Can someone check their e70 n52 ABS pump module? I don't have any dash lights or drivability issues but while working on unrelated issues I found that I have a barely audible (over the regular engine noise) whine/whistle coming from the ABS pump module.

I isolated it from other engine noises using the ghetto 3/8ths extension stethoscope method. It's definitely coming from the ABS module and those are not cheap new...

Change brake fluid? What's a good next step? I'm hoping if there is an issue that I found it early and can prevent losing the pump.