FSAE_Junkie

Besides the physcial wiring to the correct 2 pins in the ECM, is adding VVT functionality to an E38 as simple as changing the drop down for it or is this only possible on certain years? I mean, I can look at my tune and see that I can change it, but I'm not sure if the ECM will actually start outputting a signal for it.

For background, I picked up a 2007.5 silverado (E38 Gen IV) with a trashed 5.3L that has AFM/DOD but not VVT. I then grabbed an L92 out of an 08 Escalade which has no AFM, but does have VVT. Obviously, it will be easy/advantageous to remove the AFM from the tune, but I want to actually KEEP the VVT of the 6.2L since this is a truck. I took a gamble that it could be done off of 1 or 2 comments I saw around various forums and actually ordered a GPI Low Lift truck cam and new compatible phaser. As I'm putting the motor together though, I'm having some doubt about whether this is doable. Most posts are about deleting VVT, not adding it. I think my biggest reason for hope is that it appears the 07 Silverado used the same PCM as the 07/08 Escalade (12597121)

This is one of the posts I could find from an EFI Live forum thread that gave me hope this is 'easy':
https://forum.efilive.com/archive/in...p/t-24652.html:

"I have an e38 2011 L77 (non VVT) and yes I did enable the cam phasers by specifying one did exist on the intake, and for the most part works great.
Only problem is VVT spark table doesn't work, so I'm contemplating migrating to e38 2013 L99 (VVT) OS to enable the VVT spark table."

But that's about a later year ECM and the post degrades into talk about OS swaps which is not something I want to get into. I think the OS swap piece is only in reference to the spark timing piece of it which I can't yet fathom why I would need for the WOT benefits. I feel like the cam phasing will get 95+% of the VVT benefit on the WOT parts of the map at least. I could see how VVT spark timing is important for the OEM part-load emissions piece, but I'm not going after that.

Anyways, I'm sort of looking for any comments one way or the other before I go install this VVT cam in the motor.

minytrker

iTrader: (13)

I would assume its not that easy and only certain OS's would have all the coding in the background for it work 100% correctly. The OS would matter more than the service number because the same service was used in both.

FSAE_Junkie

I would tend to agree with you, but there are other examples where this is not the case. For example, I can enable Flex Fuel capability on the GTO by just changing a drop down in the tune. No GTO had this capability from the factory, but it was easier for GM to leave the functionality there and just have a switch to turn it off.

This is why I'm hopeful that with at least some of the E38's in this time frame needing the VVT and the fact that the VVT dropdown is editable in my tune, that it really is just a matter of flipping the switch. Maybe?

minytrker

iTrader: (13)

I did some more digging and was told by someone else that not every E38 can do VVT which is believable but still cant find anyone I personally know who has tried what your doing.

09TahoeSSV

I just joined tonight to search this topic. I picked up a L96 from a 2010 Express Van complete with the wiring and its E38 ECM. I'm comparing the harnesses in my 09 Tahoe and noticed the cam phaser wiring is not on my 5.3 or the LMG engine harness. It would seem that I can fish the two wires from the phaser out of the van harness and add the pins to my stock Tahoe ECM connectors and plug in the ECM that came out of the engine and be in business. Thoughts? A friend of mine suggested the wires might already be tucked into the Tahoe harness but not used for this application (assuming the harnesses were used for several models).

chase1873

Any update on this? I just swapped an L96 into my 2010 GMC 1500 and noticed my connector does not have the two pins for the VVT. I am interested in adding the wires, but have yet to locate a proper wiring diagram. If they are already in the harness that would be awesome, but I suspect not.

Novapat67

Thanks for the help. I just ordered the adapter and kept the line coming out of the computer. I plan on adding a turbo at some point so I figure that I might as well get the adapter now.