Make sure your indy or mech didn't "top off" with incorrect coolant. It could just be a faulty sensor too.

I know that when this happened to me, my local "oil changer" guy had put in a bit of coolant, off by 2 degrees and it was enough to set off the sensor.

I had it flushed by my indy and it went away.

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2003 X5 3.0i // Winter package
263,000 kM