Need Help, 07 Yukon Track/Engine Light On
Good afternoon, I have an 07 GMC YUKON 6.2 that has code P0011 CMP system performance and C0561:71 ABS system disable.
The Yukon has been to a repair shop and then to the GMC dealer where they replaced all related internal timing components including camshaft !
the suv runs fine but feels sluggish, on the scan timing data it shows 45 and 9 degree timing fluctuating, it also has a new ECM and harness, with out tearing into the engine timing area i have re checked all connections, tested all related circuits and found nothing.
any input on this ?
You verified timing completely? Does engine have any evidence of sludge or other internal problems? What is the oil pressure to the switch?
Hey Jim, yes i have an Autel, but i will post data tomorrow as i did not work on it today , thanks.
Hi Jim, Can you expand a little on the Autel handicap? I would wholesale agree with the sketchiness of GM with autel but are you speaking of something specific to this platform or a missing capability/function?
Kinda hard to follow the conversation when you delete all your posts, Jim.
P0011 can be a serious DTC if current for one it takes 14 seconds to set and would be human error if timing is advanced ,DTC Enabling Criteria is something like - Whats camshaft desired angle Vs actual angle for DTC to set will be over 6 degrees … 45/9 is a 35 degree sweep specs needed that means nothing w/o the spec 0 point ,also have Desired vs actual camshaft position …timing components…
No noises, all GM parts . All new actuators, oil pump, I removed the magnetic actuator and did a ohms test good at 7.2 ohms, powered it and pushes strong. i verified actuator torque at cam, verified part numbers, all good. Must have loss of pressure some where but oil pressure on scan tool reads 42 psi at idle.
Need to know what actual and desired cam position is and if the actual moves at all. These engines are known for wiped #2 cam bearing casuing low oil pressure to cam sprocket/phaser
Ok, Would that show lower than normal pressure at oil pressure sensor ? i can commend 5-30 degrees and pid on scan tool shows 0. not moving at all other wise i would see an increase in rpm, i put a scope on the magnetic actuator and can clearly see the commend signal.
Looks like your back to a brand new stuck actuator or no oil or a bad solenoid
Very possible, i replaced the magnetic actuator. but possible stuck phaser !. i will tear in to it. thanks.
Do you have a lab scope to use? This is a situation where I believe it is absolutely needed to verify timing and phasers operation.
Great question. From my point of view when you can't understand or believe the data you're scan tool is showing you especially with timing and timing controls a lab scope will validate what the pcm is seeing and its ability to output with the inputs it is receiving (or should be seeing) with an in cylinder analysis you can really see the whole picture. This is what I've come to learn and really…
There is a real fault, likely related to oil flow/pressure. Do some analysis and post meaningful results. Statements such as “on the scan timing data it shows 45 and 9 degree timing fluctuating” isn't specific enough to be useful in helping you.
Hi Hector, I'm wondering how this ended up at your shop and not back to the dealer, or the other shop that did all that work? Do they have any money left? I say this in jest, but… As Marlin said I'm starting with oil - full, correct viscosity, correctly spec'd - what's the oil pressure? Is there sludge in the engine? As Jim, mentioned scan data is useful while commanding the VVT - commanded…
Hey Scott, well customer said that at the end, dealer suggested a new engine. Im not sure how that turned out but what i do know is that the engine also has a new oil pump, the oil is the right viscosity and no sludge. the oil pressure reads 42 psi at idle. When i commend the VVT the timing reading on the Autel go's from 0 to 45 / 9 fluctuating ! I really think that it is an oil pressure problem…
Can you post a video of the solenoid duty cycle, the actual and desired position PIDs on scan data. No one is really able to understands “0 to 45/9” unfortunately. You should have a VVT solenoid command PID that is 0-100%. Another PID Actual cam position in degrees. Another PID desired cam position in degrees. The position PIDs will be about 0-25° and may be in 5° increments.
Ok here it is, i also scoped the magnetic actuator and clearly saw the commend increments of 5 degrees. diag.net/file/f69yvodvq…
Thanks Hector, great info. Ill answer as best I can and then itll be up too you too make a diagnostic descision. So I had an 08 6.0 with VVT that had a VVT performance fault. The cam would move but at low speeds it had a hard time keeping the actual postion matching desired. When this happened the oil pressure was only about 15 psi on scan data. It had a wiped 2nd cam bearing causing low oil…
All good, the customer and i decided that re doing the other shops job would reveal the problem. thanks for your time.
Ill be sure to post fix, thanks for all the support.