P0018 Problems

[osudoc11]

I have checked all the connections I can see and everything seems to be fine. I am getting signal from the cam position sensors and to the OCV's when I data log. I would think if something were loose then I would see interruptions in signals. Is the P0018 pretty specific for the driver side intake cam? With these complex systems now-a-days is it possible one of the others is messed up and it is just throwing that code? I put the header on myself and the 02 sensors are down near the passenger exhaust cam. If I dislodged or damaged anything I would suspect it would be around that.

Thanks for all of your help by the way. This is an extremely frustrating issue for me. I spend a lot of money and time to make my car the way I want it and now it is turning against me.

[steve99]

Originally Posted by osudoc11

I have checked all the connections I can see and everything seems to be fine. I am getting signal from the cam position sensors and to the OCV's when I data log. I would think if something were loose then I would see interruptions in signals. Is the P0018 pretty specific for the driver side intake cam? With these complex systems now-a-days is it possible one of the others is messed up and it is just throwing that code? I put the header on myself and the 02 sensors are down near the passenger exhaust cam. If I dislodged or damaged anything I would suspect it would be around that.

Thanks for all of your help by the way. This is an extremely frustrating issue for me. I spend a lot of money and time to make my car the way I want it and now it is turning against me.

the 02 sensor wiring or sensor faults would cause different codes. like P0420, but in tuned roms they are disabled especially if rear 02 has been re-purposed as flex fuel sensor input.


Im not sure if P0018 is specific to a specific side, judging by the number of TSB and the complex diagnosis of these cam issues its appears very difficult to isolate the exact cause.


As I said previously I am not an expert on this fault, however its reasnobly common and I have read of several instances of similar faults. Dealers have often had cars for several days and had several attempts for fix these cam issues, often replacing multiple expensive assemblies including the ECU to correct the problem.


It fairly unusual in a 2015 model.


My suggestion would be to return the car to stock including ecu rom and return it for repair under warrantee (you did say it now exhibits the fault with stock rom tune I believe). It likely the fault may be in manufacturing tolerance if several components and the combined effect is the fault your seeing. These assemblies OCV, cam actuators/sprockets ECU ect are all expensive , too expensive to trial and error swaps on.


Its extremely unlikely that the problems are a result of your mods, but I would swap everything to stock just to avoid a hassle at dealer.

[osudoc11]

So I am trying the stock tunes you provided first. They are in .hex format. I wanted to look at them before I flashed. I have ecutek which only seems to open .rom files. How do I flash the .hex file with ecutek?

[osudoc11]

Ok I think I'm making a little progress. I data logged some more today and threw the code. I had just reset the DTC's. I was just idling and not even moving when the code was thrown. All of the cam angles were essentially zero, as were my VVT intake angle targets. The only thing I noticed that could be off was the VVT Aim angle and the Exhaust hold learn value. These are both expressed as a % and were about 55% at idle. I may be mistaken but I thought the Aim angle was supposed to be 0% at idle. Any advice would be helpful. Also if anyone can data log these values on their car and post them for comparison that would be great. Thanks.

[osudoc11]

Update. So after logging some more the VVT aim seems to correlate with the OCV duty % which match up pretty close. However, I still don't have an explanation for the Exhaust hold learn value.

[osudoc11]

Steve, I talked to a local tuner and to him it sounds like the tune. I was going to give the stock tune you provided a try but having trouble converting .hex to .bin. Ecutek uses .bin.

[osudoc11]

Update again. Loaded a completely stock tune provided by steve. Still got the code within ten minutes. At this point I will be putting the stock header on and taking it to the dealer for them to figure it out. If software changes have not helped then this must be a hardware issue. I don't see how the modifications could have caused an internal hardware issue though. Steve, do you seen any need to put the stock overpipe/frontpipe back on. I was just going to put the stock header on. They shouldn't give me any trouble about the rest of the exhaust, right?

[_gt86_user]

Originally Posted by osudoc11

Update again. Loaded a completely stock tune provided by steve. Still got the code within ten minutes. At this point I will be putting the stock header on and taking it to the dealer for them to figure it out. If software changes have not helped then this must be a hardware issue. I don't see how the modifications could have caused an internal hardware issue though. Steve, do you seen any need to put the stock overpipe/frontpipe back on. I was just going to put the stock header on. They shouldn't give me any trouble about the rest of the exhaust, right?

If you're taking off the header you might as well replace the front pipe at least, you can leave your over pipe but yes they will say something if it's not stock and your having an issues, that's their ace in the hole most of the time.

[osudoc11]

Well the front pipe and overpipe connect via vband. And it sucked getting it snaked through.

[steve99]

Originally Posted by osudoc11

Well the front pipe and overpipe connect via vband. And it sucked getting it snaked through.

Correct it should not matter about the overpipe\front pipe. But some dealers will try and blame anything

Those cam faults are a pain to fix and require a lot of labour parts diagnosis, if it was me i send the car in completly stock engine wise just to be sure and also any other weird electrical stuff like aftermaket headlights tailights etc anthing they can blame on electrical or engine problems

[osudoc11]

So I understand that the cam position sensors are supposed to have certain waveforms. I logged the cam positions at idle. They all have regular waveforms except intake angle 2. Here is the log.

http://www.datazap.me/u/osudoc11/tim...0&data=0-1-2-3

[steve99]

Originally Posted by osudoc11

So I understand that the cam position sensors are supposed to have certain waveforms. I logged the cam positions at idle. They all have regular waveforms except intake angle 2. Here is the log.

http://www.datazap.me/u/osudoc11/tim...0&data=0-1-2-3

Seems reasonable to suspect their is a problem with intake cam 2


suppose it could be


The Cam sensor itself
The clearance between cam sensor and pickup
Wiring issue
Ecu input issue

[osudoc11]

So I just got a multimeter to check electrical on the components. Cam position sensor and OCV valve seem to check out fine.

From my earlier data logs, one of the intake cams was going to -29 degrees at idle. This hasn't happened since my engine flush and oil change. Reviewing the TSB, it seems that anything less than -28 degrees can trigger the code. I am wondering if this is the dreaded ecu glitch that just can't seem to get rid of the code.

[osudoc11]

Update. More data logging. It seems that one of the cams oscillates more than the other. This is most noticeable at idle. The set point is 0. The "good cam" stays pretty close, within about 0.4 degrees. However, the "bad cam" oscillates between -0.6 and 0.6. Watching the OCV duty it seems that when it gets to -0.6 the duty will increase slightly to bring it back to 0. But then it overshoots a little and hits 0.6. Thus the dugy cycle drops to bring it back to 0. But it overshoots a little and hits -0.6...and so on. It seems just a little sluggish. As mentioned I have swapped ocv's from one side to the other, so I doubt it is that. Any ideas on other bottlenecks that could be causing this "slow" response and oscillation?