As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRFOIL ICE PROTECTION PRESSURE ABNORMAL LIGHT ILLUMINATED WHEN ANTI-ICE WAS ACTIVATED. FLIGHT RETURNED TO MSP AND LANDED WITHOUT INCIDENT. REPLACED THE PRESSURE REGULATOR VALVE AND SHUTOFF VALVE. OPERATIONAL CHECK OK. AIRCRAFT RETURNED TO SERVICE.