Update on the P0017...I replaced the actuator solenoid, no change. What I saw of the wiring harness seems OK...are the sensors next on the list to investigate?

Hummerz, thanks for the link to the P0449 issue. I was going to wait on that one until the P0017 was done, but I may not. I'd like to know when the engine light pops up what exactly is going on, right now I know it's one of two things.

Update: Curiously, the Ebay ad linked says that part is incompatible with the Hummer, as does Amazon when I input that part number. In the video the guy says that IS the Hummer number I think...so that's a little confusing. That being said, it's even cheaper than that video now, so if it works I'm definitely game.

 

https://www.700r4transmissionhq.com/p0017-hummer-h3/

 

So, an update here: I just replaced the cam position sensor B, I believe this is the exhaust cam sensor...on the passenger side front of the engine. Again, no change in either error code or engine behavior.

I chose this particular sensor to start with because the description of P0017 suggests a position mismatch between that particular cam and the driveshaft. Does it make sense to assume that the driveshaft sensor being wonky would impact both cams, and so I'd also be likely to get a P0016? It seems unlikely to me that a P0017 would get triggered by the crankshaft sensor or the other cam position sensor, with no other error codes, but maybe I'm taking these error codes too literally?

The other thing I've been wondering...when I replaced the actuator solenoid, I didn't use an AC Delco part, I used something much cheaper from Amazon. It had generally decent reviews, and was said to be a direct replacement. Dimensions were perfect, although it didn't look identical to the one that came out (the old one didn't have any obvious issues from a visual inspection, for what it's worth).

Regarding wiring, a lot of the corrugated plastic split look has crumbled away, so I've replaced a bunch of that. The wires inside look fine. That doesn't mean they are, of course, but I'm really not sure how to test that I'm getting the right signals to these parts. Some of the stuff on youtube shows guys with a device that can trigger those signals but I don't have that.

At any rate, I'm considering replacing the crank position sensor or maybe getting a proper AC Delco actuator solenoid, but I'd feel better about that if there were some better indicators that either is a likely solution.

 

One other observation, in case it triggers something: When I first start the truck up, I do not see/feel the vibration. If I let it sit there idling for about a minute, it will start vibrating. I can see it in the wheel and hood, and feel it in the wheel as well. As soon as I give it a little gas it smooths out, and the whole process happens in reverse when I come to a stop: The vibrations start once the truck is back at idle.

 

Stop throwing parts at it!
Here you go, a look in on my network of confirmed fixes:
(note: timing chain/sprocket replacement has highest count, next is the actuator, lowest is flush/replace engine oil)
Simple stuff first, then if all else fails, replace chain/sprockets. GL

 

Have you tried cleaning the MAF and throttle body?

 

Yeah, first thing I tried, back when I had a whole flurry of issues, actually. I also changed engine oil pretty recently.

Q for Hummerz: Have you seen cases where the timing chain needed to be replaced or adjusted and the ONLY symptoms were an error code and a vibration at idle? I have not, not that that proves anything. As for camshaft end play, I have no idea how to do that on this vehicle, but from what I've read if that's the problem you need a new engine or at least an engine rebuild, if the thrust bearing damage is repairable. If that's my problem then I'll just dump the vehicle when it finally dies. I'm not going down that road.

The part about using the scan tool to command it to do certain things sounds promising but my scan tool won't do any of that, unfortunately.

It sounds like the phaser/actuator solenoid thing has a high probability of fixing this issue for you, so my question about the AC Delco vs the no-names is still relevant: Is this a part where the no-name replacements tend to be crap?

So is all the ancillary info I've provided not relevant in your experience? You've told me to stop throwing parts at it, and I get that, but I spent less on that part than I would on new engine oil that was just replaced a few months ago? You have a lot more experience than I do with this truck, of course, so maybe all that other stuff I've listed really doesn't matter, I don't know. But it seems like it would?

 

I can only advise you on the steps I would take in your case(@180k miles, without knowing what oil you have been using?):
#1: Flush engine, refill with new mobil1 5w30 full synthetic & replace filter with AcDelco UPF61R
#2: Replace solenoid with ACDELCO 12615873
If code returns;
#3: Replace timing chain/sprockets.

GL

 

you know half of the timing is on the back of the motor. need to drop tranny or pull the motor.

 

If you have that much time on your hands, you should also replace with an LSA and 6L80