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I am getting P0011 and/or P0014 after about 10 mile run, Thursday it was the Intake camshaft, today the Exhaust. OIL is FULL and NEW. connected scan tool, could see a variance between desired and actual camshaft angle. Have tested the solenoids sat. (they were new not long ago) , Today I connected the scope to the solenoid input, and then moved it to the PCM output for that circuit with the exhaust cam angle at 0 and the desired at 8. The PWM signal I see has huge gaps in it.I forgot to reset the code before taking data. Is this normal or is my PCM bad. Or am I seeing bad data due to not reseting the P0014 code?
From this, I doubt that your PCM is bad. I'm always slow to condemn a PCM. LOL
Are you getting any misfires counts? Any other codes?
Is your oil the proper viscosity and specification? I once helped an owner of a VW vehicle and just using the proper oil fixed all his VVT issues, maybe he just got lucky. LOL
How's your power as you drive? Are you feeling normal power for the car as it moves through the RPMs? VVT should give you the sensation of a flatter torque curve. Given your symptoms, I would guess your car gets sluggish at high RPMs. Yes/No?
Do you have a bidirectional Scan Tool allowing you to command these two solenoids? If so, command them to advance at idle and your idle should turn to crap. I suggest performing a O-Scope capture during these tests.
You're right as well in that many diagnostics bi-directional tests will be disabled if there is an Check Engine Code in that associated area, meaning you'll need to clear the codes. But before you do, please look at freeze frame data. Engine temperature, oil pressure, rpm, load,...
HI ,
You stated that the oil is new and full. Did you change the oil and if so did you use the proper oil that GM wants you to use? The viscountcy is very important in VVT. Next I would test the sensors
Test for less than 5 ohms between the low reference circuit terminal B and ground.
• If greater than the specified range, test the low reference circuit for an open/high resistance.
Test oil psi make sure its in range..
other this to look at:
Intake Camshaft Position (CMP) Actuator Solenoid
• Engine Oil Condition or Level
• Engine Control Module (ECM)
• Excessive Timing Chain Play.
I agree with the others, that control signal looks fine. The driver in the PCM is clearly working, otherwise you wouldn't see the 12V pulses.
Was the variance PID showing a constant value? Or, did it just spike occasionally during load changes? That screenshot you posted would suggest that the exhaust cam actuator or solenoid is completely stuck in the parked position. Either the solenoid isn't moving, the screens are plugged, or the actuator is stuck parked.
Thanks all for the suggestions. Yes it's the right oil. the actuator solenoids are both new (one was stuck, so I replaced both) , The trace I posted was with a code present, so I think the PCM was just in fail safe mode, caught the same trace today in the other solenoid circuit when the other code was locked in.
I have checked all the wiring, and even re-tested the new solenoids. It runs great with 0 degree's of camshaft variance, until one of the phasers gets stuck(i've seen it happen on the scan tool for both the intake and the exhaust , then it diesels, lugs, even stalls some times.
I think I discovered the root of the problem today. I had replaced both timing chains, tensioners and guides due to stretch and weak balance chain tensioner. This was causing camshaft correlation code and that famous timing chain rattle sound when started after sitting overnight. I had also seen some debris on the screens, I assume the debris is from the timing chains. Today I pulled the NEW solenoids and found considerable debris on the intake screens of both. a tiny bit of debris could also be seen on the output screens. I cleaned them , re-installed, ran it for 10-12 miles, then re-checked the screens. A little debris had been caught by the intake screens again. I plan to repeat this drive, inspect and clean routine for the next few days and see if the amount of debris tapers off indicating that I'm getting it out. I plan to replace the phasors too, and do another oil and filter change this weekend.
Do you think I'll be able to remove most of the debris this way? Is there a better way?
I dunno that you'll get all the debris out that way? But I'm not sure what the better method would be. :silly: Only a small part of the engine oil ends up going through the VVT system, so you might end up cleaning screens for awhile.
If it's that bad, I'd consider removing the lower oil pan and cleaning it out. Have a look at the pickup tube screen while you're there, just in case any of this junk is accumulating. Remove the solenoids and the oil filter at the same time to allow everything to drain out.
It'll be work, but you're guaranteed to have sparkling clean oil at the end. :lol:
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