Help identifying wire disconnected by firewall, back of manifold.

[Eish12]

2013 GMC Yukon XL 5.3L vortec

Hey y'all. I would really appreciate some help. I can't seem to identify this wire by the back of the manifold. It's part of a harness coming out by the firewall. I've included a picture.

Recent history of the situation : Yukon is throwing evap codes. I had it at a garage about a week and a half ago. The codes started after that along with a ticking noise that sounded like a lifter.
This particular garage is a ways away from where I am now, so I wasn't bringing it back. I started investigating the evap system. They left the hose coming from the purge valve disconnected in the back of the engine. I reconnected that. While I was back there I noticed this wire that was disconnected. I've looked at diagrams, I've been fishing around looking for the mail connecting piece. Can't find it. Any help would be appreciated, thanks in advance.

 

[Doubeleive]

2013 GMC Yukon XL 5.3L vortec

Hey y'all. I would really appreciate some help. I can't seem to identify this wire by the back of the manifold. It's part of a harness coming out by the firewall. I've included a picture.

Recent history of the situation : Yukon is throwing evap codes. I had it at a garage about a week and a half ago. The codes started after that along with a ticking noise that sounded like a lifter.
This particular garage is a ways away from where I am now, so I wasn't bringing it back. I started investigating the evap system. They left the hose coming from the purge valve disconnected in the back of the engine. I reconnected that. While I was back there I noticed this wire that was disconnected. I've looked at diagrams, I've been fishing around looking for the mail connecting piece. Can't find it. Any help would be appreciated, thanks in advance.

weird I personally can only guess it is supposed to be connected to something down lower, normally right there is where the oil pressure sensor is but that connector is a 3 pin
what kind of work did you have done? i wonder if that harness goes down under somewhere....
no check engine light?

 

[j91z28d1]

vlom?

 

[Fless]

vlom?

Looks like it might be that. Sus.

 

[Foggy]

Looks like the VLOM connector
Do you have your afm/dod disabled ????

 

[Eish12]

weird I personally can only guess it is supposed to be connected to something down lower, normally right there is where the oil pressure sensor is but that connector is a 3 pin
what kind of work did you have done? i wonder if that harness goes down under somewhere....
no check engine light?

At first I thought it plugged in next to the oil sensor, the clip looked like it had a spot for it, but it it doesn't fit next to it.

I cleared the two codes that were there. One was an evap code, the other is a catalyst system code p0420.
Now that I plugged that evap hose back in, the EVAP code did not come back, however, the catalyst system code did come back, p0420.

Yukon went in to the shop for them to put the deactivation solenoid in for the fuel management system couple weeks ago. Only for them to tell me that it didn't need it because it didn't fit. So they took the manifold apart to put the solenoid in, that never went in. I got the vehicle back with this situation.
I'd already used my Diablo scanner to deactivate the fuel management system, as it's a newer engine.

History:
I had a new engine dropped in just over a year ago. Same garage did a bit of a rush job, and with that they failed to program the fuel system, to deactivate the fuel management.
When I went back in and they realized they hadn't done it, they tried to pass it off on me by saying they told me that I was supposed to deactivate it. At the time I just assumed they did it, and they never mentioned it. So then they wanted me to purchase a deactivation solenoid. Which I did, as long as they did the work. Then they tell me the solenoid won't work.

 

[Doubeleive]

yep goes on the vlom, I don't think that is the reason for your cat code though

 

[Eish12]

yep goes on the vlom, I don't think that is the reason for your cat code though
View attachment 451405

That's it .. thanks!

 

[Eish12]

vlom?

Looks like the VLOM connector
Do you have your afm/dod disabled ????

I disabled the AFM with a Diablo scanner. It's the second engine in the Yukon. The scanner came with a crate engine, it was pre-programmed to disable the AFM.

 

[Eish12]

That's it .. thanks!

Yep, I agree that it's not likely to be the reason for the cat code

 

[j91z28d1]

what's a deactivation solenoid?

 

[Doubeleive]

what's a deactivation solenoid?

That's what I'm wondering

 

[Foggy]

The VLOM contains the deactivation solenoids for the cylinder deactivation
And that's the connector for it at the rear of the intake...
I would think you'd still have it connected as the diablosport just
prevents it from going into the afm/dod mode. And I would think that with
it disconnected, it would throw codes

 

[j91z28d1]

so did they buy the vlom plate and tell him there was a deactivation solenoid on it that turned afm off?


I'm so confused by this whole thing haha. feels like the shop didn't understand how afm works and just made things up.

but no, once turned off in the ecm, that doesn't need to be plugged in. since with a true delete kit with standard lifters you replace the vlom with a smooth lifter valley plate anyways. there's nothing to plug into.

 

[Eish12]

what's a deactivation solenoid?

This explains best........

"An "active fuel management deactivation solenoid" is a component in a car engine, specifically in General Motors vehicles, that electronically controls the activation and deactivation of cylinders by collapsing the valve lifters, essentially "turning off" some cylinders under light load conditions to improve fuel efficiency; it's also known as a cylinder deactivation solenoid or part of the "Displacement on Demand" (DoD) system. "

 

[Eish12]

This explains best........

"An "active fuel management deactivation solenoid" is a component in a car engine, specifically in General Motors vehicles, that electronically controls the activation and deactivation of cylinders by collapsing the valve lifters, essentially "turning off" some cylinders under light load conditions to improve fuel efficiency; it's also known as a cylinder deactivation solenoid or part of the "Displacement on Demand" (DoD) system. "

Dorman Cylinder Deactivation Solenoid 917-162XD

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[Eish12]

The VLOM contains the deactivation solenoids for the cylinder deactivation
And that's the connector for it at the rear of the intake...
I would think you'd still have it connected as the diablosport just
prevents it from going into the afm/dod mode. And I would think that with
it disconnected, it would throw codes

That would make sense, because that's what was being looked at. And I agree, you would think you'd be throwing codes if it was disconnected. Evap code still hasn't come back, but the catalytic code is still there. Thanks for the reply!

 

[Eish12]

From what I can assess, the shop didn't fully understand the system, or they did but they just rushed through it. They didn't deactivate the AFM with the Diablo sport that came with the crate engine. When I went back to them, they then realized it, tried to put it on me, then told me I needed to order this deactivation solenoid.
When I brought them the deactivation solenoid, they attempted to put it in and realized that it had a smooth plate already in there. Thus, they gave it back to me and said that the solenoid wouldn't work, go ahead and return it. At that point I had already taken it upon myself to deactivate the AFM with the Diablo sport.
So when I recently got the vehicle back, it was throwing an evap code and it has what sounds like lifter noise. That's when I realized they hadn't connected an evap hose. In the process. I saw this plug that was disconnected, and that's where my confusion came in.