I saw a similar problem once but that was on a chrysler minivan - the problem resolution was replacement of the body control module.

I dont think the ML is setup like that but the gauge unit itself is a module. Check the wiring or board condition.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)