Instrument cluster resets during start

Couple questions. First did you just purchase this vehicle or what is the history of this happening? Did you replace the cluster and this started happening or did you replace it attempts to fix this and the new cluster is doing the same thing?

Clearly you don't need this video as it appears you have it apart but this is a video on a GMC cluster replacement that may help others as this process is similar on a Hummer:

https://youtu.be/_HEC44xENxw

Basically we are needing find out if this is different and what happened to cause the change? The cluster is responsible for running its own diag tests and initialization processes so if this is a new cluster and it was not doing it before then I suspect the cluster is the issue.

If this is a new cluster and it was doing this before then the only thing that would make sense is there is an issue with the BCM or one of the inputs from the BCM to the cluster.

The cluster does this sweep and chimes as a normal process to make sure it can communicate with everything it needs too.

Let's start with this info and we can go from there. Clearly it should not do this twice but without this info there are a number of things I am thinking this could be.

Thanks

Sorry. I should have asked if there were aftermarket parts as that will cause this type of issue. GM used their own form of a CAN bus and this is like an electrical highway where the modules all communicated with each other.

Here is a guide that will help with this:

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

The reason these initialization processes repeat or fail is due to a module that it doesn't recognize or get a bad message from one.

You can try unplugging all the aftermarket components to see if this will correct it but even if it doesn't I suspect it is still an issue along these lines.

Does it do this if you just put the key in and start the engine or does it only do it once then?