I fly out of an uncontrolled airport that has an unmanned, automated weather reporting site with a precipitation sensor (AO2). The METAR often has a \$ symbol at the end of the report, indicating that maintenance is needed on the equipment. Can I use this METAR, or any METAR with a "\$" as a reliable indication of the current weather?
Do the indications match up and make sense compared with indications of a nearby airfield and other weather sources?
Legally the FARs require that pilots obtain "all available information" (FAR 91.103). $ could mean a number of things and since Metars are still available, you should be able to trust them, but I recommend to check more then one source regardless.