The dash, the speedometer, oil pressure and fuel gauge and tachometer randomly quit working?

Hello, what code numbers are setting? A failing module can cause issues like this, but just as likely is a wiring issue or corroded connectors, affecting one of the network communications which in turn, can affect another network. These is the diesel engine too I assume. There are different options for this vehicle, but intermittent issues like this can be difficult to catch sometimes, depending on how often it happens or under different conditions. Swapping out modules will get very expensive quickly and rarely is a fix. The Cluster is on the Low-speed network, whereas the TCM, ABS, ECM, are on the High-Speed network, the BCM(both networks). Because of the trailer brake module location, you could take a look at its connector and see if there's any corrosion inside, make sure the key is off, so the modules go to sleep before unplugging anything. With it unplugged you can try clearing the codes and see if that resolves anything, obviously other modules are exposed to the elements as well, but this one being above the spare tire really gets hit with everything from the road, salt, water, etc. But post your codes so we can see exactly what is happening. I'll post a diagram of the trailer brake module's location.

Diagrams 1 and 2 are the Trailer brake control module, but there was also listed a Recall (diagrams 3-8) for corroded control modules (diagram 6), so that's a good place to start looking, you may run into some corrosion somewhere, hopefully that might be an easy find.

That could be the BCM what are the codes you have? I have seen the cluster go out and cause all of these issues but let's have the codes so we can get the right direction going for the repair. You can get a CAN scanner (Controller Area Network) which will work on most cars from Amazon.

Here is a video to show you how:
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https://youtu.be/u-4syLc-ifQ

Please go over this guide and get back to us.