Final Update (I hope). With a new dash sitting in the garage waiting to be installed I took the Tahoe down to my local Chevy Dealer here to look at the Oil Life Percentage issue in the (new-to-me) used cluster I installed. The last hurdle to getting back to the normal OEM cluster with OEM functions I had six years ago BEFORE I took it in for a "cluster repair".
According to the Dealer, the percentage is not working because I installed a "salvage yard" cluster (they weren't wrong lol) and it now needed to be re-coded for my truck. So 1 point for
@Rocket Man and 0 points for the local "Cluster Repair" guy who said nothing else needed to be coded to the cluster except the mileage. Note to others here: There are hundreds of places to get a cluster "repaired" but take it from me, most probably only know how to fix the solder joint and/or replace the bad diode and update your mileage, that's it. If you swapped clusters (or now have to swap clusters due to a "failed" repair) they are NOT going to know how to address the other issues I listed below. The Dealer charged me too much for this coding service ~$250 but it works again and FINALLY, 6 years later I have a 100% functioning cluster again WITH the DIC repair.
So word of advice to other owners. If you run into the problem with the DIC display, if all they do is repair the solder joint for the diode in question or replace the diode on your
original cluster and re-install you will probably be just fine. If however, there is any problem with your cluster or they "mis-handle" the repair and you have to install a used one from a salvage yard etc... please keep these things in mind:
1) Depending on the cluster you get, it may be "coded" for different options as seen in this thread. In my original cluster I had the option to re-learn new keyless entry remotes but not the option to re-learn the TPMS sensors. The used cluster the original "repair" shop sold me had the opposite. It had the option to re-learn TPMS but not re-learn new remotes. In my opinion this was a problem because there is a way to re-learn the TPMS sensors without using the DIC at all. I am not aware of a method to re-learn new remotes without using the DIC. If someone else has a verified way of doing it, feel free to post the steps here.
2) If you change the instrument cluster, more than likely you will have at least these three problems, maybe others:
1. Your mileage will be incorrect (obvious, but worth listing), this can be fixed but requires the right tool to change it. As mentioned above this is about the only thing the "repair" shops can do.
2. You will likely need to go through the process to have the ECM re-learn the TPMS settings. I posted a link above to do this manually, yourself.
3. You will likely need a dealer to re-code your instrument cluster to restore the functionality of the Oil Life Percentage feature which I find to be useful since its not just strictly a measure of how long its been or how many miles you've travelled but takes several factors into account. This may also be something someone can do with a Tech II but I have not confirmed that.
If there are other "issues" other owners have run into swapping clusters, please feel free to list them here but keep in mind this thread was meant more to document my challenges just swapping from one OEM cluster to another. There are other threads for other types of custom cluster swaps.