had more but still low power at RPM <3k.
P0021 code did not show up on start.
Oily exhaust from plug wells went away after idling for a few minutes.
P0021 did not come back driving back and forth gently until running the car in neutral for 5min revving to higher 2-5k RPM.

[CaduTwo]

Finally found the problem.....

When the shop was looking into the P0021 and changing the oil to measure consumption along with seeing what other standard maintenance needed to be done, they'd mentioned the usual dealer $$ transmission fluid dirty, recommend flush(regardless of whether it had just been done).....

Someone had drained the transmission totally. So when the car had been driven a few hundred miles to measure the loss it'd burnt up whatever was left inside and the trans was in limp mode coming off the ramps from the oil change.

TY for the help along the way, it appears all those other problems were incidental(and also missed by the techs?!?). Adding transmission fluid instantly brought the the power back, but at higher speeds the P1759 is now there...probably from the trans damage. What a mess.

[VStar650CL]

Glad you got it straight, but that's pretty f#cked about the transmission being drained and not refilled. "Someone" needs a spanking.